The Distal Metatarsal Articular Angle (DMAA) was previously described as an increase in valgus deformity of the distal articular surface of the first metatarsal (M1) in hallux valgus (HV). Several studies have reported poor reliability of this measurement. Some authors have even called into question its existence and consider it to be the consequence of M1 pronation resulting in projection of the round-shaped lateral edge of M1 head. Our study aimed to compare the DMAA in HV and control populations, before and after computer correction of M1 pronation and plantarflexion with a dedicated weightbearing CT (WBCT) software. We hypothesized that after computerized correction, DMAA will not be increased in HV compared to controls. We performed a retrospective case-control study including 36 HV and 20 control feet. In both groups, DMAA was measured as initially described on conventional radiographs (XR-DMAA) and WBCT by measuring the angle between the distal articular surface and the longitudinal axis of M1. Then, the DMAA was measured after computerized correction of M1 plantarflexion and coronal plane rotation using the α angle (3d-DMAA). The XR-DMAA and the 3d-DMAA showed higher significant mean values in HV group compared to controls (respectively 25.9 ± 7.3 vs 7.6 ± 4.2 degrees, P < .001, and 11.9 ± 4.9 vs 3.3 ± 2.9 degrees, P < .001). Comparing a small subset of precorrected juvenile HV (n=8) and nonjuvenile HV (n=28) demonstrated no significant difference in the measure DMAA values. On the other hand, the α angle was significantly higher in the juvenile HV group (21.6 ± 9.9 and 11.4 ± 3.7 degrees; P = .0046). Although the valgus deformity of M1 distal articular surface in HV is overestimated on conventional radiographs, comparing to controls showed that an 8.6 degrees increase remained after confounding factors’ correction. After pronation computerized correction, an increase in valgus of M1 distal articular surface was still present in HV compared to controls. Level III, retrospective case-control study.
Background: Recurrence of hallux valgus (HV) following corrective surgery is a frequent concern. A recent systematic review estimated recurrence of HV in only 4.9%, which may be an underestimation, as most included studies had short- to mid-term follow-up. The purpose of this systematic review and meta-analysis was to assess long-term outcomes of distal osteotomies of the first metatarsal (M1) to treat HV without inflammatory disease or degenerative arthritis, and to assess HV recurrence rates reported in studies that had a minimum follow-up of 5 years. Methods: This systematic review conforms to the PRISMA guidelines. The authors conducted a search using PubMed, Embase, and Cochrane Central Register of Controlled Trials databases. Studies that report outcomes of distal osteotomies of the M1 for noninflammatory and nondegenerative HV at a minimum follow-up of 5 years. Results: We found 17 eligible studies comprising 18 data sets, reporting outcomes of 4 categories of osteotomies: Chevron, Mitchell, Bösch, and “others.” The HV recurrence rate was 64% considering the threshold of >15 degrees hallux valgus angle (HVA), 10% having >20 degrees, and 5% having >25 degrees. Conclusion: At a minimum of 5 years following distal osteotomies of the M1, the mean weighted postoperative HVA was significantly higher for Mitchell osteotomies compared with the 3 other osteotomies reviewed. There were otherwise no significant differences in recurrence rates using the 3 HVA thresholds, or intermetatarsal angle among any of the surgical techniques reported in 2 or more studies. The pooled HV recurrence rates considering the various thresholds of HVA were as follows: 64% having >15 degrees, 10% having >20 degrees, and 5% having >25 degrees. The recurrence rates in the long term for all categories of surgical procedures suggest that better understanding of pathogenesis and prognosis of HV is required before modifying or introducing new surgical techniques. Level of Evidence: Level IV, meta-analysis.