Primary Isolated Arthrodesis of the First Metatarsophalangeal Joint for Hallux Rigidus: Clinical, Radiologic, and Pedobarographic Evaluation.

Background: Arthrodesis of the first metatarsophalangeal joint is an effective treatment of advanced hallux rigidus. Numerous options have been described for performing this intervention. The aim of this study was to evaluate the outcomes following a consistent surgical technique of joint preparation with hand tools and fixation with 2 crossed screws and a dorsal compression plate.

Methods: Thirteen patients (16 feet) who underwent primary isolated arthrodesis of the first metatarsophalangeal joint between March 2019 and June 2021 were available for clinical, radiologic, and pedobarographic evaluation at a minimum of 12 months after surgery. American Orthopaedic Foot & Ankle Society scores, numerical pain rating scale, the radiologic hallux valgus and intermetatarsal 1-2 angles as well as the distribution of plantar pressure during gait were compared between the pre- and postoperative conditions.

Results: After an average follow-up period of 26 months, union was achieved in all cases and the mean AOFAS score raised significantly by 39 points. All the patients were satisfied with the result. Only 1 patient complained of mild residual pain at walk. Hardware removal was performed in 2 cases. The mean hallux valgus angle dropped from 12.3 to 6.3 degrees. The mean postoperative dorsiflexion angle was 21.6 degrees. After the procedure, peak pressure was significantly higher beneath the first metatarsal head and heel, whereas pressure-time integral was significantly lower beneath the hallux and medial lesser toes.

Conclusion: Arthrodesis of the first metatarsophalangeal joint with 2 crossed screws and a dorsal compression plate is a safe and effective treatment of advanced hallux rigidus. This procedure provides adequate pain relief and functional improvement of gait.

Level of evidence: Level IV, therapeutic, retrospective case series.