Influence of metatarsal head displacement on metatarsal pressure distribution after hallux valgus surgery.

We reviewed 63 feet after plain subcapital osteotomy for simultaneous correction of hallux valgus and metatarsus primus varus. Results were evaluated clinically and by radiographs and force plate measurements. Eighty-three percent of the patients were satisfied with their surgery. The hallux valgus angle was improved by 9.3 degrees and the intermetatarsal angle by 6 degrees. The osteotomy resulted in a displacement of the metatarsal head in the lateral direction (10 mm) and in the plantar direction (11.3 mm). Normalization of the load distribution on the metatarsal head was achieved in the group with 11 to 15 mm of plantar displacement. Based on our results, we recommend plain subcapital osteotomy for hallux valgus deformities with moderate metatarsus primus varus. After correction of the intermetatarsal angle and sufficient plantar displacement a physiological distribution of load on the metatarsal head can be expected.