Hindfoot Valgus and First Ray Insufficiency: Is There Correlation?

The first metatarsal has the greatest inclination of all metatarsals and carries about 40% of body weight during the static stance. The rearfoot and the first ray (FR) are two distinct structures, but they are strongly related to the latest studies in the literature; however, their mutual involvement in the foot biomechanics appears not to be fully explored. Understanding their interdependence is essential to approaching the patient in his totality. This overview aims to analyze the current evidence from the latest studies that examine the correlation between FR insufficiency (FRI) and hindfoot valgus (HV), focusing on their biomechanical interaction, clinical implications, and treatment approaches. All analyzed studies showed that plantarflexion of the first metatarsophalangeal (MTP1) joint in correct alignment increased by 26% compared to a deviated articulation. In FRI, the “windlass” mechanism appears compromised, and FR lacks the necessary stability and plantarflexion; consequently, the medial arch collapses, and the foot moves into excessive pronation. On the other hand, in HV condition, the pulley system is significantly diminished, and peroneus longus contraction cannot stabilize the FR with resultant FRI and dorsal migration. A significant correlation was found between hindfoot alignment and first metatarsal rotation (86% of patients) and between HV and hallux valgus. Foot orthoses, physical therapy, and exercise programs, especially in the initial stages of symptomatic HV, provide satisfactory results in 67% to 90% of cases, improving foot alignment and pain relief in FRI patients. In more severe cases, surgical intervention to realign the hindfoot is indicated with a very low complication rate (1–4%), which can vary from 24% to 55% in stage 4 flatfoot. No study in the literature has been found to address both pathologies simultaneously from a treatment point of view, and, although not all HV patients are affected by FRI, most patients seem to benefit from surgical stabilization of the FR in 80% of individuals with symptomatic HV. However, despite a predominance of FRI among HV individuals, not all clinical studies have confirmed this correlation.