The excessive length of first ray as a risk factor for hallux valgus recurrence

It is still unknown whether the excessive length of the first ray is a risk factor for hallux valgus recurrence. The purpose of this study is to clarify the relationship between the excessive length of the first ray and the recurrence of hallux valgus.

Between 2008 and 2011, a total of 186 feet (left 105, right 81) who underwent chevron osteotomy combined with distal soft tissue procedure in our foot and ankle center were retrospectively reviewed. A postoperative hallux valgus angle(HVA) ≥20° was defined as recurrence. Patients were divided into two groups: recurrence and non-recurrence group. Weight-bearing radiographs were evaluated preoperatively and at the time of last follow-up for both groups. Radiographic parameters including the length of the great toe(P1), the length of the second toe(P2), the length distance between the first and second metatarsal(D), the hallux valgus angle(HVA) were obtained. The excessive length of the first ray(EL) was calculated using the equation of EL = P1-P2-D.

A total of 45 patients (24.2%) had hallux valgus recurrence at the time of last follow-up with a mean follow-up of 83.7 ±12.1 months (range, 66-110). The mean postoperative P1 was 5.06±0.39cm for recurrence group and 4.84±0.34cm for no recurrence group(p<0.001). The mean post operative EL was 5.71±5.01mm for recurrence group and 1.61±4.09mm for no recurrence group(p<0.001). The predictive cutoff value of postoperative P1 and postoperative EL for hallux valgus recurrence was 4.9cm [odds ratio (OR) = 8.67, p = 0.03] and 0.4cm (OR = 6.79, p = 0.001) respectively.

Significant relationships between postoperative P1, postoperative EL and hallux valgus recurrence were identified according to our radiographic results. A postoperative P1>4.9cm and postoperative EL>0.4cm can be risk factors for hallux valgus recurrence. The appreciation of the excessive length of the first ray prior to surgery may help to improve the surgical outcome.