Injury to the collateral ligament of the thumb metacarpophalangeal (MCP) joint is the most common ligament injury in the hand. Complete tear requires surgical treatment. Although acute injury can be treated by primary repair [1], chronic instability and primary treatment failure require reconstruction. Various reconstruction techniques have been described.

Ligament reconstruction can be dynamic or static. Dynamic reconstruction uses tendon transfer or tendon advancement [2], [3], [4], [5], while static reconstruction connects the proximal phalanx and metacarpal head directly and firmly and usually uses a palmaris longus (PL) free tendon graft to replace the injured collateral ligament [6], [7], [8], [9], [10]. Fixation with bone tunnel is most frequently used for static reconstruction. A bone tunnel is created in the metacarpal head and proximal phalanx base, and the free tendon graft is passed through the tunnel and fixed. However, fixation through the bone tunnel is often unreliable. In addition, the technique has been modified several times with respect to graft configuration and fixation [6], [7], [8], [9], [10], [11], [12], [13]. Bone-retinaculum-bone, bone-periosteum-bone and bone-ligament grafts have been reported, but in small case series [14], [15], [16].

The Jobe method, reported in 1986 for reconstruction of the ulnar collateral ligament of the elbow joint, could also be used for reconstructing the collateral ligament of the MCP joint of the thumb [17]. However, this method is technically challenging because the proximal phalanx and metacarpal bones are relatively small, and making several holes in them can be difficult. For this reason, clinical results have not been reported.

The present study introduces a novel figure-of-eight reconstruction, similar to the Jobe method, for irreparable thumb MCP joint collateral ligament injury, and reports clinical outcomes. The study hypothesis was that that Jobe-like figure-of-eight reconstruction is useful to treat irreparable thumb MCP joint collateral ligament injury. The method can reconstruct the ligament with a single skin incision on the injured side, without contralateral incision, and with rigid tendon fixation without anchor or tenodesis screw.