La luxation palmaire de l’articulation métacarpophalangienne des doigts longs A propos d’un cas

Palmar dislocation of the metacarpophalangeal (MCP) joint of the long finger represents a rare event. The first case was published by Mc Laughlin in 1965, and only nine other cases have been reported. We present one more case and discuss the mechanisms of these dislocations and treatment. Case report: A 22-year-old biker presented with complex injuries of his right hand after a road accident. Examination revealed an extensive palmar wound on the ulnar side of his right hand, with another on the MCP joint of the little finger, and shortening of the little and the ring fingers. Any attempt at active movement was impossible. Roentgenograms showed a palmar dislocation of the MCP joint of the ring finger and a very displaced fracture of the fifth metacarpal head. During surgery we observed on the ring finger a tear of the distal membranous attachment of the volar plate on the base of proximal phalanx, entrapped in the MCP joint, with an ulnar dislocation of the flexor tendons. On the little finger we observed a complex fracture of the fifth metacarpal head and a lesion of the ulnar collateral nerve. After opening the A2 pulley we repaired the volar plate by fixing it with 2 sutures through the base of the proximal phalanx and the metacarpal head fracture by a difficult open reduction and fixation with an axial pin. At the end of the operation, the fingers were immobilized on a palmar block splint for one month. Passive range-of-motion exercises were started after one month and active excercises after two months. Now, one year after initial injury, the patient has recovered complete function of the MCP joints of the two fingers. Discussion: Many different mechanisms can be discussed to explain this rare lesion. According to our case report we think that this dislocation was assumed to occur by hyperextension and translational force applied to the dorsum of the proximal phalanx. Like Wood [8] and Kaplan [3] we stress the importance of this translational force : a purely forced movement on the MCP joint generally causes a dorsal dislocation. Entrapment of the volar plate in the MCP joint is the most common mechanism for irreductibility of the dislocation (Renshaw [7],Betz [1]), but in some other cases the irreductibility of the dislocation was linked to the entrapment of the dorsal capsule of the MCP joint. A surgical approach is required in all cases where easy closed reduction is impossible. The operative approach depends on the mechanism of dislocation, but a palmar approach is preferred when no mechanism is defined. Indeed this route allows us to control the volar plate and possibly its repair or stabilisation. A sound and solid repair of these lesions seems very important to stabilize the MCP in the long term joint. Earlier range-of-motion exercises are recommended for complete rehabilitation of the MCP joint.     

Isolated dislocation of the second metacarpal at both ends

A dislocation of the second metacarpal at both ends is reported herein for the first time. Six weeks after injuring her right hand in a fall while climbing stairs, a 34-year-old woman visited our clinic with pain, swelling, and deformity of her hand. The radiographs showed a volar dislocation of the head and a dorsal dislocation of the base of the second metacarpal. The probable mechanism of injury was the hyperextension at the metacarpophalangeal joint; this force dislocated the metacarpal head toward the volar plate. Force then further continued along the second metacarpal shaft in the hyperflexed wrist, thus dislocating the base dorsally. We performed an open reduction and K-wire fixation of the second metacarpophalangeal joint and an arthrodesis of the second carpometacarpal joint. At the six-month follow-up, the patient had restricted flexion (0 to 50 degrees) at the second metacarpophalangeal joint, but full range of motion at the interphalangeal joints. The grip strength on the right side was 70% of that measured in the uninvolved hand. Key Words: Dislocation, Second metacarpal.     

Isolated complex dislocation of the metacarpophalangeal joint of the third finger

Two unusual cases of isolated closed complex dislocation of the metacarpophalangeal joint of the third finger are presented. The single most important element preventing reduction was interposition of the volar plate between the proximal end of the phalanx and the head of the metacarpal, but the deep transverse ligament was also intimately involved in the entrapment mechanism. Such dislocations require open reduction as in the two cases presented, and we found the dorsal approach to be simple and effective.     

A Case of Coronal Intra-articular and Epiphyseal Fractures of the Metacarpal Head in Early Adolescence

Intra-articular metacarpal head fracture is relatively rare. We report a case of coronal intra-articular and epiphyseal fractures of Salter–Harris type IV injury in the metacarpal head of the index finger. Surgery was performed by a dorsal approach. The volar fragment that was displaced proximally was gently reduced while bending the metacarpophalangeal (MP) joint, and it was fixed with cortical screws inserted proximal to the articular cartilage facilitating early rehabilitation. We consider the mechanism of injury to be a force applied from the distal phalanx that was transmitted unevenly to the volar side when the MP joint was slightly flexed. A three-dimensional computed tomography scan was useful in making the precise diagnosis, confirming the fracture pattern and planning fixation of the fracture.     

Ligamentous structures of the metacarpophalangeal joint: A quantitative anatomic study

The ligamentous structure of the metacarpophalangeal (MCP) joint of the index finger in human cadavers was studied by gross examination and quantitative measurement. Anatomically, the collateral ligament is separable into two layers, with the precise origin arising from the metacarpal head and inserting on the proximal phalanx. Quantitatively, the change in length of the collateral ligament was studied with biplanar radiographic techniques. The distance between the origin and insertion of the collateral ligament changed in different portions of the ligament when the joint was moved from a position of hyperextension to that of flexion. When the MCP joint was flexed from 0° to 80°, the dorsal portions of both the radial and ulnar collateral ligaments were lengthened (3–4 mm). The middle portions of both ligaments were slightly elongated (0.4–1.0 mm), and the volar portions of the ligaments were shortened (1–2 mm). When the MCP joint extended into hyperextension, the dorsal portions of the ligaments shortened 2–3 mm, the middle thirds of the ligaments shortened slightly, and the volar thirds of the ligaments lengthened. The results of this study suggest that the dorsal and volar portions of the collateral ligament provide MCP joint constraint at the flexed and extended positions, respectively.     

Ligamentous structures of the metacarpophalangeal joint: a quantitative anatomic study

The ligamentous structure of the metacarpophalangeal (MCP) joint of the index finger in human cadavers was studied by gross examination and quantitative measurement. Anatomically, the collateral ligament is separable into two layers, with the precise origin arising from the metacarpal head and inserting on the proximal phalanx. Quantitatively, the change in length of the collateral ligament was studied with biplanar radiographic techniques. The distance between the origin and insertion of the collateral ligament changed in different portions of the ligament when the joint was moved from a position of hyperextension to that of flexion. When the MCP joint was flexed from 0 degree to 80 degrees, the dorsal portions of both the radial and ulnar collateral ligaments were lengthened (3-4 mm). The middle portions of both ligaments were slightly elongated (0.4-1.0 mm), and the volar portions of the ligaments were shortened (1-2 mm). When the MCP joint extended into hyperextension, the dorsal portions of the ligaments shortened 2-3 mm, the middle thirds of the ligaments shortened slightly, and the volar thirds of the ligaments lengthened. The results of this study suggest that the dorsal and volar portions of the collateral ligament provide MCP joint constraint at the flexed and extended positions, respectively.     

Irreducible volar dislocation of the proximal interphalangeal finger joint

Volar dislocation of the proximal interphalangeal finger joint is rare. The trauma that causes this injury consists in a rotation mechanism in almost all cases. It may be initially missed and diagnosed at a late sequel stage. Closed reduction should always be attempted first but this procedure may result in failure, necessitating a surgical intervention. In irreducible cases, the surgical investigation shows a longitudinal split which separates one of the lateral bands (ulnar or radial) from the central slip of the terminal extensor tendon. In addition, the lateral band is displaced to the volar aspect of the head of the first phalanx, and partially entrapped into the proximal interphalangeal joint, the head of the first phalanx being trapped between the central slip and the displaced lateral band. Surgical relocation of the displaced lateral band gives an immediate reduction of the dislocated joint. We present a case of irreducible dislocation of the proximal interphalangeal joint of the right index finger in a 42-year-old female patient who required a surgical treatment. We present the diagnostic, anatomic and therapeutic aspects of this rare injury, together with a review of the literature.     

闭合穿针治疗掌指关节周围部位骨折

目的 探讨闭合穿针治疗掌指关节周围部位骨折的临床疗效.方法 2005年以来,对17例掌骨颈或近节指骨基底部骨折患者,采用C型臂X线机透视下闭合复位克氏针内固定治疗.单部位骨折11例,其中掌骨头或颈部骨折7例,近节指骨基底部骨折4例;多部位骨折6例,其中2处以上掌骨颈骨折3例,2～5指近节指骨基底部均骨折1例,2～4指近节指骨基底部均骨折1例,第五掌骨颈骨折伴环指近节指骨基底部骨折1例.均为闭合性骨折.急诊手术4例,伤后5 d内手术12例,伤后11 d手术1例.术后2-3周拆除石膏,4周拔克氏针.结果 术后X线片显示骨折均达到良好复位.随访6～9个月,骨折愈合良好.手功能按TAM系统评定法评定:优13例,良4例.结论 闭合穿针治疗掌指关节部位骨折创伤小、方法简单、疗效佳,是治疗掌指关节部位骨折理想的方法.     

Effects of reconstructed radial collateral ligament on index finger mechanics

Twenty fresh frozen hand specimens from cadavers were studied. Physiologic levels of extrinsic muscle loads were applied to the extrinsic flexor tendons of the index finger to simulate tip pinch of the finger on a fixed plate. The acute effects of transection of the radial collateral ligament and accessory radial collateral ligament (radial collateral ligament complex) with and without transection of the dorsal capsule and volar plate on the position of the proximal phalanx with respect to the metacarpal bone of the index finger were investigated. The acute effects of reconstruction of the radial collateral ligament, for each of two different surgical techniques, on the position of the proximal phalanx also were investigated. The spatial positions of the metacarpal bone and proximal phalanx were measured with a six-degree-of-freedom digitizing system for flexion angles from 0 degrees to 90 degrees in increments of 15 degrees. Transection of the radial collateral ligament complex resulted in significant increases in ulnar deviation (adduction) of the proximal phalanx and in volar translation. Additional transection of the dorsal capsule and volar plate caused significant increases in ulnar deviation, pronation, volar translation, and ulnar shift. The first surgical technique, one traditionally used to reconstruct the metacarpophalangeal joint of the thumb, failed to return the three-dimensional position of the proximal phalanx on the metacarpal head of the index finger to normal. The second surgical technique, based on anatomy, returned the position of the proximal phalanx to levels not statistically different from normal for most flexion angles.     

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.     

Treatment of hyperextension deformity of the thumb metacarpophalangeal joint in basal joint arthritis: a novel technique based on an anatomic study

Advanced stages of basal joint arthritis are sometimes characterized by an adduction deformity of the first metacarpal and a hyperextension deformity of the unstable metacarpophalangeal (MCP) joint. Stabilizing the MCP joint in these patients is critical to ensure a pain-free repair and efficient pinch mechanism. This study presents the anatomic basis for a novel capsulodesis technique using the volar plate that can be incorporated into any reconstructive basal joint procedure when clinically indicated. Eleven normal cadavers were dissected to expose the volar plate. The dimensions of the volar plate, relationship of the sesamoid bones to the oblique pulley, and the distance from the sesamoids to the base of the proximal phalanx were compared between specimens. The radial border of the volar plate measured 8.5 ± 1.3 mm, ulnar border 8.8 ± 1.0 mm, proximal border 7.5 ± 1.0 mm, and distal border 7.8 ± 0.6 mm. The distance between the ulnar sesamoid bone and the oblique pulley measured 12.1 ± 1.1 mm and from the radial sesamoid to the oblique pulley measured 16.6 ± 0.2 mm. The distance between the sesamoids and the base of the phalanx measured 2.2 ± 0.2 mm. The anatomic studies provide a foundation on which the surgeon can understand the complex nature of the MCP joint. This study describes a novel technique for MCP capsulodesis of the thumb in which volar plate flaps are imbricated to provide stability to the MCP joint, obviating the need for suture anchors and tendon grafts.     

A simplified technique for treating the complex dislocation of the index metacarpophalangeal joint.

The volar approach to open reduction of the complex dislocation of the index metacarpophalangeal joint as described by Kaplan proved to have certain disadvantages. Digital nerves are easily damaged during exposure and there is a limited view of the entrapped fibrocartilaginous volar plate dorsal to the metarcarpal head. A direct dorsal longitudinal incision through the skin and extensor tendon gives full exposure. The volar plate attached to the proximal phalanx and trapped over the dorsal aspect of the metacarpal head is in full view. The volar plate is split longitudinally and the dislocation reduces spontaneously as the flexor tendons and lumbrical muscle slip by the metacarpal head. The advantages of this approach as compared with the volar approach are: (1) there is full exposure of the fibrocartilaginous volar plate, the main structure blocking reduction; (2) digital nerves are not as apt to be damaged; and (3) accurate reduction and fixation of the osteochondral fracture of the metacarpal head, frequently seen with this dislocation, is possible.     

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.     

Open irreducible fracture/dislocation of the four ulnar metacarpals at the metacarpophalangeal joints: case report

Open irreducible fracture/dislocation of multiple metacarpophalangeal joints is an exceedingly rare injury and, to our knowledge, not yet described in the literature. An earlier belief that metacarpophalangeal dislocations were high-energy injuries is questioned by this case report due to an unusual case of open irreducible fracture/dislocation of the four ulnar metacarpals that occurred in a hand trauma. A 24-year-old man presented in the emergency department with an open irreducible fracture/dislocation of the four ulnar metacarpals and impaired flexion of the metacarpophalangeal joint of his left hand. The injury was described as an open injury of his third metacarpal head with an associated fracture of the fourth metacarpal head and dorsal dislocation of the four ulnar metacarpals after a fall onto the outstretched hand. Early recognition and anatomical reduction are essential to achieve good long-term outcomes. Massive edema, interposed volar ligaments, and overlapping metacarpal bases are the usual obstacles to a successful closed reduction. Use of a palmar approach was the key to reduce the displacement. Joint stability and osteosynthesis with K-wires were achieved, and the patient has been asymptomatic for more than 24 months.     

Three-dimensional geometric analysis of the metacarpophalangeal joint

No prosthesis yet designed for replacement of the metacarpophalangeal (MCP) joint incorporates all considerations of anatomy and geometry of the natural joint to restore the normal kinematics. Loss of stability, recurrent deformity, and early loosening are persistent problems. In this study, a detailed three-dimensional geometric analysis of the MCP joint was performed. The sagittal contours of both metacarpal heads and base of the proximal phalanx under loaded and unloaded conditions were analyzed. The geometric parameters of the MCP joint articulating surfaces were analyzed, including the center and radius of curvature and the location and size of the contact area. The pressures on articulating surfaces during various hand functions were also established. These findings provided important information for better understanding the kinematics of finger joint articulation, as well as the cause of joint degeneration.     

Complete dorsal dislocation of the metacarpophalangeal joint of the thumb

In the pathology of simple complete dislocation involving the metacarpophalangeal joint of the thumb, whether or not the palmar plate is interposed within the joint is controversial. Nine cases of complete dorsal dislocation of the joint were reviewed, and cadaver dissection was performed to study the pathology of this injury. Eight of the nine patients were seen within 4 days of injury and treated successfully by closed manipulation. One patient treated 7 days after the injury required open reduction. We were able to reproduce the pathological anatomy of the dislocation, wedging of the palmar plate in the joint of the cadaver. In this cadaver and in all clinical cases, radiographs showed a complete dislocation with an increased distance between the palmar edge of the base of the proximal phalanx and the metacarpal head, indicating an interposition of the palmar plate. Our study suggests that in simple complete dislocations of this joint, the palmar plate is interposed between the displaced bones. Received: 16 December 1997     

Rare double fracture-dislocation of the thumb： a case report and review of the literature

Simultaneous fracture/dislocation of the thumb carpometacarpal (CMC)joint and dislocation of the metacarpophalangeal (MCP)joint is considered as a rare injury pattern.We report an unusual case of dorsa...     

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.     

Irreducible palmar dislocation of the proximal interphalangeal joint caused by a fracture fragment: a case report

We present a case of irreducible palmar dislocation of the proximal interphalangeal joint of the little finger caused by entrapment of a fracture fragment attached to the collateral ligament. The bony fragment was trapped between the radial condyle of the proximal phalanx and the volar plate. Reduction was easily accomplished by hooking out the fragment.