Simultaneous quadruple dislocations of the hand in a motorcyclist: A case report

Abstract

Herein we present a case of four simultaneous dislocations of the hand resulting from a motorcycle accident in a young man. In this case, the 1st CMC, MCP, and IP joints of the right hand were dislocated along with right perilunate dislocation. Perilunate dislocation was treated with open reduction and internal fixation. Close reduction of IP and CMC was done and CMC was fixed by pins. MCP dislocation was treated by open reduction and pinning in addition to collateral ligament and capsular repair. In follow-up excellent functional activity and range of motion were observed.

Introduction

Finger joint dislocations are among the most common dislocations in the human body. There are reports of simultaneous dislocations in finger joints [[1], [2], [3]]. Yet, dislocation of the carpal joints and finger joints together is extremely rare. As the matter of fact, there is only one case report of concomittant interphalangeal joint of the thumb and lunate dislocation dating back to 1987 [4]. To our knowledge, this is the first report of quadruple dislocation of the hand including dislocations in the thumb interphalangeal (IP), 1st metacarpophalangeal (MCP), and carpometacarpal (CMC) joint, and perilunate dislocation.

Case presentation

A 23-year-old male was brought to the trauma bay after a motorcycle rollover accident. The patient had pain in the right hand and wrist and on physical examination, the right thumb was deformed. Neurovascular examination on the right upper extremity was unremarkable. He had no history of hyperlaxity of joints. The radiologic evaluation concluded dislocations in the interphalangeal (IP), metacarpophalangeal (MCP), and carpometacarpal (CMC) joint of the right thumb. Moreover, the lunate bone was dislocated palmary, and ulnar styloid was fractured (Fig. 1). The patient had no sign of median nerve injury. Through incision on dorsal aspect of the wrist, open reduction and internal fixation of perilunate dislocation were done by lunotriquetral and scapholunate pinning. The dorsal scapulolunate ligament was repaired. Then closed reduction of IP and CMC joints was done and CMC joint was fixed by a pin under the guide of C-arm. Closed reduction of the 1st MCP joint was tried but it was unsuccessful due to interposed volar plate and flexor pollicis longus in MCP joint blocking the reduction. Then through lateral midaxial approach, 1st MCP joint was exposed. Open reduction MCP joint was done and the reduction was secured with a pin. Finally, repair of the radial collateral ligament was performed. Fig. 2 shows the post-op x-rays.

Fig. 1.

Posteroanterior (a) and lateral (b) X-ray of right hand: simultaneous dislocations at IP, MCP, CMC of right thumb. Volar dislocation of lunate is seen.

Fig. 2.

Posteroanterior (a) and lateral (b) X-ray of right hand post operatively: reduction is performed and previously dislocated joints are now reduced congruently.

The patient was visited at the clinic and MCP, CMC, and carpal pins were removed at 3rd, 6th, and 8th week of follow-up, respectively. For each joint, physiotherapy was initiated after the removal of pins to gain functional range of motion and muscle power. The patient was followed up after 1 year (Fig. 3). He complained of no pain or motion abnormality in his right upper extremity. Full functional activity and range of motion were achieved.

Fig. 3.

Posteroanterior (a) and lateral (b) X-ray of right hand in 1 year follow-up.

Discussion

Hand and wrist dislocations remain common, yet divisive matters in orthopedic trauma. In the literature, there are numbered reports of simultaneous dislocations in a finger [3,5,6]. Concomitant dislocations of CMC and MCP are also rare in the literature [1,2,[7], [8], [9]]. These multiple dislocations in thumb have been labeled “floating thumb metacarpal” by Drosos et al. [2]. However this term shouldn't be confused with floating thumb which refers to thumb hypoplasia. There is also a report of simultaneous dislocation of IP joint and lunate in the literature [4], however, a simultaneous quadruple dislocation of hand seems quite peculiar.

A mechanism for simultaneous dislocations of 1st CMC and MCP has been proposed [1,9]; motorcyclists usually grip the handlebar with four fingers enclosing the upper surface of the handlebar and the thumb wrapped around its underside and the thumb's distal phalanx placed under the four fingers. In case of an accident, due to deceleration of the motorcycle, an axial force is imposed on the web between thumb and index finger where the base of metacarpal bone lies. This force can dislocate the 1st metacarpal bone to the dorsoradial side [1]. Accordingly, our case suffered a dislocation of the 1st CMC joint (Fig. 1). Furthermore, hyperextension of thumb while the distal phalanx was trapped under the handlebar may have been the cause for the dislocations of MCP and IP joints. Accordingly, these joints in our case were dislocated dorsally, which corroborates the hyperextension theory. Regarding the lunate dislocation, the possible mechanisms are either forceful dorsiflexion of the wrist or fall on an outstretched hand [10]. Given that a dorsiflexion of hand simultaneous with hyperextension of thumb is unlikely, it's most probable that multiple mechanisms of injury were at work here. Considering the motorcycle rolled over, it is likely that the motorcyclist outstretched his hand when the motorcycle fell to the side to protect from impact and this resulted in the lunate dislocation. Fracture of the tip of the ulnar styloid which also usually occurs due to avulsions during a fall on an outstretched hand [11] further supports the presence of this additional mechanism.

In phalangeal dislocations, closed reduction must be performed in almost all cases as soon as possible. However, there is no consensus regarding the approach for the open reduction of irreducible dislocations. Closed reduction of the dorsal dislocation 1st MCP joint might fail due to the interposition of various anatomic structures such as the volar plate, sesamoid bones, or in our case flexor policies longus tendon [2,12,13]. Both dorsal and volar approach can be used for open reduction of the MCP joint. Dorsal approach has decreased risk of injury to the neurovascular bundle. Volar approach has better exposure to the volar plate. Recently midaxial incision used for the border digits and thumb is proposed which can allow collateral ligament repair and volar and dorsal exposure of MCP joint [14]. It is surgeon's preference to choose between these approaches [15].

In the 1st carpometacarpal joint, the volar oblique ligament plays a vital role in the stability of the joint. Different concepts have been developed in the management of this rare dislocation. Similar to any other dislocation, closed reduction should be attempted. If the reduced joint was stable, non-operative treatment and thumb spica splint can be applied. However, there is no gold standard for management of an unstable or incongruent joint after close reduction. Various techniques such as percutaneous pinning, direct repair of the stabilizing ligaments, or ligamentous reconstruction have been advocated [16,17]. Classically, Eaton and Littler technique has been used in reconstruction of the ligaments using a strip of flexor carpi radialis tendon [18]. Recently similar techniques have been developed using the abductor pollucis longus [19]. Yet, due to the rarity of this dislocation, there is no comparative study on this subject.

Simonian and Trumble suggested superior long-term results in patients undergoing ligamentous reconstruction compared to percutaneous pinning [20]. However, percutaneous pinning remains a minimally invasive technique in stabilizing the joint [17,21]. In our case, we preferred closed pinning and minimally invasive intervention, since we had to perform the open reduction in both perilunate and MCP joint dislocations, making 1st CMC joint ligamentous reconstruction technically difficult.

Finally, regarding perilunate dislocation, the closed reduction should be performed as soon as possible to prevent further damage to the median nerve and cartilage. However, closed reduction in stage IV perilunate dislocations like in our our case is almost impossible making the open approach inevitable [24]. Both dorsal and volar approaches have been used in the open reduction of perilunate dislocations. The dorsal approach has the advantage of better exposure to the carpal bones. On the other hand, the volar approach provides exposure for volar ligaments repair and median nerve decompression. The goal is to achieve anatomic reduction and stabilize the joints with either a temporary k-wire or screw. However, there is controversy regarding repair of the volar or dorsal ligaments. Various techniques such as repair of the lunotriquetral interosseus ligament or scapholunate interosseous ligament have been advocated in numerous studies. Yet, it is not clear how repairing or not repairing these ligaments would affect carpal stability in the long term [22,23].

Controversy remains in the management of hand and carpal joint dislocations. Simultaneous dislocations are rare and management of these dislocations must be individualized and performed by the surgeon's preference. Further comparative studies are required to reach a consensus.

Ethics in publishing

This work has been carried out in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving humans. Written informed consent was obtained from the study subject to publish case details including the injury, treatment and radiographs.

Funding

The authors received no funding for this work.

Declaration of competing interest

The authors have no conflicts of interest to disclose.