Additional videos related to the subject of this chapter are available from the Medizinische Hochschule Hannover collection. The following videos are included with this chapter and may be viewed at https://expertconsult.inkling.com :
- 58-1.
Antegrade nailing with conventional entry point.
- 58-2.
C-arm based navigated femoral nailing.
- 58-3.
Comparison of femoral nailing in the supine position with manual reduction versus lateral decubitus position using a fracture table.
- 58-4.
Lateral decubitus position for antegrade femoral nailing.
- 58-5.
Plating the osteoporotic femur—number and placement of screws.
- 58-6.
Periprosthetic femur fractures: locking plate.
- 58-7.
Retrograde rodding of femoral fractures.
The majority of patients sustaining femoral shaft fractures are young adults and most frequently are involved in high-energy trauma. In contrast, older women sustain femur shaft fractures (spiral) from moderate- to low-energy trauma, mainly because of their poor bone stock and underlying osteoporosis.
In young males, femoral fractures present with other life-threatening injuries. Epidemiologic data from North America in the 1990s revealed an incidence of 13 femoral shaft fractures per 100,000 people. The incidence in Europe does not differ significantly. Our own data from 22,500 reported road traffic accidents between 1985 and 2003 showed that 447 patients sustained femoral shaft fractures (incidence of 2%), with 10% being bilateral.
Anatomy
The femur is the longest and strongest bone in the body ( Fig. 58-1 ). The proximal femur, which is considered a specialized metaphyseal area, is formed by the head, the neck, and both trochanters (greater and lesser). The diaphysis (shaft) represents the middle third of the femur. It is almost cylindrical in form and has a smooth anterior-posterior (AP) bow with an average radius of curvature of 6 degrees. The head of the femur is located eccentrically, resulting in a diversion of the mechanical and anatomic axes. The anteversion of the neck related to the shaft can vary interindividually, ranging from a retroversion to more than 30 degrees of anteversion. The intraindividual differences, however, are very low. The median difference has been reported to be 4 degrees, and 5% of patients are reported to have an anteversion difference of more than 11 degrees. Even though the outer surface of the femur looks cylindrical in form, the thickness of the cortex on consecutive cross-sections varies ( Fig. 58-2 ). Therefore, a potential cortical step after an injury can serve as a sign of rotational deformities (see later discussion).
The proximal area of the diaphysis up to 5 cm distally to the lesser trochanter represents the subtrochanteric area. Because of the unique biomechanical features of the subtrochanteric region and the high concentration of stresses, management of fractures in this area can be challenging. The psoas and abductor muscles may retract the short proximal fragment into flexion, external rotation, and abduction, making reduction difficult.
The distal femur consists of an expanded metaphyseal block formed by the medial and lateral femoral condyles. This is separated by the intercondylar notch and forms the support of the knee joint. Injuries to the supracondylar area and the condyles themselves are described separately from diaphyseal fractures because of their distinct anatomic and biomechanical features (see Chapter 59 ). Supracondylar fractures are typically flexed by the unopposed force of the gastrocnemius.
Figure 58-3 documents the classic deformities evident after femoral fractures as a result of the unbalanced muscle pulls. An understanding of these deforming forces is of paramount importance, both in operative and nonoperative treatment for obtaining anatomic reduction and restoration of movement.
Undoubtedly, any surgical approach to the thigh requires a comprehensive understanding of the surrounding muscle groups, their internervous planes, and the position of major neurovascular bundles. Figure 58-4 describes the major vascular anatomy of the thigh. The femoral artery enters the thigh at the midinguinal region medial to the femoral neck and shaft. It soon divides into the superficial femoral artery and the profunda femoris artery. The superficial femoral is essentially an artery of transit, passing through the thigh to supply all the tissues below the knee. The profunda femoris, however, is the artery that supplies the thigh structures, the latter giving off a number of deep circumflex branches that encircle the femur. The most proximal of these circumflex arteries provides the arterial blood supply to the femoral head, running proximally in the posterior aspect of the hip capsule close to the piriformis fossa. The more distal circumflex branches are often important during the lateral approach to the femur (usually for conventional plating of the femur); when cut, they can retract and cause troublesome bleeding. The superficial femoral artery, on the other hand, travels medially to the femur in the Hunter canal before passing through the adductor hiatus. It is then renamed to popliteal artery and lies in the midline behind the knee within the popliteal fossa. The obturator artery enters the thigh through the obturator foramen and usually supplies a small area in the thigh but is rarely of any clinical importance in this region.
All vascular structures in the thigh can be damaged during trauma. However, because of anatomic and functional differences, they produce distinct clinical pathologies. Because of its nature and the rich muscular collateral circulation in the thigh, injuries to the profunda femoris artery are commonly associated with hemorrhage rather than ischemia. In contrast, complete injuries to the superficial femoral artery are often associated with distal ischemia, which represents a limb-threatening condition that, if not promptly addressed, can lead to an amputation.
The nerve supply to the thigh consists of three major nerves: the sciatic nerve that lies within the posterior flexor compartment, the femoral nerve that lies within the anterior extensor compartment, and the obturator nerve that lies in the adductor compartment of the thigh. The hip abductors act against the adductor compartment muscles, lie in the gluteal region, and are supplied by the gluteal nerves (superior and inferior). The femoral nerve enters the thigh under the inguinal ligament lateral to the femoral artery and anterior to the iliopsoas muscle. It rapidly divides into its terminal muscular and cutaneous branches, supplying the anterior thigh and the extensor muscles (quadriceps femoris). The sciatic nerve enters the thigh through the greater sciatic notch and lies between the hamstring muscles (which it supplies) directly behind the femur. It then enters the popliteal fossa, where it separates into the common peroneal and the tibial nerves, passing on to supply the lower leg. The site of separation is variable and is often located high in the thigh. Clinically, the sciatic nerve is at risk in high-energy trauma. On the contrary, the peroneal division is damaged, either after a direct force or from an indirect injury and tethering of the nerve caused by stretching forces at the area of the hip or the fibular neck.
Pathophysiologic Aspects
Traditionally, femoral fractures were considered to be injuries associated with high mortality rates. During the early part of World War I, the mortality rate for those with open femoral fractures was reported as high as 80%. With the introduction of Thomas splint, however, there has been a dramatic reduction in the reported mortality rate, being as low as 20%. This concept was rapidly adopted by the orthopaedic community and led to the introduction of complex nonoperative management techniques based on traction that persisted in many “advanced” centers until the late 20th century. However, during the 1980s, a number of studies illustrated the survival benefit of early fracture stabilization, and today, early operative management represents the “gold standard” for treating diaphyseal femoral fractures.
As mentioned, early total care (ETC) with early definitive stabilization is essential, especially in polytrauma patients. However, in some severely injured patients, particularly with severe shock or significant chest injuries, initial temporary stabilization with external fixation and delayed definitive management is often performed. This approach, often described as damage control orthopaedics (DCO), is reported to be safer in these patients who cannot tolerate an extensive procedure during the immediate aftermath of severe trauma. An understanding of the pathophysiologic events associated with severe injury is now emerging after a considerable volume of research, but clear guidance on who fits the criteria for DCO and who can tolerate ETC are still matters of debate. Criteria for DCO include the presence of multiple fractures, bilateral femoral shaft fractures, severe chest or brain injuries, and the “lethal triad” (acidosis, hypothermia, and coagulopathy).
Femoral Fractures in the Presence of Polytrauma
In the presence of polytrauma, there is universal agreement that major fractures, particularly femoral fractures, must be stabilized early. However, in critically ill patients and especially those with severe chest injuries or hemodynamic instability, a number of studies have highlighted that early reamed nailing could lead to additional morbidity, and possibly increased mortality. The above-mentioned concept of DCO was introduced to reduce the additional physiologic insult (stress reaction) related to reamed intramedullary (IM) nailing. “Damage control” is a term taken from the emergency naval procedures designed to keep a damaged ship afloat and continue the mission (“keep the patient alive”) while delaying definitive repair. It was first popularized with emergency laparotomy for trauma and subsequently introduced in fracture management. For the management of severely injured patients, DCO involves gaining control of the bony element of the polytrauma situation with rapid temporary skeletal stabilization, primarily by means of external fixation. This facilitates hemostasis and intensive care management. It may also limit the release of inflammatory mediators, which are important to the physiologic and pathologic response to injury. A conversion to definitive fixation, usually with reamed IM nailing, is then delayed for approximately 4 to 5 days. Essentially, during this period, the systemic effect of polytrauma is minimized, and the “second hit” of definitive fracture fixation is more likely to be tolerated, with less systemic consequences. The mortality risk after this pattern of injury is multifactorial, and the contribution of timing and type of interventions remains unclear. Research into the significance of DCO is continuously emerging and will help add more light to this subject. However, it must be emphasized that despite the move toward DCO, it is essential that major fractures, especially of the femur, are stabilized early in severely injured patients, an approach that is proven lifesaving. Critical decisions must be taken promptly without any unnecessary delays.
Assessment and Initial Management
The initial assessment of the patient should be according to the Advanced Trauma Life Support (ATLS) protocol. The diagnosis of a femoral fracture can be made clinically by assessing the presence and location of the pain, swelling, bruising, deformity, and instability. Care should be taken not to focus only on the obvious shaft fracture. A thorough clinical examination is necessary to exclude concomitant injuries that may adversely alter the long-term outcome. After a femoral fracture, a high volume of blood loss may take place even in isolated injuries. It has been reported that the average blood loss after isolated femoral fractures can be as high as 1250 mL, which may result to hypovolemic shock.
Associated injuries of the knee and hip joint are also common. For instance, arthroscopic assessment of patients with femoral shaft fracture revealed pathologic findings in more than 50% of the patients (the incidence of anterior cruciate ligament ruptures was 5%, and the incidence of posterior cruciate ligament (PCL) ruptures was 2.5%). Assessment of knee stability is crucial but very difficult in the initial phase because of the floating shaft. The knee should be therefore reassessed at the end of any primary and secondary stabilization.
The presence of distal pulses and the neurologic function must be clearly documented. The presence of a vascular injury with persisting major hemorrhage or distal limb ischemia is the most important parameter in determining the survival of the patient and limb. The incidence of vascular injury after femoral fractures has been reported as high as 1.6%. The principles of assessment and management of fractures with vascular injuries are considered elsewhere (see Chapter 15 ).
Open fractures of the femur require significant energy, and their management follows standard protocols. Although the infection risk in open injuries can be significantly higher, major closed injuries can be equally severe and can be underestimated, as could the associated significant hemorrhage. Closed soft tissue injuries range from minor contusions to major closed degloving injuries and compartment syndrome, as described by Tscherne. The management of severe soft tissue injury is described extensively in Chapter 18 .
With regard to compartment syndrome, the anterior compartment has been found to be the most commonly affected. A retrospective study reporting on 21 cases of compartment syndrome of the thigh revealed that a femoral fracture was evident in only 10 patients, and five of the fractures were open. It is obvious that an open fracture cannot preclude the presence of compartment syndrome. Additional risk factors associated with the development of this complication include hypotension, compression, Military Antishock Trousers, coagulopathy, and vascular injuries.
Primary nerve injuries in the presence of femoral shaft fractures are rare. Only a few cases are reported in the literature, with a predominance of ischial nerve injuries.
Radiographic assessment of the injury should follow clinical examination. If the radiographs were obtained in the resuscitation room during the initial assessment, they should be repeated because they are usually of poor quality. Moreover, for adequate assessment of the femur, radiographs in two planes should be obtained (AP and lateral), and the joints above and below should be included ( Fig. 58-5 ). Typical ipsilateral injuries include the patella, the condyles, the head or neck of the femur, and the acetabulum. In some cases, these associated fractures can be minimally displaced and therefore not visible in plain radiographs. With the introduction of “trauma computed tomography scans (CTs),” early diagnosis of these injuries is increasing. A fractured neck of femur will have an important impact on the management and choice of surgical procedure (see later discussion) of a polytrauma patient.
Fracture Classification
There are two commonly used classification systems of femoral fractures, the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) ( Figs. 58-6 and 58-7 ) and the Winquist-Hansen ( Fig. 58-8 ).
The AO/OTA classification system is a comprehensive alphanumeric system for the entire skeleton. The femur is named as bone 3, and zone 2 corresponds to the shaft. Thus, the complete fracture classification begins with 32. In this classification system, the shaft is defined as the zone below the transverse line at the lowest point of the lesser trochanter, ending at the transition to the metaphysis. The exact location is determined by the norm of square (see Fig. 58-6 ). The maximum width of the distal condyle determines the proximal extent of the metaphysis. The center of the fracture is used for the exact location. This might be easy in simple fractures (type A). In butterfly fractures, the widest part of the wedge element determines the center of the fracture. This is usually the spike of the wedge. Complex fractures, on the other hand, can be better sectored after reduction. Shaft fractures with dislocated intraarticular extension are classified as 31 or 33 fractures. If the intraarticular part is not dislocated, they are classified as shaft fractures. If the intraarticular fracture has no relation to the shaft fracture (i.e., partial articular plus shaft), both fractures need to be classified separately. Simple two-part fractures are classified as 32-Ax.y. Even fractures with minor additional fragments are type A fractures as long as 90% of the cortical circumferences is intact. Type 32-B and 32-C fractures are multifragmentary. The characteristic of type B is the partial cortical contact after reduction; in type C, the proximal and distal shaft fragments lack any bony contact. All types are classified into three groups (see Fig. 58-7 ), which can be further divided. These subgroups describe the fracture localization for type A and B fractures. The subgroup 32-X.y.1 defines the subtrochanteric region. Subtrochanteric fractures are recognized as sufficiently different in their behavior to warrant separate consideration (see Chapter 57 ). The border between subgroup .1 and .2 is located 3 cm distal to the transverse line that separates the shaft and the proximal femur. Subgroup .2 is the middle of the shaft, and subgroup .3 the distal part of the shaft. In C-type fractures, the subgroup is based on morphology and not location. Fractures that do not fit any type are classified as 32-D1. Even though the AO/OTA fracture classification is comprehensive, substantial interobserver reliability is only found for the fracture type (A, B, or C) but not for any subgroup.
The Winquist system only considers the extent of comminution of the diaphyseal fracture. It was initially used to evaluate the need for locking of the nail or not and to determine the amount of postoperative weight bearing. However, as full locking techniques became routinely established, the importance of the fracture pattern for deciding whether to fully lock or not has been eliminated, and full postoperative weight bearing is now typically encouraged.
Principles of Management of Diaphyseal Femoral Fractures
After a femoral fracture, several cytokines and other mediators with local and systemic effect are liberated. The advantages of early fracture stabilization have already been described. Nonoperative treatment might only be indicated in developing countries with insufficient surgical facilities. Everywhere else, adult femoral shaft fractures are treated operatively. The immediate management of isolated, uncomplicated femur shaft fractures differs because of regional philosophies, facilities, or medicolegal aspects. The first author is trained to operate on each femoral shaft fracture as soon as possible with only very few exceptions. Operative stabilization includes temporary external fixation. Although initial operative stabilization might provide distinct advantages, the only study yet available has shown no advantage of immediate external fixation compared with temporary traction for patients who did not require any immediate anesthesia because of concomitant injuries. If initial surgery is postponed because of the hospital’s philosophy or facilities, skeletal traction should be applied at least. Usually a supracondylar, transosseous pin traction is used. In a randomized prospective study (RPS), no difference in patient’s pain was found between skeletal and cutaneous traction applied for 24 hours before surgery. Application of the cutaneous traction was significantly faster. Cast splinting is rarely effective.
Nonoperative Treatment
Nonoperative treatment of femoral shaft fractures with traction (skin traction or skeletal traction) has been used for many years. Nowadays in the developed world, traction is only used as a temporary measure to restore leg length and alignment and to provide pain relief and limit blood loss before surgical stabilization. However, it is still extensively used in developing countries with insufficient facilities for operative management. Closed management by traction is, however, both complex to manage and time consuming, often requiring months of bed rest. It does not offer the early return to function provided by modern fracture stabilization techniques. A recent study reporting on 69 femoral shaft fractures treated by traction showed a mean time of traction between 30 and 40 days, with only two patients needing traction for a period of 60 days. The mean hospital stay was 45 days; seven patients had a restriction of flexion to 90 degrees, and one patient developed a nonunion.
Traction can either be applied via the skin or the skeleton. Skin traction with adhesive padded tapes secured with a bandage to the leg can only be used with a light weight (5–7 lb). It is poorly tolerated by patients because it may result in local skin problems or losing hold and thus control. For adults, it only acts as a temporary measure until definitive treatment. Skin traction applied through an ankle strap on a splint designed for emergency transportation (e.g., Hare traction) is useful in the immediate prehospital environment. In contrast, skeletal traction permits use of greater traction force and can be tolerated for long-term treatment (months). A traction pin may be placed in either the distal femur or the proximal tibia. A 5-mm pin, threaded in the central portion to prevent backing out, is preferred.
Femoral Traction Systems
Historically, traction was the standard method of treatment for femoral shaft fractures, which included months of bed rest to achieve union in a reasonable position. The application and daily management of a patient on femoral traction requires skill and subsequent daily attention to detail over the healing period. Each system has its proponents with emphasis on the relevant application of balanced forces and early knee motion whenever possible. Problems associated with traction include bed and traction ring sores, skeletal pin infection and pin migration; the ability to control position that can lead to shortening or malunion (overriding of the fracture parts may occur); and the need for prolonged bed rest and immobility that often lead to knee stiffness, muscle wasting, and development of deep venous thrombosis.
Alternatively, a smaller diameter Kirschner wire that is kept under tension with a clamp can be used. This has the disadvantage of sliding medially and laterally, risking skin pressure by the clamp. Compared with the proximal tibia pins, distal femoral pins allow more direct control of the femur and have a limited effect on knee function. They are normally placed at the level of the superior pole of the patella and outside the knee capsule to avoid joint infection. Ideally, a femoral pin should be inserted with the patient’s knee flexed to 90 degrees to avoid tethering of the iliotibial band, but this is not practical in an awake patient. Proximal tibial pins are placed just behind and below the tibial tubercle. They cannot be used in the presence of an ipsilateral knee injury, and an additional disadvantage is that they restrict knee motion during rehabilitation.
Several traction systems have been popularized. Each is designed to apply a traction force along the femoral axis and balance against an opposite force. If the traction force is unbalanced, it will result in the patient being pulled down the bed, which can subsequently cause buttock and sacral skin problems from friction. A common problem is that eventually the traction weights come to rest on the floor, rendering the whole traction system ineffective.
A simple method of applying traction is to attach a rope to the clamp holding the traction pin or wire and then pass it over a pulley, finally attaching its free end to a weight hanging free at the foot of the bed. The leg is then supported by pillows arranged to minimize deformity and prevent the heel from resting on the bed (which can often result in pressure sores). Depending on the patient’s size and thigh musculature, 15 to 25 lb of traction is usually sufficient to restore femoral length during the first few days after injury when muscle spasms can be intense. Repeat radiographs are required to adjust the weight and therefore traction force. This simple technique provides only limited support for the fractured femur and restricts mobility.
Better fracture control and bed-bound mobility can be obtained by the use of a supportive splint, such as a Thomas splint. This consists of a padded ring that goes around the proximal thigh and is attached to a long steel loop that must be selected to be slightly wider and somewhat longer than the leg. Traction is then applied between the ring and the end of the splint. Fabric slings and pads are placed posterior to the thigh to support the femur directly and recreate the femoral bow. A small windlass is commonly used to tighten the traction and pulls against the leather ring, which is pushed into the groin. Suspending the splint on and applying weights to pull the whole splint out of the groin prevent ring sores. Typically, the foot of the bed must be raised slightly to balance the traction.
In many North American hospitals, a balanced suspension is made for the injured leg using a modified Thomas splint with a semicircular proximal ring. A hinged Pearson attachment is typically added to support the lower leg with the knee slightly flexed. Either both ends or just the proximal end of the Thomas splint is supported with a rope–pulley–weight combination, with the weights chosen to balance the splint so that it supports the patient’s leg and helps with fracture control while permitting some adjustment and mobility by the patient, within the limits set by the separately applied skeletal traction rope.
Another traction system is the so-called Perkins traction, often associated with the care of tibial plateau fractures. It also offers an effective and simple means of managing traction for femoral shaft fractures. It adds the benefit of knee mobilization, which may begin as soon as the patient’s comfort permits. Perkins traction is longitudinal traction applied with the patient on a split bed arranged so that the lower half of the mattress can be removed or dropped to permit knee flexion while traction is maintained ( Fig. 58-9 ). Longitudinal traction is applied from a distal femoral pin and out over pulleys off the end of the bed. The split bed allows the end of the mattress to be removed so the patient can start early knee motion while remaining on traction.
When traction is used as definitive treatment, it is usually maintained for several weeks (typically 5–6 weeks in adults) until adequate fracture healing has occurred without tenderness or movement on clinical examination. At this time, continued protection is necessary to avoid potential gradual angulation. For more distal femoral shaft fractures, this can be effectively provided with a hinged-knee cast brace, but such support may not be sufficient for proximal femoral shaft fractures, particularly in the subtrochanteric region. Alternative options are to use a spica cast (either recumbent or ambulatory) or to continue skeletal traction until mature fracture healing is present, clinically and radiographically, often as long as 12 weeks after injury. (See the discussion of nonoperative fracture treatment in Chapter 12 .)
Clearly paying attention to detail and expert nursing care are required to achieve a well-aligned femur and to prevent local complications. In addition to the previously mentioned problems of malunion, nonunion, stiffness, and pressure sores, other complications that have been reported include a higher risk of thromboembolic events and development of osteoporosis and muscle atrophy. The overall morbidity and mortality are significantly higher compared with early operative stabilization.
Contraindications of nonoperative treatment include the presence of compartment syndrome, vascular injuries, traction injury to any of the lower limb nerves, nonunion (late complication), and irreducible fracture with impending soft tissue perforation.
Operative Treatment
Nowadays, all adult femoral shaft fractures in the developed world should be treated operatively. Refusal by the patient is the only accepted reason not to operate. It is clear from the literature that early operative stabilization is superior and benefits the patient.
External Fixation
External fixation of femoral fractures as definitive treatment has a limited role given the success of IM nailing. The advantages of external fixation include its very quick application and minimal invasive approach and an implant-free fracture site. Therefore, the only current strong indications are for the temporary stabilization of a femoral fracture in polytraumatized patients, severe open fractures, or stabilization before transfer to another facility ( Fig. 58-10 ).
The application of external fixation systems to the femur can be challenging because of the extensive muscle coverage. Moreover, there is no useful subcutaneous border that will allow safe pin placement without tethering surrounding musculature and restricting knee motion. A standard external fixator that allows free independent pin placement is usually used and based on 5- or 6-mm threaded pins. Self-drilling, self-tapping monocortical pins reduce stability by 20% compared with classic bicortical pins but can be applied faster and save time, which might be important in critically ill patients with multiple extremity fractures. The pinless fixator is not recommended for the femur. The insertion of the pins can follow an arc from true lateral to anterior, limited by the position of the femoral artery and sciatic nerve. Proximal pins can be directed into the femoral neck and head. The use of AP-placed pins should be restricted because they provide tenodesis of the rectus femoris muscle with subsequent stiffness. The joint capsule of the knee should also not be penetrated. The femorotibial spanning is preferred in these cases. The pin and frame construct should be applied according to the fracture anatomy but planned to be as stable as possible. Standard external fixator mechanics should be used, with the most stable construct involving near–far pin placement and the rods applied as close to the soft tissues as practical for skin care. A pin placement too close to the fracture site might increase the risk for infection. In practice, an emergency fixator for damage control can be applied very quickly, especially anterolaterally. The aim is to provide adequate stability during the initial critical care process. A definitive reduction at this time is not essential. If general or local difficulties predominate, a frame providing good alignment and stability will be satisfactory, and protracted attempts at a perfect reduction should be avoided. However, later definitive nailing will be facilitated by maintenance of good tissue tension with normal length and good alignment if this is easily achievable (see Secondary Nailing ).
In polytrauma patients, conversion of a primarily externally fixed femoral fracture to definitive nailing should be performed after the patient’s systemic response to injury settles down (usually by 5 days).
In severe open fractures, most surgeons perform immediate definitive fixation after wound débridement and lavage. If there is an indication not to proceed to definitive fixation, an external fixator should be applied after débridement, which acts as a very good temporary stabilizing device. The patient can then be considered for transfer or for definitive care. In this situation, local soft tissue conditions and the availability of an experienced surgeon will determine the timing for conversion. Definitive treatment, however, should not be delayed unless additional severe polytrauma issues are evident; indeed, current evidence supports that in severe open fractures, the sooner definitive skeletal stabilization and healthy soft tissue cover is provided, the better the outcome.
Open Reduction and Internal Fixation
The use of plating for fracture fixation was first popularized by the AO group in the 1960s and 1970s. Nevertheless, in recent years, plating systems are more rarely used for femoral fixation because of the established success and superiority of femoral nailing. There are, however, specific occasions when plating still has a role, essentially as alternative femoral stabilization when nailing is impractical or inadvisable, as well as in the treatment of recalcitrant nonunions.
Open reduction and plating became popular before our current understanding of the mechanisms and mediators and cellular elements involved in fracture healing and how fracture healing is affected by the operative insult and the type of implant used. Although seemingly straightforward, successful plating of the femur requires highly skilled surgery and is much more demanding and operator dependent than IM nailing. The skill is to apply a plate providing the appropriate degree of stability without causing more damage to the viability of the fracture fragments and thereby to facilitate fracture healing. If the likely mode of fracture healing is not understood and the correct principles are not applied during surgery, poor results may occur. The fracture healing process will be compromised and delayed, the rate of complications will be increased, and eventually implant failure or progression to nonunion may occur. The mechanism of failures of healing can sometimes be difficult to understand, particularly because even if the initial postoperative radiographs are ideal, the condition of the soft tissues and their insult during the operative procedure cannot be demonstrated and is usually underestimated.
The classic approach for femoral plating is the so-called subvastus approach. The vastus lateralis and vastus intermedius are reflected anteriorly and medially after being lifted off the periosteum. The exposure to the fracture is excellent but with a negative impact on the biology. With this approach, the perforator arteries have to be ligated, and the periosteum is extensively stripped, leading to a dramatic reduction of periosteal perfusion.
Bridging plates have been used for comminuted fractures that could not be anatomically reduced. The soft tissue insult and periosteal stripping was kept to a minimum, allowing fracture healing with callus formation, similar to closed nailing. This type of osteosynthesis was characterized as unstable or semirigid.
Current understanding of the bone healing process with bridging plates has led to the era of biologic plating. The paradigm of absolute stability was abandoned, and restoration of the axes was defined to be “anatomic reduction.” As with the nail, the plate was inserted far away from the fracture site ( Fig. 58-11 ). The soft tissues around the fracture were left intact. The plate was then slid submuscularly but epiperiostealy. Locking plates facilitate the minimally invasive plate osteosynthesis (MIPO). The goals of MIPO were improved fracture biology and therefore better healing, less risk of refracture and need for bone grafting, and reduction of infection rates.
Nonetheless, MIPO is a highly demanding technique. In contrast to nailing, the plate itself does not provide the same amount of “self-reduction.” Satisfactory reduction of the fracture is a prerequisite for definitive fixation ( Fig. 58-12 ). It is recommended to use specially formed and usually big clamps for percutaneous stabilization ( Fig. 58-12, A, D, and E ). The plate can then aid the reduction technique. Many of the reduction tricks described later for closed nailing can be applied. A temporary external fixator or distraction mechanism can be very useful ( Fig. 58-11, B ), having an easier application compared with nailing procedures.
Specific situations for consideration include femoral fractures in polytrauma patients and open injuries, especially with vascular compromise. In polytrauma (see earlier discussion), the surgeon may judge not to instrument the medullary canal but to stabilize the fracture with a plate, to reduce the risk of acute respiratory distress syndrome/multiple organ dysfunction syndrome (ARDS/MODS). Although this is a reasonable option, Bosse and colleagues were unable to identify any improvement in survival in patients in whom the femoral fracture was plated rather than nailed.
In severe soft tissue injuries, particularly open injuries with vascular damage, it may be easier and more practical for the skilled surgeon to quickly apply a plate than anything else, even an external fixator. There are major advantages of early definitive fixation, but this must not delay limb revascularization. If revascularization is required, a vascular shunt may be placed before definitive fixation. In principle, the orthopaedic surgeon working with a vascular surgeon should wait until the vascular injury is defined, and then, often as vein is harvested from another site, the plate can be applied. This is a good technique that will create stable fracture fixation often via extensions to the initial wound and without the manipulations required for nailing.
Overall, femoral nailing is the standard procedure for stabilizing fractures of the femoral shaft. However, there are specific indications when biologic plating might be advantageous:
- •
Closed medullary cavity (because of the presence of another implant or sclerosis)
- •
Very narrow medullary cavity (which can cause heat necrosis during reaming)
- •
Presence of contamination of the entry point of the nail
- •
Suspicion or proof of IM sequestrum
- •
Increased bowing of the femur that does not allow the insertion of the nail (in such cases, additional osteotomy has to be considered)
- •
Open fracture with vascular injury
Intramedullary Nailing
Intramedullary nailing is considered the “gold standard” for treating femoral shaft fractures. The implant is placed centrally within the bone medullary canal. The surgical approach is located far from the fracture site, thus causing minimal disruption to the biology of the fracture, and most of the time, there is no need for an open reduction.
It is important to differentiate IM nailing and elastic stable IM pinning, which is often incorrectly termed nailing . These elastic pins are usually used in the pediatric setting. The elastic pins act as a spring and provide a three- or four-point support. This mechanical construct, however, fails in adult femur fractures because it does not offer adequate stabilization.
Gerhard Küntscher is considered the initiator of IM nailing. The classic Küntscher nail has similar mechanical features with a carpenter’s nail, where the nail is hammered into wood. The nail is seized up because of the equilibrium of the radially oriented force vectors, the so-called normal force. This normal force induces friction that impedes rotational and axial movement of the nail. The friction depends on the contact area and the normal force.
The classic Küntscher nail was hollow and slotted. Two mechanical principles stabilize the fracture, inner mounting and friction ( Fig. 58-13 ). The ideal nail has a 100% contact area with the bone. Thereafter, no movement between the nail and fragments would occur when bending moments were applied. However, because the femoral cavity is not round on transverse sections and is shaped like a sand glass on frontal sections, some toggling between the nail and the bone occurs. This toggling is smallest if the fracture is localized within the isthmus, where the canal size is the smallest.
The hollow, slotted, and clover leaf–shaped Küntscher nail deforms while hammered into the medullary canal. This deformation is responsible for the normal force within the contact areas. The resulting friction can neutralize axial and rotational forces. This effect is only seen for fractures within the isthmus.
Reaming of the medullary canal converts the inner aspect of the femur to a more tubelike structure with benefit for both stabilizing aspects (see Fig. 58-13, A ). The contact area increases, providing increased friction force, even for fractures that are not directly located within the zone of the isthmus. Second, the toggling effect is reduced. The mechanical reaming effect is limited to the proximal and middle part of the femur shaft because the distal part has the shape of a trumpet. It is impossible to equalize the inner diameters in this region. Other technical techniques such as interlocking or blocking of the nail have been used. Another positive mechanical effect of reaming is due to the nail’s metrics. The widened cavity fits a thicker nail. The increased diameter leads to higher stiffness and failure loads of the nail. In interlocking nails, much thicker locking bolts can be chosen with the same effects on stability of the nail.
The classic reamed Küntscher nail can stabilize type A and B fractures in the proximal and middle shaft. The direct contact of both main fragments impedes axial shortening. In complex fractures, only the very low friction counteracts the axial forces. In 1968, Gerhard Küntscher developed the so-called “distensor,” which was the prototype of interlocking nails.
The unit of bone–locking screw–nail is now the main antagonist to axial load and rotation. All three parts of this unit can fail (screw breakage, nail breakage, or screw loosening within the bone). Friction between the nail and bone is of less importance. For this reason, the more deformable slotted hollow construction of the nail is replaced by a more or less solid construction. The excessive hammering of Küntscher nails is now contraindicated. Modern nail systems are mostly cannulated and made from titanium. Inner mounting is an important mechanical issue even in interlocking nails.
In elderly adults, the screw–bone interface usually represents the weakest point. Attempts have been made to improve the stability of the screw within the bone. Some nailing systems offer spiral blades instead of screws. These blades might improve stiffness by 40% and stability by 20%. In younger patients, however, the interlocking screw itself is the point of weakness. In the tibia, it has been reported that failure of locking screws was associated with higher rates of nonunion and malunion. Mechanical tests revealed a 70% higher fatigue failure load with a 20% increase in diameter.
Some years ago, inflatable nails were promoted to overcome the problem with interlocking ( Fig. 58-14 ). The mechanics of these nails are similar to those of the Küntscher nail. In contrast, the nail was not hammered in but inflated with the means of a solution. The expansion of the nail toward the bone led to the normal force. An extended contact area could therefore be obtained. However, torsional stiffness was significantly lower compared with that of interlocking nails. The only relevant clinical study showed a high failure rate, especially for C-type fractures. Its usage in femoral fractures cannot be recommended.
Even solid nails show some deformation with insertion. Nevertheless, some deformation is necessary especially for long nails; otherwise, the sliding might be dangerous. This deformation can be 20 mm at the nail’s tip in the frontal and sagittal plane. The rotational deformity is of minor relevance.
Role of Reaming
As mentioned before, Küntscher used the technique of reaming to enable larger nails to be inserted into the femoral canal, improving the fit of unlocked nails that rely on friction to gain a tight fit on the central diaphyseal segment of the femur. One of the big debates in trauma surgery at the turn of the century was the role of reaming because it exerts both a local and systemic impact.
First, both reamed and unreamed nails interfere with the endosteal perfusion. The cortical perfusion is significantly reduced after reaming. This reduction is reversible but delayed. Nevertheless, experimental data of a closed fracture model showed a positive effect on fracture healing despite this cortical minor perfusion. In this study, reaming promoted the perfusion within the soft tissues, which might explain the positive effect. A positive effect of the reaming debris as an inner bone graft was postulated earlier. The viability and osteogenic potential of the debris has been previously reported. A significant accumulation of the debris within the fracture site is shown. Reaming enhances the serum levels of growth factors. The effect of reaming is probably multifactorial. In addition to the healing effect, there are mechanical reasons to ream. A number of patients have relatively small femoral canals with a result that even the smallest nail cannot be passed without reaming, and as more advanced generation nails are used with more complex proximal locking options, the proximal diameter is often larger and mandates reaming. Today, the positive effect of reaming for femur fractures with minor soft tissue trauma is unquestionable, and reaming is definitely recommended. The nonunion risk with unreamed nails is more than fourfold. These observations, however, are not transferable in the treatment of open fractures. The debris is usually washed out, but with periosteal stripping, the cortical perfusion might regain importance. The unreamed nail might offer advantages. However, clinical data are only available for the tibia where low infection rates for the unreamed nail in Gustilo grade OIIIb fractures are reported.
During the process of reaming, as a result of the friction between the reamer head and the medullary canal, heat is produced. This heat might be disadvantageous, and some authors have reported segmental necrosis of the bone. If the reaming is properly performed, no thermal damage is to be expected. In special situations such as cases with very small canal or sclerotic bone, very careful reaming is required. Blunt reamers or oversized reamers might increase the risk for thermal necrosis. It might be prudent to start with a small hand reamer. In rare cases, extramedullary stabilization might be indicated.
Another disadvantage of reaming is the potential adverse effect of the surgical insult in polytrauma patients and the additional time required for the reaming. Küntscher reported the increased risk of fat embolism and advised against IM nailing in severely injured patients. The direct cardiovascular effect of fat embolism itself is not the main problem. However, the flushed substances might activate the complementary system, leading to a cascade of events, especially in polytraumatized patients. The IM pressure depends on several factors that can be easily influenced by the surgeon. Forceful propulsion of the reamer can increase the IM pressure more than fourfold, but blunt reamers also increase the pressure. Careful reaming must not lead to low rotational speed, which correlates adversely with pressure. Recently, so-called suction-irrigation reamers were developed that reduce the IM pressure significantly and lower both the pulmonary pressure increase and the systemic response.
If no relative contraindications are present, reaming should be used because it still provides the most reliable results. However, it is essential for the surgeon to understand that reaming is a technique related to, but essentially independent of, the nail choice. In addition to the mechanical effects of preparing the bone for the nail, reaming has specific biologic effects that are only just starting to be understood. On the negative side, there is no doubt that reaming causes embolization of the medullary canal, activates local cytokines, and raises the temperature of the involved bone. The relevant importance of each of these effects is currently unknown and seems to be tolerated in the majority of patients although in some situations, significant deleterious effects can occur. The primary positive effect of reaming is activation of the healing process by the mechanism discussed earlier.
Role of Locking
Interlocking nails can be locked either dynamically or statically. Dynamic locking means that either the proximal or distal fragment can slide over the nail. This slide causes axial compression of the fracture on load bearing (i.e., dynamization of the nail). In the beginning, dynamic locking was achieved by leaving the proximal or distal locking holes empty. Nowadays, most nails provide additional oval holes that allow axial sliding but prevent rotation. Dynamic locking promotes healing. However, only distinct fracture types are suitable for primary dynamic locking. Transverse fractures are ideal. Further, A- and B-type fractures can be locked dynamically if telescoping can be excluded. Routine secondary dynamization was recommended after 6 to 8 weeks in the beginning of locked nailing. Today routine dynamization is not recommended because union rates do not differ, but it might be indicated if delayed healing is present.
Antegrade Nailing
Antegrade nailing is the standard technique for femoral shaft fractures. It is also the preferred method of treatment of subtrochanteric fractures, but this is extensively described elsewhere (see Chapter 57 ). Antegrade nailing of fractures close to or within the distal metaphysis is possible but technically very demanding. Retrograde nailing might be advantageous in this location (see later discussion). Antegrade nailing can be used as the primary or secondary stabilization technique. Although primary nailing is mostly performed as an emergency procedure, preoperative planning is always essential.
As already mentioned, a fracture of the neck of femur or the femur condyles must be excluded because it has a major impact on the strategy of stabilization. Intraoperative diagnostics by an image intensifier is of less conclusiveness.
Special risks or side effects of antegrade nailing have to be explained to the patient during the process of consent. These include, but are not limited to, hip pain, abductor weakness, limitation of hip motion, heterotopic ossification, iatrogenic neck of femur fracture, and postoperative rotational deformity. Preoperative antibiotic prophylaxis is recommended.
Positioning of the patient is one of the most crucial steps in antegrade nailing of the femur. Insufficient positioning can make the nailing very difficult or even impossible. Different positioning techniques exist, each with pros and cons. The most popular techniques are the supine or lateral decubitus positions with or without a fracture table.
The supine position without a fracture table ( Fig. 58-15 ) is the most variable position because it allows access to all four extremities, the pelvis, the abdomen, the chest, the neck, and the head. Parallel surgery is possible, and this might be of great importance in multiply injured patients. The setup time is the shortest of all positions. The supine position with a fracture table has been popularized by Küntscher ( Fig. 58-16 ). Proponents refer to the permanent traction with some reduction of the fracture. Many, but not all, nailings might be performed without any further assistance besides the scrub nurse. The latter point is not supported by the literature. Two prospective randomized studies compared the supine position with and without a fracture table. The fracture table group showed longer setup times, longer operation times, and a higher rate of malrotation. Pudendal nerve palsy with concomitant erectile dysfunction has been described after femoral nailing with a fracture table.
Well-leg compartment syndrome is a dreaded but well-known complication of antegrade nailing in the supine position whether with or without a fracture table. This complication refers to the necessity of axial intraoperative imaging of the proximal femur. Most surgeons prefer a hemilithotomy position of the contralateral side. A direct correlation between increased compartment pressure and the hemilithotomy position in a well-leg holder is shown. Increased patient body mass index is an additional risk factor. In prolonged operations, the contralateral leg held in the hemilithotomy position should be unfastened for some minutes. An alternative option is the sterile coverage of both legs. This allows elevation of the contralateral leg on demand. Furthermore, the contralateral side can be used as a reference for length and rotation.
The lateral decubitus position facilitates the proximal approach to the greater trochanter, which might be advantageous in obese patients ( Fig. 58-17 ). To our knowledge, there are no comparative studies in the current literature. Rotational control of the contralateral side as a reference is impossible. However, one retrospective study did not show any influence of the position on rotational malalignment. Moreover, the decubitus position takes more setup time. The access to other regions is limited, which might limit the use of this setup position in multiply injured patients. In patients with head and thorax trauma, it might even be contraindicated.
Entry Point
The so-called conventional entry point is localized in the piriformis fossa, where the insertion of the tendon of the piriformis muscle is found (just medial to the greater trochanter and slightly posterior). It has to be pointed out that the entry point is not defined by the fossa itself. The point is defined by the intersection point of the projection of the nail onto femur in the AP and lateral planes ( Figs. 58-1 and 58-18 ). The conventional nails are straight with some antecurvature (usually about 6 degrees). A straight nail with no antecurvature would have a more anterior entry point. Less stiff nails do tolerate some deviation of the entry point because their deformation allows more adaption. Even solid nails deform with insertion. The deviation is better compensated in the middle of the shaft. The more proximal the fracture, the greater the importance of the correct entry point. A too lateral entry point can fracture the medial cortex ( Fig. 58-19, A ). Furthermore, it can rotate the proximal fragment in a mechanically less favorable varus alignment (see Figs. 58-14 and 58-19, B ).
If the entry point is too medial, the risk of iatrogenic fracture of the neck of femur rises. The piriformis fossa is sometimes difficult to access, especially in obese or very muscular patients. A slight adduction is necessary to get access to the fossa and not to interfere with the sprawling iliac crest. The piriformis fossa has sometimes no direct access. A cadaver study on 100 femurs showed in 37 femurs 50% bony coverage by the tip of the greater trochanter. Splitting of the gluteus medius muscle is mandatory for the access, and therefore injury to the muscle to some extent is unavoidable. The starting reamer might further damage the muscle and spread some bony debris into the muscle, which can later lead to heterotopic ossification. In fact, the rate of proximal ossification is about 60% with mostly Brooker grade 1 or 2. Finally, long-term follow-up of antegrade nailed patients show some remaining abductor weakness.
All of these issues with the conventional entry points led to the search for alternatives. A more lateral entry point might be easier to access. A straight nail would cause the above-mentioned problems. A modification of the antegrade femur nails was deemed necessary. The so-called trochanteric nail was designed. A double curvature (antecurvature and lateral bend) allows a safe and more lateral access ( Fig. 58-20 ). Experimental data showed less iatrogenic soft tissue damage, especially of the medius gluteus muscle, with the more lateral entry point. Clinical data did not find any profit in abductor strength or hip pain, but operation time and fluoroscopy time were reduced with the more lateral starting point. The starting point can vary from the tip of the trochanter to an even more lateral entry just above the innominate tubercle. The exact lateral entry point depends on the nail’s curvature and differs among different manufacturers’ types. A slightly more medial entry point is better tolerated than a too lateral entry point. This applies especially to proximal fractures. A too anterior entry point is a risk factor for iatrogenic fracture in these double-curved nails.
Technique of Antegrade Nailing
Even though some small technical steps differ among surgeons, the basic technique should be the same. The following operation guide is not apodictic and reflects some preferences of the first author, who mainly but not exclusively performs antegrade nailing in a supine position without a fracture table. The senior author uses the supine position with a fracture table.
The patient is placed on a radiolucent operating table (see Fig. 58-15 ). A folded blanket is placed centrally beneath the sacrum to slightly elevate the buttocks. It is important to place the blanket centrally. Tilting of the patient aggravates the correct orientation of rotation. The patient is slightly moved to the edge of the table. The elevation and lateral move ease access of the slight posterior entry point of the proximal femur.
Before routine skin preparation and draping, the contralateral leg can be used as a reference point for rotation control and leg length. The rotation is checked with the hip in 90 degrees of flexion (see Fig. 58-27 ). Another tool to reduce the risk for postoperative malrotation is the so-called “minor trochanter sign” described by Krettek (see Fig. 58-28 ). The leg length can be measured fluoroscopically. A conventional ruler can be used, and two reference points (i.e., acetabulum roof and medial joint line of the knee) have to be defined. The reference points must be imaged centrally. Otherwise, the oblique projections will distort the values (see Fig. 58-30 ). Nail length can also be measured using the contralateral uninjured limb. In case of unreamed nailing, the isthmus width needs to be measured to decide the diameter of the nail to be used. The preoperative radiographs can only be used if a marker is used to correct for magnification. If a preoperative CT scan is available, the scout is precise and should be used as long as the isthmus region is imaged. If a ruler is used to measure the diameter of the isthmus, care has to be taken. The distance of the ruler differed in relation to the image intensifier from that of the bone, and therefore the magnification differs. As a result, the isthmus is usually enlarged, and the nail would be oversized. This effect is marked with very thick thighs. When in doubt, the smaller nail diameter should be chosen. The next step is for the contralateral leg to be placed in the leg holder. It is mandatory to ensure unlimited fluoroscopic access to all areas before skin preparation and draping.
The conventional entry point leads to a more proximal and dorsal skin incision. Therefore, the skin preparation should be done with the leg in slight adduction ( Fig. 58-21 ). Beginners should mark the greater trochanter and the shaft axis and its extension on the skin. The skin incision is on the extended line. Access to the piriformis fossa can be obtained 5 to 8 cm proximal to the tip of the trochanter. Usually a 2-cm incision is adequate. The leg is hold in maximal adduction. The knife points toward the piriformis fossa. Skin and fascia layers can be cut by one incision. The muscle is then dissected bluntly with scissors. The medial edge of the greater trochanter can now be palpated with the finger. The guidewire is laid on the palmar side of the index finger, and the finger is reinserted into the wound. The right index finger is used for the right leg and the left index finger for the left leg. The index finger is used as a slide on which the wire is carefully protruded. It is mandatory to control the correct position on orthogonal images. If the wire is placed incorrectly, it should be left in place. The wire can be used as a reference for the next wire insertion ( Fig. 58-22 ). Some manufactures offer special offset adapters. After reassessing the correct fit of the wire, the starting reamer should be inserted as distal as the minor trochanter. With lateral trochanteric nails, the skin incision is slightly more distal. Depending on the nail type, it might be 2 to 4 cm above the tip of the greater trochanter.
Cannulated nails are preferred because their insertion is easier. The long ball-tip guidewire is inserted just proximal to the fracture ( Fig. 58-23 ). Before insertion, it is essential to ensure that the reamers and the nail can pass over the wire. The next important and sometimes most difficult step is the reduction. The advantages of closed nailing are uncontested and should not be sacrificed to ease the reduction. Only a few exceptions justify an open nailing. In long spiral fractures, especially in the subtrochanteric region, a cerclage wire or clamp might be necessary to close the tube and to create the requirements for the inner mounting of the nail ( Fig. 58-24 ). In rare cases, the fracture spike is jammed within the fascia and cannot be freed by closed means. The incision and especially soft tissue dissection should be as minimal as possible. An open fracture, of course, can be reduced by open means. However, no additional soft tissue dissection apart from the necessary wound débridement should be done.
The aim is to slide the guidewire into the distal medullary canal (see Fig. 58-23 ). The problem is the restricted direct manipulation of the main fragments through the bulky thigh. Traction either manually or through a fracture table can aid with restoring length. Most of the time, simple traction is not adequate to reduce the fracture. The inserting muscles responsible for the different patterns of fracture dislocation need to be neutralized. In proximal fractures, the proximal fragment is nearly always externally rotated, abducted, and flexed. In distal fractures, the distal fragment tends to recurvature, shortening, and varus. Slight manipulation maneuvers can be done through the soft tissues by pushing a hammer or pulling a sling. Better control of the fragments can be achieved by direct manipulation. A percutaneous awl allows more exact guided pushing ( Fig. 58-25 ). Inserted unreamed nails can also manipulate the proximal fragment. Similar manipulation can be done by a special IM reduction tool that is offered by some of the manufacturers. The instrument is often called the finger. A cannulated bar, which is bent and flattened at its end, allows manipulation of the proximal fragment. The end is threaded into the far fragment. After correct placement, the guidewire is introduced and inserted. Another easy and minimally invasive manipulation technique is the so-called joystick technique (see Figs. 58-23 and 58-25 ). A percutaneous Schanz screw is inserted into the proximal and distal fragment. The pin has to be placed monocortically in the proximal fragment to allow sliding of the wire. A T-handle is mounted onto the screws. The surgeon can then reduce the fracture while feeling the contact of the fragments. In very rare situations, the axial length cannot be restored, and the use of a femoral distractor can restore length. The exact pin position is crucial. Exact alignment is not mandatory in the middle part of the shaft because the insertion of the nail will eventually reduce the fragments.
After correct placement of the guidewire, the reaming starts. Some manufacturers recommend measuring the nail length with the aid of the guidewire. The femur is reamed as described earlier. A slight overreaming of 1 to 1.5 mm is recommended. The point when the reamer can be felt and heard cutting the inner cortical bone of the narrower diaphyseal segment of the bone is called cortical chatter. At this point, the nail will obtain some grip on the diaphyseal segment of the femur, and assuming a nail can be inserted, excessive reaming beyond this point is not usually required. Surgeons now ream considerably less than was common practice some years ago. With a middiaphyseal fracture, the passage of the nail will correct any simple residual fracture malalignment other than rotation, and a satisfactory position is usually obtained. The proximal and distal positions of the nail are checked by fluoroscopy. After the nail is correctly inserted, the nail should be locked dynamically or statically (see earlier discussion). As mentioned earlier, the nail deforms with insertion. For this reason, proximally mounted aiming devices for the distal locking will fail. Some mechanical aiming devices rely on direct contact with the distal nail tip and work well in experienced hands. Most surgeons prefer distal locking under image-intensifier control. Different techniques have been described. A radiolucent drill offers direct imaging. Recent techniques use electromagnetic features for fluoroscopy-free locking. The bolts are usually placed bicortically. Medial protrusion of the bolt can cause knee pain, which is reported in 10% of patients. The classic AP control does not exclude protrusion because the condyle is trapezoid shaped ( Fig. 58-26 ).
Before locking proximally, the rotation needs to be checked. Malrotation leads to the cortical step sign as the cortical width differs sectorial (see Fig. 58-2 ). Further techniques have been described earlier. In comminuted fractures, the leg length is measured as described earlier. Forward slashing of the distal locked nail will lengthen the femur, and back slashing will shorten the femur. Back slashing should be done in A- and B-type fractures to compress the fracture and promote healing. With proper rotation and length, the proximal locking can be done. A tight fit of the insertion handle with the nail has to be checked to guarantee proper use of the mechanical locking guide. At the end, the proper placement and length of all bolts should be checked. Rotation is checked twice: first before removal of the sterile sheets and second after repositioning of the contralateral leg. If necessary, rotation should be corrected within the same anesthesia. Knee stability has to be tested and documented. In case of secondary nailing, the knee and hip joint should be mobilized under anesthesia.
In fractures with proximal extensions or associated proximal fracture lines, a cephalomedullary locking device into the femoral neck can be used (see Fig. 58-20, D and E ). This extends the effective working length of the nail from the femoral neck to the distal femur and can effectively stabilize virtually any femoral fracture. The routine use of reconstruction nailing is discussed. A recent study focused on the cost effectiveness of reconstruction nails. A threshold was found for implant costs, which might differ among countries and hospitals.
Retrograde Nailing
Retrograde nailing was initially used for fractures that were not amenable for antegrade nailing. Swiontkowski and colleagues reported a retrograde nailing of a femur shaft fracture with an ipsilateral neck of femur fracture that was stabilized with screws. An early series of retrograde nailing was published by Sanders and colleagues in 1993. Both groups of authors used an extraarticular approach via the medial condyle. This approach was associated with some malalignment and a high risk of condylar fractures. The intercondylar transarticular approach, however, allowed a straight insertion without the reported problems. Retrograde nailing is now well established and accepted by the orthopaedic community.
Preoperative planning does not differ from that of antegrade nailing. Specific risk factors need to be explained to the patient. Septic arthritis of the knee is reported in 0.5% to 1.0% of the patients ( Table 58-1 ). Postoperative knee pain, restricted knee motion, and retropatellar arthritis are not clearly supported by the literature but should be discussed on consent.
| Reference | Patients ( n ) | Treatment | Open Fractures | Union * | Malalignment or Shortening | Implant Failure † | Deep Infection | Other | Level of Evidence |
|---|---|---|---|---|---|---|---|---|---|
| Bezabeh et al. | 69 | Traction | 25/69 (65%) | 68/69 (99%) | 1/69 malunion | — | 0/69 | 7/69 (10%) knee flexion >90 degrees | IV |
| Alonso et al. | 24 | External fixation | 13/24 (54%) | 21/24 (88%) | >2 cm: 2/24 (8%) | — | 1/24 (4%) | Restricted knee motion: 11/24 (46%) | IV |
| Bonnevialle et al. | 49 (34 FU) | External fixation | 40/49 (82%) | 25/34 (74%) | 1–2 cm: 53% Frontal >5 degrees: 14% Frontal >10 degrees: 2% Sagittal >5 degrees: 86% Sagittal >10 degrees: 2% | — | — | Restricted knee motion: 28/34 (82%) 14 closed mobilization 14 arthrolysis | IV |
| Rüedi and Lüscher | 131 | Conventional plate | 28/131 (21%) | 122/131 (93%) | ≥5 degrees: 7 (5%) ≥10 degrees: 1 (1%) ≥1 cm: 5 (4%) | 9/131 (7%) | 8/131 (6%) | Bone grafting recommended | IV |
| Magerl et al. | 67 | Conventional plate | 9/67 (13%) | — | — | 7/67 (10%) | 2/67 (3%) | Secondary bone grafting: 13% | IV |
| Geissler et al. | 71 | Conventional plate | 13/71 (18%) | 66/71 (93%) | ≥10 degrees: 1 (1%) ≥1 cm: 5 (7%) | 1/71 (1%) | 0 | Secondary bone grafting: 69% | IV |
| Apivatthakakul und Chiewcharntanakit | 36 | MIPO | 0 | 33/36 (92%) | ≥1 cm: 2 (6%) Frontal ≥10 degrees: 1 (3%) Sagittal >10 degrees: 2 (6%) | 0 | 0 | IV | |
| Angelini et al. | 57 | MIPO | 6/57 (11%) | 54/57 (95%) | Frontal >5 degrees: 6 (11%) | 2/57 (4%) | 1/57 (2%) | Only type A fracture | IV |
| Wolinsky et al. | 551 | Reamed nailing | 90/551 (13%) | 534/551 (97%) | >5 degrees: 16/418 (4%) | 1 (0.2%) | 3/551 (0.5%) | IV | |
| Tornetta und Tiburzi | 83 | Reamed nailing | 6/83 (7%) | 100% | >5 degrees: 2 (2%) | 0 | 0 | 37/83 gunshot injury | II |
| Canadian Orthopaedic Trauma Society | 121 | Reamed nailing | 14/121 (12%) | 119/121 (98%) | — | — | — | — | I |
| Hersovici et al. | 125 | Unreamed nailing | 38/125 (30%) I: 4 II: 18 IIIa: 13 IIIb: 3 | 120/125 (96%) | >5 degrees: 44/125 (35%) | 1 (1%) | 0 | — | IV |
| Tornetta und Tiburzi | 89 | Unreamed nailing | 8/89 (9%) | 100% | >5 degrees: 4/89 (4%) | 0 | 0 | 39/89 gunshot injury | II |
| Canadian Orthopaedic Trauma Society | 107 | Unreamed nailing | 12/107 (11%) | 99/107 (93%) | — | — | — | — | I |
The positioning of the patient is much easier. The operation is done supine. Some authors have suggested tibial traction so they would not require an assistant, but this is not widely recommended. The hemilithotomy position of the contralateral side is not required unless axial imaging of the proximal femur is necessary for concomitant injuries (see later).
The transarticular entry point is the intersection of the shaft axes in AP and lateral projections (see Fig. 58-1 ). This point might differ between different nail designs, but it is always anterior to the femoral insertion of the PCL. The average difference between PCL and entry point differs among studies. Referring to the condyle width a central or slightly medial entry point is preferred. The entry points should be defined under fluoroscopic control ( Fig. 58-27 ). The guidewire should fit as perfectly as possible the extension line of the shaft axes. A good orientation in the lateral view is the Blumensaat line. The entry point is 2 to 4 mm anterior to its distal end. It is important to mention that the shaft axis is not perpendicular to the joint line. The wire has to be angulated 6 to 8 degrees medially. Although the entry point is close to the PCL insertion, no iatrogenic PCL rupture is recorded so far even on arthroscopy. The entry point is located in the so-called “safe zone” of the patellar joint. Experimental data showed pressure altering only if the nail was at least 1 mm prominent to the cartilage. The nail end should be placed subchondral at least. The knee should be flexed between 30 and 45 degrees, but too much flexion sets the tip of the patella at risk.
Technique of Retrograde Nailing
Again, the described technique is one reliable operation guide but not apodictic. The patient is placed supine, with the image intensifier placed on the opposite side. Rotation and leg length are compared with the contralateral side (see earlier discussion). Nail diameter and nail length are determined as described for the antegrade procedure. Usually, the nail should end at the minor trochanter. In special situations, it can be protruded into the cancellous region.
The knee is flexed to 40 degrees, which releases the tension of the gastrocnemius muscle and allows an unproblematic entry point. The skin incision is between 15 and 20 mm in length. The author prefers a slight paraligamentous medial incision. The joint capsule is sharply dissected. The entry point has to be determined under fluoroscopic control. The guidewire might be only protruded if it is placed on the correct entry point and lined with shaft axis in AP and lateral projection (see Fig. 58-27 ). A wrong orientation of the guidewire leads to malalignment. A drill sleeve is mandatory, which is slightly pressed against the condyle. A noncovered reamer sets the patellofemoral joint at risk ( Fig. 58-28 ).
Reduction and reaming are similar to those in the antegrade technique. The nail end and nail tip have to be controlled by fluoroscopy. The nail end requires special attention. Protrusion might induce retropatellar arthritis, but too deep insertion leads to instability ( Fig. 58-29 ).
The locking starts distally. Length and rotation are controlled next and corrected if necessary. A- and B-type fractures should be slightly compressed by forward slashing. The proximal locking is done with the above-mentioned techniques. Most nails offer an AP locking, which facilitates the perpendicular imaging of the holes. Lateromedial locking is even more difficult because the contralateral leg interferes with a perpendicular imaging of the hole. The nail end has to be palpated after the insertion handle is removed. Subchondral placement is mandatory. Adequate irrigation of the joint is recommended.
Antegrade or Retrograde Nailing
The straightforward positioning, the simple intercondylar approach, and the usually easier reduction led retrograde nailing to become an inviting alternative. Comparative studies showed no differences regarding fracture union or knee motion. The antegrade groups showed significantly more hip pain; in the retrograde group, significantly more knee pain was reported. The risk for retropatellar arthrosis is still controversial. The incidence of septic arthritis is very low but still a problem. Until long-term results for retrograde nailing are available, antegrade nailing will remain the standard in the treatment of fractures of the femoral shaft. Retrograde nailing can be considered in special indications ( Table 58-2 ).
| Step | Patient’s Condition | ||
|---|---|---|---|
| Uncritical | Intermediate | Critical | |
| 1 | Supine position without traction | ||
| 2a | Retrograde nail femur | Femoral distractor | External fixation femur |
| 2b | Tibia nail | Tibia nail | External fixation tibia |
| 3 | Reevaluation: patient stable: antegrade nail; patient unstable: leave distractor, transfer to ICU | Transfer to ICU | |
| 4 | Antegrade nail | Antegrade nail | |
Poller Screws
Poller screws, also known as blocking screws, were promoted by Krettek to overcome problems in nailing of metaphyseal fractures that were associated with higher rates of malalignment. The malalignment might be primary or secondary caused by instability. As described earlier, the principle of inner mounting leads to a “self-reduction” in the narrow diaphysis. The distal part of the femoral shaft opens like a trumpet. The principle of inner mounting loses its validity in the wider part. The nail loses its central location with consequent malalignment. The poller screw narrows the corridor. Poller is a German word meaning bollard . These nautical bollards are hit by the tip of the ship. The ship is urged to slide along the poller. The same principle can be applied in nailing. The poller screws lock the wrong way of the nail. The nail slides along the screw and runs in the right corridor ( Fig. 58-30 ). The poller screws take over the buttressing effect of the cortex within the diaphysis. The main effects of the poller screw are (1) direction of the nail in the central corridor and (2) narrowing of the canal and lateral support. Poller screws can be inserted in AP or lateromedial direction. The use of poller screws requires experience because cases of iatrogenic fractures have been reported. Their application within the shaft is especially critical. Poller screws can further be used to correct the wrong entry point (see Fig. 59-66 , Fig. 59-68 , Fig. 59-69 ).
Secondary Nailing
The concept of DCO has been described previously. Primary external fixation of fractures of the femoral shaft might be indicated. The definitive fracture care is delayed. The preferred stabilization technique is still the antegrade nail. The risk of infection is not significantly increased, but infected pin sites should be addressed before surgery. Prolonged external fixation might make secondary nailing even more difficult, especially if the fracture is fixed in contraction. Slight overdistraction might ease the reduction. This distraction can be done daily after the soft tissues are cured and the risk for compartment syndrome is reduced ( Fig. 58-31 ).
Complications of Nailing
Nerve Injury
Different mechanisms of nerve injury have been reported during femoral nailing. Traction injury might be related to the use of a fracture table, especially if the traction is applied via the foot. The peroneal nerve is the one most at risk. If extensive traction can be anticipated, femoral pin traction is recommended, but traction should be released as soon as possible. Overdistraction should be avoided. Nerve injuries related to distraction usually carry a favorable prognosis. In nine of 10 published cases, the palsy recovered within 1 year after surgery.
Traction-generated pressure is another source of intraoperative nerve damage. The risk of pudendal nerve damage from the use of a fracture table is described earlier. Prospective assessment is rarely done. One prospective study showed 9% damage after the use of a fracture table, with 90% of the patients recovering within 3 months after the surgery.
Open injury to a nerve during nailing is uncommon. Damage to the superior gluteal nerve is discussed but not directly proven in the literature. The infrapatellar ramus of the saphenus nerve may be at risk in retropatellar nailing. The ramus runs from proximal-medial to lateral over the patellar tendon. Neuroma formation has been reported that requires operative revision. The risk is reduced if the incision is close to the patella pole. Parts of the femoral nerve are at risk with the sagittal proximal locking of retrograde nails. A cadaver study found no parts of the nerve proximal to the minor trochanter. The clinical impact of injury of these peripheral rami is estimated as low. Nevertheless, careful blunt dissection in this region is recommended.
Vascular Injury
The rate of vascular injury is reported to be about 2%. The distal part of the femur is mostly affected because the vessels run very close to the bone. Iatrogenic intraoperative vascular injuries are rarely reported. The incidence of postoperative hematoma that requires revision ranges between 0% and 1.6%. Branches of the femoral vessels are at risk with the sagittal proximal locking in retrograde nailing. These branches cross the femur 4 cm below the minor trochanter. Locking proximal to this point is recommended. Embolization is the treatment of choice if significant bleeding persists.
Iatrogenic Fracture
The neck of femur is at risk for iatrogenic fracture (see earlier discussion). In one study, all patients with postoperatively diagnosed fractures of the neck of femur who had preoperative CT scans were analyzed if occult fracture were present. Six of eight fractures could be retrospectively confirmed on the CT. Additional fragmentation of the shaft is reported in about 10% of nailings. Static locking is sufficient as long as the fracture line does not extend into or beneath the locking holes.
Malalignment
Most authors use 5 degrees of angulation in the frontal and sagittal planes as their threshold for malalignment after nailing of the femoral shaft without any direct evidence of negative biomechanical effects. The incidence is reported to be between 2% and 18%. The highest percentage is found for proximal third fractures, and the lowest percentage is found for midshaft fractures. The effective use of poller screws (see earlier discussion) may reduce the risk of malalignment.
Malrotation is one apparent problem of closed nailing ( Fig. 58-32 ). Different techniques to reduce its incidence were reported earlier. The most reliable technique for quantification is measurement of the anteversion by CT scan. Because CT scanning is not available in most operating rooms, postoperative CT control is the only reliable method for quantification of malrotation. Studies that performed routine postoperative CT scans report the incidence of malrotation to be as high as 40%. The critical difference was set at 15 degrees. Recent studies showed a direct correlation between femoral anteversion and foot orientation with walking. Patients who cannot compensate for their difference in anteversion have more complaints and worse functional results. The compensation cannot be predicted individually. Patients with a difference of more than 15 degrees have more difficulties in performing complex activities. Rotation deformities should be corrected as soon as they are as detected. Nail removal is rarely necessary. Usually, the distal locking screws are removed for antegrade nails, the distal fragment is rotated, and relocking is done.
Aftercare
In addition to the general management of any trauma patient, the specific postoperative management after femoral fracture is fairly standard. After initial observation to exclude the presence of compartment syndrome and wound problems (usually on the first or second day), the patient is allowed to mobilize. The choice of the amount of weight bearing differs among surgeons. Patients stabilized by plate or external fixation should perform partial weight bearing for the first 6 to 8 weeks if possible. After nailing type A and B fractures, weight bearing as tolerated might be advised. In truth, local discomfort prevents the patient from taking much weight in the early phase, but a locked nail will be strong enough to support the patient. No general recommendations for type C fractures or unreamed nailed fractures with small-diameter nails exist. Partial weight bearing is advised by some surgeons. Subsequent progress should be followed both clinically and radiographically with bony union expected between 12 and 24 weeks. A number of factors are active in the healing process, but with the nail in situ, a few local mechanical signs are useful to confirm healing. Full radiographic healing is usually defined as cortical bridging with callus on three of four sides of the bone, seen on AP and lateral radiographs. Clinically, radiographic healing lags behind clinical functional healing by a few weeks, but with a functioning nail in situ, as long as healing reliably takes place, the patient can progressively rehabilitate without restriction. The best sign of bony healing remains the ability of the patient to progressively take weight and use the limb for increasing activity without discomfort. The overriding principles of the postoperative management are therefore to encourage active rehabilitation with free joint range and progressive muscle strength and weight bearing and to avoid factors that will reduce the bony healing. Factors associated with the primary injury and surgical treatment cannot be changed at this stage, but it is good policy to encourage the positives and avoid all factors that have been shown to decrease bone healing. This means active encouragement of weight bearing and general activity with a regular diet. However, there is no evidence that specific dietary supplements will help normally nourished patients. Avoidance of smoking and use of nonsteroidal antiinflammatory drugs (NSAIDs) is essential. During the rehabilitation process, patients with right femur fractures should be advised that they cannot drive until they can bear weight without aids and use the leg safely to brake. Additional injuries clearly increase the inability to drive and complicate general rehabilitation.
Implant Removal
Implant removal is not recommended as a routine procedure. Published data of routine removal of femoral nails in asymptomatic patients showed long-term complaints in one fifth of the patients. Symptomatic patients should be carefully assessed. Symptoms are mainly referred to the head or tip of a screw. Partial implant removal has to be discussed. Fewer data have been published on removal of femoral plates or retrograde inserted nails. One case of a condyle fracture after retrograde nail removal is reported. Arthroscopic-assisted removal might be recommended with the additional advantage to assess specific knee pathologies.
Special Fracture Constellations
Concomitant Ipsilateral Injuries
The presence of ipsilateral fractures can be challenging. In closed injuries, the sequence of stabilization is usually from proximal to distal. General aspects of the patient have to be respected. The status of the patient has to be reevaluated during surgery and might change the surgeon’s plan.
Ipsilateral Neck of Femur Fracture and Intertrochanteric Fracture
An ipsilateral neck of femur fracture is different from the classic isolated subcapital neck fracture that results from a fall on the lateral side. The neck fracture that is combined with a femur shaft fracture is usually minimally dislocated, extraarticular, and has a good prognosis with regard to the risk of developing avascular necrosis. Before the wide use of CT scans in polytraumatized patients, many of these fractures were just diagnosed intraoperatively or postoperatively after antegrade nailing. It remains uncertain whether these fractures were trauma related or iatrogenic. If the fracture is still minimally displaced after the nailing procedure, internal fixation with a screw-in “miss-a-nail” technique is preferred ( Fig. 58-33 ). If the fracture is displaced, the nail will usually impede reduction. The nail has to be removed before reduction and internal fixation. The nail might be reinserted after careful reaming. It is often more prudent to switch to a retrograde nail.
