Flexor Hallucis Longus Tendon Transfer for Hallux Claw Toe Deformity and Vertical Instability of the Metatarsophalangeal Joint

Abstract

Background: Historically, operative treatment of hallux claw toe deformity has been the Jones procedure or one of its modifications. Review of the literature confirms its ability to maintain alignment and achieve patient satisfaction; however, several complications have been reported. Many of these are related to altered biomechanics across the metatarsophalangeal (MTP) joint. A similar approach to this clinical problem involves restoration of the flexion moment across the MTP joint without an interphalangeal (IP) joint arthrodesis. Methods: We conducted a retrospective review of 10 patients who had a flexor hallucis longus (FHL) tendon transfer to the proximal phalanx of the great toe for hallux claw toe deformity, as well as for symptomatic vertical instability. Four patients had a positive drawer test indicating vertical instability without static deformity. Two patients with vertical instability were found to have a dynamic deformity. Mean followup was 24 (SD 15.2) months. Results: All deformities were corrected and alignment was maintained at the time of followup. Pain under the first metatarsal head was reliably improved in symptomatic patients ( p < 0.05). Patient satisfaction also was assessed. All six patients treated for hallux claw deformity were satisfied with their outcomes. Two of the four patients treated for vertical instability were satisfied. The other two patients expressed dissatisfaction because of persistent pain that occurred during strenuous exercise. Their symptoms during routine activity were improved, however. Conclusion: Based on initial results, the FHL transfer to the proximal phalanx appears to be a viable treatment option for hallux claw deformity in terms of deformity correction, pain relief, and patient satisfaction. Further evaluation is warranted regarding the indication of vertical instability.