Does screwless scarf osteotomy for hallux valgus increase the risk of transfer metatarsalgia?

Introduction: The scarf osteotomy is a reliable surgical technique for treating hallux valgus. The aim of our study was to analyze the occurrence of transfer metatarsalgia after surgery on the first ray using a screwless Scarf osteotomy technique that we have been using in our department since 1995, which consists of stabilization by axial impaction without internal fixation. We hypothesized that the alleged shortening of the first metatarsal produced by this technique may be at the origin of postoperative metatarsalgia.

Patients And Methods: This was a case series of first ray metatarsal screwless Scarf osteotomies reviewed in the medium term. We did a clinical and radiological review of all patients operated using this technique between 2012 and 2017 who did not meet the following exclusion criteria: procedure on the other lateral metatarsals, concurrent hindfoot pathology, incomplete medical records.

Results: Of 114 feet, 96 were included in the study and 18 were excluded. The mean follow-up was 1 year and 8 months [1-4years]. The mean AOFAS score was 90.3 and 96% of patients were either satisfied or very satisfied with the outcome. All the parameters improved significantly: shoe wearing, pain, function, alignment. Fourteen feet had transfer metatarsalgia, which appeared during the first year postoperative (AOFAS 75/100). Ten other complications occurred: two Morton's neuromas, three cases of complex regional pain syndrome, one superficial infection, one paresthesia, two recurrences with surgical revision, one nonunion. No general complications were found. Based on radiographs, the mean M1 shortening was 3.3mm (6.3mm in metatarsalgia group versus 3.0 mm in the non-metatarsalgia group, P=0.2) and the mean angular correction was 16.2° (±6°).

Discussion: The overall results of screwless Scarf osteotomy are comparable and satisfactory, allowing large deformities to be corrected (28°±8° preoperatively in our cohort). M1 shortening and the transfer metatarsalgia rate appear to be higher than with other techniques.

Conclusion: Screwless scarf osteotomy of M1 yields good functional and radiological outcomes in the medium term. However, it appears to cause more shortening and transfer metatarsalgia.

Level Of Evidence: IV Retrospective, non-interventional in current practice (Recommendation grade C, low level of scientific proof).