Screwless scarf osteotomy for hallux valgus: Evaluation of radiologic correction.

BACKGROUND: The scarf osteotomy is a standard procedure to correct hallux valgus. Recent modifications in the technique allow for important translations of the bone fragments without the need for screw fixation. We performed the first prospective analysis of radiographic parameters after a screwless scarf osteotomy. Prospective study of pre- and postoperative standing radiographs of the feet let us quantify angle reduction and shortening, lengthening or lowering of the first metatarsal.

METHODS: 100 patients undergoing a screwless scarf osteotomy were evaluated radiographically before and after surgery. The 1-2 IM angle, HVA, length of the first metatarsal, protrusion length and height of the first metatarsal head were measured.

RESULTS: The mean 1-2 IM angle was reduced significantly, to a normal range. The mean reduction of the first metatarsal length and protrusion length was 0.3 and 0.14cm respectively. The metatarsal head was lowered 0.3cm on average.

CONCLUSIONS: A minimal mean reduction of the first metatarsal length was observed, but it is possible to lengthen the first metatarsal if necessary. In 23% of cases, an increase of protrusion length was obtained. The screwless scarf osteotomy results in a good correction of the 1-2 IM angle and HVA. If necessary, plantarisation of the first metatarsal head could be obtained. Secondary displacement was seen in 1 patient.

LEVEL OF EVIDENCE: IIa, prospective controlled trial.