Hallux Valgus Definition
Hallux valgus, commonly known as a bunion, is a forefoot deformity characterized by lateral (outward) deviation of the great toe and medial (inward) deviation of the first metatarsal bone, often accompanied by a prominent medial bump at the first metatarsophalangeal joint. 1, 2
Anatomical Description
The deformity involves valgus deviation of the big toe combined with varus deviation of the first metatarsal bone (metatarsus primus varus), creating a three-dimensional structural malformation. 1, 3
The medial prominence at the first metatarsal head (the visible "bunion") results from both bony deviation and potential soft-tissue enlargement. 2, 4
The hallux may also exhibit pronation (rotation) as part of the complex deformity. 4
Epidemiology and Risk Factors
Prevalence is approximately 23% in adults aged 18-65 years and increases to 35-36% in those over 65 years of age. 1, 5
Women are disproportionately affected with a female-to-male ratio of 9:1, likely due to joint laxity, biomechanical factors, and restrictive footwear. 2, 4
The deformity typically develops between ages 30-60 years. 1
Risk factors include female gender, hereditary predisposition, restrictive footwear, pes planus (flat feet), and other foot deformities. 5, 4
Clinical Significance in Foot Care
Hallux valgus represents a significant foot deformity that requires recognition during comprehensive foot examinations, particularly in high-risk populations such as patients with diabetes or peripheral artery disease. 6
The deformity is classified as a bony deformity (along with hammertoes, prominent metatarsal heads, pes cavus, and Charcot foot) that increases risk for foot ulceration in vulnerable patients. 6
Patients with hallux valgus and other foot deformities may require extra-wide or depth shoes to accommodate the altered foot structure and prevent pressure-related complications. 6
The presence of bunions creates pressure points from shoe conflict that can lead to pain, restricted mobility, and in high-risk patients, skin breakdown or ulceration. 6, 1
Associated Conditions
Hallux valgus frequently coexists with other foot pathologies including metatarsal adductus, equinus contracture, hammertoe deformity, and pes planus. 4
Hallux rigidus (degenerative arthritis of the first metatarsophalangeal joint) is the second most common cause of pain in this joint and can occur concurrently with hallux valgus. 1
Physical examination and imaging are essential to differentiate hallux valgus from hallux rigidus and assess deformity severity. 1
Clinical Implications
Hallux valgus is the most common pathologic condition affecting the great toe and represents a progressive deformity for which conservative management cannot reverse the structural changes but may prevent worsening and provide symptom relief. 2, 4
The first ray plays a critical role in weight-bearing during gait, and factors that compromise its integrity contribute to hallux valgus development. 5
Referral to a podiatrist or foot care specialist is appropriate for patients with symptomatic hallux valgus or those at high risk for complications. 6