Isolated radial palmar dislocation of the fifth carpometacarpal joint with ulnar neuropathy associated: successful treatment with closed reduction and internal fixation

Carpometacarpal dislocations may be dorsal, volar or divergent type but most are dorsal with involvement of fourth and fifth metacarpal. Isolated volar dislocation of the fifth carpometacarpal joint is an uncommon injury specially when there is no associated fracture. We report a case of radial palmar dislocation of the base of fifth carpometacarpal joint associated to compression of the fourth interdigital nerve in the hand.     

骑缝钉固定治疗钩掌关节损伤

目的：探讨应用骑缝钉固定治疗钩掌关节损伤的疗效。方法： 2009年5月至2012年11月应用骑缝钉固定治疗钩掌关节损伤16例,其中男10例,女6例;年龄21～57岁,平均33.6岁。单纯第4和（或）第5掌骨基底脱位11例;第4和（或）第5掌骨基底脱位伴钩骨背侧撕脱性骨折5例。定期复查X线片了解骨折愈合、关节复位及骑缝钉位置情况,采用手指关节总活动度（TAM）系统评定法评价腕掌关节及掌指关节功能。结果：所有患者切口均I期愈合,未发生感染。所有病例均获随访,时间6～24个月,平均（10.0±2.7）个月,无再发脱位,内固定位置良好,无退钉、断钉。5例伴有钩骨背侧撕脱性骨折的患者获得良好骨性愈合。腕掌关节及掌指关节功能：优10例,良5例,中1例。结论：骑缝钉固定治疗钩掌关节损伤具有操作简单,创伤小,固定可靠,术后早期功能锻炼等优点,是治疗钩掌关节损伤的理想手术方式。     

Hamatometacarpal fracture-dislocation: distinctive three dimensional computed tomographic appearance

We report here two fully documented cases of hamatometacarpal fracture-dislocation following trauma and treated in our hospital. In our cases, the patients suffered hamate fracture in association with metacarpal dislocation. In the first case, a dorsal oblique fracture of the hamate was associated with a dorsal dislocation of the base of the fourth metacarpal. In the second case, a dorsal oblique fracture of the hamate was not associated with a dorsal dislocation of the base of the fifth metacarpal. This diagnosis should be suspected on initial review of plain radiographs, which must include an oblique view because of diagnostic difficulty for this injury. We recommend three dimensional computed tomography (3D-CT) in any patient presenting with pain after blunt trauma to the hand to prevent in diagnosis. Open reduction and internal fixation of the fracture is indicated and relevant for displaced fracture.     

Divergent dislocation of the carpometacarpal joints: a case report

A motorcyclist presented for treatment with divergent dislocation of the bases of the four medial metacarpals, avulsion of the hook of the hamate, dislocation of the trapezium from the scaphoid, and palmar fracture-dislocation of the wrist. This constellation of injuries has never been described. The carpometacarpal joints were reduced at surgery and pinned. The patient is doing well 8 years later despite nonunion of the hook of the hamate.     

« Un cinquième métacarpien flottant ». À propos d’un cas

We present the case of a patient with a fracture-dislocation of the fifth metacarpal and a dislocation of the metacarpophalangeal joint (floating fifth metacarpal) combined with a fracture of the fourth metacarpal. The mechanism of injury and management of this uncommon injury is reported. The “floating fifth metacarpal” and the fourth metacarpal fracture were reduced by closed techniques with percutaneous fixation. Twelve months later, the patient had a full range of wrist and finger movement, he was pain-free and without any residual disability.     

Fourth and fifth carpometacarpal fracture and dislocation of the hand: new classification and treatment

Cain’s classification of fourth and fifth carpometacarpal (CMC) fracture and dislocation does not include the intraarticular metacarpal (MC) base fracture that may influence the treatment outcome. We reviewed 37 cases of fourth and fifth CMC fracture and dislocation treated with operative method, and we have devised a new classification based on the articular surface of the hamate and the involvement of the MC base. These injuries were divided into three types (type I, involved less than one-third of hamate articular surface; type II, involved more than one-third; and type III, coronal splitting of hamate). Each type was divided into four subtypes (a, absence of intraarticular MC base fracture; b, fourth MC base fracture; c, fifth MC base fracture; d, both fourth and fifth MC base fractures). Twenty cases were classified as type I, 16 as type II and 1 as type III. Stable hamate fracture (type I) was treated with closed reduction and percutaneous fixation, whereas unstable fracture (II and III) was treated with open reduction. Thirty-five of 37 patients showed excellent or good outcomes according to the Kumar’s criteria at 1?year postoperatively. The new classification classifies the fourth and fifth CMC fracture and dislocation in detail and appears to be more useful clinically.     

Unstable dorsal fractrue-dislocation of the fifth carpometacarpal jont

Four cases of unstable fracture-dislocation of the fifth carpometacarpal joint are reproted, including 3 isolated dorsal fracture-dislocation and 1 dorsal fracture-dislocation associated with a fracture of the fourth metacarpal bone. All cases required open reduction and Kirschner wire fixation which resulted in good function. Attention is drawn to the frequent delay in diagnosis. The applied anatomy is discussed.     

Isolated palmar dislocation of the fifth carpometacarpal joint diagnosed by stress X-rays

Isolated palmar ulnar dislocation of the fifth carpometacarpal (CMC) joint is a rare injury which often yields only subtle radiographic findings that may be easily overlooked, especially when there is no associated fracture. We reported a case of an isolated palmar dislocation of the fifth CMC joint, diagnosed correctly by means of simple stress X-rays (traction and axial compression stress views). This method proved to be useful and needs no special equipment. Received: 7 January 1999     

"Floating thumb metacarpal" or complete dislocation of the thumb metacarpal: a case report and review of the literature

We present a case of a patient with a simultaneous dislocation of the metacarpophalangeal (MP) and the carpometacarpal (CMC) joint of the thumb as an isolated injury, and we review the relevant literature. We found only three previous reports in the literature, two reports as an isolated injury and another similar injury combined with a carpometacarpal fracture-dislocation of all four fingers. A closed reduction of both joints followed by an open repair of the torn ulnar collateral ligament of the MP joint and Kirschner-wire (K-wire) stabilization of the CMC joint led to a good result at 1 year. This rare injury has been described as a "complete dislocation of the thumb metacarpal" or as a "simultaneous dislocation of the MP and CMC joints of the thumb". We suggest it is a "floating thumb metacarpal".     

The Measurement of the Inclination Angle of the Hamate and Analysis of the Inclination Angle for the Rotation Deformity of the Little Finger in the Fixation of the Carpometacarpal Joint

ObjectiveComplex base fractures of the fifth metacarpal bone and dislocation of the fifth carpometacarpal joint are more prone to internal rotation deformity of the little finger sequence after fixation with a transarticular plate. In the past, we have neglected that there is actually a certain angle of external rotation in the hamate surface of transarticular fixation. This study measured the inclination angle of the hamate surface relative to the fifth metacarpal surface for clinical reference.MethodsIn a prospective single‐center study, we investigated the tilt angle of 60 normal hamates. The study included thin‐layer computed tomography (CT) data from 60 patients from the orthopaedic clinic and inpatient unit from January 2017 to March 2020, including 34 men and 26 women who were 15~59 years old, average 35 years old. The CT data of 60 cases in Dicom format of the hand was input into Mimics and 3‐Matics software for three‐dimensional (3D) reconstruction and measuring the angle α between hamate surface and the fifth metacarpal surface. According to the possible placement of the transarticular plate on the fifth metacarpal surface, we measured the angle β between the hamate surface 1 and the fifth metacarpal surface and the angle γ between the hamate surface 2 and the fifth metacarpal surface.ResultsThe average angle between the hamate surface and the fifth metacarpal surface was 11.66°. The hamate surfaces 1 and 2 have an external rotation angle of 7.30° and 7.51° on average with respect to the fifth metacarpal surface, respectively. There is no statistically significant difference in the angles between the two groups (P > 0.05).ConclusionsThe horizontal angle of the dorsal side of the hamate is different from the back of the fifth metacarpal surface, and the hamate has a certain external rotation angle with respect to the fifth metacarpal surface. No matter how the transarticular plate is placed, the plate always has a certain external rotation angle relative to the fifth metacarpal surface. When the fixation is across the fifth carpometacarpal joint, if the plate does not twist and shape, it will inevitably cause internal rotation of the fifth metacarpal, resulting in internal rotation deformity of the little finger sequence.     

Combined fractures of the body and hook of hamate: A form of ulnar axial injury of the wrist

Fractures of the hamate are rare, and usually associated with athletes. We describe an unusual form of the injury involving fractures of the hook as well as an intra-articular medial facet. It is likely to be a result of high velocity ulnar component of the axial injury. Surgical treatment is advocated to achieve accurate reduction and apposition of the fifth carpometacarpal joint.     

Combined fractures of the body and hook of hamate: a form of ulnar axial injury of the wrist.

Fractures of the hamate are rare, and usually associated with athletes. We describe an unusual form of the injury involving fractures of the hook as well as an intra-articular medial facet. It is likely to be a result of high velocity ulnar component of the axial injury. Surgical treatment is advocated to achieve accurate reduction and apposition of the fifth carpometacarpal joint.     

Dorsal dislocation of the fifth carpometacarpal joint

A case of isolated dorsal dislocation of the fifth carpometacarpal joint treated conservatively is reported. The mechanism is thought to be a force hitting the head of the fifth metacarpal in a dorso-palmar direction, along the longitudinal axis of the metacarpal. Both clinical and radiological results 1 year after injury are satisfactory.     

Complex carpal dissociation with open, complete, and divergent trapezium, capitate, and hamate dislocation: a case report

We report a patient with a unique complex carpal dissociation involving complete and divergent dislocation of the hamate, capitate, and trapezium with total ligamentous disruption of the distal carpal row and midcarpal joint, associated with a transverse shaft fracture of the fifth metacarpal. The mechanism of injury was a sustained torsional force resulting in a simultaneous distraction and bidirectional dorsopalmar (ulnar)-palmodorsal (radial) crushing force at the carpus.     

Displaced dorsal oblique fracture of the hamate treated with a cortical mini lag screw

A dorsal oblique fracture of the hamate was associated with a dorsal dislocation of the base of the fifth metacarpal. Open reduction and internal fixation of the fracture with a cortical mini lag screw achieved an excellent result in union, joint restoration, and function.     

Irreducible palmar metacarpophalangeal joint dislocation due to junctura tendinum interposition: a case report and review of the literature

Three different anatomic structures have been reported to prevent reduction of a palmar dislocation of metacarpophalangeal joint: dorsal capsule, palmar plate, and a ruptured collateral ligament. In our case, extensor digitorum communis of the fifth finger and extensor digiti minimi subluxated on the ulnar side of the fifth metacarpal neck. Extensor digitorum communis of the fourth finger remained in its anatomic location. The junctura tendinum connecting the fourth and fifth extensor digitorum communis tendons slipped distal and then palmar to the metacarpal head, where it was trapped between the metacarpal neck and the base of the proximal phalanx. It was easily pulled out and the joint promptly reduced. Residual subluxation persisted due to rupture of the radial collateral ligament and the dorsal capsule. Repair restored joint reduction and stability. (J Hand Surg 2000; 25A:166-172.     

Luxation carpo-métacarpienne palmaire du cinquième doigt : à propos d’un cas

Pure carpo-metacarpal dislocations without any fracture are rare, their volar component is exceptional. Untreated injuries can result in instability and early articular degeneration. We report a 72-year-old female patient who underwent an isolated closed volar dislocation of her fifth finger carpo-metacarpal joint after a fall. The clinical examination showed a 10°-defect in rotation with limited adduction (radial deviation). The X-rays showed a gap between the base of the fourth and the fifth metacarpal bones with volar dislocation of the base of the fifth carpometacarpal joint. The dislocation was successfully treated by closed reduction maintained with two K-wires. Immobilisation of the joint was applied for 6 weeks. At 2 years follow-up evaluation, the patient was pain free with no clinico-radiological evidence of instability and had returned to her previous level of activity.     

The fourth carpometacarpal joint

The base of the fourth metacarpal and the corresponding hamate/capitate articulation were the areas of most significant variation in 142 cadaveric wrists that were dissected to assess the variation of the shapes of the second through the fifth carpometacarpal joints. Five different shapes of the fourth metacarpal base were identified. The base of the fourth metacarpal was generally either flat (85.9%) or conical (14.1%). There was a fourth metacarpal/capitate articulation present in 81.7% of the specimens. The presence or absence of a fourth metacarpal/capitate articulation and whether or not the fourth metacarpal base was flat or conical were easily identifiable on radiographs. Specific types of fourth metacarpal bases could not, however, be identified by radiography.     

Percutaneous Pinning of Fifth Carpal–Metacarpal Fracture–Dislocations: An Alternative Pin Trajectory

Traditional management of unstable fourth and fifth carpal-metacarpal (CMC) fracture-dislocations (fx-dislocs) of the hand includes closed reduction and percutaneous pinning (CRPP) versus open reduction internal fixation (ORIF). Traditional trajectory of pin placement is toward the base of the hook of the hamate. Our case series of CMC fx-dislocs treated with this trajectory led to the development of ulnar deep motor branch symptoms (sxs). We attempt to propose an alternative trajectory that could lower the chance of iatrogenic injury. Five fresh frozen cadaveric specimens underwent percutaneous pinning of the fifth CMC joint using fluoroscopic guidance. Each cadaver was dissected, and the proximity of the deep motor branch of the ulnar nerve was measured in relation to a pin that penetrated the volar cortex. Our results confirm the close proximity of the deep motor branch of the ulnar nerve to the volar cortex of the hamate and demonstrate the potential for iatrogenic injury during CRPP of the fifth CMC fx-dislocs, especially with penetration of the volar cortex. By demonstrating the close proximity of the deep motor branch to the volar cortex of the hamate in cadavers, we highlight the potential for iatrogenic injury with CRPP of CMC fx-dislocs as seen in our case series. We recommend a more midaxial starting point on the proximal metacarpal with a trajectory aimed at the midbody of the hamate to prevent penetration of the hamate volar cortex and limit the chances of iatrogenic injury.     

Carpometacarpal dislocation of the fifth finger: descriptive study of 31 cases

OBJECTIVES: Carpometacarpal dislocation of the little finger is a rare and little known injury. We performed a 10 years retrospective study of all the cases in our unit in order to improve comprehension and treatment of this disease. METHODS: Thirty-one patients were included in this study. All the dislocations were dorsal with 5 isolated fifth carpometacarpal dislocations, 6 fracture-dislocations of the base of the fifth metacarpal, 19 fourth and fifth dislocations and one third-fourth-fifth dislocation. Diagnosis of the injury was made early in only 19 patients. 30 had surgical management, 28 with percutaneous K-wires, and 2 through a metacarpalhamate arthrodesis. RESULTS: Twenty-six patients were available for follow-up at an average of 6 months and 5 patients were lost for follow-up. Twenty-five patients had satisfactory results. A reflex sympathetic dystrophy delayed the recovery for one patient. There was no recurrence of dislocation at follow-up. There was no complication necessitating revision surgery. CONCLUSION: Diagnosis of carpometacarpal dislocation of the little finger can be performed with conventional radiographic examination; computer-tomography is helpful to confirm an associated fracture of the carpus. The goal of treatment is early reduction and fixation of the metacarpal. There is no recommendation for operative technique based on scientific evaluation. Early diagnosis is the key to success.