Abstract
Introduction
Hallux valgus surgical correction has a variable but significant risk of recurrence. Symptoms result from an iatrogenic first brachymetatarsia following the index surgical procedure. First metatarsal shortening has been shown to correlate with the onset of transfer metatarsalgia. We describe the use of the scarf osteotomy to both correct the recurrent deformity and lengthen the shortened first metatarsal.
Methods
36 lengthening scarf osteotomies were undertaken in 31 patients. Clinical (AOFAS and SF12 scores) and radiographic measures (IMA, HVA) were taken pre- and post-operatively. The maximum theoretical lengthening was 10mm, to prevent first MTP joint stiffness post-operatively. The actual lengthening was determined and measured intra-operatively.
Results
There were 28 female and three male patients, with mean age at presentation 53.4 years. The mean follow-up was 3.9 years. Four cases were lost to follow-up. The mean first metatarsal lengthening achieved was 4.9mm (range 1–8mm). All of the osteotomies united without complication. The mean IMA reduction was 4.0° (p<0.001) and HVA 13.0° (p<0.001). The mean AOFAS score increase was 33.8 (p<0.001). There was no correlation between change in IMA and AOFAS score (r=−0.13) or between improvement in HVA and AOFAS score (r=−0.02). There was a positive trend but no correlation (r=0.28) between amount of metatarsal lengthening and change in AOFAS score. The inter- and intra-observer correlation was excellent. The SF12 physical sub-domains improved more than the mental sub-domains.
Conclusion
We describe the largest series of lengthening scarf osteotomies for recurrent hallux valgus and symptomatic iatrogenic first brachymetatarsia. The significant improvement in both clinical and radiographical measures suggests the procedure is successful, with a low complication rate. Lengthening did not reduce the MTPJ range of movement. We hypothesise that restoring both the length and alignment enables greater weight-bearing under the first metatarsal head, reducing biomechanical transfer metatarsalgia.
