Hallux Valgus (Bunion) Surgery — How It Works, Benefits & Recovery — Procedure Guide, Recovery & Risks | MyMedicPlus

Hallux valgus (commonly known as a bunion) is a progressive structural deformity of the first metatarsophalangeal (MTP) joint in which the great (big) toe deviates laterally toward the second toe, while a bony prominence forms on the medial (inner) aspect of the foot at the MTP joint. The deformity involves not only the toe itself but the first metatarsal, the joint capsule, and the surrounding soft tissues. Hallux valgus is the most common forefoot deformity, affecting up to 23% of adults and 35% of those over 65 years, with a strong female preponderance (4–15:1). When conservative measures (wide-toed footwear, orthotics, toe spacers) fail to adequately control pain and functional impairment, surgical correction is indicated. Surgery — collectively termed bunionectomy — corrects the underlying bony malalignment through osteotomy (a controlled bone cut) and realigns the soft tissues around the MTP joint. The goal is to restore the anatomical alignment of the first ray, relieve pain, and allow the patient to wear appropriate footwear comfortably. Over 50 surgical techniques have been described for hallux valgus; the most evidence-based are the scarf, chevron (Austin), and Lapidus (first tarsometatarsal arthrodesis) procedures.

Surgery is recommended for patients with symptomatic hallux valgus who have failed conservative management for a minimum of 3 months. Indications for surgery include: persistent pain at the MTP joint or bunion prominence during daily activities or with appropriate footwear; pressure sores, bursitis, or skin breakdown over the bunion from shoe-fitting difficulties; functional limitation of walking or standing due to foot pain; and progressive deformity causing hammer toe deformity of the lesser toes from the displaced great toe. The severity of deformity is quantified radiologically by the hallux valgus angle (HVA, normal <15 degrees) and intermetatarsal angle (IMA, normal <9 degrees) — these guide surgical technique selection. Mild-to-moderate deformity (HVA 15–40 degrees, IMA 9–20 degrees) is treated with distal metatarsal osteotomy (chevron, scarf). Severe deformity (HVA >40 degrees, IMA >20 degrees) or hypermobility of the first tarsometatarsal joint requires proximal or combined osteotomy or Lapidus arthrodesis. Purely cosmetic correction of bunion deformity without pain or functional impairment is not an accepted surgical indication. The procedure is performed by foot and ankle orthopaedic surgeons.

Hallux valgus surgery is performed under regional ankle block anaesthesia (popliteal and saphenous nerve blocks) or general anaesthesia, with a thigh tourniquet to maintain a bloodless field. A medial or dorsomedial incision exposes the first MTP joint and medial eminence. The medial eminence (bony prominence) is resected with an oscillating saw. Soft-tissue balancing: the contracted lateral joint capsule is released (lateral release) through a separate web space incision, and the medial joint capsule is tightened (medial capsulorrhaphy) to realign the toe. Osteotomy: for the scarf procedure, a Z-shaped cut through the metatarsal shaft allows lateral translation of the metatarsal head to close the IMA; for the chevron (Austin) technique, a V-shaped distal cut achieves similar correction. Both are fixed with titanium screws or plates. For the Lapidus procedure, the first tarsometatarsal joint is arthrodesed with plate fixation to correct hypermobility driving the deformity. An Akin osteotomy — a closing wedge cut at the proximal phalanx — corrects residual toe valgus. Post-operative radiographs confirm bone cut position and hardware placement. A post-operative shoe or boot is applied in theatre. Operative time for a standard Scarf or Chevron osteotomy for hallux valgus correction is typically 45–75 minutes under ankle block or general anaesthesia.

Hallux valgus surgery achieves good or excellent patient-reported outcomes in 80–90% of patients at 5 years, with significant reductions in pain (average VAS reduction 4–5 points) and patient satisfaction rates of 80–90% in prospective cohort studies. Radiological correction is predictable: the scarf osteotomy corrects IMA by an average of 8–10 degrees and HVA by 16–20 degrees. The Lapidus procedure achieves the greatest IMA correction (average 10–12 degrees) for severe or recurrent deformity with hypermobility. A 2023 randomised controlled trial (JBJS) comparing scarf to chevron osteotomy found equivalent patient-reported outcomes (MOXFQ score) at 2 years with similar complication profiles. Minimally invasive hallux valgus surgery (MICA — minimally invasive chevron Akin) using fluoroscopically guided percutaneous osteotomy through 3 mm stab incisions achieves comparable correction with faster recovery and is increasingly available at specialist foot and ankle centres. Functional benefits include the ability to wear normal footwear, relief of pressure-related skin problems, and correction of lesser toe deformity caused by displacement from the hallux.

Hallux valgus surgery is a generally safe procedure but specific complications must be discussed. Pain and swelling are universal after foot surgery and typically persist for 3–6 months; prolonged swelling lasting 12 months is common. Hallux varus (over-correction causing the great toe to deviate medially) occurs in 2–5% and may require further surgery if symptomatic. Recurrence of hallux valgus (under-correction or re-deformity) affects 10–30% over the long term, particularly with non-compliance with post-operative footwear guidance, persistent use of narrow or high-heeled shoes, or underlying hypermobility. Nerve injury affecting the dorsomedial cutaneous nerve to the great toe causes numbness or neuroma pain in 5–10% of cases. Non-union or malunion of the osteotomy occurs in less than 5%; avascular necrosis of the first metatarsal head is a rare but serious complication requiring further surgery. Transfer metatarsalgia — pain under the second or third metatarsal heads from altered weight distribution after first ray surgery — affects 5–15% and is managed with orthotics or, rarely, further surgery. Deep infection requiring implant removal is rare (<1%) in non-diabetic patients.

Post-operative management is determined by the osteotomy technique. Most patients are weight-bearing immediately in a post-operative forefoot offloading shoe or walker boot, avoiding full forefoot weight bearing. Driving is restricted for 6–8 weeks for right foot procedures. Elevation of the foot on pillows for the majority of the first 2 weeks is essential to reduce swelling. Sutures are removed at 10–14 days. X-rays at 6 weeks confirm early bone healing; transition to normal wide-toed footwear typically begins at 8–12 weeks. Return to low-impact exercise (cycling, swimming) is possible from 8–12 weeks; running and high-impact activity from 4–6 months. High-heeled shoes and narrow shoes should be avoided for at least 6 months post-operatively and ideally permanently, as they are the primary driver of recurrence. Physiotherapy to restore MTP joint range of motion, toe flexor and extensor strength, and gait retraining is important from 6–8 weeks. Most functional recovery is achieved by 3–4 months; final cosmetic and functional result may take 9–12 months as swelling fully resolves.