Trapeziometacarpal osteoarthritis sometimes results in hyperextension of the thumb metacarpophalangeal (MCP) joint, which could negatively impact outcomes following trapeziectomy with ligament reconstruction and tendon interposition (LRTI) arthroplasty. Although algorithms on performing trapeziectomy with LRTI for the management of this deformity are available, they lack clear evidence. Here, we investigate the function of the thumb MCP joint after trapeziectomy with LTRI and whether this procedure alone corrects preoperative MCP hyperextension, and also analyze clinical factors correlated with MCP hyperextension post-surgery.
Twenty-eight patients who underwent trapeziectomy with LRTI and followed up for at ≥ 1 year (mean, 27.2 months) were retrospectively analyzed. No patient had concomitant surgery to the thumb MCP joint at the time of trapeziectomy with LRTI. Patients were divided into the < 30° (n = 19) and > 30° (n = 9) hyperextension groups as per their preoperative passive range of motion (ROM) of the MCP joint. Changes in ROM of the MCP joint post-surgery, clinical factors correlated with postoperative MCP hyperextension, and correlations between clinical outcomes and postoperative MCP extension were analyzed.
In the < 30° MCP hyperextension group, active and passive extensions of the MCP joint did not significantly change after surgery, and no worsening of postoperative MCP hyperextension was observed. In the > 30° hyperextension group, passive extension of the MCP joint significantly decreased (mean, 49.6°-29.8°). Preoperative MCP hyperextension improved in seven patients, was unchanged in 1, and worsened in 1. Postoperative passive MCP extension was negatively correlated with active/passive radial abduction, MCP flexion, trapezial space height, subjective outcomes, and hand strength post-surgery.
Trapeziectomy with LRTI alone could prevent postoperative thumb MCP hyperextension deformity for patients with thumb MCP extension < 30° and improve preoperative thumb MCP hyperextension. However, for patients with loss of radial abduction and MCP flexion due to the contracture, indirect correction of the MCP hyperextension was improbable.