Background: Postoperative hallux varus is often accompanied by an abnormal decrease in the first-second (M1M2) intermetatarsal angle, which we have sought to correct by a reverse scarf-type osteotomy.
Methods: A series of 36 hallux varus operated on by reverse scarf osteotomy, including 14 with prior osteotomies, was reviewed with an average follow-up of 56 months. The measurements were clinical: American Orthopaedic Foot & Ankle Society (AOFAS) score, visual analog scale (VAS) pain score, subjective satisfaction index, joint mobility, and radiologic angles: M1M2 and first metatarsophalangeal angle.
Results: The M1M2 angle increased on average from 3 to 8 degrees whereas the average M1P1 angle of varus went from -21 to +9 degrees, including 2 patients who had a reoccurring valgus of 20 degrees. The median AOFAS score increased from 47 to 79, the VAS from 6.7 to 2.3, joint mobility lost an average of 9 degrees, and all those operated on were satisfied with the result. All operated bones healed without secondary displacement.
Discussion: The reverse scarf osteotomy is capable of correcting the intermetatarsal angle and at the same time correcting the postoperative hallux varus. Functional scores generally improved, including in patients with a reoccurring valgus and those with reduced mobility.
Conclusion: The reverse scarf osteotomy can be performed to treat postoperative hallux varus with a mild intermetatarsal angle with reasonable clinical and radiologic results.
Level of evidence: Level III, retrospective cohort study.
Keywords: hallux varus; iatrogenic deformity; intermetatarsal angle; reverse scarf osteotomy.