Fracture dislocations of the carpometacarpal (CMC) joint secondary to trauma are rare injuries, with an incidence of <1% of hand and wrist injuries ^[1]. CMC joints are saddle joints, with the ulnar-sided CMC joints being more mobile than the radial-sided CMC joints ^[2]. The dorsal and volar CMC ligaments support the CMC joints and have CMC, intercarpal, and intermetacarpal components ^[3]. Although the dorsal ligaments have greater strength as compared to the volar ligaments, it is intriguing to note that dorsal dislocations are more common ^[4]. Cases that present early are amenable to closed reduction and can be managed accordingly along with internal fixation. Such injuries are generally associated with favorable outcomes. On the other hand, cases that present late are associated with a comparatively poorer prognosis. If managed appropriately, patients with such injuries can be still achieve a satisfactory grip strength so as to return independently to their activities of daily living and their job. The present report is a systematic effort to highlight the appropriate surgical technique of such neglected cases of multiple CMC dislocations.

Case 1

A 42-year-old, right-hand dominant male, presented six weeks after injury with a dorsal CMC dislocation involving all digits. Since the injury was not amenable to closed reduction, an open reduction was planned. Under regional anesthesia, a dorsal S-shaped longitudinal incision was taken. As the tendons were contracted and were preventing the relocation, a tenolysis of all the extensor tendons was done with a Z-plasty of the extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris. Manual sustained traction was given to achieve reduction, which was confirmed under fluoroscopy, and the second, third, and fourth metacarpals were transfixed on the trapezoid, capitate, and hamate respectively, using retrograde K-wires (Fig. 1). The fifth metacarpal was pinned similarly on the hamate using retrograde K-wires. The patient had an associated trapezium dislocation that was accessed through the initial incision. However, due to an unsuccessful reduction of the trapezium, a trapeziectomy was done followed by transfixing the first metacarpal base to the scaphoid (Fig. 2). The patient’s quick disabilities of the arm, shoulder, and hand (DASH) score improved from 75 at four weeks postoperatively to 20.5 at one year. His visual analog scale (VAS) score improved from 7 at four weeks postoperatively to 2 at one year and his handgrip strength improved from 12 kg at four weeks postoperatively to 36 kg at one year. The patient developed wound dehiscence post-surgery that was managed with split-thickness skin grafting. He had some residual ulnar deviation at the latest follow-up of one year but was able to perform his activities of daily living.

Case 2

A 53-year-old right-hand dominant male presented five weeks after injury with a dorsal CMC dislocation involving second to fifth digits and a third metacarpal base fracture. He was managed with open reduction and internal fixation with transfixing retrograde Kirschner wires using the dorsal approach (Fig. 3). The metacarpal fracture was managed conservatively. Postoperatively, he had decreased sensations on the radial aspect of the index finger which was most likely due to a digital nerve injury. His Quick DASH score improved from 70.5 at four weeks post-surgery to 18.2 at one year, his VAS score improved from 8 at four weeks post-surgery to 3 at one year, and his hand-grip strength improved from 14 kg at four weeks post-surgery to 34 kg at one year.

Case 3

A 32-year-old right-hand dominant male presented five weeks post-trauma with a dorsal CMC dislocation involving the second to the fifth digits. He was managed with open reduction and internal fixation with transfixing retrograde K-wires and a transverse wire passed across the distal radioulnar joint as it was unstable clinically (Fig. 4). Postoperatively, he had no complications. His Quick DASH score improved from 72.7 at four weeks post-surgery to 15.9 at one year, his VAS score improved from 7 at four weeks post-surgery to 2 at one year, and his hand-grip strength improved from 14 kg at four weeks post-surgery to 38 kg at one year.

Case 4

A 36-year-old right-hand dominant male presented four weeks post-trauma with a dorsal CMC dislocation involving the third and fourth digits. He also had an associated second metacarpal head and shaft fracture. He was managed with open reduction and internal fixation with retrograde transfixing Kirschner wires through the dorsal approach. He had an uneventful post-operative course. His Quick DASH score improved from 54.3 at four weeks post-surgery to 9.1 at one year, his VAS score improved from 7 at four weeks post-surgery to 2 at one year, and his hand-grip strength improved from 22 kg at four weeks post-surgery to 46 kg at one year. Table 1.

Post-operative protocol

Post-operatively, the patients were immobilized in a below-elbow plaster of Paris slab for one week until the pain and edema subsided. The slab was removed and a splint was given in the functional position for the next three weeks. Active movements of the fingers were initiated two weeks post-surgery. The patients were followed up each week to detect any evidence of infection at the sites of pin insertion. The splint was discontinued and K-wires were removed at four weeks following which active and passive range of motion exercises of the hand and wrist were begun under the supervision of a dedicated hand physiotherapist. Following this, a rigorous physiotherapy protocol consisting of resistive active stretching exercises was started and continued until satisfactory hand grip strength was achieved. No patient exhibited any clinical or radiological signs of arthritis of the CMC joint at the end of the final follow-up.

CMC dislocations have been classified in the literature using multiple classification systems. A common method of classification is to classify the dislocations into dorsal, volar, and divergent based on the direction of dislocation. Another simple method is to distinguish fractures based on the involvement of the articular surfaces and also based on whether they demonstrate communication with the external surroundings or not ^[5]. Volar dislocations involving the CMC joint of the fifth digit are further classified into volar-radial and volar-ulnar based on the direction, in which the metacarpal base is displaced ^[6]. Another method of classifying the same is on the basis of the pattern, in which the hamate is involved ^[7]. The above system was further modified for the inclusion of the radial two lesser digits and it included three subtypes, namely, trans-metacarpal, CMC, and trans-carpal ^[8]. Furthermore, it was demonstrated that CMC and transcarpal subtypes were unstable injuries that needed open reduction along with the addition of repair of the ligaments and internal fixation ^[9]. The direction of force decides the type of fracture-dislocation with dorsal dislocation being the commonest type. A divergent type is a rare variant that involves ≥1 joint sustaining a dislocation in the volar direction with ≥1 joint simultaneously dislocating in the dorsal direction ^[10]. CMC joint injuries are usually associated with other fractures and are often missed on radiographs due to the overlapping nature of the bones ^[11]. Moreover, these injuries are frequently missed at presentation as the patients sustaining these have more serious injuries and the hand trauma is often neglected. To avoid this in the acute setting, a dorsopalmar, true lateral, and oblique view of the hand is essential. The posteroanterior view shows obliteration of the normally seen 1–2-mm CMC joint space, while the lateral view shows the direction of displacement ^[12]. These injuries can be treated using closed maneuvers and immobilization or internal fixation, with an open reduction being preferred for injuries that are difficult to reduce by closed methods. Due to the proximal location of the third metacarpocapitate articulation, it forms the keystone of the CMC joint articulations, due to which its stabilization is essential for the reduction of the other CMC joints ^[13]. Although the consensus while surgically managing fractures is to wait till the settling of edema, this is not recommended in the case of multiple CMC joint injuries as the persistent displacement of the bones does not allow the resolution of swelling ^[14]. Open reduction is performed in cases with gross damage to the articular congruity and cases presenting as late as three weeks post-trauma. Another advantage of open reduction is that it avoids the complication of transfixing the tendons as seen with pinning performed after achieving reduction using closed maneuvers. Table 2 compares the findings of the present report with the existing literature. A distinguishing point of the present case series is that it highlights an extremely rare pattern of injury that involved all digits. We advocate the use of a single dorsal longitudinal incision followed by release of the contracted structures if present and fixation with retrograde transfixing K-wires for managing neglected multiple CMC dislocations not amenable to closed reduction.

Fracture-dislocations of the CMC joint that are diagnosed early can be managed with closed reduction, while the cases presenting late usually require open reduction. We recommend a dorsal S-shaped longitudinal incision along with tenolysis and Z-plasty of extensor tendons whenever they cause a hindrance to reduction, followed by gradual distraction and reduction with adequate stabilization using K-wires for neglected cases. A supervised rehabilitation protocol after the period of immobilization should be followed until satisfactory grip strength is achieved.

Adequate imaging using radiographs and computed tomography scans are essential to avoid missing CMC dislocations at presentation. Multiple CMC dislocations presenting late require open reduction and internal fixation followed by supervised physiotherapy to regain satisfactory grip strength and range of motion.