Entorse grave du pouce: opérer selon la position des sésamoïdes lors des clichés en stress

Radiological evaluation of ulnar thumb metacarpophalangeal ligament reconstruction for chronic thumb instability in cadavers

Various techniques have been described to restore metacarpal stability in the thumb. Ligament reconstruction techniques that position the bone tunnels in a triangular configuration, with the apex proximally, are optimal for stabilizing the metacarpophalangeal (MCP) joint, while preserving the thumb's range of motion. Using an interference screw ensures this reconstruction is as strong as the native ligament. Our purpose was to evaluate a new technique designed to treat cases of chronic thumb instability. We created metacarpal instability in 10 fresh cadaver forearms by sectioning the ulnar collateral ligament (UCL). Ulnar thumb MCP ligament reconstruction (UTMP) was performed in five thumbs and Littler reconstruction in the other five. Radiographic analysis was performed after ligament transection and after ligament reconstruction to compare MCP angles on posterior-anterior (MCPFA) and lateral views (MCPLA), and to evaluate MCP congruence and sesamoid bone parallelism. After UCL transection, thumb instability was present in all cadaver specimens. A significative increase in the MCPFA value was found: Littler (P=0.01) and UTMP (P=0.01). The MCPFA with thumb loading was not significantly changed with the Littler (P=0.83) or UTMP (P=0.46) relative to pre-transection. All parameters were significantly improved, reflecting a return to normal values. There was no significant difference between the two reconstruction techniques. Based on the findings in this cadaver study, UTMP reconstruction appears to correct the radiologic features of lateral thumb instability. It is a simple technique that restores MCP stability without limiting MCP flexion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Floating thumb metacarpal in a motorcyclist: A case report

We present a case of simultaneous dislocation of the carpometacarpal and the metacarpophalangeal joints of the thumb (floating thumb metacarpal) in a 47-year-old motorcyclist. The treatment consisted of closed reduction of both joints with cast immobilization. After 24 months, the functional result was excellent. The mechanism of this rare injury and its therapeutic management are discussed.

Comparison of results after surgical repair of acute and chronic ulnar collateral ligament injury of the thumb

This study sought to demonstrate that successful outcomes can be achieved with the new technique presented here for chronic ulnar collateral ligament (UCL) injury of the thumb metacarpophalangeal (MCP) joint, as well as with K-wire pinning for acute UCL injury. We followed 19 patients who suffered an UCL rupture (mean follow-up: 14.26±4.65 months) and 32 patients who presented with UCL avulsion fracture (mean follow-up: 16.81±7.54 months). We used a free tendon graft for UCL reconstruction in the UCL rupture group. Both ends of the graft were stabilized with bioabsorbable suture anchors, which were used as biotenodesis interference screws. Closed reduction and K-wire fixation was used in UCL avulsion fracture group. There were no statistically significant differences between operated and contralateral healthy thumb MCP joint in both groups in the grip strength, tip pinch strength, flexion, extension, ulnar deviation, and radial deviation movements at final follow-up. Grip strength, tip pinch strength, ulnar deviation and radial deviation were significantly better in the avulsion group than the rupture group. All patients regained full stability at the MCP joint in avulsion group; 16 patients regained full stability and 3 patients presented with mild laxity (less than 10° laxity) in rupture group. Glickel grading scale used as a functional score was excellent for 30 patients and good for 2 patients in avulsion group; it was excellent for 17 patients and good for 2 patients in rupture group. Our study shows that closed reduction and percutaneous K-wire fixation of acute displaced large UCL avulsion fracture is a simple technique and achieves adequate stability of UCL. For UCL rupture, free tendon reconstruction with bioabsorbable suture anchors provides adequate stability and stable fixation within the tunnels.