Mobility of the First Ray in Patients With or Without Hallux Valgus Deformity: Systematic Review and Meta-Analysis

The hypermobility theory of the first ray is the reason for the popularization of procedures such as the modified Lapidus procedure involving arthrodesis of the first tarsal–metatarsal joint for correction of hallux valgus deformity. Although many studies have involved motion of the first ray in hallux valgus patients, the presence and clinical significance of hypermobility in the first ray remains controversial. We performed a systematic review and meta-analysis to evaluate the difference in the first ray range of motion between patients with or without hallux valgus deformity. The databases used for the present review included Ovid EMBASE, Ovid MEDLINE, CINAHL, and the Cochrane Database. We searched for comparative studies that had evaluated the motion of the first ray in patients with or without hallux valgus. After screening for inclusion and exclusion criteria, we identified 3 studies that were relevant to our study question. All 3 studies showed more first ray motion in the hallux valgus group. Our quantitative synthesis showed a mean difference in the range of motion of the first ray of 3.62 mm (95% confidence interval 2.26 to 4.98) between those with and without hallux valgus deformity. Thus, we found statistically significantly increased first ray motion in patients with hallux valgus deformity compared with those without hallux valgus deformity. However, the clinical significance of this small amount of increased sagittal plane motion as a response to or a cause of hallux valgus remains unanswered.