THE EFFECT OF CHEVRON OSTEOTOMY WITH LATERAL CAPSULAR RELEASE ON THE BLOOD-SUPPLY TO THE FIRST METATARSAL HEAD

The chevron osteotomy is one of the most widely used distal metatarsal osteotomies for the treatment of hallux valgus in adults. Because the osteotomy interrupts the intraosseous blood supply to the metatarsal head, there has always been a concern that the operation could produce osteonecrosis of the metatarsal head, particularly if the important e xtraosseous blood supply was also damaged. We used latex injection and a modified Spalteholz technique in cadaveric specimens to demonstrate the effect of the chevron osteotomy, with and without lateral capsula r release, on the vascular supply to the first metatarsal head. We fou nd an extensive network of extraosseous vasculature to the metatarsal head both proximal and distal to the site of the osteotomy. Both of th ese vascular networks were preserved when the osteotomy was done prope rly. Also, an extensive plantar and plantar lateral network of vessels provided circulation to the head. Potential technical flaws in the pe rformance of the osteotomy included cutting of the first dorsal metata rsal artery by overpenetration of the saw blade and incorrect placemen t of the proximal arms of the osteotomy inside the joint capsule. Thes e technical errors, alone or in conjunction with extensive capsular st ripping, can result in damage to the vessels that supply the metatarsa l head.