Radiographic Evaluation

Dedicated posteroanterior and true lateral radiographs of the digit or magnified views of the joint itself must be obtained to determine if recent or preexisting articular involvement is present. Radiographs of the hand alone are not adequate. A subtle fracture or subluxation may otherwise be missed. Keep in mind that the joint may have spontaneously reduced, masking the pathologic situation of a dislocation. Look for the “V” sign dorsally to identify incongruent or dorsally subluxated joints ( Figure 8.2 ). Pronated and supinated oblique radiographs can also be helpful in evaluating fractures at the base of the middle phalanx.

Subtle proximal interphalangeal joint subluxation is recognized by dorsal joint widening known as the “V” sign.

(Copyright © Elizabeth Martin.)

Clinical Evaluation

The ultimate determinant of treatment is whether the joint remains concentrically reduced with active motion. This requires adequate pain control from a digital block. Functional stability may be determined by the following two-phase test, after a nerve block.

• 1.
  

  Active stability. The patient voluntarily moves the digit through its normal range of motion. Completion of a full or nearly full range indicates that, despite ligament disruption, adequate joint stability remains. Redisplacement with motion, however, indicates significant ligament disruption (i.e., at least two sides of the “box”). The position at which displacement occurs is a clue to the specific site of ligament injury, as well as the optimum position for joint immobilization.

  
  
• 2.
  

  Passive stability. A final assessment of stability is determined by passive manipulation. Examine the uninjured side first to establish the baseline level of ligamentous laxity in the patient. Gentle lateral stress is applied to each collateral ligament in full extension and 30 degrees of flexion. The flexion examination tests primarily the collateral ligaments. The examination in extension gives an indication of the secondary stability afforded by the bony anatomy, accessory collateral ligaments, and volar plate. Dorsovolar stability is tested by shearing the joint surfaces dorsally and volarly.

Collateral ligament injury with the corresponding stability is classified into three grades:

• 
  

  Grade I: Pain, but no laxity

  
  
• 
  

  Grade II: Laxity, but a firm end point and stable arc of motion

  
  
• 
  

  Grade III: Gross instability, but no firm end point

Acute Dorsal Proximal Interphalangeal Dislocations

The mechanism of injury in dorsal dislocations is usually PIP joint hyperextension combined with some degree of longitudinal compression, most frequently exemplified by a ball striking a fingertip. The greater the longitudinal force, the more likely it is that the volar lip of the middle phalanx will be sheared off or impacted, producing a fracture-dislocation. In a pure dislocation, the collateral ligaments are torn, but after reduction they remain functionally intact whereas the volar plate is sheared off the base of the middle phalanx. A small avulsion fracture of the base of the middle phalanx is common with dorsal dislocations (44% in one series of 57 hyperextension dislocations) and does not change the diagnosis or treatment.

A simple dorsal dislocation presents in one of two ways: A type I injury is a hyperextension deformity with joint surfaces still touching, and a type II injury is in a bayonet position. Type III injuries are fracture-dislocations and are discussed later. The hyperextension deformity typically reduces very easily with a small amount of force directed volarly and in flexion after a digital block. In a bayonet dislocation, after digital block, extension stress should be applied to the middle phalanx and the examiner’s thumb can be used to hook the base of the middle phalanx back over the head of the metacarpal. If pure longitudinal traction is used, it can trap the condyles by the collateral ligaments and pull the volar plate into the joint, turning a reducible dislocation into an irreducible dislocation. The stability examination, as described previously, is performed after reduction. If the joint is stable through a full range of motion, immediate motion should be encouraged with protection via buddy taping. Stiffness from prolonged immobilization is the most common complication from treating these injuries.

If the joint is unstable, it is placed in an extension block splint at 10 degrees more flexion than the point at which it begins to subluxate. Each week the splint is extended 10 degrees. The goal is to have patients out of splints by 3 weeks or sooner. A cadaveric study suggests that extension block splinting in slight flexion reliably places the avulsed volar plate in a nearly anatomic position to facilitate healing. If the digit requires flexion past 30 degrees to maintain congruency and stability, operative repair should be considered. Patients should be counseled to expect occasional pain, swelling, and stiffness for at least 6 months because recovery is typically prolonged.

Lateral Proximal Interphalangeal Dislocations

The critical anatomic lesions in a lateral dislocation of the PIP joint are rupture of one collateral ligament and at least partial avulsion of the volar plate from the middle phalanx. More than 20 degrees of deformity on gentle static lateral testing in extension indicates complete collateral ligament disruption and injury to at least one other secondary stabilizer. This is a major disruption of the four-sided ligamentous box, but with few exceptions the ligaments heal when the joint is reduced and early controlled motion begun. The joint should be protected with buddy tapes to an adjacent uninjured digit. Irreducible lateral dislocations typically demonstrate interposition of the lateral band on operative exploration.

Repair of the ruptured collateral ligaments has been frequently reported after PIP dislocations in general and lateral dislocations in particular. Most of these series involve athletes, and it has been suggested that surgery will enable a faster return to sport. Kato and colleagues reported on 11 primary repairs of acute PIP joint collateral ligament tears in athletes and manual laborers. Suture anchors were used in the repair, active motion was initiated at 2 to 3 weeks, and unlimited activities were allowed at 6 weeks. Nevertheless, because the usual sequela of ligament injury of the PIP joint is stiffness and not instability, the surgical trauma of ligament repair may have an adverse effect on the ultimate range of motion after lateral dislocations.

Volar Proximal Interphalangeal Dislocations

Volar dislocations of the PIP joint are rare injuries. The base of the middle phalanx may dislocate volarly without rotation (volar dislocation) or may rotate on one intact collateral ligament so that the opposite side subluxates in a volar direction (volar rotatory subluxation). Appreciating the difference between these two related injuries and identifying them clinically can help ensure appropriate management.

A typical mechanism of injury involves catching a digit in a clothes dryer that has not stopped spinning. As the middle phalanx displaces volarly, the proximal phalangeal condyle ruptures through the extensor mechanism, usually between the central slip and the ipsilateral lateral band. The lateral band may entrap the condyle, creating a situation in which traction and joint extension further tighten the noose and block reduction.

When a volar dislocation occurs without a rotatory component, the central slip is ruptured. If the dislocation is irreducible, there is a high likelihood of an interposed structure such as the central slip, a collateral ligament, or a fracture fragment. Puckering of surrounding skin is suggestive of a joint that still has soft tissue interposition. If the joint reduces easily, one must still be wary of a central slip disruption, and the ability to actively extend the digit fully must be confirmed. If there is any doubt about the integrity of the extensor mechanism, immobilization in PIP extension is mandatory.

Volar fracture-dislocations are quite rare. Injuries with a large dorsal fragment should be treated with open reduction and internal fixation (ORIF) via minifragment lag screw fixation to allow early motion. Open reduction will permit inspection or repair of the central slip insertion. Tekkis and coworkers reported two such cases with excellent clinical outcomes. Care must be taken to avoid screw extension into the flexor sheath. Dorsal screw head prominence may require later screw removal. Another option is to secure the fragment with a wire loop. Volar fracture-dislocations with smaller fracture fragments but an intact central slip and concentric joint can be splinted in extension for 1 to 3 weeks followed by active range-of-motion exercises.

The management of chronic volar dislocations of the PIP joint is complex and requires the simultaneous surgical correction of an incongruous and contracted joint as well as an incompetent extensor mechanism. There may be degeneration of the articular cartilage; if so, the prospect of restoring normal joint function is greatly diminished. Therefore, it is important to recognize a volar PIP joint dislocation at the time of injury and adequately treat the disrupted extensor mechanism. Peimer and colleagues also recommended repair of the ruptured collateral ligament. In this relatively large series of 15 patients with volar PIP dislocation, inspection at the time of surgery revealed disruption of the extensor mechanism, the volar plate, and one collateral ligament in all patients. In each, the extensor mechanism and collateral ligament were repaired, the joint was pinned in extension, and motion with therapy was started at 4 weeks after removal of the Kirschner wire. Although all patients had painless, stable PIP motion, no patient achieved preinjury PIP motion.

Dorsal Dislocations and Fracture-Dislocations of the Proximal Interphalangeal Joint

There are two fundamental parameters that guide treatment of these injuries: stability and joint congruity. These parameters are the basis for the treatment algorithm seen in Figure 8.3 .

Treatment algorithm for proximal interphalangeal (PIP) joint fractures and dislocations. A/PROM , Active/passive range of motion; ORIF , open reduction and internal fixation; ROM , range of motion.

Stable fracture-dislocations have a volar fragment that represents less than 30% of the volar articular surface and a concentric joint after reduction. In this case, the disruption occurs through the base of the phalanx rather than at the insertion of the volar plate. Sufficient volar bone remains to render the joint stable. The collateral ligaments, torn or not, do not influence the stability of the reduction other than by contributing to lateral stability on stress. These usually behave like a simple dorsal dislocation. Radiographs tend to underestimate the percentage of volar fracture involvement, as frequently the fracture will involve a greater amount of one middle phalanx articular facet than the other. Stable fracture-dislocations can generally be treated conservatively with 3 weeks of dorsal block splinting, allowing range-of-motion exercises while the splint is worn. It is important to check both active and passive motion ( described in the previous examination section ) because the volar fracture fragment may become trapped within the flexor sheath and inhibit motion. Fluoroscopy after a digital block can help determine how much extension is possible while fracture and joint reduction is maintained. Many patients will require formal hand therapy to regain full motion and function.

Tenuously stable fracture-dislocations involve 30 to 50% of the volar buttress and reduce with less than 30 degrees of flexion. In cases with less than 40% of volar articular involvement, the joint is usually stable in all positions. With 40 to 60% volar articular involvement, progressively greater flexion is required to render the joint stable.

Unstable fracture-dislocations demonstrate greater than 60% involvement of the volar articular surface. Beyond 60% involvement, joints tend to be unstable in all positions or require more than 60 degrees of flexion to obtain a congruent reduction. Accurate closed reduction is difficult to achieve and even more difficult to maintain. The main element contributing to instability is the loss of the buttressing effect of the volar margin of the middle phalanx that partially cups the proximal phalangeal condyles ( Figure 8.4 ).

A, Fracture-dislocation with less than 40% of proximal articular surface allows some collateral ligament attachment to middle phalanx. B, A fracture-dislocation with more than 40% involvement of the middle phalangeal articular surface ensures that the collaterals are attached only to the fragment and not to the phalanx. The injury is unstable without operative fixation.

(Copyright © Elizabeth Martin.)

Pilon Fracture

When a high-energy axial compressive force is delivered to a fully extended digit, a pilon fracture of the PIP joint may occur. There is often widening of the base of the middle phalanx as dorsal and volar fragments are driven apart and more central cartilage surfaces are impacted into the cancellous bone.

Depression of the concave articular fossae of the middle phalangeal base mimics certain tibial plateau fractures. Angular deformities are common, especially if only one facet is involved. These fractures are subtle on plain radiographs of the involved digit, and the clinician should maintain a low threshold for obtaining a CT scan of the PIP joint to better visualize the articular depression. Operative reduction is usually necessary, however, and excellent results are difficult to achieve ( Figure 8.5, A and B ).

A and B, Unicondylar depression fracture of the proximal interphalangeal joint. C and D, The depressed phalangeal “plateau” was elevated with a Kleinert/Kutz elevator, supported by bone graft, and fixed with a Kirschner wire tension band construct.

(Courtesy Scott W. Wolfe, MD.)

Treatment of Unstable Proximal Interphalangeal Fracture-Dislocation and Pilon Injuries

Unstable PIP fracture-dislocations and PIP pilon fractures are some of the most challenging injuries treated by hand surgeons. Patients should be counseled about the severity of the injury and the possibility of residual stiffness and arthritis because they often consider a “broken finger” to be a relatively minor injury from which they will recover completely. There are a variety of treatments described, because no single technique has demonstrated clear superiority. The techniques of extension block splinting or pinning, ORIF, dynamic traction, hemihamate autogenous grafting, cerclage wiring, hemiarthroplasty, and volar plate arthroplasty can all be difficult and may be appropriate for different types of cases. Detailed step-by-step guidelines follow for each of these techniques.

Cerclage Wiring.

For pilon or comminuted fractures with fragments too small for individual screw fixation, one may consider elevation and grafting of depressed fragments followed by cerclage wiring to prevent widening of the articular surface ( Figure 8.6 ). This technique is most appropriate for the rare case where there is minimal joint subluxation but significant comminution of the joint surface. In a series of 12 patients, Weiss demonstrated an average range of motion of 89 degrees with an 8-degree extensor lag. The technique is described in detail in the following text .

After shotgun exposure of joint, fragments are managed with elevation and bone graft as needed. Cerclage wire is passed around proximal end of phalanx, preventing typical dorsal/volar expansion in pilon-type injuries and holding small fragments that otherwise may not be amenable to interfragmentary fixation.

(Technique courtesy of Dr. A.P.C. Weiss. From Weiss AP: Cerclage fixation for fracture dislocation of the PIP joint, Clin Orthop Relat Res (327):21–28, 1996.)

Authors’ Preferred Methods of Treatment

For less severe fracture-dislocations, we have found extension block splinting to be quite effective for cases where there is a congruent joint following reduction and the articular involvement is less than 40% ( Figure 8.7 ). Care must be taken to ensure that dorsal subluxation (loss of reduction) does not occur during the course of treatment with the splint in place. If the PIP joint injury is amenable to extension block splinting but the digit is too short, stocky, or swollen for such treatment, I will occasionally use an extension block pin. In general, if a fracture is unstable enough to warrant pinning over a simple splint, the fracture fragment is likely large enough to warrant operative fixation.

A, Type III fracture-dislocation of proximal interphalangeal (PIP) joint in which approximately 40% of volar articular surface is displaced with fracture fragment. B, Fracture-dislocations with 40% or less of articular surface involved may be successfully treated with dorsal extension block splinting. The patient is allowed to actively flex the PIP joint, which is progressively extended over approximately 4 weeks. The key to this mode of treatment is concentric reduction of the PIP joint.

Several satisfactory options exist for the treatment of unstable PIP joint fracture-dislocations, but none is perfect. The authors are not wedded to a particular modality of treatment and allow the injury characteristics to guide the approach (see algorithm in Figure 8.3 ).

The hand surgeon will often see a PIP fracture-dislocation after it has been initially treated elsewhere, and the true nature of this complicated injury may not have been appreciated or conveyed to the patient. The patient must understand from the outset that while normal PIP joint function is possible, it is highly unlikely. Patients must also be told that the best functional result will only be possible with extensive and dedicated compliance with postoperative hand therapy. Overall results diminish as the time from injury to treatment increases, even with a delay beyond 2 weeks, but especially beyond 6 weeks.

Dynamic Skeletal Traction.

Dynamic skeletal traction is useful in select cases, especially with increased comminution and fracture lines extending dorsally (pilon) or distally through the base of the middle phalanx. The fracture is viewed under traction using fluoroscopy to get a sense of the amount of reduction possible and to consider whether the fracture may be more amenable to a different technique ( Figure 8.8 ). Although many fixators have been described, in the authors’ opinion the easiest, least expensive, and most effective is a fixator constructed in the operating room using three Kirschner wires and dental rubber bands. The fixator requires 9-inch Kirschner wires (check ahead of time because many centers stock only short Kirschner wires). The fixator is assembled by placing two Kirschner wires perpendicular to the digit along the midaxial plane through the proximal and middle phalangeal condyles ( Figure 8.9 ). It is critical for the initial wire to be placed in the center of rotation of the proximal phalangeal condyles. The proximal phalanx wire is bent distally and fashioned into hooks. The second wire is inserted through the center of rotation of the middle phalangeal head, and this condylar wire is also bent and fashioned into hooks ( Figure 8.10 ). The distance between the proximal and distal hooks is approximately 2.5 cm ( Figure 8.11 ), which allows for an adequate but not excessive distraction force by dental rubber bands. Give extra rubber bands to the patient to take home in case one ruptures. Prior to applying the rubber bands, a third midaxial wire is placed in the middle phalanx, which acts as fulcrum, blocking dorsal dislocation of the PIP joint ( Figure 8.12 ). This third wire is not seen in all publications on the subject but is crucial in unstable pilon-type fractures to provide joint reduction in the sagittal plane without excessive distraction force. Typically, two rubber bands are applied to each set of hooks. Intraoperative fluoroscopy is used to confirm concentric reduction through a full arc of motion ( Figure 8.13 ), and additional rubber bands are applied as necessary to tailor the distraction. If impacted central fragments remain, one can consider open reduction and bone grafting, or alternatively, an 18-gauge needle or Kirschner wire can be directed fluoroscopically into the fracture site to tamp up the impacted fracture fragment ( Figure 8.14 ).

Critical Points

Dynamic Skeletal Traction

Preoperative Planning

• •
  

  The construct requires long 0.045-inch Kirschner wires; short Kirschner wires are insufficient.

  
  
• •
  

  Sterilizable dental rubber bands of 3/8 inch are used.

  
  
• •
  

  Less effective if neighboring digits are injured, given width of the construct

  
  
• •
  

  Excellent technique for unstable injuries with comminuted fragments

Technical Points

• •
  

  Careful placement of the proximal phalanx Kirschner wire in the center of rotation of the condyle is needed, as viewed on posteroanterior and lateral radiographs.

  
  
• •
  

  Add a third Kirschner wire to prevent dorsal subluxation and minimize the needed distraction force.

  
  
• •
  

  Measure 2.5 cm between anchor points for rubber bands on proximal and distal wires.

  
  
• •
  

  Confirm motion and reduction in flexion and extension (it helps to advise the hand therapist).

Postoperative Planning

• •
  

  Give the patient extra rubber bands to take home in case some break.

  
  
• •
  

  Patient dedication is required in the rehabilitation process.

A, Anteroposterior radiograph of pilon proximal interphalangeal joint injury with distal extension, shortening, and subluxation. B, Lateral radiograph of same injury before traction. C, Lateral radiograph after closed reduction.

A, Lateral radiograph of proximal wire placement in center of rotation. B, Anteroposterior radiograph of proximal wire placement transverse to longitudinal axis of finger.

Demonstration of wire placement with hooks made for dental rubber bands.

Hooks are bent such that there is 2.5 cm between proximal and distal hooks, a typically reliable amount of traction.

A third wire is added in middle axial line through middle phalanx. By placing this dorsal to the proximal phalangeal wire, a volar-directed moment is applied to the joint to prevent dorsal subluxation without excessive traction.

Full extension is typically the most unstable position. A, Lateral radiograph shows some overall widening or cupping at the joint, but no subluxation or secondary incongruity. B, Lateral view with joint flexed also shows congruity.

A, Percutaneous introduction of 18-gauge needle to elevated impacted fragments. B, Reduction after tension is applied to the dynamic fixator and joint is reduced percutaneously.

Postoperative protocol.

Patients are instructed to elevate and rest the hand for 2 to 3 days to decrease swelling before beginning hand therapy. Patients are permitted both active and passive range of motion as tolerated. Postoperative motion with the fixator in place is typically less than what was demonstrated in the operating room. Pins are swabbed with half-strength peroxide for the first week twice a day and thereafter only if they have drainage. Patients are permitted to get the fixator wet in the shower once wounds are sealed and benign in appearance. Pin tract redness, swelling, or drainage is treated with antibiotics and rest. Radiographs are taken at 1 week to ensure that fracture and joint reduction are maintained. Distraction can be adjusted with rubber band application or removal as indicated by radiographs; ideally, the joint should be only minimally distracted when compared with neighboring PIP joints. After 4 weeks, adequate healing is confirmed by removing the dental rubber bands and obtaining lateral radiographs of the digit in flexion and extension. Fixator removal as early as 3 weeks has been reported with successful results. If there is evidence of fracture healing and the joint stays congruent, the fixator is removed; otherwise, it is rechecked in 1 to 2 weeks.

Expected outcomes.

A review of several recent reports showed an average range of motion of approximately 85 degrees at follow-up after 1 to 2 years. Superficial pin tract infections are present in 10 to 30% of cases, but they typically resolve without incident. Patients demonstrate 92% grip strength on average. Only a few patients in these series have reported residual pain. On subset analysis, patients with significant joint comminution or a delay to surgery perform less well.

Our own results, although good for this difficult injury, have had more instances of residual pain than these case series may suggest. Perhaps the degree of joint comminution was more than the case examples shown in radiographs presented in these papers.

Open Reduction and Internal Fixation.

ORIF is an excellent form of treatment when there is a single large volar fragment. The procedure is performed through a volar zigzag incision; the flap is based radially in the index and long fingers and ulnarly in the ring and small fingers to reduce the potential for contact hypersensitivity. The A3 pulley is excised or everted for later repair. The flexor tendons are retracted. A self-retaining operative tray with ball-and-chain hooks or an aluminum or lead hand may be helpful to retract the neighboring digits. The PIP joint is entered in the A2 to A4 interval between the flexor sheath, and the sheath is excised or everted for later reattachment. It is important to fully visualize the articular surface to ensure anatomic reduction, which may require a “shotgun” hyperextension approach ( Fig 8.15, A and B ). To do this, the neurovascular bundles are mobilized to prevent traction injury, the flexor tendons are protected and retracted with a Penrose drain, and the collateral ligaments that remain attached to the middle phalanx are excised except for the most volar remnants. These are preserved for later use in the procedure to suture each corner of the volar plate margin. The volar plate is generally left attached to the volar fracture fragment but can be detached as necessary. Although preservation of the volar plate insertion on the fragment will maintain the blood supply, fracture healing is usually not dependent upon this. Detaching the collateral ligaments allows the joint to be maximally hyperextended, as one would open a shotgun. With both articular surfaces completely exposed, the feasibility of reduction and fixation of the fragments can be determined. Impacted fragments of the dorsal articular surface may be elevated with a dental pick or Freer elevator, and the subchondral void filled with a small autologous or allograft cancellous crouton.

Shotgun approach for proximal interphalangeal joint exposure. A, Flexor sheath between A2 and A4 pulleys is incised along one edge and elevated. When closing, it can be passed under the tendon to prevent adhesions at repair site. B, After recession of collaterals, joint can be “shotgunned” open.

(Courtesy Hill Hastings, MD.)

If the volar fragment is large, the joint is reduced and the fragment held with one or two 1-mm lag screws, the goal being an anatomic, stable reduction. In hard bone, the small screw head(s) are countersunk to minimize flexor sheath irritation, and care is taken to avoid screw tips extending beyond the dorsal cortex where they may irritate the extensor mechanism. Release of the collateral ligament attachments to the fragment greatly improves visualization and eases manipulation. When there is comminution of the volar fragment(s), a 1.3-mm volar buttress plate can be applied. The flexor digitorum superficialis inserts laterally, so a centrally placed plate is well tolerated. Protected early motion is the goal.

Critical Points

Open Reduction and Internal Fixation

Preoperative Considerations

• •
  

  Have a backup plan (i.e., hemihamate autograft or dynamic skeletal fixation) because comminution is often worse than demonstrated on preoperative radiographs.

  
  
• •
  

  The technique is best for a single, large fragment pattern, but smaller implant systems with 1-mm screws and 1.3-mm plates can render stable reduction with certain fracture types.

Technical Points

• •
  

  Sharp dissection with meticulous handling of soft tissues cannot be overemphasized.

  
  
• •
  

  Inspect the dorsal surface carefully to make sure it is anatomic, and elevate impacted fragments and bone graft as needed.

  
  
• •
  

  After fixation, check a lateral in flexion and extension to make sure the joint maintains a congruent reduction and does not subluxate in extension.

Postoperative Planning

• •
  

  Construct must be sufficiently stable to permit early motion. If unstable, consider adding an additional Kirschner wire fixator to maintain stability during early motion. Avoid overdistraction.

Postoperative protocol.

Patients begin immediate active range-of-motion movements of the joint. Between exercises the digit is immobilized in a gutter splint with the PIP joint maintained in full extension (as long as there is no joint subluxation) to prevent flexion contracture. Passive range-of-motion movements and dynamic splints are started based on the surgeon’s assessment of the integrity of the repair; we prefer to start as soon as possible.

Expected outcomes.

Four recent case series of 54 patients who had undergone volar miniscrew ORIF demonstrated PIP motion of 55 to 115 degrees (average, 80 degrees) with a 10-degree flexion contracture. Strength averaged 85% of the uninjured side.

Volar Plate Arthroplasty.

The PIP joint is exposed using a radially based flap through a chevron-shaped incision with its apex at the ulnar midaxial point. The flexor sheath is excised between the A2 and A4 pulleys, and the flexor tendons are atraumatically retracted with a Penrose drain. The articular surfaces are very difficult to assess with the joint reduced. Hyperextension of the joint will usually expose the distal edge of the fracture fragment, facilitating entrance into the joint. A shotgun joint is exposed using a radially based flap through to gain access and to release any preexisting joint contracture.

Congruous reduction may not be possible if the fracture fragments are markedly comminuted or impacted. Loose bone fragments and the segment attached to the volar plate are excised and saved for potential bone graft material. The defect in the volar rim of the middle phalanx is shaped into a transverse groove perpendicular to the long axis of the phalanx. Deeply impacted fragments should be left undisturbed to serve as a buttress for the volar plate. The interval between the volar plate and both collateral ligaments is incised, and the fibrocartilaginous plate is mobilized if necessary to allow its advancement 4 to 6 mm distally into the defect in the middle phalanx. The more recent the injury, the more easily the plate will advance. In late cases, it is usually necessary to partially release ( Figure 8.16 ) the proximal checkrein ligaments to gain sufficient length for advancement.

Step-cuts can be made along checkrein ligaments to allow distal advancement of volar plate into the defect. MP , Metacarpophalangeal; PP, proximal phalanx.

(Copyright © Elizabeth Martin.)

The volar plate is advanced into the middle phalangeal defect by means of a pull-out wire or suture, which spirals along the lateral margins of the volar plate and is passed through drill holes in the lateral margins of the middle phalangeal defect ( Figure 8.17 ). The holes are made by drilling a Keith needle from volar to dorsal, and the needles are threaded with the suture and pulled out dorsally. These holes should be as proximal as possible (immediately deep to the remaining dorsal subchondral plate) to draw the plate against the edge of the remaining articular cartilage. They should exit the dorsum of the middle phalanx more centrally through the triangular ligament of the extensor mechanism to avoid binding down the lateral bands. The DIP joint should be flexed 30 degrees as the suture is passed through the extensor mechanism to avoid tethering the tendon. Traction on the sutures emerging from the dorsum of the middle phalanx facilitates reduction of the joint as the plate is advanced into the defect.

A, Volar plate advanced into defect of reduced joint and held with pull-out wires over a button. B, Radiograph showing a reduced joint with volar plate advancement.

Lateral radiographs are obtained before tying the sutures, to confirm that a congruous reduction throughout a full arc of motion has been achieved. Maintenance of the reduction with articular gliding through the flexion arc (as opposed to hinging on the dorsal articular surface) must be documented. This is particularly true in chronic fracture-dislocations with dorsal adhesions. If hinging is present, additional release is necessary, usually of the dorsal capsule, which may have become scarred and inelastic over time. Once a congruous reduction and arc of motion are ensured, the pull-out sutures are tied over felt and a button. Alternatively, a small incision can be made dorsally and sutures tied down just distal to the central slip insertion, taking care to avoid the lateral bands. A secondary suture is placed between each lateral margin of the volar plate and its adjacent remaining collateral ligament remnant. This reestablishes three-dimensional stability and ensures broad coverage of the condyles and phalangeal base. If there is too much laxity in the volar plate with the joint reduced, additional tightening sutures may be placed to further imbricate the sides of the volar plate to the accessory collateral ligaments, although this is rarely necessary. An oblique Kirschner wire is used to maintain the reduced joint in 20 to 30 degrees of flexion. In large defects, bone graft should be applied deep to the advanced volar plate to reduce the chance for recurrent subluxation.

Postoperative management.

DIP joint motion is started immediately. Three weeks after surgery, the Kirschner wire is removed and active, unlimited flexion of the PIP joint is begun using a dorsal extension block splint. Unrestricted active extension is permitted at 4 weeks after surgery, and dynamic extension splinting is begun if full active extension is not regained by 5 weeks after surgery. Unlimited sports activities are allowed at 8 weeks with buddy taping, and buddy taping is continued for 4 to 6 months. Swelling may persist for several months, and it may take up to 6 to 8 months to achieve final range of motion.

Critical Points

Volar Plate Arthroplasty for Dorsal Fracture-Dislocations of the Proximal Interphalangeal Joint

Preoperative Evaluation

• •
  

  Determine whether the remaining dorsal articular surface is anatomic or impacted.

  
  
• •
  

  Appropriate for unstable fracture-dislocations unsuitable for ORIF; indicated for fractures in which 40% or less of the articular surface is involved and in occasional cases with articular depression of more than 40% but less than 1.5 to 2 mm; not advised for volar fracture involvement exceeding 40% to 50%

Technical Points

• •
  

  Use volar approach with chevron incision

  
  
• •
  

  “se volar approach with chevron incisionnatomic or impact

  
  
• •
  

  Excise comminuted fragments and elevate dorsal, impacted articular surface

  
  
• •
  

  Place holes for pull-out sutures as proximal as possible and avoid lateral bands dorsally

  
  
• •
  

  Establish ideal length of volar plate with joint reduced

  
  
• •
  

  Reduce joint, tie sutures with DIP flexed, and document congruency radiographically in flexion and extension

  
  
• •
  

  Pin in 20 to 30 degrees of flexion for 3 weeks only

Pitfalls

• •
  

  Leaving stable but impacted dorsal articular surface unaddressed

  
  
• •
  

  Impaling lateral bands with pull-out sutures

  
  
• •
  

  Failing to spread volar plate broadly across condyles

  
  
• •
  

  Failing to identify hinged versus gliding flexion via dorsal adhesions

  
  
• •
  

  Applying technique to fracture-dislocations with more than 40% volar articular involvement (failure is likely)

Postoperative Care

• •
  

  Immobilize joint with Kirschner wire and splint for 3 weeks.

  
  
• •
  

  Remove pin at 3 weeks and obtain radiographs after pin removal.

  
  
• •
  

  Use extension block flexion for 1 to 3 weeks and then unlimited extension.

  
  
• •
  

  Use a dynamic extension splint at 5 to 6 weeks as needed.

Eaton and Malerich reported on 24 patients who underwent volar plate arthroplasty for both acute and chronic PIP fracture-dislocations, with a 10-year average follow-up. The seven procedures performed within 6 weeks of injury attained an average of 95 degrees of motion and a 6-degree flexion contracture. In contrast, the 17 patients with chronic injuries (>6 weeks after injury) achieved 78 degrees of motion and 12 degrees of contracture. Only 3 patients reported pain, and only with strenuous use. Other reports have also noted good results in most patients. Our own experience has not been as optimistic. The procedure is more appropriate for patients with volar articular involvement of less than 40 to 50%, and it has failed when we have used it for joints with greater involvement.

Complications

Redisplacement.

Failure to achieve a stable reduction, pull-out suture failure, or inadequate protection during mobilization may result in recurrent dorsal subluxation. One cause of pull-out suture failure is damage from the transarticular Kirschner wire fixation. This complication may be obviated by prepositioning of the wire in the middle phalanx after Keith needle passage but before the sutures are pulled through. With close clinical and radiographic follow-up, such problems can be more expeditiously addressed and their effects minimized.

Angulation.

Asymmetric impaction of the base of the middle phalanx or failure to create a trough for the volar plate that is perpendicular to the long axis of the middle phalanx will occasionally result in angulation of the middle phalanx. Although postoperative angular deformity is usually mild and not functionally significant, patient satisfaction may be compromised and secondary corrective osteotomy at the base of the middle phalanx may become necessary.

Flexion contractures.

Immobilization of the PIP joint in more than 30 degrees of flexion and failure to begin dynamic extension splinting by 5 weeks may result in lack of full extension. Recognition of this potential and common problem should help minimize it. Even with early motion and formal hand therapy, a certain percentage of patients will develop a PIP flexion contracture.

Distal interphalangeal joint stiffness.

Failure to flex the DIP joint approximately 30 degrees or impaling the lateral bands while passing the pull-out suture through the extensor mechanism on the dorsum of the middle phalanx may cause limitation of DIP flexion. Modifications in the technique help to decrease the risk of DIP stiffness. These include using two separate sutures for each side of the volar plate, tying the suture knots beneath the skin dorsally, or using small suture anchors in lieu of the pull-out suture. It is imperative to start DIP motion immediately postoperatively to regain the maximal motion possible.

Cerclage Wiring.

A volar chevron incision is made from the MP joint to the DIP joint. The neurovascular bundles are mobilized away from the flexor sheath to avoid traction injury during the shotgun approach ( previously ). A dental pick is used to align and elevate fragments. Bone grafting of impacted subchondral bone is done as needed. Sharp dissection is used to clear the proximal 1 to 2 mm of the middle phalanx from the periosteum to allow the wire to be seated. A loop of 24-gauge wire is formed and twisted on itself, placed around the bone, and gently tightened (see Figure 8.6 ). The joint is gently distracted and reduced. The joint is placed through a range of motion to assess congruency and stability. A “V”-shaped wedge is removed from the volar plate and the lateral edges are repaired ( Figure 8.18 ). This prevents hyperextension but eliminates bulk under the flexor apparatus. This also decreases tension on the repair, allowing for immediate full or nearly full extension in therapy.

A, “V”-shaped segment is removed from volar plate. B, Edges are repaired to minimize bulk while allowing volar stabilization.

(From Weiss AP: Cerclage fixation for fracture dislocation of the PIP joint, Clin Orthop Relat Res (327):21–28, 1996. Redrawn by Elizabeth Martin.)

Postoperative protocol.

Therapy is initiated after 2 to 4 days to allow for edema control. Active and passive motion is allowed with interval gutter splinting. Dynamics are added at 2 weeks if motion is slow to progress.

Authors’ preferred technique for hemihamate reconstruction

A midaxial incision is made centered on the PIP joint and extended obliquely across the proximal and middle phalanges ( Figure 8.19 ). Sharp dissection passes superficial to the neurovascular bundle down to the flexor sheath, elevating the subcutaneous tissue off the sheath and including the neurovascular bundle on the hinge side of the retracted flap (see Figure 8.15 ). Incise the sheath between the A2 and A4 pulleys, and retract the flexor tendons. The accessory collateral insertion into the volar plate should be incised longitudinally from the volar plate. The volar plate is divided transversely at its distal insertion and elevated to its proximal insertion. Release the collateral ligaments from their proximal insertion as much as needed until the joint can be shotgunned open. In chronic cases, a Freer elevator may be required to free dorsal capsular or extensor adhesions. Confirm on fluoroscopy that the dorsal residual intact articular base of the middle phalanx reduces anatomically with the head of the proximal phalanx. After exposing the articular base of the middle phalanx fracture, measurements are taken for the replacement graft with respect to the radioulnar width, anteroposterior height, and proximodistal length. It is best to harvest the hamate graft prior to final preparation of the recipient bed to preserve as much of the middle phalanx as possible and maximize the ability to properly position the graft.

Incision for hemihamate arthroplasty extends obliquely proximally and distally, but continues along midaxial line at proximal interphalangeal joint to maximize exposure.

(Courtesy Hill Hastings, MD.)

Next a longitudinal incision is made over the bases of the fourth and fifth metacarpals, taking care to protect the ulnar sensory nerve branches. Retract the extensors to the fifth finger ulnarly and the fourth finger radially. Incise and elevate the capsule to expose the hamate and metacarpal articulation. Measure and mark the appropriate size for the donor graft, adding a few extra millimeters. The proximal end of the graft should be thicker than the articular portion to allow the graft to re-create the volar lip and appropriate buttress ( Figure 8.20 ). To harvest the hamate graft, mark the required dimensions on the dorsal surface of the hamate. Usually it will extend all the way to the ulnar border of the hamate. Place a Freer elevator in the fourth/fifth CMC joint to lever the joint open slightly. Use a thin sagittal saw blade to make sagittal cuts in the hamate radially and ulnarly, being sure that the depth of each cut is slightly greater than the needed anteroposterior thickness of the recipient defect. Be sure that the cuts extend distally though the articular surface of the hamate into the CMC joint. Make a similar transverse cut proximally at least 2 to 3 mm deeper than the axial cuts. The graft can be harvested in one of two ways. The goal is to create a coronal plane cut from the articular surface into the more proximal hamate in a direction that passes from distal into a more volar direction proximally. This will provide a graft that has a greater dorsal/volar depth or thickness proximally than distally. A curved osteotome is placed within the CMC joint to an appropriate depth that conservatively exceeds the required anteroposterior height of the desired graft. Once it is driven through the chondral and subchondral articular surfaces, a cleavage plane will usually propagate proximally through the bed of the prepared graft dimensions ( Figure 8.21 ). The second, and perhaps safest, method is to make a coronal plane cut with a sagittal saw directed from the ulnar border of the hamate to the radial side. In most cases, in order to obtain a wide enough graft, harvest to the far ulnar side of the hamate will be required. This method provides the best control for ensuring that the plane of osteotomy is from a distal dorsal to a proximal volar direction. The shape of the graft obtained will ensure that the volar buttress of the articular base of the middle phalanx is properly restored ( Figure 8.22 ).

Graft is planned to be shaped such that when in place it tilts to re-create volar lip. PIP, Proximal interphalangeal.

(From Strickland JW, Graham TJ, editors: Master techniques in orthopaedic surgery: the hand, 2nd ed, Philadelphia, Lippincott Williams & Wilkins, 2004.)

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