Introduction
Phalangeal fractures and metacarpal fractures account for 18% and 23%, respectively, of below-elbow fractures in the general population. Their management has continued to evolve in recent years. , Whereas extraarticular fractures should be treated primarily by closed reduction with splinting or percutaneous pinning, surgical treatment is indicated for displaced intraarticular fractures to restore articular congruency. Plating is rarely indicated or necessary. Intraarticular fractures and joint dislocations have specific and particular characteristics, and decision-making on appropriate surgical technique can be complex.
Phalangeal fractures
Plain radiographs usually indicate the diagnosis. A neurovascular examination is essential. If necessary, a digital block may help with fracture reduction.
Distal phalangeal fractures
Distal phalangeal fractures can be divided into tuft, shaft, and base fractures. They are often caused by a crushing force as, for example, by a slamming car door or hammer blow. , Their management will usually include treatment of the associated soft tissue injuries.
Tuft fracture.
Tuft fractures are inherently stable because of the dense fibrous volar septa and the nail plate dorsally. They are usually associated with injury to the nail plate and nail bed. If the nail plate is intact but there is a subungual hematoma, we can either leave the hematoma untreated or drain it, if large ( Fig. 3.1 ). Draining will reduce painful throbbing in the first 48 hours. If the nail plate is damaged, the nail bed may have been injured and should be examined and repaired if possible.
No splinting is necessary for fracture healing even with some displacement of the fracture. However, protective splitting distal to the proximal interphalangeal (PIP) joint and allowing free PIP movement may be used to reduce pain and allow daily hand use.
Shaft and base fracture.
As with tuft fractures, Kirschner (K) wire fixation of an extraarticular fracture is seldom necessary, even where there is some fracture displacement. Splinting is sufficient and rarely results in nonunion. With intraarticular fracture at the distal phalangeal base, with displacement, or when deemed unstable, K-wire fixation is beneficial.
Middle and proximal phalangeal fractures
These include shaft fractures without articular involvement and intraarticular fractures with, or without, displacement. A fracture in the middle part of the proximal phalanx can develop obvious angulation, particularly dorsal distal angulation because of the pull of the extensor tendon.
Buddy strapping or finger splint.
When the fracture is stable, minimally displaced, and with no intraarticular involvement, relative immobilization by buddy strapping to a neighboring finger ( Fig. 3.2 ) or a finger splint extending to the distal palm is sufficient. Immobilization is generally for 2.5 to 4 weeks, although some consider splinting to be necessary for only 2 to 3 weeks. ,
We consider a minimum of 2.5 weeks to be necessary, with splinting often being discarded at the end of week 3, even if radiographs do not show callus formation. Signs of fracture healing on radiographs should not be expected this early and do not need to be considered when starting mobilization of the finger. Radiographs are only used to examine the quality of fracture reduction and alignment, ruling out secondary displacement.
Displaced oblique phalangeal shaft fractures with good longitudinal alignment rarely need surgical intervention. The extensor apparatus will usually prevent further displacement. Byrne et al. performed a prospective, observational study of 101 isolated stable, or initially unstable, proximal phalangeal fractures treated by immediate mobilization without surgery. The patients achieved a median PIP joint extension of –4 degrees, with a mean total active range of finger joints motion of 253 degrees and minimal pain. They concluded that splinting should be used for patients with isolated proximal phalangeal fractures, following closed reduction of any rotation and angular deformity.
Surgical treatment.
Surgical treatment is indicated in several instances: (1) spiral fractures of the phalangeal shaft, as these have a high incidence of rotational deformity; (2) displaced intraarticular fractures, to achieve joint congruency; (3) fractures deemed unstable after close reduction; and (4) multiple phalangeal fractures.
K-wiring, two or three interfragmentary lag screws for oblique fractures, and intramedullary fixation with cannulated headless screws are current treatment options. One or two K-wires can be used to stabilize unstable shaft fractures when necessary ( Figs. 3.3–3.5 ) ( Boxes 3.1 and 3.2 ). Intramedullary cannulated headless screws have become popular in recent years. Plates should mostly be avoided in digits in acute management of these fractures, as they interfere with the extensor apparatus, and other, simpler methods are adequate. For condylar fractures, K-wiring or one screw is commonly used to restore the integrity of the articular surface.
- 1.
Have your equipment ready in advance on the table next to you, so you won’t need to look for the equipment while trying to hold the reduction.
- 2.
Take fluoroscopy images before you start reducing the fracture, and find out which is the best view of the fracture. Not rely on one view to approve fracture reduction or quality of fixation.
- 3.
Aim for inserting two K-wires if possible. If one wire falls, or is pulled out during dressing changes, etc., there is the other.
- 4.
When open reduction is needed, screws may be best for oblique fractures.
- 5.
Avoid performing open reduction for a fracture that can be managed closed.
- 6.
Good alignment without rotation is crucial for a finger.
- 1.
Under field sterility and a mini C-arm, insert K-wires to the bone after closed reduction.
- 2.
Oblique fractures are fixed with multiple transverse K-wires after reduction.
- 3.
Metacarpal fractures are fixed with one or two intramedullary K-wires.
- 4.
K-wires are removed as early as 2 weeks after injury when the fracture has had clinical healing (not radiographic evidence of callus), manifested with no pain upon pressing on the site of the fracture line.
- 5.
Plating is almost unnecessary and can be harmful to fracture healing.
- 6.
Dynamic traction is an often option for proximal interphalangeal (PIP) fracture-dislocation. Active PIP motion starts immediately after treatment.
Intramedullary fixation with cannulated screws can be performed percutaneously through the relevant joint surface ( Fig. 3.6 ). The screws are inserted retrograde through a small arthrotomy of the joint distal to the fracture. The merit of this technique is that the finger can be mobilized immediately after surgery.
Long oblique and spiral diaphyseal fractures are unstable injuries, which can be treated with traction and percutaneous pinning. If such an attempt fails, open reduction can be used with either pinning or interfragmentary screw fixation. Lag screws provide rigid fixation for long oblique or spiral fractures and allow early motion. Screws are placed perpendicular to the fracture line in multiple planes and at multiple sites after anatomical reduction ( Figs. 3.4 and 3.7 ).
Giesen et al. reported 26 patients with 31 displaced or unstable base and shaft fractures of the proximal and middle phalanges, and Poggetti et al. reported on 173 similar cases. , All were treated with intramedullary headless compression screws. , After surgery, the patients underwent early mobilization without splinting with no major complications. The results confirm the reliability of this technique in cases without articular involvement.
For extraarticular proximal phalangeal fractures (transverse or short oblique), Saied et al. compared transarticular fixation with parallel K-wires (29 patients) and an extraarticular technique with two crossed K-wires passed through the base of the proximal phalanx (31 patients). There was no significant difference between the two methods 6 months after surgery. The range of motion was graded as excellent in most patients with no major complications.
Neck fractures of the middle or proximal phalanges.
Phalangeal neck fractures are common in children. They can be undisplaced, displaced with some remaining cortical contact (which are the most common), and displaced with no cortical contact ( Fig. 3.8 ). Neck fractures are often difficult to reduce and remain unstable. If the reduction fails, or remains very unstable, either a single or two K-wires can be used for fixation. The fracture is reduced by traction with one of the surgeon’s hands, with the contralateral thumb pushing, and so reducing the fracture. Then, with the distal interphalangeal (DIP) joint flexed, a single K-wire may be passed across the fracture and out of the skin through the flexed PIP joint to fix the reduced phalangeal head. However, our preference is percutaneous internal fixation with two crossed K-wires after closed reduction ( Fig. 3.9 ).
Tan et al. reviewed 35 patients aged 16 and younger with displaced phalangeal neck fractures treated nonsurgically. They showed that displaced neck fractures in children can be reduced and treated by splitting, making the case for closed reduction without surgery. They experienced no further displacement of the fracture after splinting. A randomized, prospective, comparative study of 62 patients compared the outcomes of percutaneous antegrade flexible intramedullary nailing and crossed K-wire techniques for displaced proximal phalangeal neck fractures. They found no difference in the time to union or finger range of motion between the two methods.
Base fractures of the middle or proximal phalanges.
Transverse fractures at the base of the proximal phalanges are commonly treated by closed reduction and splinting or buddy strapping. There is a risk of loss of the reduction, creating angular or rotational malunion. In this regard, some surgeons prefer percutaneous pinning after closed reduction, which negates the need for close monitoring for displacement of the fracture ( Fig. 3.10 ).
The Salter-Harris classification is popularly used for fractures in children. However, we did not find this classification useful in the hand, as treatment of these fractures is almost always conservative in children. Some fractures may have a mild deformity, which can be corrected easily in children by manual reduction ( Fig. 3.11 ) and then splinting or buddy strapping to hold the reduction for about 3 weeks.
Salter-Harris type 2 fractures (those involving the articular surface but not having joint surface step-off) are those most often seen in children. Buddy strapping for 3 to 4 weeks after reduction is usually sufficient if there is no, or minimal, displacement.
Eberlin et al. reviewed the results of periarticular K-wiring in 50 proximal phalangeal base and shaft fractures. Most fractures were transverse or oblique, and more than half had comminution and/or impaction. Twenty-six fingers had excellent results (63%), lacking less than 10 degrees of total motion. One patient had a poor result. Three patients (7%) developed stiffness requiring tenolysis. Shewring et al. reported the outcomes of treating 101 patients with 113 fractures of the proximal phalanx at the junction of the diaphysis and the proximal metaphysis. These fractures were stabilized using a single extraarticular percutaneous K-wire passed across the fracture to engage the lateral cortex and into the phalangeal base lateral to the metacarpal head. The metacarpophalangeal (MP) joint was splinted in flexion with the PIP joint free to move. After 24 days, the wire was removed and full mobilization commenced. The mean total active motion of the finger was 230 degrees at 11 weeks (range 3–24) after surgery.
Condylar fractures of the middle phalanx.
Condylar fractures are intraarticular and may be unicondylar, bicondylar, or intercondylar. They can be unstable, even if undisplaced, particularly the bicondylar fractures. Operative treatment is recommended to minimize articular incongruence. Percutaneous methods are preferred to open methods, whenever possible, because of the significant soft tissue stripping necessary for exposure, risking longer recovery time and postoperative stiffness. Furthermore, the vascular supply to the condyle is adjacent to the collateral ligament, and excessive stripping risks avascular necrosis of the fracture fragment. A towel clamp or pointed reduction forceps should be applied above the midaxial line when reducing the fragment to minimize the risk of neurovascular injury. Finger-trap traction can be helpful.
Percutaneous screw fixation is a useful option, followed by early mobilization in a protective splint. Cannulated headless compression screws achieve maximum stability without the morbidity of open reduction and soft tissue stripping. Laterally placed miniplate fixation is possible, but other simpler options are adequate and less invasive.
K-wires can be used percutaneously, or after open reduction, if necessary. One or two K-wires in each fragment will maintain the reduction ( Figs. 3.12 A–C and 3.13 ). For a comminuted unicondylar fracture, splinting may be the first choice after reduction, as open reduction of small fracture fragments is impossible. If there is a bony defect, reconstruction of the condyle with osteochondral grafts from the ulnar base of the small finger metacarpal has been described ( Fig. 3.12 D).
Therapy is necessary for most of these intraarticular fractures, usually starting from week 2 or 3, and continuing for 1 to 2 months. Even with anatomical reduction and therapy, DIP joint motion may not recover entirely because of the soft tissue injuries around this small joint, which do not return to normal after injury and healing.
Karim et al. reported the results of surgical treatment of unicondylar phalangeal fractures in 34 pediatric patients. They used closed reduction and percutaneous K-wiring, open reduction and internal fixation, osteoclasis or osteotomy and fixation, and corrective osteotomy. Radiographic alignment and digital motion improved with surgical reduction and fixation, regardless of the time from injury. Shewring et al. reported 74 patients with phalangeal condylar fractures treated nonoperatively by splinting after reduction or internal fixation using a single lag screw through a lateral approach. Thirty-eight patients had fixed flexion contractures at the PIP and thumb IP joints and extensor lag of the DIP joints. They had loss of extension due to these problems of between 10 degrees and 35 degrees (with an overall mean of 10 degrees). They found that these fractures can be released and reduced, even 8 weeks after the injury. If nonoperative treatment is attempted initially, close monitoring is required with weekly radiographs up to 3 weeks, as these fractures frequently displace subsequent to reduction.
Condylar fractures of the proximal phalanx.
Condylar fractures of the proximal phalanx can be treated by similar methods to those described above, but these fractures, at the PIP joint, are more complicated and often require surgery, particularly for large displaced articular fragments, or the use of external dynamic traction for multiple fragment fractures. These fractures are discussed in more detail under fractures of the PIP joint.
Fractures of the thumb
Thumb phalangeal fracture can be treated similarly to those of the other digits, with conservative treatment being the first choice. If reduction and fixation are indicated, percutaneous K-wiring should be considered first ( Fig. 3.14 ).
Metacarpal fractures
Metacarpal fractures are frequently caused by an axial load, such as a punch or crush injury with a closed fist, or a fall. Accepting mild deformity has little functional consequence and avoids the risks of surgical intervention. This is particularly true of the common fifth metacarpal neck fracture (the “boxer’s fracture”).
Fractures of the second to fifth metacarpal
A key point in treating these fractures is to check the rotational deformity of the fracture and, when possible, finger range of motion and hand function. Physical examination will reveal rotational deformity. Overlapping of the fingers (scissoring) after metacarpal fracture is a good indicator of rotational deformity, although the swelling after a fracture will also cause some rotation. It should be noted that in hands without pathology, there is some rotation of the fingers when a fist is made, and examining the other hand may help in decision-making. Finger range of motion and hand function should also be considered when deciding whether correction of rotation is needed, and this is sometimes a difficult decision to make in the acute phase. For metacarpal fractures, there are conflicting data regarding the best treatment. In general, most metacarpal fractures are stable and some shortening can be well tolerated, including angulation of 20 degrees of the fracture, without hand function being affected. For neck fractures, angulation of 40 to 50 degrees may not affect hand function. The degree of angulation on a radiograph alone should not be the indication for surgery.
In fact, many displaced metacarpal shaft fractures can be reduced manually, so only a very small percentage with obvious angulation after reduction need surgery after failed closed reduction ( Box 3.3 ). Therefore, techniques of closed reduction should be learned, and, often, repeated reduction achieves acceptable reduction. This is often not sufficiently taught or stressed in some countries, resulting in unnecessary surgery. Applying gentle but gradual and persistent force with the surgeon’s thumb to the angulation site is the usual technique of closed reduction. This should be performed in almost all patients with displaced shaft or neck fractures of the metacarpals.
- 1.
Many metacarpal fractures, especially in the shaft and base, can be treated with closed reduction and splinting. Some angulation is allowed provided the hand functions well.
- 2.
Degrees of radiographic angulation only serve as a rough guide for reduction or surgery, not as an absolute indication for surgery.
- 3.
Rotational deformity causing scissoring of fingers during digital flexion should be corrected through closed or open reduction.
- 4.
Metacarpal neck fractures can be reduced with the fingers in flexion and pushing the fragment dorsally. In the fifth metacarpal, hand function may be good when angulation of a neck fracture reaches 40 to 60 degrees, which may not need surgical correction.
- 5.
Surgical indications can be looser when the patient wishes to restore normal anatomy for the purpose of hand cosmetics.
- 6.
K-wire fixation remains a commonly used method. Intramedullary headless screw fixation is popular as well, which allows immediate mobilization without a splint.
Such a maneuver can be repeated even 2 to 3 weeks after splinting when the reduction is lost, as in the initial 4 to 5 weeks after injury, the callus forming in the fracture site is soft and adjustable, such reduction (with slow and persistent force) will correct the angulation. It is a misconception that any loss of reduction 2 to 3 weeks after initial reduction and splinting should proceed to surgery. Soft callus can be manipulated under stress, which may restore close to anatomical reduction because the soft callus glues the fracture together to maintain the reduction. Splinting can be used to correct any deviation of the fracture even 4 to 6 weeks after fracture. We call this correction through stressing soft callus. This method is most often used for metacarpal shaft fracture, but it can be used for proximal or middle phalangeal shaft fracture as well. The callus is hardened 6 to 7 weeks after fracture, so closed stress correction is no longer possible from that time on.
Nonoperative treatment.
For a fracture of a single metacarpal, the majority of patients do not need surgical treatment, since mild palmar angulation of the fractured metacarpal is functionally well tolerated. The rotational deformity is frequently of limited significance because of the derogating action of the intermetacarpal ligaments. Each metacarpal will tolerate a different degree of angulation and displacement, depending on its location. Generally, angulation of the fourth and fifth metacarpals is better tolerated than that affecting the second or third metacarpal because of the increased mobility of the carpometacarpal (CMC) joints of the ulnar fingers and the arch configuration of the palm.
A dorsal splint from the distal forearm to the proximal phalanges leaving the PIP joint free is sufficient to stabilize the fracture ( Box 3.3 ). A recent report showed that a short cast only (from the carpus to the MP joint) can be sufficient. An ulnar gutter splint can be used for fractures of the fourth and fifth metacarpals. Using a radial gutter splint is inadvisable because it will limit thumb motion. Instead, a dorsal splint can be used ( Fig. 3.15 ). The functional position of the hand, with the MP joint in about 30 degrees of flexion, is the recommended position of splinting. The intrinsic plus position, with the MP joint in nearly 90 degrees of flexion, is uncomfortable and unnecessary. The splint should not be too long, only having to extend just distal to the MP joints to immobilize these joints, while leaving the PIP joints, beyond the splint, free to move.
Peyronson et al. reported a prospective, randomized controlled trial of 42 patients in Sweden. They found nonoperative treatment with unrestricted mobilization for a single displaced spiral and/or oblique finger metacarpal shaft fracture had an outcome comparable to those treated by screw fixation, and metacarpal shortening did not affect the outcomes. Street et al. reported that a short, molded metacarpal cast is an effective nonsurgical treatment for angulated extraarticular metacarpal fractures of the diaphysis and the diametaphyseal junction. After cast removal, 68% had a full range of finger motion, and 68% were pain-free. Most patients did not require formal hand therapy. Fifteen patients experienced minor complications, primarily soft tissue irritation from the cast and mild extensor lag. In cadaveric hands, Strauch et al. reported that every 2 mm of metacarpal shortening caused an average of 7 degrees of extensor lag. Metacarpal shortening may also affect interosseous muscle anatomy and forces, thus reducing grasp and grip strength. In our experience, shortening for about 1 cm is acceptable clinically. The accepted degrees of deformity are still questioned because of the limited clinical data demonstrating loss of function in relation to shortening and angulation.
Indications for surgical treatment.
Absolute indications for surgical intervention are unstable (single or multiple) fractures that may cause reduction in hand function ( Fig. 3.16 and Box 3.3 ). Other indications for surgery are open fractures, displaced crush injuries, and displaced intraarticular fracture-dislocations of the CMC joints. Unstable fractures that demonstrate displacement or malalignment or that are severely angulated should undergo operative treatment. It is inappropriate to designate exact degrees of angulation as surgical indications. Surgery should be decided based on whether there will be functional impairment and cosmetic needs of the patients. Previously held “exact” degrees for surgery are inaccurate.
Often used methods of internal fixation.
Closed reduction and percutaneous K-wiring are frequently used ( Fig. 3.17 ), followed in popularity by intramedullary screw fixation . Unstable transverse, spiral, and oblique fractures can be stabilized with percutaneous K-wires or screws through miniincisions. Transverse or oblique intermetacarpal K-wiring percutaneously is also useful. When a patient requires open reduction, cerclage wiring or interfragmentary screws may be used. External fixation is an option for crush fractures with severe soft tissue lesion.
Intramedullary bouquet K-wiring does not provide rigid fixation and is only recommended for neck or shaft fractures of the ring and little finger metacarpals when the surgeon has a preference for this method, as these can tolerate a greater degree of angulation. However, currently popular percutaneous K-wire can achieve the same goals.
Lag screws are useful, particularly for long oblique fractures when the fracture line is at least twice the diameter of the bone ( Fig. 3.18 ). Lag screw fixation achieves more stable fixation than K-wire fixation, allowing earlier mobilization.
Plate fixation may be used for those injuries with bony defects and in treating malunited fractures needing cortical bone grafting. The plate can be used alone or in conjunction with lag screws, depending on the fracture morphology. This method risks interference with extensor tendon function and possible delayed union as a result of periosteal stripping. The authors use plates for metacarpal fractures less than once a year, and they have not used a plate on any acute fracture in the hand for years. Most colleagues agree that plating is unnecessary for acute hand fractures, being a cause of unwanted complications. Plate fixation is avoided in most cases. ,
Metacarpal fractures in the shaft, base, neck, and head have slightly different features and treatment goals, which are outlined below.
Metacarpal shaft fracture.
This fracture is easy to diagnose, and treatment can follow the methods and principles as detailed above. Closed reduction is the easiest for shaft fractures. If open reduction is needed, a surgical incision of 1 to 2 cm right at the site of fracture is sufficient to reduce the fracture, followed by K-wires or screws.
Metacarpal neck fractures.
Angulated neck fractures should be treated by immediate reduction. The Jahss maneuver, in which the proximal phalanx is used to lever the metacarpal head dorsally while maintaining dorsal pressure on the fracture site, is recommended ( Fig. 3.19 ).
Most reports indicate no significant difference in functional outcomes of fifth metacarpal neck fractures treated without fracture reduction, reduction and immobilization, or surgical treatment. The patients treated with surgery had greater satisfaction in respect to hand appearance but more complications and longer sick leave. Patients treated without surgery must be willing to accept the change in hand appearance, mainly the loss of the metacarpal head prominence, but this is more a cosmetic problem than a functional one.
Studies have not demonstrated a correlation between residual or initial fracture angulation and clinical results, despite acceptance of more severe angular deformities. Boeckstyns reported that 90% of fractures of the metacarpal neck with apex angulation up to 70 degrees can be treated with a functional metacarpal brace without reduction. Fifth metacarpal neck fractures with up to 70 degrees apex dorsal angulation and without rotational deformity may be treated successfully without surgery. When indicated, various surgical methods are available ( Fig. 3.20 ).
Metacarpal head fractures.
Displaced metacarpal head fractures, which are intraarticular, require anatomical reduction and rigid fixation. , The best method is fixation with a headless compression screw through a dorsal, possibly extensor-splitting, approach. When shearing or comminution is encountered, K-wire fixation may be more adequate to stabilize the small fragments ( Fig. 3.21 ), or a screw fixation may be used.
A fracture of the metacarpal head can be very difficult to reduce, and multiple fragments may preclude anatomical reduction of the articular surface. If a metacarpal head fracture cannot be fixed, arthrodesis or arthroplasty are the alternatives, but these are usually not done in the acute phase.
Metacarpal base fracture.
These fractures rarely need surgical correction, as the angulation is usually mild, which does not affect function. Comminuted intraarticular fractures may need fixation with two K-wires to stabilize the fragment and to prevent further displacement. There is no need to restore smooth CMC joint surface, as this is often difficult and rarely causes arthritic changes in the second to fifth CMC joints. A splint should be applied for 4 to 5 weeks for protection.
Fractures of the first metacarpal
Due to the thumb’s large range of motion, up to 30 degrees of angulation may be tolerated in a fractured first metacarpal bone. Compared to fractures of the other metacarpals, rotational deformity may be more difficult to diagnose both clinically and radiographically. Special consideration should be given to intraarticular fractures of the first CMC joint. K-wire fixation is the recommended method for most fractures of this bone, and two K-wires are commonly used to maintain fixation of the reduced fracture. The thumb is splinted in an abducted position after surgery and the K-wires removed about 4 weeks after surgery.
Articular fractures and dislocation
Articular fractures and dislocations of the hand include those of the DIP, PIP, MP, and CMC joints. They are most commonly avulsion fractures at the base of the phalanx or metacarpal, with the exception of pilon and comminuted fractures. Articular fractures and dislocations typically experience ligamentous or tendon dysfunction along with the bone avulsion (e.g., Bennett fracture of the thumb metacarpal base, skier’s thumb avulsion of the ulnar collateral ligament of the thumb MP joint, and mallet finger DIP joint dysfunction). The residual stability of the joint depends on the size of the avulsed fragment, and the treatment plan is based largely on clinical and radiographic assessment of joint stability.
Fractures and dislocation of DIP joint
The most common intraarticular fracture of the DIP joint is an avulsion fracture of the base of the distal phalanx as a result of longitudinal impaction. The tendon injuries associated with these fractures include flexor dysfunction after volar fragment avulsion (“Jersey finger”) and extensor dysfunction after dorsal fragment avulsion (bony mallet injury). 29-31
“Jersey finger.”
Flexor dysfunction is the main consequence of these injuries. , Tendon avulsion should be identified by clinical examination. The bone fragment of an avulsion fracture can be seen on radiographs ( Fig. 3.22 ). Ultrasound or MRI confirmation may be helpful in making the diagnosis. An avulsed bone fragment should ideally be fixed within 7 to 10 days after injury for optimal outcome. Fixation techniques include K-wiring and screw fixation and are determined by the size of the fragment. The results are good, but may decrease DIP motion and have nail deformities. , If the fragment is too small to reduce and stabilize, the fragment may be removed and the tendon reinserted into the distal phalanx.
Bony mallet finger.
A “bony mallet finger” is a dorsal avulsion impaction fracture of the distal fracture including the extensor tendon terminal insertion. This commonly occurs as a result of an axial force to the fingertip causing forced flexion of the DIP joint from an extended position. Most other mallet fingers with a purely tendon rupture are due to rupture of the extensor tendon slightly proximal to the insertion rather than avulsion from the distal phalanx.
Avulsion of a large dorsal fragment (greater than one-third of the articular surface on lateral radiographs) has been considered to increase the risk of volar subluxation of the distal phalanx at the DIP joint, although this has been disputed recently in articles suggesting that this cutoff value is unreliable in predicting subluxation ( Fig. 3.23 ). Giddins et al. have demonstrated that extension stress lateral radiographs are helpful in predicting subluxation. Pivoting (rotation) of the main distal phalanx creates a V-shape in a palmar direction between the articular surfaces and may be a more reliable method of predicting subluxation ( Fig. 3.23 ). Subluxation of the DIP joint requires treatment, however. It is not known how frequently patients with persistent subluxation develop symptomatic osteoarthritis. Surgical reduction and fixation of large fracture fragments (over one-third of the articular surface) is the required treatment for optimal outcome (see also “mallet finger” in Chapter 17 ).
Multiple techniques have been described to treat these injuries. Wehbé and Schneider reported that joint subluxation and the size and displacement of the bone fragment are not an indication for surgery. Currently, most surgeons prefer splinting alone for closed injuries involving less than one-third of the articular surface and without DIP joint subluxation for 6 to 8 weeks. It is under question whether only 4 to 5 weeks are sufficient for the fracture healing for bony mallet finger (see more in Chapter 17 ). For a displaced fragment larger than one-third of the articular surface but without subluxation, splinting is also feasible, but repeated radiographs after 1 and 2 weeks are necessary to assure preservation of reduction. , No surgical technique is necessarily superior. Late-presenting fractures require debridement of the fracture, and then fixation if the deformity is not tolerated.
Trickett et al. reported 218 mallet fractures treated with a thermoplastic splint. The joints were congruent in 168 and subluxed in 50 fractures. There were no differences in the size of the articular fragment, the final range of motion, or the extensor lag. Preexisting joint degeneration also did not influence the outcome. They believed that conservative treatment achieved a predictably good outcome, regardless of fragment size or subluxation in most patients, and should be considered when discussing treatment with patients with bony mallet fractures. If using the extension block technique, no difference was found between one and two dorsal K-wires in terms of clinical or radiological outcome and complications. The dorsal counterforce technique effectively supplements the two-extension block K-wires technique and aids in control of dorsal fragment rotation.
Fractures and dislocation of PIP joint
Injuries of the PIP joint are usually the result of an axial force. The long finger is the most exposed and, therefore, the most likely to be injured. The differential diagnosis of joint contusion, commonly from a direct blow, needs to be considered because fractures and ligamentous injuries can have similar clinical appearances. Radiographs should be obtained before physical examination after PIP joint injuries, followed by gentle examination of the competence of the collateral ligaments, the central slip ( Elson test : PIP extension against resistance), and the volar plate. Injuries can range from intraarticular fractures of the phalanges to fracture-dislocations of the joint and can be divided into stable and unstable injuries.
Intraarticular fractures of the PIP joint are challenging and treatment choice is debatable because of the importance of joint function to finger motion and the tendency of this joint to become stiff. The benefits of reconstructive precision weigh heavily against the damage caused by soft tissue (surgical) dissection, which can result in more limitation of joint motion. Each case should be considered according to the likelihood of improving the gap, step-off, and subluxation of the articular surface by surgery.
Avulsions fracture of the palmar base.
Despite the inherent stability of the PIP joint, avulsion of the palmar base remains a common injury as a result of a hyperextension or axial force. , The treatment of these injuries is guided by the assessment of joint stability. Avulsions of the palmar base of the middle phalanx may be relatively easily managed, but dorsal subluxation can be overlooked.
The presence of a small intraarticular volar fragment on a lateral radiograph should be evaluated clinically for stability. With undisplaced fractures involving less than 40% of the intraarticular base of the middle phalanx, a period of immobilization initially in a splint ( Fig. 3.24 ), followed by buddy strapping and mobilization for 4 weeks, is sufficient.
It is believed that the larger the base of the middle phalanx volar fragment, the more likely it is that dorsal subluxation will occur. , Stability of the joint is maintained with a 20% volar fragment of the middle phalangeal base, with the threshold for instability being approximately 40%, with the unstable, displaced middle phalanx forming a dorsal V-sign on the lateral radiograph ( Fig. 3.24 ). If, on true lateral radiographs, the dorsum of the base of the middle phalanx forms a V-shape with the dorsal aspect of the proximal phalangeal head, the joint should be considered incongruent ( Fig. 3.25 ). If the undisplaced fracture is greater than 40% of the joint surface, dorsal extension block splinting with repeated radiographs or operative fixation is needed.
Operations previously described include closed reduction and percutaneous K-wiring (through the center or dorsal of the joint), open reduction and internal fixation, dynamic external fixation, and volar plate arthroplasty. 45-48 None of these alternatives shows clear superiority. If the PIP joint is unstable under stress, the joint should be stabilized with K-wires. A hemihamate arthroplasty for resurfacing of the volar lip of the middle phalanx at the PIP joint is a possible option after severe comminution. Here we explain the indication and technical keys of each method.
Dorsal blocking pinning : In the acute phase, if the fragment is large and dorsal subluxation is remarkable, a common and simple treatment method is to reduce the joint and insert a K-wire percutaneously across the joint or as a dorsal block ( Fig. 3.26 ).
Dynamic traction: Dynamic traction is used if there are multiple intraarticular fragments that are unstable ( Box 3.2 ). , The merits of such a method are simplicity and less damage to the structures around the joint. Traction allows reduction and the extensor tendon to compress the fragments to maintain reduction. Motion with the traction frame in later weeks maintains mobility of the PIP joint, preventing joint stiffness. This traction is often made with K-wires, which are inserted and bent in the emergency room or a minor procedure room, loaded with rubber bands (see the contents under pilon fracture for how to make this traction). In some countires, this is commercially available.
This is a popular and cost-effective method. Most surgeons in many countries like it. This is used in patients if the fracture fragments and subluxation can be reduced quite well when the surgeon applies a longitudinal traction to the patient’s injured finger distally. This traction method should be used immediately after trauma or in the first a few days after trauma. If delayed for more than 2 weeks, the reduction is difficult, so it is sometimes impossible to use this traction. Then the patient should proceed to open reduction and internal fixation.
Percutaneous or open fixation with small compression screws: If the fragment is large enough, it can be fixed with a small compression screw ( Fig. 3.27 ), which is a choice of some surgeons for acute patients. The screws can be placed percutaneously under fluoroscopy or with a small incision. The merit of this surgery is to allow early active motion of the joint, but it has additional damage and edema if it is an open surgery. When open reduction is necessary, the collateral ligament attachments are preserved for the vascular supply to the condyles.
Because of these considerations, the majority of hand surgeons now use closed reduction and dynamic traction if the fragment is reducible. However, if the surgeons are experienced with minimally invasive screw fixation, then screw fixation is an option. If the fragment is too small or comminuted, dynamic traction is clearly preferable or K-wires can be used to fix the fracture.
Open reduction and fixation: This becomes necessary in an open injury with an intraarticular fracture or complicated fracture-dislocation with damage to the tissues such as extensor tendons or collateral ligaments. Several approaches can be used depending on the need of reduction. (1) A dorsal incision can be used, especially when there is injury of extensor tendons. (2) A lateral approach can also access the volar plate and volar fragments, with less surgical damage to the tissues. The fragments are fixed with screws or K-wires after reduction. Collateral ligaments can be repaired with this approach if they are torn. (3) A shotgun approach can be used as well, which entirely exposes the articular surface of the phalangeal base for reduction and fixation ( Figs. 3.27 and 3.28 ). The flexor tendon sheath is opened between the A2 and A4 pulleys, and the volar plate is released. Screws can be used for internal fixation. K-wires can also be used to fix the volar fragment. The K-wires can be inserted through the small fragment if possible or can be placed over the reduced fragment to prevent displacement of the fragments that cannot be fixed with screws or K-wires directly ( Fig. 3.29 ).
Postoperatively, the finger is placed in a dorsal splint at 30 degrees for a week, during which hand therapy is initiated for edema control and to progressively increase active motion. A large bony defect in the PIP joint in open injuries is not common, but if it occurs, hemihamate osteochondral autograft can be used to reconstruct the defects.
There are a number of reports of outcomes of the above methods. Extension block pinning has been reported to achieve good results. , Waris et al. reported 39 patients with 41 unstable dorsal fracture dislocations of the PIP joint treated by closed reduction and extension block pinning. The mean range of motion was 80 degrees at the PIP joint with a mean extension loss of 6 degrees at a mean follow-up of 5 years, excluding two joints that were ultimately treated by arthrodesis. The mean range of motion of the DIP joint was 68 degrees. Reduction of the joints was achieved in all cases. However, minimal subluxation was observed in 12 cases after hardware removal. Badia et al. presented a design modification of a simple dynamic fixation system described previously. It was applied to six patients who sustained fracture dislocations of the PIP joint. The average range of motion of the PIP joint was 5 to 89 degrees (range, 0–100 degrees) at the final follow-up evaluation after average 24 months (range, 7–43 months). Only one patient complained of mild pain with extreme flexion. Proper reduction and congruency of the joint were noted on final radiographs.
Volar buttress plating was used by some surgeons, which was reported to restore close to 90 degrees of the PIP joint. , In one report, when compared to volar plating, dynamic external traction achieved slightly less extension of the DIP joint. Kibar et al. reported 13 fingers with acute PIP fracture-dislocations treated with hemihamate osteochondral autograft. All of these PIP joints were stable on coronal and sagittal stressing at the first postoperative year, and wrist motion was normal. Union was achieved in all cases except one. The mean active PIP motion was 82 degrees with 87 degrees for the MP joint. Because hemihamate osteochondral autograft is used for defects after pilon fracture of the PIP joint, please see later contents on pilon fractures about the surgical methods and outcomes.
Central slip avulsion fracture.
This injury results in dysfunction of the central slip of the extensor tendon, which is attached to the avulsed dorsal fracture fragment at the base of the middle phalanx. Injury to the articular surface of the proximal phalanx is possible and may be seen on follow-up radiographs. Stable intraarticular fractures without dislocation of the joint require 4 weeks of immobilization of the PIP joint in extension with the DIP joint free. Unstable fractures may be treated surgically by closed reduction to restore articular surface continuity and percutaneous K-wiring ( Fig. 3.30 ). Open reduction and internal fixation are needed when seen late or when adequate closed reduction cannot be achieved. A screw or K-wires can be used to stabilize the fragment in place. Extensor tendon laceration should be ruled out and repaired if present, especially in open injuries.
The treatment methods are the same as those stated above. The only difference is the fracture is at the insertion site of the central slip.
Pilon fracture-dislocations.
Intraarticular pilon fracture-dislocations of the PIP joint are the most challenging. They can be treated by reduction and joint transfixation, but the risk of stiffness and residual pain is high. Multiple surgical techniques have been described, including dynamic external traction, mini cannulated screw fixation, conventional screw fixation, plate and screw fixation, and palmar plate arthroplasty. Table 3.1 summarizes these methods for PIP simple and PIP pilon fractures.
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