With metacarpal and phalangeal skeletal fractures, early mobilization remains the most effective way to counter edema, joint stiffness and tendon-periosteum adhesions. Early mobilization can, however, only be undertaken following reduction and stabilization of the fracture.
The average time off work due to a fracture of the proximal phalanx is 4.3 to 8.4 weeks according to Barton. This variability is due to different fracture patterns and the nature of the physical trauma. The socioeconomic impact of these injuries is thus far from negligible, and this may justify opting for surgical treatment because this allows for early mobilization.
This chapter is not aimed at providing unconditional support for fixation, since we deem 80% of fractures to be amenable to nonoperative treatment. If fixation is opted for, it must be executed with technical precision so as to ensure almost anatomic reduction and to guarantee the stability necessary for early active mobilization.
It was at the beginning of the 20th century that Albin Lambotte first used a nail system to treat metacarpal fractures. Since then, the major stages in the development of fixation of the hand skeleton have been the following:
Clifford, Nemethi and Lister developed the Robertson technique, which consists of directly approaching the site of the fracture to stabilize it with wires and bands.
Evrard proposed centromedullary nailing of the metacarpals in 1973. Foucher adapted this technique by adding a tissue cement to perform digital replantations and treat complex fractures.
In 1958 Kilbourne and Paul pioneered screw fixation of small bones. Tupper, then Michon, introduced microbolts that were 1 mm in diameter with the aim of treating joint fractures. In 1974 Ikuta and Tsuge used small-sized screws.
In the 1970s AO (Arbeitsgemeinschaft für Osteosynthesefragen) members Simoneta and Heim and Pfeiffer developed a wide range of devices intended for use with hand injuries. Their bulk and their implantation under the extensor apparatus was, however, the source of numerous functional shortcomings and even rupture of the extensor apparatus.
The need for miniaturization was spearheaded by Foucher, Merle, Michon and Constantinesco. Based on biomechanical studies and in light of the the low stresses placed on the fingers, miniaturized apposition devices were designed to encroach only minimally on the tendon gliding spaces. This concept of miniaturization has been widely adopted over the last 30 years with use of titanium, cannulated microscrews and other such innovations.
The current therapeutic arsenal also includes the use of external fixation devices, which in their most rudimentary form are Kirschner wires (Crockett). Allieu developed a new generation of external fixation devices adapted for the hand with a focus on salvage of complex injuries, while Schuind and Burny greatly promoted the indications for external fixation. Models for dynamic fixation designed for joint fractures have emerged more recently. The most suitable and easiest to use is the Ligamentotaxor developed by Arex.
The use of absorbable materials is a more recent phenomenon. Since 1989 we have developed and used high-strength intramedullary wires made from polylactic acid. Although they have so far only seen very limited use, this new generation of resorbable implants heralded the further development of miniscrews with the same properties.
This inventory of fixation methods shows that miniaturization of the devices has made it possible to be more assertive with operative treatment. Since 1961 Robins has clearly identified fixation as being particularly appropriate for diaphyseal phalanx fractures that do not respond to nonoperative treatment, joint and juxtaarticular fractures and complex injuries. Treatment of metacarpal and phalangeal fractures requires a good level of knowledge regarding hand biomechanics and mechanisms of deformity. The therapeutic approach must distinguish between closed fractures and open fractures, as well as their associated injuries. These are entirely different entities, with each having their own therapeutic decision tree.
As far as closed fractures are concerned, the most recent randomized studies have shown that in fractures of the fifth metacarpal neck that have an angulation of 40–50 degrees, splinting yielded outcomes equivalent to those of the series that was surgically treated by the bouquet wiring technique. Likewise, if the shortening is less than 5 mm and the intermetacarpal ligament is intact, the functional outcome with spiral metacarpal fractures using only early mobilization without a splint is faster than that obtained by fixation. Additionally this allows avoidance of complications inherent with any surgery. These therapeutic choices are favored by our Northern European colleagues whose decisions are swayed not only by the results of clinical studies but also by the cost of surgical treatment. It is important to bear in mind, however, that excessive angulation and shortening of the fingers that will have an impact on the function and appearance of the hand are not acceptable.
When articular or juxtaarticular fractures are unstable, it is preferable to rely on percutaneous fixation using wires or cannulated microscrews. Only prior failures or insurmountable technical difficulties should lead to an open approach to the fracture, while being cognizant that the introduction of any device, even the most miniaturized, does not protect against extensor apparatus adhesions and joint stiffening.
Open fractures necessitate surgical intervention because they are often the consequence of direct and contaminating injury affecting other structures (eg, the cutaneous cover, tendons, neurovascular pedicles). Reduction and stabilization of these fractures are prerequisites for ensuring treatment of the associated injuries with techniques that are compatible with early mobilization. The risk of infection must be addressed by complete debridement followed by cutaneous coverage that may use any of the local flap techniques. All other treatment methods will only result in a secondary tenolysis or arthrolysis surgery, a malunion or pseudarthrosis, with a concomitant loss of function.
Physiology and Pathophysiology
Arches of the Hand
The hand is composed of two arches: one of these is transverse and corresponds with the metacarpophalangeal (MCP) joints; the other is longitudinal and is aligned along the third digital ray. These two arches of the palm give the hand its cupped shape, which facilitates prehension. The second and third metacarpals are fixed to the second carpal row, whereas the first, fourth and fifth metacarpals are mobile and contribute to cupping of the hand and improved prehension.
The fixed second and third metacarpals do not tolerate angulation well, and all therapeutic options must be considered to restore their anatomy. The fourth and fifth metacarpals, however, tolerate angulation better owing to both their carpometacarpal (CMC) mobility and the possibility of hyperextension of the MCPs.
Hand grip strength is retained if the metacarpal arch is restored. It is hence desirable to reduce oblique and spiral fractures so as to reestablish the length and axis of the metacarpals. Meunier has shown that a metacarpal shortening of just 2 mm results in an 8% loss in the intrinsic functional strength. He determined the loss to be 55% when the shortening was of the order of 10 mm. Low noted a decrease in extrinsic function starting with 3 mm of shortening and a variation of 30 degrees in the angle.
The digits are articulated around the MCPs, which have an active flexion of 90 degrees. The proximal interphalangeal (PIP) joint and distal interphalangeal (DIP) joint flex to 100 degrees and 70 degrees, respectively.
Each digital chain can achieve this function only if its metacarpal and phalangeal lengths match with Fibonacci’s numerical series (0, 1, 1, 2, 3, 5, 8, 13, 21 …). Thus the length of the first phalanx is the sum of that of the middle and distal phalanxes. This highlights the need for a treatment that accurately restores the length of each component of the skeleton. In this context Strauch noted a loss of 7 degrees of extension for every 2 mm of skeletal shortening.
Although they appear parallel in extension, the long digital chains converge toward the scaphoid tubercle upon flexion. The occurrence of a rotational malalignment by more than 5 degrees has an adverse impact on function, particularly if there is scissoring. The thumb retains its key functions as long as the trapeziometacarpal (TMC) joint is free and the first commissure has not been compromised by any contracture. Furthermore, it can tolerate a certain degree of stiffness of the MCP and IP joints.
Mechanisms of Deformity
These have been well described and analyzed by McNealy and Lichtenstein.
The action of the flexor tendons and interosseous muscles results in palmar flexion of the distal bone fragment and dorsal opening of the fracture site. This deformation is even more pronounced with regard to metacarpal neck fractures ( Fig. 7.1 ).
The interosseous muscles also induce an axial rotation of the distal fragment. The second and third metacarpals have a tendency to pronate (ulnar rotation), whereas the fourth and fifth metacarpals have a tendency to supinate (radial rotation). These deformities may go unnoticed when the fingers are in extension. Only placing the digits in flexion will reveal the deformity, which manifests itself as an overlap of the fractured finger with its neighbor ( Fig. 7.2 ).
All attempts to reduce a fracture must ensure that they restore the convergence of the fingers toward the scaphoid tubercle.
Through their contractile power the interosseous muscles shorten metacarpals that have long oblique or spiral fractures.
With a Bennett fracture the first metacarpal is displaced upward and outward through the action of the abductor pollicis longus and thenar muscles ( Fig. 7.3 ).
A fracture at the base of the fifth metacarpal triggers the same phenomena through the action of the extensor carpi ulnaris (see Fig. 7.3 ).
Direct and axial traumas to the metacarpals of the digits generate fractures and dislocations at their base. The palmar bone fragment remains associated with the carpal bone. Through the action of the radial wrist extensors, the second and third metacarpals become dislocated in an upward and proximal direction, thereby generating a dorsal bulge like the “back of a dinner fork,” although this is often masked by edema and a hematoma.
Proximal Diaphyseal Fractures
Through the action of the interosseous muscles the proximal fragment flexes, whereas the distal fragment is placed in extension by the action of the lateral bands of the extensor apparatus. This results in a recurvatum with palmar opening of the fracture site ( Fig. 7.4 ).
Lateral tilting of the distal fragment is more clinically obvious; it depends on the nature of the injury and pattern of the fracture. On the other hand, axial rotation is common but can only be diagnosed clinically or by radiography with the finger in a flexed position.
Middle Diaphyseal Fractures
When the fracture is proximal to the superficial flexor tendon insertion, the proximal fragment is pulled into extension by the central slip of the extensor tendon and the distal fragment is flexed by the action of the superficial flexor. The deforming forces create an open dorsal angulation ( Fig. 7.5 ). When the fracture is distal to the superficial flexor tendon insertion, the proximal fragment moves with flexion and the distal fragment in extension. This creates an open palmar angulation ( Fig. 7.6 ).
Consolidation Time Frames
These are typically from 3–5 weeks for metacarpal and epiphyseal fractures, 5–7 weeks for diaphyseal fractures of the proximal phalanx, 7–10 weeks for the middle phalanx, and 3–4 weeks for fractures of the distal phalanx. Open fixation doubles these times. Finally, additional factors come into play, such as the extent, the mechanism, the energy of the injury-causing trauma and the presence of associated injuries (eg, joint involvement, soft tissue contusion, comminution of the site, neurovascular pedicle injuries). Just like the quality of the reduction and fixation, the patient’s age, their metabolic state and possible tobacco use also affect the prognosis.
Clinical and Radiologic Examination
Hand deformities resulting from one or more skeletal fractures are not always readily apparent because they may remain hidden by edema or hematomas. Although a recurvatum deformity of the phalanges can be readily diagnosed, oblique or spiral fractures are often not apparent on a finger in extension. It is through careful flexing of the finger that a rotatory malalignment can be seen. Flexion of the MCP joints reveals the metacarpal arch. In the case of a fracture of the metacarpal neck, the knuckle becomes less prominent, and if there is much angulation, the head can be felt in the palm of the hand at the distal palmar crease. This can be a hindrance with physical labor, especially when gripping. The clinical examination must always be completed by an assessment of the tendon apparatus and neurovascular pedicles.
The radiologic examination of a fracture must be performed carefully and should not be limited to a single posteroanterior (PA) and lateral view of the hand.
For the metacarpals, angled exposures at 45 and 60 degrees allow for resolution of the bone overlaps that occur with a lateral view ( Fig. 7.7 ). Anomalies of the metacarpal rays are searched for on the PA exposures, with any shortening arousing suspicion if there is no obvious injury. Despite the overlap, an entirely side-on view is very useful to assess interfragment separation in the case of a long oblique fracture to rule out an associated CMC dislocation. The latter are often difficult to see on PA and oblique exposures (see Chapter 6 ).
For the thumb we use the Kapandji views :
Static PA views ( Fig. 7.8 ): the forearm and hand rest on their ulnar side, with the hand in semipronation, the wrist at 15 degrees of extension, the coronal plane of the thumb parallel with the table. The adjacent digit is inclined obliquely in a vertical position at a proximal angle of 30 degrees and centered on the MCP joint.
Static lateral views ( Fig. 7.9 ): the wrist is in ulnar inclination and in 20 degrees of extension, the thumb aligned with the radial side of the forearm, the hand in pronation. The thumb and forearm rest on their radial side, the fingers flexed so as to lift the metacarpal off the surface of the table by 30 degrees. The beam is vertical and centered on the MCP joint.
Dynamic exposures assume the same positions as for static ones, with the thumb in hyperabduction, then in hyperadduction for the PA exposure, then in hyperflexion and hyperextension for the lateral view.
The Brewerton scale, originally for assessment of erosive injuries encountered at the head of the metacarpals with rheumatoid arthritis, is equally of great relevance for assessing traumatic MCP joint injuries. The hand is placed with its dorsum on the radiographic cassette, with the MCP joints bent to 65 degrees and the digit at an inclination of 15 degrees toward the ulnar side of the hand ( Fig. 7.10 ).
The range of fractures and their functional consequences demand an appropriate therapeutic choice. Tubiana has classified the various methods into six categories:
immobilization with a splint
closed reduction and early mobilization
closed reduction, fixation by percutaneous wiring and splinting
closed reduction, fixation by external fixation
open reduction, “minimal” fixation that does not allow for early mobilization
rigid fixation, immediate mobilization
It seems more instructive to us to define the treatment as a function of the stability of the fracture site, and the proposed fixation according to the degree of surgical intervention and by increasing severity:
splinting with or without prior reduction
percutaneous fixation by wires or screws
treatment by open rigid fixation
treatment by external fixation
The vast majority of stable closed fractures undergo consolidation with nonoperative or functional treatment. Function can hence remain adequate with a deformity of the hand that does not affect its ability to grip. Legal and economic considerations of the risks associated with surgery and the costs of implants and hospitalization have led some countries to adhere to and develop this conservative attitude. These societal considerations aside, we have witnessed an increase in surgical indications owing to the continuous improvement in fixation devices and a better biomechanical understanding of the limitations of fixation of fractures. Furthermore, patients are often adamant about obtaining an outcome that is functional and presentable in appearance so as to reduce the time spent idle.
On the other hand it should be pointed out that surgery must provide the patient with an outcome that is at least equal to a conventional treatment. For patients to make a fully informed choice, they should be made aware of the various therapeutic options, the time frames involved and the outcomes that may be expected. A level of understanding of the therapeutic program by patients will enhance compliance with their treatment. The surgeon must, among other things, make the patient aware of the risk of infection and the necessity for removal of the material. The discussion of technical risks (eg, additional secondary fracture lines, nerve or tendon injuries, protrusion of screws, etc.) should not be avoided or trivialized.
Functional treatment relies on immediate and careful mobilization. Weeks, de La Caffinière and Mansat observed that one-quarter of cases of finger stiffness are due to a hand fracture. Early, if not immediate, mobilization is the best way to combat edema and joint stiffness and to preserve tendon gliding. The best dynamic orthosis to promote mobilization while also protecting against excessive movement is achieved by buddying the injured finger with its neighbor with Elastoplast or Velcro bands that hold them together ( Fig. 7.11 ).
Splinting with or without prior reduction requires immobilization in a position that minimizes hand stiffness. Immobilization with a splint is a necessity for fractures that are deemed to be unstable, although this results in stiffness in numerous joints. Too many fingers are assigned to tongue depressors, which should never have left the otorhinolaryngology setting.
Attention must therefore always be given to the immobilized position, also referred to as the safe position, because it prevents joint stiffness by keeping the collateral ligaments stretched. This is the intrinsic-plus position, with the wrist in extension at 20 degrees, the MCP joints flexed between 40 and 60 degrees and the IPs in extension or very slight flexion (15 degrees at the most). The various positions of immobilization are derived from this basic position.
Immobilization follows the principle of stabilization of the injured segment and the adjacent joints.
Immobilization With a Bonvallet Bowl
Immobilization over a Bonvallet bowl belongs to the historical archives of surgery. The closed hand is bandaged over a plaster. The position of the hand is close to the so-called safe position, but the cutaneous tolerance and amenability for radiologic examination are poor. Rehabilitation of uninjured digital segments is impossible. This rudimentary technique is still used for exceptional indications such as humanitarian situations or when it is not possible to get the patient to comply otherwise (eg, intemperate splint removal due to dementia).
Use of Orthoses Made From Thermoplastic Materials
Use of orthoses made from thermoplastic materials is preferable because they are customized to fit the injured person’s anatomy, thereby leaving the uninjured fingers and joints free so as to limit stiffness. These orthoses can be altered successively to match reduction in edema or resized if progress with the consolidation allows additional digital segments to be freed ( Figs. 7.12 and 7.13 ).
As a general rule, 3 weeks are sufficient to stabilize the fracture site. Beyond this time frame, active rehabilitation with use of a dynamic orthosis will allow for functional restoration. From 3–6 weeks are required to regain mobility in a sector, beyond which manual labor is allowed.
Nonoperative management should not be seen as withholding more advanced therapies, and the choice of a suitable method is paramount if a favorable outcome is to be expected. Indeed, the majority of hand fractures are amenable to nonoperative treatment.
Percutaneous Fixation With Wires and Screws
Percutaneous fixation with wires and screws is recommended when reduction can be achieved by external means. The closed approach avoids devascularization, limits injuries at the surgical site and preserves the hematoma and its valuable growth factors. It is indicated for cases of simple displaced fractures, and the conferred stability often allows early mobilization.
Conversely, this method is also suitable for highly comminuted fractures, for which access to perform a direct fixation has little chance of success. The aim is then to restore the length and proper rotation of the injured segment, even if this arrangement will not always allow for immediate mobilization. Furthermore, it will allow stabilization of a fracture for which the contused or injured adjacent covering does not allow for open fixation ( Fig. 7.14 ).
Axial and Cross-Wiring
Pratt and Von Saal proposed the use of Kirschner wires for hand surgery. They are preferably introduced from the dorsolateral side of the finger, while avoiding damaging or blocking the extensor apparatus ( Fig. 7.15 ). Depending on the size of the bone, the Kirschner wires are 1.0 or 1.2 mm and are introduced with a powerful driver at a slow rotational speed to avoid heating and burning of the cortical bone. The use of wires must avoid fixing uninjured joints, and it is preferable to perform oblique wiring through the lateral surfaces of the metacarpal and phalangeal heads. A single wire is insufficient to stabilize the fracture site and can act as a rotational axis. The second wire must be introduced from the opposite side so as to form a crossed assembly. It is best to manually maintain axial compression of the fracture site at the time of introduction so as to avoid creating a physical separation of the bone at the fracture site.
When wiring of an unstable fracture proves to be difficult, it is prudent to introduce a temporary axial wire that will restore the alignment. Once the two crossed wires are in place the assembly is strong enough to remove the axial wire. This assembly, referred to as an “Eiffel Tower,” was proposed by Tubiana and assists the surgeon with his or her effort while also protecting the injured individual from a malunion ( Fig. 7.16 ). Wires in the vicinity of joints impede capsular-ligament movement, and the risk of neurovascular pedicle injuries is not insignificant. Furthermore, the rate of sepsis, pseudarthrosis and/or malunions remains relatively high (25.3%).
Intramedullary Wiring of Metacarpals and Phalanges
This is based on the principle of elastic fixation promoted by Hackethal and Ender. For extraarticular fractures of the base of the first metacarpal, Kapandji has proposed a crossed ascending double wiring whereby the wires are introduced through the lateral surfaces of the first metacarpal head ( Figs. 7.17 and 7.18 ). A similar technique can be used for the intermediate phalanges by following the three-point support by elastic stable intramedullary nailing (ESIN) of Métaizeau. For the fifth metacarpal, Foucher uses multiple intramedullary wires introduced through a cortical window at the base of the fifth metacarpal ( Fig. 7.19 ).
Transverse Metacarpal Wires ( Fig. 7.20 )
In 1973 Lamb published his experience with transverse wiring of unstable metacarpal fractures. He thereby paid homage to a little known old idea of Berkmann and Myles. The healthy metacarpal constitutes a “biological” external fixator, allowing stabilization at the fractured digit while maintaining its length and its axis. Furlong used this to stabilize unstable fractures of the fifth metacarpal neck (see Fig. 7.20,  ). James (see Fig. 7.20,  ) also recommended it for the treatment of unstable metacarpal fractures. This method is starting to be developed to treat metacarpal fracture-dislocations and to maintain the length of the metacarpal when there is bone loss ( Fig. 7.21 ; also see Fig. 7.20,  ). It is the best way to neutralize the palmar flexion stresses exerted by the interosseous muscles on one or more distal fragments of fractured metacarpals. Johnson proposed single transverse wiring to treat Bennett fractures (see Fig. 7.20,  ). In the same way, Iselin uses two divergent wires to better stabilize the first metacarpal and prevent retraction of the first commissure.
Treatment by Rigid Open Fixation
Treatment by rigid open fixation requires specific equipment. Following a period of great enthusiasm that was prompted by the emergence of AO devices, many users pointed out that the bulky size of the implants—the screws and plates in particular—injured the extensor apparatus when applied to the dorsum of the metacarpals and phalangeals. In 1974 Heim and Pfeiffer, who were the initial proponents of this method, observed that treatment of the phalangeals with such implants ultimately yielded mostly unsatisfactory outcomes, while the surgery could prove very difficult in and of itself. Biomechanical studies have now established that the stresses placed on the digital chain during extension and flexion motion are minimal. Based on these measurements, Foucher and Merle have developed Osteo, which is a miniaturized apposition device that has now been reproduced by the majority of manufacturers of such biomechanical items. Stryker Leibinger ( Fig. 7.22 ) and DePuy Synthes have developed a wide range of screws and plates. In practice, screws of 1.1, 1.2, 1.5, 1.7, 2.0, and 2.3 mm in diameter and straight “L” and “T”-shaped plates with thicknesses of 0.55 and 1 mm cover the various fixation requirements that are typically encountered. These sectionable plates are sufficiently malleable to be custom designed and applied as close as possible to the bone ( Fig. 7.23 ).
Osteosynthesis of the hand conforms with the biomechanical principles laid out by the AO and with conventional assemblies. Primary stability and contact are key parameters. Direct screw fixation with compression perpendicular to the fracture line is used on long oblique or spiral fractures. Short oblique or spiral fractures call for a compressive interfragment screw fixation with a neutralizing plate in apposition. Complex fractures combine screw fixation, plates and cerclage wiring to align the intermediate fragments on the plate.
The plates are preferably installed on the dorsolateral sides of the phalangeals to avoid tendon adhesions ( Fig. 7.24 ). Full dorsal application of the device leads to exposure to a double risk of adhesion of the extensor to the plate and catching of a flexor tendon by a protruding screw. On the metacarpals, the implantation is lateral on the distal part and more dorsal at the level of the median and proximal diaphysis; this is to counter strong stresses during flexion. In the last few years, bioengineering has allowed for the use of locking screws with these miniplates. This simplifies the treatment of highly comminuted injuries and multifragmented epiphyseal plates while offering increased stability that allows early mobilization.
Treatment by External Fixation
Treatment by external fixation is not often used in the hand. It is essentially restricted to multitissue injuries of the thumb column and for PIP joint fractures. In 1974 Crockett suggested the use of an external construct to fix digital arthrodeses with Kirschner wires that are joined together with acrylic resin. Scott and Mulligan and then adherents of Vilain’s teachings specified their indication in complex traumas of the hand and in osteoarthritis ( Fig. 7.25 ). In 1973 Allieu adapted Hoffmann’s external fixator for the hand, and they recommended assembly in a single section with transfixing wires for the thumb column.
In terms of the digits, to retain full joint movement it is best to use oblique dorsal wires joined together by small tie rods. Hoffmann’s minifixator allows such assemblies on the digital chain, and it is compatible with mobilization. Its use remains tenuous, however, when the wires are anchored in small juxtaarticular bone fragments. This necessitates reliance on the adjacent skeleton and on the bridging of intact joints. The use of this must remain restricted to complex traumas of the thumb column when the loss of bone and skin cannot be treated in an emergency ( Fig. 7.26 ). For the first metacarpal the Orthofix Pennig Minifixator allows stabilization by a “minirail” system or ready-for-use articulated device, but its size limits its use almost entirely to the thumb.
More recently, dynamic external fixation processes with varying degrees of complexity have emerged that allow joint distraction mobilization. These devices are suitable mainly for smashed PIP joints, with entities as described by Suzuki or the Ligamentotaxor (Arex) developed by Pélissier ( Fig. 7.27 ; also see Fig. 7.50 ).
Temporary fixation is useful for severe multitissue injuries or with major loss of bone. A minimal fixation is performed in light of the frequent contamination of these injuries. It relies on wires and individual screws to reassemble an epiphyseal plate, along with a wire cerclage that makes a multifragmented diaphysis look like a bundle of wood. The length and axis of the digital chain are maintained in neutral by an external fixator or by interposition of a spacer that may be cemented in and equipped with wires. Once there is no risk of infection and there is adequate soft tissue coverage, the spacer is replaced by a corticocancellous graft or a more stable fixation (see Figs. 7.21 and 7.26 ).
Fractures Based on Site of Injury: Mechanism, Classification, Treatment
Distal Phalanx Injuries
Fractures of the distal phalanx are the most common and most often affect the thumb and the middle finger. The diagnosis is strictly by PA and lateral x-rays. Schneider distinguishes between fractures of the tuft, the diaphysis and the base.
Tuft fractures are the result of crushing that may or may not be associated with avulsion injuries or loss of pulp and nail. These comminuted fractures result in multiple small fragments that are minimally displaced and do not warrant fixation.
Closed Tuft Fractures
Closed fractures of the tuft are associated with a very painful subungual hematoma that is treated by perforation of the fingernail using a small drill bit, a trocar or a red-hot paper clip (see Chapter 13 , Fig. 13.5a ). This indication only concerns new and painful hematomas that affect the entire nail. Treatment of these fractures is functional by encouraging immediate mobilization, since the tuft is not engaged by tendon contraction. Efforts to desensitize the pulp are necessary to reintegrate the digit’s function.
Open Tuft Fractures
Open tuft fractures are often associated with a loss of distal pulp tissue (see Chapter 9 ) and soft tissue contusion. If the injury is substantial, administration of an oral antibiotic for 5 days is advisable following debridement of the wound. Treatment involves surgery with debridement of tissues likely to undergo necrosis and of small bone fragments that may become sequestra. It is best to limit phalangeal shortening to avoid development of a hook nail. When the fragments are still linked by the phalangeal periosteum and the palmar fibrous partitions, placement of a small 0.8-mm wire or an intradermic needle for 15 days to 3 weeks will restore stability and alignment of the phalanx. If the fracture is longitudinal, cerclage with PDS 4-0 improves interfragment contact and limits the risk of a split phalanx. Coverage of these injuries is achieved by a straightforward suture of the nail bed using Monocryl 6-0 (see Chapter 13 , Fig. 13.4 ) and by a cutaneous suture or by creating a local flap in the pulp area.
Progression of fractures to pseudarthrosis is common. The presence of a painful distal bone fragment may warrant renewed surgery to excise it or to perform an intermediate graft in the case of a split phalanx ( Fig. 7.28 ). In the exceptional case of a painful and unstable pseudarthrosis, regrowth of the nail will have to be complete before undertaking a surgical intervention, because the fingernail has a major stabilizing effect.
Diaphyseal fractures are divided into the more common transverse fractures and longitudinal fractures. The presence of a displacement or an open fracture determines the specifics of the treatment.
Nondisplaced Closed Fractures
Closed or nondisplaced fractures are amenable to immediate mobilization or splinting depending on the patient’s requirements and the location of the fracture line relative to the fingernail. Mobilization is preferable for longitudinal injuries and with the most distal transverse diaphyseal fractures, provided the patient is not required to perform manual labor. In this case a dorsal splint must be worn nightly for 3–4 weeks to act as an analgesic and shock absorber ( Fig. 7.29 ). The same splint must be worn continuously for 3–4 weeks if the patient engages in strenuous physical activities or if the pain is substantial and the fracture line is situated in the middle or distal third of the diaphysis. In this case the fingernail cannot be considered to be a substitute for a splint.
Displaced Closed Fractures
Displaced closed fractures are to be treated surgically when bone contact is insufficient or the dorsal cortex exhibits a separation that will lead to ungual dystrophy. Fixation is achieved by percutaneous wiring with wires, preferably divergent, following manual axial compression of the site. The wires are introduced 1–2 mm under the distal edge of the nail under fluoroscopic control. The DIP joint is not immobilized by the fixation ( Fig. 7.30 ). If the fracture is juxtaepiphyseal, however, the hold of the wires can be tenuous, and performing a temporary arthrodesis will provide the stability required for consolidation while also facilitating mobilization of the PIP joint. The wires may be countersunk to reduce the risk of infection and perturbation of the distal pulp, because a delay in consolidation cannot be ruled out.
Displaced Open Fractures
Open fractures, whether displaced or not, require antibiotic therapy and irrigation of the fracture site. Osteosynthesis is then performed with two 0.8- or 1.0-mm wires introduced through the fracture site in opposite directions. The first wire is axial, the second oblique, traversing the fracture site, which is maintained in compression on the axis of the first wire. The nail bed is sutured by a slow-absorption monofilament running stitch. The nail is not routinely replaced, because it has mainly an analgesic role and this could also lead to a secondary infection (see Chapter 13 , Fig. 13.3 ).
Foucher describes a technique for reducing the nail with a needle and using it to brace the fracture in distal diaphyseal injuries (see Chapter 13 , Fig. 13.6c and 13.7 ). A longitudinal fracture can be reduced and stabilized by cerclage with doubled PDS 4-0 and sutured laterally according to the Nice knot technique. With injuries from thick-bladed cutting tools the fracture is accompanied by loss of bone that is treated initially by interposition of a cement spacer stabilized by an axial wire. Once healing has occurred and infection has been avoided, a second surgery will replace the spacer with a corticocancellous bone graft taken from the radius ( Fig. 7.31 ).
Seymour’s Juxtaepiphyseal Fracture
Seymour’s juxtaepiphyseal fracture is a transverse extraarticular fracture of Salter type I or II, affecting the growth cartilage of the distal phalanx. This fracture results from trauma by hyperflexion of the phalanx. It often involves an open fracture of the growth cartilage, with avulsion or rupture of the ungual matrix. A Seymour fracture presents clinically as a mallet finger, because the extensor tendon inserts on the proximal epiphysis, whereas the deep flexor tendon inserts on the distal fragment. This results in angulation with dorsal protrusion of the fracture ( Fig. 7.32 ). It is imperative that PA and lateral radiographic images are taken of the injured finger.
With closed fractures that can readily be reduced, proper treatment is ensured by the wearing of a splint for 4 weeks.
Surgery is required when the reduction is incomplete due to confinement of the ungual matrix. Removal of the nail allows access to the fracture and matrix release. After cleaning the fracture site, fixation is ensured by a 0.8-mm axial wire. The nail matrix and its bed are sutured with Monocryl 6-0. The nail is put back to serve as a guide for healing of the matrix. Complications are the same as for all growth cartilage fractures. Premature epiphyseal arrest may occur following the trauma or a secondary infection.
Diaphyseal distal phalanx fractures can develop into pseudarthrosis, particularly when the severity of the injury is underestimated and the splinting is inadequate. This can result in perpetuation of an interfragmentary gap. Usually the fibrous tissue of the pseudarthrosis and the dorsal stabilization by the fingernail ensure a reasonable functional outcome. When there is a painful instability, surgery is performed when the nail has regrown. Following freshening of the bone ends and the possible addition of a bone graft, stabilization is achieved by a compressive screw or two 0.8- or 1.0-mm Kirschner wires. If the bone quality is poor, Merle has proposed performing an intramedullary bone bilboquet taken from the ulnar crest.
Intraarticular Fractures of the Base of the Distal Phalanx
Intraarticular fractures of the base of the distal phalanx are frequently encountered with ball sports. Avulsion injuries, corresponding with bony mallet fingers and jersey fingers, are different from injuries with an axial component.
Approximately 30% of mallet fingers are fractures of the base of the distal phalanx, versus 70% of tendon injuries. Mallet finger injuries have been classified by Doyle (see Chapter 11 ), but the Wehbe and Schneider classification describes mallet fractures more specifically ( Table 7.1 ). Indications for treatment are controversial. A dorsal splint is generally recommended, and this yields satisfactory results for injuries without subluxation and affecting less than a third of the joint surface. Beyond a third, or when there is DIP joint subluxation, surgery is the rule because functional outcomes and physical appearances are unpredictable with nonoperative treatment. Giddins emphasizes the importance of the stability of interfragment contact (which can be tested by taking a radiography image in hyperextension) and the presence of subluxation. The technique of Ishiguro, improved by Hofmeister with the DIP joint blocked in extension, is the protocol of choice for injuries with small fragments (see Chapter 11 , Fig. 11.13c-g ). When the fragment is of a bigger size, we prefer direct percutaneous interfragment screw fixation or placement of a plate (see Chapter 11 , Fig. 11.13h ).
|I||No distal interphalangeal joint subluxation|
|II||Distal interphalangeal joint subluxation|
|A||<1/3 joint surface|
Jersey Finger Injuries
Modified Leddy-Packer type 3, 4 and 5 jersey finger injuries involve a fracture of the base of the distal phalanx. The main issue to be addressed in this situation is reconstruction of the flexor apparatus (see Chapter 10 , Table 10.1 and Fig. 10.9 ).
With injuries due to hyperextension or that have an axial compression component, a T-shaped or a Y-shaped fracture is seen at the base of the distal phalanx. Horiuchi has shown that when the axial trauma is applied to a flexed IP joint, there is a dorsal dislocation of the phalanx with a palmar fracture. In the case of hyperextension of the DIP joint the deformation is the opposite, with a palmar dislocation of the phalanx and a dorsal fracture ( Fig. 7.33 ). Treatment of these fractures, which are usually displaced, requires surgery to restore joint alignment. The treatment can be performed by closed reduction or by percutaneous screw fixation. In the case of incomplete reduction, directly accessing the fracture site is necessary for fixation by screw fixation or by a hook plate. In cases involving very unstable injuries, it is prudent to add an arthrodesis wire.