Arthroscopic Flexor Hallux Brevis and Plantar Capsule Release (Cochrane Procedure) for Hallux Rigidus: Case Presentation with Long-Term Follow-Up

<b>Background</b>: In 1927, Cochrane observed persistent elastic resistance to hallux dorsiflexion after cheilectomy for hallux rigidus, attributing it to soft tissue tightness beneath the first metatarsophalangeal (MTP) joint. An innovative surgery was introduced using a plantar approach, dividing the plantar tissues. This procedure achieved complete pain resolution and high satisfaction in 12 patients. Despite addressing the etiology of hallux rigidus, this approach has not been adopted in current surgeries. This report presents a case treated with the arthroscopic Cochrane procedure with a long-term follow-up. <b>Methods</b>: A 73-year-old male with hallux rigidus presented with limited dorsiflexion, a painful bony prominence, and pain during walking at the first MTP joint, treated with the arthroscopic Cochrane procedure. <b>Results</b>: During surgery, hallux dorsiflexion did not improve after resecting all spurs in the MTP joint, but the dorsiflexion angle immediately improved from 55° to 85°after releasing the flexor hallucis brevis tendon, plantar capsule, and plantar portion of the lateral ligament. Improvements in both visual analog scale scores (70-0) and Japanese Society for Surgery of the Foot scores (57-88) were noted from preoperatively to 9 years and 6 months postoperatively. No postoperative cockup deformity was observed. <b>Conclusions</b>: The arthroscopic Cochrane procedure can yield favorable long-term outcomes without postoperative cockup deformity.