Inverted Z-scarf osteotomy for hallux valgus deformity correction: intermediate-term results in 55 patients.

The Z-scarf osteotomy is used for hallux valgus deformity correction by foot and ankle surgeons worldwide. Inverting the Z-scarf osteotomy configuration strengthens the construct in both sawbone and cadaver models, but clinical results of this configuration have not been reported in the literature. This retrospective study evaluates the subjective and intermediate-term postoperative radiographic results of 73 inverted Z-scarf osteotomy procedures for hallux valgus correction in 55 patients from January 1994 to December 2003. The modified University of Maryland 100-Point Painful Foot Center Scoring System demonstrated 52 patients (95%) with good to excellent results at a mean follow-up of 5 years (range 2-11 years). Radiograph measurements revealed the following: first-second intermetatarsal angle mean, 6.1° (range 2-14°), average reduction 4.6°; hallux abductus angle mean, 11.0° (range -8-30°), average reduction 10.1°; tibial sesamoid position mean, 2.3; first metatarsal protrusion distance mean, -2.1 mm. Two patients (2 of 73 feet) developed major complications: one progressed to clinically acceptable hallux varus; another sustained compromise of one fixation screw with minor displacement at the distal osteotomy that healed in satisfactory position after non-weight-bearing immobilization. There were no cases of osteonecrosis, delayed union, or nonunion. The inverted Z-scarf osteotomy, with advantages in both mechanical strength and technique of execution over the traditional configuration, demonstrates high patient satisfaction, restoration of normal radiographic parameters, and a low complication rate in this study.