Pulley-Augmented EIP to EPL Transfer: A Novel Solution to Prevent Ulnar Subluxation at MCPJ

In zone 3 injuries, the Extensor indicis Pollicis to Extensor Pollicis Longus tendon transfer comes with the problem of ulnar subluxation at the metacarpophalangeal joint (MCPJ), which results in ineffective extension of the thumb, which, in the long term, results in boutonniere deformity. Objectives: To observe the effects of stabilizing this transferred tendon at the MCPJ by adding a tendinous pulley and achieving significant improvement in extension of the thumb. Methods: A Total of 12 patients were in this study with delayed presentation (i.e., 6 to 12 weeks after trauma) of zone 3 EPL injuries, over a period of 2 years. Among these patients, 8 were males, and 4 were females. Surgery was performed under local anesthesia in 10 patients and general anesthesia in 2 patients. The EIP tendon was transferred to the transected EPL with a tendinous pulley reconstructed at the MCPJ. Postoperatively, a splint was applied for 4 weeks. Physiotherapy started on the first post-op day. Mean follow-up time was 5 months. Results: As per the Geldmacher score, an excellent score was achieved in 7 (58.3%) patients, a good score in 3 (25%), and a satisfactory score in 1 (8.3%) patient, a poor score in 1 (8.3%) patient. No extension lag was observed in the index finger in any case. Conclusions: This traditional transfer done in zone 3 gives excellent results when done with the addition of a pulley at MCPJ, improving the vector of excursion of the transferred tendon by stabilization at MCPJ and inhibiting its ulnar subluxation.