Overview
Hallux valgus is not a single disorder but a complex deformity of the first ray, often with lesser toe deformity and symptoms. The intermetatarsal angle is frequently above the 8 to 9 degrees considered normal, and the hallux valgus angle above 15 to 20 degrees. Beyond about 30 to 35 degrees of valgus, the great toe usually pronates; the abductor hallucis slips plantarward and the flexor hallucis brevis, flexor hallucis longus, adductor hallucis and extensor hallucis longus increase the valgus moment. The crista flattens under tibial sesamoid pressure and the fibular sesamoid drifts into the first intermetatarsal space, shifting load to the lesser metatarsal heads (transfer metatarsalgia, calluses). (Campbell)
Etiology
The strongest evidence supports lateral deviation of the hallux as the primary deformity in most patients, followed by medial angulation of the first metatarsal; metatarsus primus varus may be primary in adolescents. Familial tendency (especially in adolescents) and poorly designed footwear contribute. First-ray hypermobility is a controversial factor. Recent studies suggest medial eminence hypertrophy is not part of the pathoanatomy. (Campbell)
Assessment (Campbell)
Examination
Activity goals and shoe requirements; toe morphology (short and wide versus long and thin).
Lesser toe deformities, especially second toe varus or valgus; quality-of-life measures are worse with lesser toe deformity or metatarsalgia than with hallux valgus alone.
Plantar callosities and lesser metatarsal head tenderness, arch height, clinical pronation of the hallux (pronation on extension signals intrinsic malalignment), first MTP motion.
Sensation of the dorsal medial hallucal nerve; gastrocsoleus contracture; smoking, weight, age and sex (men and adolescents commonly have congruent joints); generalized hypermobility.
Radiographs
Standing dorsoplantar and lateral views, a nonstanding lateral oblique view and axial sesamoid views. The axial view helps judge intrinsic malalignment when the tibial sesamoid is in position 4 or 5 on the AP view.
Assess the hallux valgus angle (HVA), intermetatarsal angle (IMA), MTP joint congruency, distal metatarsal articular angle (DMAA), pronation, hallux valgus interphalangeus, MTP arthritis, first metatarsal length, first TMT plantar gapping (hypermobility), metatarsocuneiform obliquity, sesamoid position, metatarsus adductus and metatarsal width (a wider metatarsal allows greater lateral translation of a distal osteotomy).
Draw HVA and IMA on the standing dorsoplantar view by bisecting the shafts. Interobserver variation is about 6 degrees for HVA and 4 degrees for IMA, so do not overemphasize angles, which do not always correlate with outcome. An os intermetatarseum may prevent a soft-tissue procedure from correcting the IMA.
Procedure Selection (Campbell, modified Coughlin algorithm)
Congruent joint: distal metatarsal osteotomy (chevron) with or without Akin osteotomy; double or triple first-ray osteotomy for larger deformities.
Incongruent joint, mild (IMA under 13 degrees, HVA under 30 degrees): chevron (age under 60), scarf or minimally invasive osteotomy, or a distal soft-tissue procedure.
Incongruent joint, moderate to severe (IMA 13 degrees or more, HVA up to 40 degrees or more): distal soft-tissue procedure with proximal metatarsal osteotomy, scarf or minimally invasive osteotomy.
Hypermobile first metatarsocuneiform joint: first metatarsocuneiform fusion with a distal soft-tissue procedure.
Degenerative joint disease: first MTP arthrodesis (or, rarely, prosthesis).
Differing procedures can achieve similar correction, so selection also depends on the surgeon's training and preference.
Modified McBride (soft-tissue) procedure
Removal of the medial eminence, release of the adductor tendon and lateral capsule with or without fibular sesamoid excision, and medial capsular imbrication. The usual candidate is a 30- to 50-year-old woman with HVA 15 to 25 degrees, IMA under 13 degrees, interphalangeal valgus under 15 degrees and no MTP degeneration. If a firm forefoot wrap reduces the IMA and HVA, the procedure can correct the deformity. Fibular sesamoidectomy increases correction but risks hallux varus; then close the medial capsule with the hallux in 5 to 10 degrees of valgus. Today it is usually combined with bony procedures.
Technique 87.4: Distal Chevron Metatarsal Osteotomy (Campbell)
Good results are reported in 85% to 95% of patients. It is generally recommended for patients younger than 50 with HVA under 40 degrees and IMA under 15 degrees, although successful results are also reported over 50. Advantages: it runs through cancellous bone, shortens the metatarsal less, is inherently stable, narrows the forefoot and preserves first MTP dorsiflexion. When HVA exceeds 35 degrees (especially with IMA over 12 degrees), the hallux is usually pronated and capsulorrhaphy alone cannot correct it.
Incision. Use a straight midline medial incision. Preserve the dorsomedial sensory nerve (terminal branch of the medial division of the superficial peroneal nerve) and as many superficial veins as possible to limit edema.
Capsulotomy. Make a longitudinal medial capsular incision over the eminence, extending along the proximal phalanx and metatarsal shaft. Do not release all proximal capsular attachments on the neck, and do not strip the dorsolateral or lateral capsule from the head and neck, to protect the capital blood supply.
Medial eminence removal. Start dorsomedially at the sagittal groove and direct a 9-mm blade proximally and medially toward the junction of the eminence and the shaft. Avoid scooping out cancellous bone of the head, which reduces contact and can delay union.
V-shaped osteotomy. Start the apex in the head near subchondral bone, about 3 to 4 mm proximal to the medial articular edge. Angle each arm about 30 degrees from the long axis so the arms are 60 to 70 degrees apart; a narrower angle (under 50 to 60 degrees) puts the arm ends in cortical neck bone, and a wider one reduces stability. Keep the cuts parallel to each other, make the arms about 10 to 12 mm long, and do not overpenetrate laterally (blood supply).
Lateral shift. Stabilize the shaft by hand or with a towel clip and push the capital fragment laterally 4 to 5 mm, no more than 40% to 50% of metatarsal width. Do not lever the osteotomy open, which can destabilize it.
Remove the medial projection of the proximal fragment with a dorsomedial-to-proximal saw cut and smooth with a rongeur.
Fixation and capsulorrhaphy. Hold the hallux in 5 degrees of valgus and check stability; fix with one or two K-wires, a cortical screw or a bioabsorbable pin if unstable. Perform a pants-over-vest (or side-to-side after excision) capsulorrhaphy holding 5 to 10 degrees of valgus; pulling the plantar flap dorsally helps reposition the sesamoids. Release the adductor through the joint before the osteotomy if HVA is 30 degrees or more.
Modified (extracapsular) chevron
The apex is placed more proximally in the head, allowing correction of more severe deformity (up to about 35 degrees HVA and 15 degrees IMA), with about 83% satisfaction. It must be internally fixed because instability and reduced metaphyseal contact are risks. An Akin osteotomy can add a few degrees of cosmetic correction only if the MTP joint is congruent after correction. Use an absorbable pin in a wide metatarsal with mild to moderate deformity, and K-wires or screws for more severe deformity or a narrow metatarsal.
Postoperative Care (Campbell)
At 3 days, remove the bulky dressing and apply a small dressing and a short leg walking cast with dorsal and plantar toe plates; touch-down weight bearing on crutches until the osteotomy heals (6 to 8 weeks). Return to driving after right-sided surgery is commonly advised about 6 weeks after initial weight bearing, by analogy with lower-extremity fractures. Persistent opioid use occurred in about 6% after hallux valgus correction in a large database, more after metatarsocuneiform arthrodesis than after distal osteotomy. Depression and a low mental component score are associated with lower satisfaction and function.
Complications (Campbell)
Neuroma (dorsomedial cutaneous nerve), transfer metatarsalgia, recurrent deformity, osteonecrosis of the metatarsal head (protect the lateral capsule and avoid overpenetration), limitation of MTP motion, claw toe from intrinsic imbalance, and iatrogenic hallux varus (especially after fibular sesamoid excision or overcorrection).
References
Grear BJ. Disorders of the hallux. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Philadelphia: Elsevier; 2026. Chapter 87.