A healthy 34-year-old woman has had “bunion pain” for 5 years. Her custom-made orthoses alleviate 50% of her pain. On examination, she has severe lateral deviation of the hallux (Figure 208-1), a mildly dorsiflexed second digit, tenderness at the medial prominence, painless first metatarsophalangeal (MTP) range of motion, and a callus under the second metatarsal head. Radiographs (Figure 208-2) show medial angulation of the first metatarsal and lateral deviation of the hallux.
Laterally deviated hallux resulting in a bunion (hallux abducto valgus deformity). (Courtesy of Naohiro Shibuya, DPM.)
A weight-bearing dorsoplantar plain radiograph helps in assessing severity of the deformity and determining treatment plan. (Courtesy of Naohiro Shibuya, DPM.)
The patient was referred to podiatry for surgical correction of the bunion deformity. After surgery, she was placed in a short-leg cast for 6 weeks. She progressed to a regular shoe over the next month and was encouraged to use the custom-made orthoses for her flatfoot to prevent recurrence of the bunion.
Bunion deformity is characterized by the presence of a medial prominence at the first MTP joint, caused by an abducted hallux and adducted first metatarsal. The deformity causes irritation in a tight shoe and pain in the MTP joint. Initial therapy can be conservative with correction of footwear and padding. Surgical procedures correct the misalignment, rather than shave the medial prominence.
Hallux valgus, hallux abducto valgus, metatarsus adductovarus.
- The prevalence of bunions ranges from 2% to 50%.1
- It is far more common in women.
Bunion deformities are caused by multiple factors:
- Genetic and hereditary factors.
- Abnormal biomechanics (limb length discrepancy, hypermobility/ligament laxity, flatfoot deformity, malaligned skeletal structures, and ankle equinus).2
- Neuromuscular diseases.
- Ill-fitting shoes.
- Iatrogenic causes.
- Family history.
- Ligamentous laxity.
The diagnosis of hallux abducto valgus deformity is made clinically and radiographically.
- Laterally deviated hallux, erythema, edema.
- Tenderness on the medial eminence at the first MTP joint and pain through the first MTP joint range of motion.
- Associated signs—Hypermobility, flatfoot deformity, second MTP joint pain, pain under the second metatarsal head, overlapped second digit, decreased ankle dorsiflexion, concurrent gout, decreased first MTP joint range of motion, sesamoiditis, hyperkeratosis, and hammer toe deformity (see Chapter 209, Hammer Toe, Figure 209-4).
- Often bilateral (Figure 208-3).
- A unilateral bunion deformity is often caused by a limb length discrepancy (Figure 208-4).
Severe bilateral bunion deformities causing lateral ...