Arthrodesis of the First Metatarsophalangeal Joint for Idiopathic Hallux Valgus: Intermediate Results

BACKGROUND: Followup studies documenting the outcome of primary metatarsophalangeal (MTP) joint arthrodesis for treatment of hallux valgus deformities are rare. The purpose of this report was to evaluate the results of first MTP joint arthrodesis as treatment for moderate and severe hallux valgus deformities over a 22-year period in a single surgeon's practice. METHODS: All living patients treated between 1979 and 2001, for moderate and severe idiopathic hallux valgus deformities with first MTP joint arthrodesis were contacted and asked to return for a followup examination. Outcomes were assessed by comparing preoperative and postoperative pain, function, and radiographic appearance. First ray mobility and ligamentous laxity also were assessed postoperatively. RESULTS: Eighteen of 21 of the first MTP joints had successfully fused with the primary procedure at an average followup of 8.2 years (range 24 to 271 months). The time to union averaged 10 (range 7 to 15) weeks. Two of the three nonunions, both in the same patient, were asymptomatic and were not revised. One required a revision to achieve fusion. The average corrections in the hallux valgus angle and 1-2 intermetatarsal (IM) angle were 21 degrees and 6 degrees, respectively, and the average postoperative dorsiflexion angle was 22 degrees. Subjective satisfaction was rated as excellent in seventeen of 21 cases (80%) and good in the remaining four (20%). There was significant reduction in postoperative pain (p < 0.001), complete resolution of lateral metatarsalgia, and the postoperative American Orthopaedic Foot and Ankle Society (AOFAS) scores averaged 84 (range 72 to 90) at final followup. Major activity restrictions after surgery were uncommon, and all patients were able to wear conventional or comfort shoes. Interphalangeal (IP) joint arthritis progressed in seven of 21 feet (33%), but all of these changes were mild. CONCLUSIONS: In the present study, arthrodesis of the first MTP joint for idiopathic hallux valgus resulted in a high percentage of successful results at an average followup of over 8 years.