The effect of Scarf osteotomy on the distal metatarsal articular angle in hallux valgus: a case series.

BACKGROUND

Hallux valgus is a deformity of the forefoot involving a phalangeal valgus and a metatarsal adductus. In most cases its correction requires surgical treatment with different types of osteotomies. The best known is Scarf osteotomy.

AIM

To study the effet of Scarf osteotomy on distal metatarsal articular angle (DMAA) as well as the validitiy of this angle and the value of its correction after review of the literature.

METHODS

It was a retrospective study including patients operated on for severe hallux valgus by a Scarf osteotomy. The clinical assessment was based on the the American-Orthopedic-Foot-and-Ankle-society (AOFAS) score. Radiologically, we calculated the metatarsophalangeal angle, the inter-metatarsal angle and the DMAA. This assessment was performed preoperatively and one year postoperatively.

RESULTS

We collected 37 cases of evolved hallux valgus. The average AOFAS score went from 60.7 to 85.8 / 100 postoperatively with a gain of 25 points. We've noted a significant correction of the 3 angular measurements at one year postoperatively (the metatarsophalangeal angle, the inter-metatarsal angle and the DMAA) which went from 38.8° to 20.5°, from 17° at 10° and 13.5° to 8.5° respectively (p<0.05).

CONCLUSION

The literature has shown that there is no consensus regarding the effect of HV surgery on the DMAA. As for the accuracy, reproducibility and interest of correcting this angle we deduce that the DMAA is an interesting measure in the pathology of HV. Its correction seems not to be necessary in order not to hamper the correction of metatarsus varus. But in cases where the preoperative DMAA is high (> 15 °), efforts should be made to correct it to avoid recurrence.