Outcomes after scarf osteotomy with and without Akin osteotomy a retrospective comparative study

Abstract

Background: The scarf osteotomy is a well-established surgical method for correcting a hallux valgus deformity. It is often combined with an Akin osteotomy. However, clear guidelines defining indication criteria are missing. The purpose of this study was to analyze the radiological outcome after scarf osteotomy in dependence of additional Akin osteotomy.

Methods: This study included 184 patients in whom a hallux valgus deformity was corrected with a scarf osteotomy (group S), and 63 patients in whom an additional Akin osteotomy was performed (group SA). Weight-bearing radiographs were evaluated preoperatively, postoperatively, after 6 weeks, after 3 months and at a follow-up with a mean of 45.4 months. Analysis was made for the following radiological parameters: the intermetatarsal angle (IMA), the hallux valgus angle (HVA), the distal metatarsal articular angle (DMAA), the proximal to distal phalangeal articular angle (PDPAA), and the position of the sesamoids as well as the joint congruity.

Results: Radiographic recurrence (HVA > 20°) was detected in 1 patient (1.6% of recurrence) in the SA group, and in 27 patients in the S group (14.7% of recurrence) at follow-up. Outcome between the two groups differed significantly showing reduced loss of HVA correction in the SA group (p < 0.001). The subgroup with a preoperative PDPAA above eight degrees showed significant inferiority of outcome for the S group compared to the SA group.

Conclusion: Radiological outcome after scarf osteotomy is superior with concomitant Akin osteotomy. A preoperative PDPAA above eight degrees makes additional Akin osteotomy recommendable.

Level of evidence: Therapeutic, Level III, retrospective comparative series.

Keywords: Akin osteotomy; Hallux valgus deformity; PDPAA; Preoperative deformity; Proximal to distal phalangeal articular angle; Radiological outcome; Scarf osteotomy.

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1

Dorsoplantar standing radiograph showing the projection of the PDPAA (red lines) and the HIA (yellow line)

Fig. 2

Boxplot showing HVA preoperatively, postoperatively, after 6 weeks, 12 weeks, and at follow-up for the S and the SA cohort. The black line indicates the median of the postoperative HVA of the S cohort. HVA preop, hallux valgus angle preoperative; HVA postop, hallux valgus angle postoperative; HVA 6 weeks, hallux valgus angle after 6 weeks; HVA 3 months, hallux valgus angle after 3 months; HVA FU, hallux valgus angle at follow-up

Fig. 3

Boxplot showing IMA preoperatively, postoperatively, after 6 weeks, 12 weeks, and at follow-up for the S and the SA cohort. The black line indicates the median of the postoperative IMA of the S cohort

Fig. 4

Scatterplot showing correlation of preoperative PDPAA (vertical axis) and loss of correction at follow-up (horizontal axis) for the S and the SA cohort. Black line representing regression line. Cohort S—on top, Cohort SA—below