Radiographic changes in the first metatarsal head after distal chevron osteotomy combined with lateral release through a plantar approach.

The purpose of this study was to evaluate the development of clinically significant avascular necrosis of the head of the first metatarsal after: (1) distal metatarsal osteotomy of the chevron configuration beginning apically at the center of the metatarsal head and extending into the head metatarsal neck junction and (2) release of the adductor hallucis muscle, the lateral capsulosesamoid ligament, and the lateral head of the flexor hallucis brevis via fibular sesamoidectomy in the majority of procedures (71/77). Although there were initial radiographic findings suspicious of avascular necrosis, subchondral lucencies (28 feet), mottling (40 feet), and focal lucencies (29 feet) in 76% of the feet, at final follow-up (12-43 months, average 25 months) this figure had fallen to 25%. The range of motion of the first metatarsophalangeal joint and articular symptoms were important in this study because of the assumption that these two parameters of evaluation would correspond to the severity of radiographic evidence of avascular necrosis. Only those patients (8 feet) with persistent mottling at final follow-up had a statistically significant decrease in the average range of motion (P = .013), with 51 degrees total arc of motion compared with 64 degrees total arc of motion for the remainder. There were no patients with persistent radiographic changes suggesting avascular necrosis who complained of pain.(ABSTRACT TRUNCATED AT 250 WORDS)