Interpositional Arthroplasty with Iliotibial Band Autograft Fixation to the Proximal Phalanx: Clinical Outcomes in Advanced Hallux Rigidus

Background and Objectives: Hallux rigidus is a degenerative condition of the first metatarsophalangeal joint that causes pain and limitation of motion. The aim of this study was to evaluate the clinical outcomes of a modified interpositional arthroplasty technique using an iliotibial band autograft fixed to the proximal phalanx in patients with advanced hallux rigidus. Materials and Methods: This prospective observational case series included 19 patients with Coughlin–Shurnas Grade III or IV hallux rigidus who underwent surgery between February 2023 and February 2025. Clinical outcomes were assessed using Visual Analog Scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS), and range-of-motion (ROM) measurements preoperatively and at postoperative 1, 6, and 12 months. Results: The mean VAS score decreased from 9.0 ± 0.82 preoperatively to 1.58 ± 0.51 at 12 months (p < 0.001). The mean AOFAS score increased from 35.1 ± 2.7 to 74.8 ± 10.9 (p = 0.001). ROM improved significantly at 1 and 6 months; however, the 12-month ROM was not significantly different from the preoperative value (36.3° ± 5.6° vs. 31.0° ± 5.5°, p = 0.082). Conclusions: Interpositional arthroplasty using an iliotibial band autograft fixed to the proximal phalanx was associated with short-term reductions in pain and improvements in functional scores. However, the early increase in range of motion was not maintained to the same extent at 12 months.