Reconstruction of chronic radial collateral ligament injuries of the thumb metacarpophalangeal joint using a modified abductor pollicis brevis tendon transfer was associated with improved stability, satisfactory alignment, and return to daily activities in two patients, with no reported complications or radiographic failure at final follow-up (2 years in one patient and 6 months in the other), despite a 20° reduction in metacarpophalangeal joint flexion compared with the uninjured side.
Radial collateral ligament (RCL) injuries of the thumb metacarpophalangeal (MCP) joint account for approximately 10% to 40% of thumb collateral ligament injuries and are often diagnosed late, resulting in chronic instability when untreated. In these cases, the ligament is frequently unsuitable for direct repair, necessitating reconstructive approaches. The abductor pollicis brevis (APB) tendon, which can be used in situ, may offer an alternative to free tendon grafts such as palmaris longus or flexor carpi radialis while potentially reducing donor-site morbidity, Marta Montanari, of the Department of Hand Surgery and Microsurgery, Policlinico di Modena, and colleagues wrote.
In the case report, the researchers described two male patients aged 58 and 66 years with chronic RCL injury presenting with pain, weakness, and MCP joint instability. Radiographs showed volar subluxation of the proximal phalanx without significant osteoarthritic changes, and clinical examination demonstrated dorsoradial prominence and increased laxity under ulnarly directed stress.
Both patients underwent reconstruction using a modified technique based on a prior method described by Iba et al. The procedure was performed under wide-awake local anesthesia with no tourniquet (WALANT). A dorsal half-slip of the APB tendon was harvested proximally while preserving its distal insertion. A 1.2-mm antegrade Kirschner wire was used to reduce subluxation of the proximal phalanx and restore alignment before tensioning the reconstruction. After confirming that no viable RCL remnant was present, the tendon slip was anchored to the metacarpal neck with a suture anchor, and the capsule was closed over the construct.
Postoperatively, the thumb was immobilized in a splint for 5 weeks, after which the K-wire was removed. Active motion of the interphalangeal joint began immediately, while MCP motion was initiated after immobilization. At 3 months, both patients reported satisfaction with thumb appearance and stability and had resumed work and daily activities.
The authors also reviewed prior APB-based reconstruction techniques, including those described by Camp, Horch, and Iba. In a previously published series by Iba et al. involving eight patients, outcomes were similarly favorable. Compared with that series, the current report demonstrated greater postoperative loss of MCP joint flexion (20° vs approximately 6°), while the reported timeline for return to work or sport (6 months vs 3 months in the Iba series) appears longer despite the authors’ characterization of recovery as quicker.
As a small case report, the findings are limited by the inclusion of only two patients, lack of a comparison group, and short follow-up in one patient, which may limit assessment of long-term degenerative changes or recurrent instability. In addition, no standardized outcome measures were reported.
“Reconstruction of chronic radial collateral ligament tears using a modified APB tendon transfer technique as described by Iba et al. … appears to offer a reliable and effective alternative with reproducible functional outcomes,” Montanari and colleagues wrote. Based on their experience, they added that the technique may avoid donor-site morbidity and simplify the surgical procedure.
The researchers declared no conflicts of interest.
Source: Clinical Case Reports