Definition
Hallux valgus is a complex first-ray deformity with lateral deviation/pronation of the great toe and medial deviation of the first metatarsal. It is not simply a medial eminence problem.
Contributing factors
- genetic predisposition
- first-ray instability in some patients
- footwear may aggravate symptoms but is rarely the sole cause
- metatarsal morphology
- ligamentous laxity
- neuromuscular conditions
Assessment
History:
- pain over medial eminence
- transfer metatarsalgia
- footwear difficulty
- second-toe symptoms
- first MTP arthritis
Examine standing:
- severity and flexibility of hallux valgus
- first-ray mobility
- pronation of great toe
- lesser-toe deformity
- plantar callosities
- arch and hindfoot alignment
Radiographs
Use weight-bearing AP and lateral foot radiographs. Important measurements include:
- hallux valgus angle
- first-second intermetatarsal angle
- distal metatarsal articular alignment
- joint congruity
- sesamoid position
- first MTP arthritis
Measurements guide planning but should not dictate treatment without the clinical picture.
Non-operative treatment
- wider toe-box footwear
- activity and shoe modification
- pads or orthoses for associated metatarsalgia
Splints do not reliably correct an established structural deformity in an adult.
Operative principles
Operate for symptoms and functional limitation, not cosmetic appearance alone.
Options depend on the site and severity of deformity:
- distal or diaphyseal first-metatarsal osteotomy
- proximal correction in selected larger intermetatarsal deformity
- Akin osteotomy for hallux interphalangeus when required
- first TMT fusion for selected instability or deformity patterns
- first MTP fusion for severe arthritis, rigid deformity or selected neuromuscular cases
Soft-tissue balancing is combined with bony correction where appropriate.
Procedure selection depends on:
- severity and location of deformity
- joint congruence and arthritis
- first-ray/TMT instability
- patient age and demand
- previous procedures
- associated lesser-toe pathology
Options include distal or proximal metatarsal osteotomy, diaphyseal scarf-type correction, first-TMT fusion and first-MTP fusion in selected arthritic or severe/revision cases.
Soft-tissue balancing complements bony correction; soft-tissue release alone is usually insufficient for established deformity.
Deformity
Hallux valgus is a three-dimensional deformity involving:
- lateral deviation/pronation of the hallux
- medial deviation of the first metatarsal
- prominence of the medial eminence
- displacement of sesamoids relative to the metatarsal head
- imbalance of soft tissues around the first MTP joint
It should not be reduced to the size of a “bunion”.
History and examination
Ask about:
- medial eminence pain
- transfer metatarsalgia
- shoe difficulty
- second-toe symptoms
- first MTP pain
- family history
- previous surgery
Examine:
- deformity flexibility
- first-MTP range and crepitus
- first-ray stability
- lesser-toe deformity
- plantar callosity
- pes planus
- neurovascular status
A painless cosmetic deformity is not an indication for surgery.
Radiographic assessment
Weight-bearing radiographs are essential.
Assess:
- hallux valgus angle
- intermetatarsal angle
- distal metatarsal articular orientation where relevant
- sesamoid position
- first-MTP arthritis
- first TMT alignment/instability
- lesser-metatarsal pattern
Numbers assist planning but should not replace clinical assessment.
Non-operative management
Wide toe-box footwear, padding and symptom-directed measures may reduce pain but do not reliably reverse established bony deformity.
Complications
Discuss:
- recurrence
- overcorrection/hallux varus
- stiffness
- transfer metatarsalgia
- non-union
- avascular necrosis with some procedures
- nerve irritation
- infection
- hardware symptoms
FRCS synthesis
The operation should correct the deformity at its principal level while preserving or replacing a painful joint appropriately. Avoid choosing a procedure from one angle alone.