Treatment of hallux valgus with biplane Mitchell osteotomy: technique presentatiton

Abstract

Objective: To present the changing of Mitchell’s osteotomy in moderate intensity hallux valgus treatment, allied to Herbert’s screw fixation. Methods: Twelve patients were submitted to surgert, 7 females, aged between 51 to 80 years old, with average age of 62.8, and with complaints of disabling pain in in the medial prominence of the first metatarsal, as well as clinical deformity and difficulty in wearing shoes. All patients had already been treated with analgesic measures such as physiotherapy, cryotherapy, orthotics and footwear with wide camera before, with no success. Exclusion criteria were patients previously operated, and mild and severe hallux valgus. The follow-up ranged from 17 to 27 months, with mean of 22.5 months average. Results: We observed an average decrease of 6.3o in the intermetatarsal angle, of 16.4 o in the hallux valgus angle and 4.5o in the distal metatarsal articular angle. The relative length I-II metatarsal decreased on average 2.6 mm, and the deviation sesamoideo decreased on average 1o.. There was no loss of reduction in radiographic evaluation, pseudarthrosis or necrosis of the head of the first metatarsal in any patient, and the previously complaints were resolved in all cases. We have achieved improvement according to American Orthopaedic Foot and Ankle Society criteria for halux from 57.7 to 91.5. Conclusion: The modification of Mitchell technique, by means of double osteotomy similar to Chevron osteotomy instead of two parallels osteotomies as usual, allied to fixation with Herbert cannulated screw type, allows greater stability of the focus relative to suture steel. The modification of the technique, with the screw and the two planes suggests less risk of pseudoarthrosis, and prevent loss of lateral displacement of the metatarsal head. It is believed that this is a safe and suitable for the treatment of moderate hallux valgus.