Isolated ulnopalmar dislocation of 5th carpometacarpal joint: a rare case report

<p class="abstract">Isolated volar dislocations of the fifth carpometacarpal joints are an uncommon injury. They are classified as ulnopalmar or radiopalmar dislocations. It can be easily missed on standard radiographs. A high degree of suspicion and accurate reduction is pivotal in restoring the functional outcome of the hand. In our case report, a forty year old man presented with ulnopalmar dislocation of the fifth carpometacarpal joint and was treated with open reduction and K wiring. We review the literature and discuss the available methods of management.</p>

An Uncommon Presentation of Fracture-dislocation of the 4th and 5th Carpometacarpal Joints with Volar Displacement and its Management

Introduction: Carpo-metacarpal joint fracture-dislocations are rare injuries. They constitute less than 1% of all hand injuries [1]. They often go unnoticed [2]. Of these, dorsal fracture-dislocations on the ulnar side are more commonly seen [3] because of the greater stabilizing dorsal structures. Volar fracture-dislocations are very rare and difficult to diagnose for which, one should have a keen eye on. Case Report: This is a case of a 51-year-old female with a closed injury to her wrist. With clinical suspicion and appropriate radiographs fracture-dislocation of the 4th and 5th carpometacarpal joints with volar displacement was diagnosed. She underwent closed reduction and percutaneous Kirschner wire fixation, followed by 6 weeks of immobilization. At the final follow-up in 4 months, the patient was noted to have a satisfactory outcome following intense physiotherapy. Conclusion: Fourth and fifth carpometacarpal joint fracture-dislocations of the fingers are unique; their diagnosis can be challenging and often overlooked [4], which if missed can have very poor outcomes. The functional prognosis depends on the precocity of diagnosis and appropriate reduction and vigorous rehabilitation. Keywords: Carpometacarpal joint, fracture-dislocation, volar displacement, wrist injury.

A Preliminary Model of the Wrist Midcarpal Joint

Background A challenge to deciphering the effect of structure on function in the wrist involves difficulty in obtaining in-vivo information. To provide a platform to study wrist mechanics using in vivo acquired forces, we developed a model of the midcarpal joint based on computed tomography (CT) scans of normal wrists. Finite element analysis (FEA) can enable application of in vivo collected information to an ex vivo model. Objectives The objectives of this study are to (1) create a three-dimensional model of the midcarpal joint of the wrist based on CT scans and (2) generate separate models for the midcarpal joint based on two distinct wrist types and perform a pilot loading of the model. Methods CT scans from a normal patient database were converted to three-dimensional standard template library (STL) files using OsiriX software. Five type 1 and five type 2 wrists were used for modeling. A simulated load was applied to the carpometacarpal joints in a distal-to-proximal direction, and FEA was used to predict force transfer in the wrist. Results There were 33% type 1 and 67% type 2 wrists. The midcarpal joint dimensional measurements estimated from the model had intermediate agreement between wrist type as measured on CT scan and as predicted by the model: 56% Cohen's kappa (95% confidence interval) = 0.221 (0.05–0.5). Surface stress on the carpometacarpal joints is different in type 1 and type 2 wrists. On loading the neutral wrist, the capitolunate angle was 90 degrees in type 1 wrists and 107 degrees in type 2 wrists (p < 0.0001). Conclusions The model predicted differences in movement and force transfer through the midcarpal joint dependent on structural type. This knowledge can improve our understanding of the development of disparate patterns of degeneration in the wrist.

Open Reduction for Dorsal Dislocation of Second to Fifth Carpometacarpal Joints: A Case Report

Background Fracture-dislocations of all four ulnar (second to fifth) carpometacarpal (CMC) joints are rare hand injuries and frequently overlooked or missed. These injuries can be treated conservatively when closed reduction is successfully achieved, though they are sometimes irreducible and unstable. Case Description We report the case of a 17-year-old boy involved in a vehicular accident. Clinical images showed dorsal dislocation of all four ulnar CMC joints of the left hand associated with a fracture of the base of the fourth metacarpal. Although closed reduction was attempted immediately, the affected joints remained unstable and easily redislocated. Therefore, we performed open reduction and percutaneous fixation of all ulnar CMCs. He showed excellent recovery after 1 year postoperatively, reported no pain, and demonstrated complete grip strength and range of motion of the affected wrist and fingers. Literature Review Accurate clinical diagnosis of this lesion is difficult because of polytrauma, severe swelling masking the dislocated CMC joint deformity, and overlapping of adjacent metacarpals and carpal bones on radiographic examination. As for the treatment strategy, it has yet to obtain a consensus. Some reports value open reduction to guarantee anatomical reduction, and it is definitely needed in the patients with interposed tissues to be removed or with subacute and chronic injuries. Clinical Relevance Delayed diagnosis or treatment could lead to poor outcomes. Therefore, surgeons must be aware that precise preoperative assessment is critical, and anatomical open reduction of interposed bony fragments, like our case, may be required even in an acute phase.

Carpometacarpal Dislocation of the Third to Fifth Fingers and an Associated Fracture of the Hamate in a Military Paratrooper

Multiple carpometacarpal dislocations with a simultaneous fracture of the hamate represent less than 1% of all injuries to the hand and wrist regions, with a scarcity of published cases. These injuries usually require a great force, and diagnosis can be missed or delayed because of the high likelihood of other severe concomitant injuries. We report a case of acute closed dislocation of the third through fifth carpometacarpal joints and an associated fracture of the hamate in a military paratrooper. The injury was caused by a wrong landing technique during parachuting. The patient was managed with primary surgical repair, and after a six-month follow-up, he has excellent functional results. The fact that both this clinical entity and the mechanism of injury are very unusual a high index of suspicion is needed, especially for orthopedic surgeons working in military hospitals. Additionally, given that there is a paucity of published cases and optional treatment is controversial, this study corroborates the superiority of surgical repair in a long-term basis.