Medial longitudinal approach to the first metatarsal, from mid-proximal phalanx to mid-metatarsal shaft · advanced
- The scarf is for moderate-to-severe hallux valgus (HVA 30-40°, IMA 13-18°) — a Z-shaped diaphyseal osteotomy of the first metatarsal.
- Critical geometry: the horizontal cut sits at a 2:1 dorsal-to-plantar ratio (dorsally based) and MUST be parallel to the plantar cortex — this prevents troughing, the signature complication.
- The proximal vertical limb exits dorsally and the distal limb exits plantarly (both at 60°); the opposite orientations give the construct inherent stability.
- Scarf allows true multi-planar correction — lateral translation (primary, for the IMA), rotation (for DMAA), shortening, and plantarflexion — its main advantage over chevron.
- TROUGHING (dorsiflexion malunion, 5-10%) is the most common technical error; prevent it by keeping the horizontal cut parallel to the plantar cortex throughout (palpate the cortex while cutting).
- Fix with TWO headless compression screws placed perpendicular to the osteotomy plane; sesamoid reduction under the metatarsal head is a critical endpoint (perform a lateral release if they remain subluxed).
- Medial capsular reefing (imbrication) maintains correction — soft-tissue balance is as important as the bony correction.
When & Why
Indication. Symptomatic moderate-to-severe hallux valgus — a painful bunion with difficulty with shoe wear — with HVA 30-40° and IMA 13-18° on weight-bearing radiographs, that has failed conservative management (appropriate shoes, orthotics, NSAIDs). The patient must have adequate bone stock for osteotomy and screw fixation and understand the rehabilitation requirements. Assess the whole ray, not just the angle. Before committing, measure the HVA, IMA and DMAA on weight-bearing AP and lateral radiographs (a sesamoid axial view if available), grade the tibial sesamoid subluxation (0-3), and judge joint congruency. Normal values to anchor against: HVA less than 15°, IMA less than 9°, DMAA less than 10°. Also check MTP range of motion (limited motion suggests arthritis — a contraindication), foot alignment (pes planus, metatarsus adductus), lesser-toe deformities that may need concurrent correction, and the neurovascular status. Plan the correction from the IMA: roughly 1 mm of lateral translation corrects 2° of IMA. Where the scarf sits in the deformity spectrum.
HVA 30-40° and IMA 13-18° — the scarf's home territory. Multi-planar correction lets you translate, rotate, shorten and plantarflex in one osteotomy.
Severe MTP osteoarthritis (fuse it instead), very severe deformity with IMA greater than 20° (proximal osteotomy or Lapidus), poor bone quality, active infection, inadequate vascularity, or inflammatory arthropathy (higher recurrence).
An Akin osteotomy of the proximal phalanx in roughly 30-40% of cases (residual HVA greater than 15° or elevated DASA), and a lateral soft-tissue release whenever the sesamoids remain unreduced.
Relative caution. Mild deformity (HVA less than 30°, IMA less than 13° — favour a chevron), significant medical comorbidities, a smoker (impaired healing), and unrealistic patient expectations. Counsel for 85-90% satisfaction with significant pain relief, a 6-week period of protected weight-bearing and 3-4 months back to activity, and the complication profile: recurrence 5-10%, transfer metatarsalgia 10-15%, nerve injury 5-10%. Hardware is usually retained unless prominent, and a wider toe box may be needed permanently.
The Operation
The goal: through a medial longitudinal exposure of the first metatarsal, resect the medial eminence, cut a Z-shaped (scarf) osteotomy, translate the capital fragment laterally to correct the IMA, restore sesamoid reduction, and balance the soft tissues with medial capsular reefing. The exposure is laid out in full as the first steps below (and in depth on the dorsomedial approach to the first MTP joint page).
Operative sequence
- Supine, foot at the end of the table, bump under the ipsilateral hip so the foot sits in neutral rotation.
- Anaesthesia: an ankle block is preferred (it allows immediate post-operative assessment of correction and neurovascular status) or a general anaesthetic.
- Tourniquet at the ankle (250 mmHg) or thigh (300 mmHg), exsanguinate by elevation.
- Equipment: small-fragment set with 2.5-3.0 mm headless compression screws, a sagittal saw with a 0.5-1.0 mm blade, K-wires for provisional fixation, fluoroscopy, and a microsagittal saw if an Akin is planned.
- Medial longitudinal incision 6-8 cm from the mid-proximal phalanx to the mid-metatarsal shaft, centred over the first metatarsal and 2-3 mm dorsal to the joint line to avoid the plantar digital nerve.
- Longer than a chevron incision because the whole metatarsal shaft must be exposed; sharp dissection through subcutaneous tissue.
- Identify and protect the dorsomedial cutaneous nerve branches (they cross 2-3 mm dorsal to the approach); use self-retaining retractors.
- Watch for: dorsomedial cutaneous nerve injury (5-10%), the medial plantar digital nerve if the incision drifts plantar (8-10 mm plantar to the joint), and an incision too short to expose the osteotomy.
- Inverted-L or linear capsulotomy along the dorsomedial metatarsal and MTP joint, extended proximally along the entire shaft to the planned proximal osteotomy; preserve the capsular flaps for later repair.
- Full-length exposure is critical for the scarf; expose the medial eminence, metatarsal neck and shaft, and palpate the plantar cortex (it guides the osteotomy orientation).
- Protect the lateral capsule (it holds the sesamoids) and keep lateral periosteal stripping minimal (avascular necrosis risk).
- Watch for: excessive stripping raising AVN risk (1-2%), lateral capsular damage destabilising the sesamoids, and loss of capsular tissue compromising closure and raising recurrence.
- Remove the medial eminence with the sagittal saw in line with the medial border of the shaft, typically 3-4 mm; smooth the edges with a rongeur and palpate plantarly to confirm no plantar prominence.
- Cut in line with the shaft; over-resection destabilises the sesamoid complex and significantly raises hallux varus risk.
- Watch for: over-resection causing sesamoid instability and varus (2-5%), the plantar digital nerve if the cut extends plantarward, and thermal injury (use irrigation).
- Plan the Z-shaped osteotomy with THREE cuts: a horizontal limb (longitudinal, dorsally based at 2:1 dorsal-to-plantar, parallel to the plantar cortex); a proximal vertical limb at 60° exiting dorsally; and a distal vertical limb at 60° exiting plantarly.
- The horizontal limb covers the middle 60-70% of the metatarsal (typically 25-30 mm); mark it carefully with methylene blue or electrocautery.
- The horizontal cut MUST be parallel to the plantar cortex (prevents troughing); the 2:1 ratio keeps it in the dorsal two-thirds; the opposite vertical orientations give inherent stability; adequate length prevents stress risers.
- Watch for: a wrong ratio (1:1 or plantar-based) causing troughing (5-10%), non-parallel cuts causing instability and malunion, a horizontal limb too short causing a stress-riser fracture (2-5%), and wrong angles altering stability.
- With a 0.5-1.0 mm sagittal saw blade, make the horizontal cut along the shaft, parallel to the plantar cortex, in the dorsal two-thirds (2:1 ratio), 25-30 mm long; continuous irrigation prevents thermal necrosis.
- Palpate the plantar cortex continuously while cutting to keep the blade parallel; stop before fully penetrating the far cortex.
- Watch for: a non-parallel cut (the cause of troughing), thermal necrosis and AVN without irrigation, an inadvertent complete fracture, and plantar penetration risking the neurovascular bundle.
- Make the proximal vertical cut exiting dorsally at about 60° to the horizontal limb, connecting to its proximal end; complete it through both cortices — this is the proximal arm of the Z.
- Watch for: an incomplete cut making translation difficult and risking fracture during manipulation, an exit point too dorsal or plantar altering geometry, and propagation beyond the intended endpoint.
- Make the distal vertical cut exiting plantarly at 60° to the horizontal limb, connecting to its distal end; this completes the Z and frees the capital fragment.
- The opposite orientation to the proximal cut gives rotational stability; confirm the capital fragment is mobile before translating.
- Watch for: a cut too plantar risking the sesamoids, an incomplete cut fracturing during manipulation (2-5%), loss of orientation losing stability, and the plantar neurovascular bundle if the cut is too deep.
- Translate the capital fragment laterally, typically 5-8 mm (up to 10 mm or 70% of shaft width); roughly 1 mm of translation corrects 2° of IMA.
- Multi-planar capability is the scarf's advantage: primary lateral translation for the IMA, rotation for a DMAA abnormality, shortening to reduce soft-tissue tension, and slight plantarflexion to prevent transfer metatarsalgia; impaction gives initial stability.
- Watch for: translation greater than 70% (instability and AVN risk), dorsiflexion malposition causing transfer metatarsalgia (10-15%), overcorrection causing hallux varus (2-5%), and loss of bony contact risking nonunion.
- Hold the correction manually or with a K-wire and check alignment in all planes, sesamoid reduction, no rotational deformity, appropriate length, and that the capital fragment sits flush on the shaft with no step-off; fluoroscopy confirms position.
- Check before definitive fixation — it is far easier to adjust now than after the screws are placed.
- Watch for: fixing a malpositioned fragment (needs revision), a missed step-off causing prominence and pain, and unreduced sesamoids forecasting recurrence.
- Fix with TWO headless compression screws (2.5-3.0 mm) placed perpendicular to the osteotomy plane; insert the proximal screw first for control, then the distal screw; both achieve bicortical purchase with a lag technique for compression.
- Two screws are needed (the osteotomy is longer than a chevron); perpendicular placement maximises compression; headless screws avoid prominence and routine removal.
- Watch for: prominence if not headless, loss of correction if not perpendicular, penetration into the MTP joint, intraoperative fracture during insertion, and inadequate purchase in osteoporotic bone.
- Assess the final correction clinically (straight toe pointing ahead, appropriate length, no rotation) and on fluoroscopy (hardware, alignment, sesamoids); the critical endpoint is the sesamoids reduced under the metatarsal head.
- If the sesamoids are not reduced despite good bony correction, perform a lateral soft-tissue release (Step 13); unreduced sesamoids carry a recurrence risk up to 50%.
- Watch for: unreduced sesamoids (very high recurrence risk), subtle rotational malalignment, and hardware malposition into the joint or with prominence.
- Through a separate small dorsal incision in the first web space between the first and second metatarsals (preferred), release the lateral capsule and detach the adductor hallucis from the lateral base of the proximal phalanx; stay on the capsular layer.
- Protect the lateral digital neurovascular bundle, which runs about 5 mm lateral to the capsule; recheck the sesamoid position after release.
- Watch for: lateral digital neurovascular injury (5 mm from the capsule) causing numbness and chronic pain, overcorrection causing hallux varus (2-5%), and vascular compromise from excessive release.
- Add an Akin if there is residual HVA greater than 15° after the scarf, a DASA greater than 10° (interphalangeal valgus), or to fine-tune alignment; it is a medial-based closing wedge at the proximal phalanx base (2-3 mm wedge) fixed with a single headless screw or staple.
- Used in roughly 30-40% of cases; addresses the interphalangeal component; avoid overcorrection.
- Watch for: overcorrection into interphalangeal varus, inadequate fixation with displacement, IP joint stiffness from stripping, and neurovascular injury if dissection is too aggressive.
- Reef the medial capsule to restore soft-tissue balance; overlap the capsular edges (imbrication, "pants-over-vest") with balanced tension using absorbable 2-0 or 3-0 Vicryl.
- Soft-tissue balance is as important as the bony correction; aim for the toe to rest in slight overcorrection but remain mobile.
- Watch for: overtightening (stiffness, limited ROM, overcorrection), inadequate closure allowing recurrence from persistent medial laxity (5-10%), and devascularisation from excessive handling.
- Close in layers: absorbable subcutaneous (3-0 Vicryl), then subcuticular 4-0 Monocryl or interrupted 4-0 nylon.
- Apply a proper bunion dressing — gauze between the first and second toes to prevent drift back into valgus, the toe held in the corrected position, circumferential compression (not too tight), and a stiff-soled postoperative shoe to protect the osteotomy for the first 6 weeks.
- Watch for: wound dehiscence (5-10%, especially in thin skin over the eminence), loss of correction if the dressing is inadequate, vascular compromise if too tight, and skin necrosis at pressure points.
The most common technical error is troughing (dorsiflexion malunion, 5-10%), in which the capital fragment sinks dorsally into the shaft and creates a trough, causing transfer metatarsalgia to the lesser rays. Prevent it by keeping the horizontal cut parallel to the plantar cortex throughout its length, at a 2:1 dorsal-to-plantar ratio (dorsal two-thirds of the shaft), and by palpating the plantar cortex continuously while cutting. In early-learning-curve series troughing reached 35% (Coetzee 2003); it is preventable with disciplined geometry.
Fix the scarf with two headless compression screws perpendicular to the osteotomy plane — not parallel to the shaft — and insert the proximal screw first to control the capital fragment. Perpendicular placement is what gives compression across the osteotomy; this is a common exam question, so be specific about the orientation.
After fixation, confirm the sesamoids sit reduced under the metatarsal head. If they remain subluxed despite good bony correction, the lateral soft tissues are tight and a lateral release is required — protecting the lateral digital neurovascular bundle 5 mm lateral to the capsule. Unreduced sesamoids carry a recurrence risk up to 50%.
Aftercare & Complications
Rehabilitation | Phase | Timing | Weight-bearing & immobilisation | Therapy | |-------|--------|--------------------------------|---------| | 1 | 0-2 weeks | Bunion dressing; heel and midfoot weight-bearing only in a stiff-soled shoe; no forefoot loading | Strict elevation above heart level; ice; multimodal analgesia; wound check at 48-72 h; sutures out at 10-14 days | | 2 | 2-6 weeks | Stiff-soled shoe continued; bunion dressing to 2-3 weeks then light compression stocking | Gentle passive ROM from 2-3 weeks; X-ray at 6 weeks to confirm union | | 3 | 6-12 weeks | Out of the postoperative shoe into supportive wide-toe-box shoes once united; progressive forefoot weight-bearing | Progressive MTP ROM and strengthening; swimming and cycling from 8-12 weeks; avoid impact | | 4 | 3-6 months | Supportive shoes; avoid high heels until at least 6 months | Impact activities and sport from 3-4 months if pain-free; final radiographs at 6 months | Most patients return to desk work by about 6 weeks, with 85-90% reporting significant pain relief and high satisfaction, and return to sport by 4-6 months. Long-term footwear advice — a wider toe box, limiting high heels, and custom orthotics for pes planus — is part of the outcome. Complications
- Recognition
- Transfer metatarsalgia to the lesser rays; radiograph shows dorsal angulation at the osteotomy with the capital fragment elevated
- Prevention
- Horizontal cut parallel to the plantar cortex throughout; 2:1 dorsal-to-plantar ratio; verify with a finger on the plantar cortex; slight plantarflexion of the capital fragment
- Management
- Mild: observation, orthotic offloading. Moderate-severe: revision osteotomy with plantar displacement and bone graft
- Recognition
- Progressive bunion pain; increasing HVA and IMA on radiograph; sesamoid subluxation returns
- Prevention
- Adequate lateral translation (typically 5-8 mm); sesamoid reduction before closure; proper capsular reefing; lateral release if sesamoids unreduced; address pes planus
- Management
- Identify the cause (undercorrection vs soft-tissue failure); revision scarf or salvage with MTP fusion if poor bone stock or multiple failures
- Recognition
- Medial deviation of the hallux; difficulty with push-off; second-toe irritation; flexible or fixed
- Prevention
- Avoid excessive lateral translation (greater than 70%); limited eminence resection (3-4 mm in line with shaft); balanced capsular closure; avoid aggressive lateral release
- Management
- Flexible: observation, splinting, medial capsular release. Fixed: revision with medial translation, lateral capsular reconstruction, or MTP fusion if rigid and symptomatic
- Recognition
- Progressive pain at 3-6 months; radiograph shows sclerosis then collapse; MRI confirms (edema then necrosis)
- Prevention
- Minimise soft-tissue stripping especially laterally; preserve the periosteal sleeve and lateral capsular attachment; avoid excessive translation
- Management
- Early: protected weight-bearing, observation. Progressive collapse: core decompression, arthroplasty or MTP arthrodesis; bone graft if caught early
- Recognition
- Plantar pain under the 2nd/3rd metatarsal heads; callus formation; possible stress fracture on X-ray
- Prevention
- Slight plantarflexion of the capital fragment; avoid excessive shortening (greater than 3 mm); maintain the metatarsal parabola; address lesser-toe deformities
- Management
- Orthotic metatarsal pads, activity modification, NSAIDs. Persistent: lesser metatarsal Weil osteotomy for decompression
- Recognition
- Numbness dorsomedial forefoot, plantar hallux, or lateral hallux; possible painful neuroma
- Prevention
- Identify and protect the dorsomedial cutaneous nerve; stay 2-3 mm dorsal to the joint line; limit plantar dissection; gentle lateral release (bundle 5 mm lateral)
- Management
- Most resolve over 3-6 months. Neuropathic pain: gabapentin, desensitisation. Painful neuroma: injection trial, then excision
- Recognition
- Crack heard or felt during manipulation or fixation; fluoroscopy confirms; fragment instability
- Prevention
- Complete osteotomy cuts before manipulation; avoid thin wafer fragments; adequate horizontal cut length (25-30 mm); parallel cuts; gentle manipulation
- Management
- Extend fixation across the fracture; additional screw or plate; a period of non-weight-bearing; bone graft if comminution
Additional complications. Nonunion is rare (1-2%) given the large bony contact area; risk factors are smoking, NSAIDs and poor fixation, and management is revision fixation with bone graft. Stiffness or reduced ROM occurs in 15-25% — some loss is expected, prevented by early gentle ROM at 2-3 weeks and managed with aggressive therapy (occasional manipulation under anaesthesia). Wound complications (dehiscence, infection, skin necrosis) occur in 5-10%, higher in thin skin over the eminence. Hardware prominence is avoided by using headless screws, with removal after union (around 6 months) if symptomatic. Complex regional pain syndrome (1-2%) demands early recognition and aggressive therapy, desensitisation, neuropathic medications and sympathetic blocks.
Viva & Exam Focus
Z-PLANEZ-PLANE — the scarf geometry
PARALLELPARALLEL — preventing troughing
- Location
- Crosses the incision 2-3 mm dorsal to the approach
- How to protect
- Identify and retract it during superficial dissection; stay on capsule
- Location
- 8-10 mm plantar to the MTP joint line
- How to protect
- Limit plantar dissection during eminence removal; stay on bone
- Location
- 12-15 mm plantar to the metatarsal shaft
- How to protect
- Maintain the periosteal sleeve; avoid excessive plantar dissection
- Location
- 4-5 mm plantar to the articular surface
- How to protect
- Visualise during eminence resection; avoid over-resection
- Location
- 5 mm lateral to the lateral capsule
- How to protect
- Gentle lateral release staying on the capsule; no blind dissection
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“What is troughing and how do you prevent it during a scarf osteotomy?”
“Compare scarf and chevron osteotomies — when would you choose each, and what are the key differences?”
“After completing a scarf osteotomy with good bony correction, you check fluoroscopy and note the sesamoids are not reduced. What do you do, and why is this important?”
Indications
- Moderate-severe hallux valgus: HVA 30-40°, IMA 13-18° (memorise these numbers)
- Symptomatic bunion with failed conservative management (shoes, orthotics, NSAIDs)
- Adequate bone stock for osteotomy and screw fixation
- Chevron insufficient (IMA greater than 13°), proximal excessive (IMA less than 18-20°); scarf is the middle ground
- Contraindicated: severe MTP OA (consider fusion), inadequate vascularity, very severe IMA greater than 20°
Key anatomy & danger zones
- Dorsomedial cutaneous nerve crosses the incision 2-3 mm dorsal to the approach; 5-10% injury rate
- Medial plantar digital nerve 8-10 mm plantar to the MTP joint line; at risk during eminence removal
- Plantar medial neurovascular bundle 12-15 mm plantar to the shaft; maintain the periosteal sleeve
- Medial plantar sesamoid 4-5 mm plantar to the articular surface; preserve during eminence resection
- Lateral digital neurovascular bundle 5 mm lateral to the lateral capsule; at risk during lateral release
Critical steps
- Incision: medial longitudinal 6-8 cm (longer than chevron), mid-proximal phalanx to mid-shaft
- Capsulotomy: full metatarsal shaft exposure; preserve capsule for closure
- Eminence resection: 3-4 mm in line with the shaft (excessive resection causes varus)
- Scarf geometry: Z-shape, 2:1 dorsal-to-plantar ratio, proximal exits dorsally, distal plantarly
- Horizontal cut parallel to the plantar cortex (palpate while cutting) — prevents troughing
- Translation: 5-8 mm lateral typically (1 mm corrects roughly 2° of IMA); up to 70% width maximum
- Fixation: two headless compression screws perpendicular to the osteotomy plane
- Confirm sesamoid reduction — lateral release if unreduced (critical endpoint)
Technique pearls
- Z-PLANE: Z-shape, Proximal dorsally, Long horizontal, Angle 60°, Ninety percent contact, Exit distal plantarly
- PARALLEL: Plantar cortex reference, 2:1 ratio, Level cuts prevent troughing
- Troughing prevention: horizontal cut parallel to the plantar cortex, 2:1 dorsal-to-plantar ratio
- Multi-planar correction: primary lateral translation for the IMA; secondary rotation, shortening, plantarflexion
- Proximal screw first (control), then distal screw — both perpendicular to the osteotomy
- Sesamoid reduction is the critical endpoint — lateral release if unreduced
- Medial capsular reefing (imbrication) for soft-tissue balance — as important as bone
- Bunion dressing with gauze between the toes maintains correction during healing
Complications
- Troughing (5-10%) — most common; dorsiflexion malunion from a non-parallel horizontal cut
- Recurrence (5-10%) — higher if inadequate correction or unreduced sesamoids
- Hallux varus (2-5%) — from overcorrection or excessive eminence resection
- AVN (1-2%) — higher than chevron from more extensive dissection
- Transfer metatarsalgia (10-15%) — from excessive shortening or dorsiflexion
- Nerve injury (5-10%) — dorsomedial cutaneous or digital nerves
- Intraoperative fracture (2-5%) — troughing, incomplete cuts, or manipulation
Post-op protocol
- Bunion dressing 2 weeks; sutures out at 10-14 days
- Heel and midfoot weight-bearing only for 6 weeks in a stiff-soled shoe — no forefoot loading
- ROM exercises from 2-3 weeks (gentle passive)
- X-ray at 6 weeks to confirm union before progressing weight-bearing
- Supportive shoes at 6-8 weeks if united; normal shoes 8-12 weeks; impact at 3-4 months; high heels after 6 months
- 85-90% satisfaction; return to sport at 4-6 months
Exam tips
- Know the numbers: scarf for HVA 30-40°, IMA 13-18° (chevron less than 13°; proximal greater than 18-20°)
- Troughing is the classic scarf complication — know its prevention (parallel cuts, 2:1 ratio)
- Multi-planar correction is the scarf's advantage over chevron — be specific about every plane
- Sesamoid reduction is the critical endpoint — always mention checking it
- Two screws perpendicular to the osteotomy (not parallel to the shaft) — common exam question
- Lateral release technique and protecting the nerve at 5 mm — high-yield viva topic
- Compare scarf vs chevron (indications, technique, complications) — frequently asked
- Soft-tissue balance (capsular reefing) is as important as the bony correction
Background & Evidence
Epidemiology. Hallux valgus prevalence rises with age and is markedly higher in women; pooled data estimate roughly 23% in adults aged 18-65 and over 35% in those older than 65, with a strong female predominance. Bunion correction is among the most commonly performed elective foot operations worldwide, and distal or diaphyseal osteotomy (chevron, scarf) dominates for mild-to-moderate-severe deformity.
- IMA
- under 13 degrees
- Preferred correction (global)
- Distal chevron (single-plane, simple, low AVN)
- IMA
- 13-18 degrees
- Preferred correction (global)
- Scarf (diaphyseal, multi-planar) or extended-indication chevron with lateral release
- IMA
- over 18-20 degrees
- Preferred correction (global)
- Proximal or basal osteotomy, or Lapidus (first TMT fusion)
- IMA
- any
- Preferred correction (global)
- First MTP arthrodesis
- BOFAS (British Orthopaedic Foot & Ankle Society) / UK — supports distal and diaphyseal osteotomy for the majority; reserves fusion for arthritic or recurrent disease.
- AO Foundation — standardises the scarf as a stable, screw-fixed diaphyseal osteotomy, emphasising the parallel horizontal cut to avoid troughing.
- Growing global interest in minimally invasive chevron-Akin (MICA) as an alternative to open scarf for moderate deformity, with comparable radiographic correction in early series. Frontal-plane (rotational) deformity — contemporary debate. Weight-bearing CT has highlighted metatarsal pronation as a driver of recurrence that a translation-only osteotomy does not correct. This underlies renewed enthusiasm for Lapidus and rotational correction; the scarf can incorporate a rotational component but does not reliably derotate the first ray — a recognised limitation in recurrent disease. Thromboprophylaxis. Forefoot osteotomy is a low-VTE-risk procedure; most national guidance (NICE, AAOS, ACCP-derived) recommends early mobilisation and does not mandate routine pharmacological prophylaxis. Reserve chemoprophylaxis (aspirin or LMWH) for patients with additional VTE risk factors, weighing bleeding risk. Scarf vs chevron. Both are highly effective for hallux valgus. The scarf handles more severe deformity (IMA up to 18° versus 13° for chevron), allows greater translation (up to 70% versus 50%), and offers multi-planar correction; satisfaction is similar at 85-90%. Long-term correction. Short-term correction is reliable — HVA typically improves from 33-35° to 14-17° (Crevoisier, Aminian, Adam series) and IMA from 15-16° to 7-10° (roughly 6-8° of correction), with sesamoid reduction in the majority when a lateral release is added. But long-term recurrence is high — up to 30% (HVA at least 20°) at 10-14 years in randomised and cohort data (Bock 2015; Jeuken and Deenik 2016). Patient satisfaction. 85-90% are satisfied or very satisfied; VAS pain falls from 6-7 to 1-2; 80-90% return to normal footwear; return to sport by 4-6 months. Complication rates (meta-analysis). Overall 20-30%; troughing 5-10% in experienced hands (up to 35% in early-learning-curve series, Coetzee 2003); recurrence 5-10% short-term but up to 30% radiographic recurrence at 10-14 years (Bock 2015; Jeuken and Deenik 2016); AVN 1-2%; hallux varus 2-5%; transfer metatarsalgia 10-15%; nerve injury 5-10%; reoperation 5-10%. Modifications. Extended scarf (a longer horizontal cut for very severe deformity, greater translation, higher technical demand); Scarf-Akin combination (addresses both metatarsal and phalangeal components, used in 30-40%, better correction of high DASA); Mini-scarf (a shorter construct for moderate deformity — less invasive but less powerful).
References
Scarf osteotomy for hallux valgus correction: local anatomy, surgical technique, and combination with other forefoot procedures
The foundational technique description that popularised the scarf in Western practice. It frames hallux valgus correction as four steps — lateral release, scarf osteotomy, medial capsulorrhaphy, and (where needed) an Akin phalangeal osteotomy — and defines the contraindications of a very thin first metatarsal, a severely arthritic MTP joint, and hypermobility with severe pes planus (which favours a Lapidus). No DOI was assigned to this 2000 review.
The scarf osteotomy for the treatment of hallux valgus deformity: a review of 84 cases
A review of 84 scarf osteotomies reporting the clinical and radiographic outcomes that helped establish the scarf as a reliable correction for moderate-to-severe deformity.
Scarf osteotomy for hallux valgus. A prospective clinical and pedobarographic study
A prospective clinical and pedobarographic study correlating radiographic correction of the scarf with pressure-platform (pedobarographic) findings.
Scarf osteotomy for hallux valgus repair: the dark side
The classic cautionary series of 20 consecutive scarf osteotomies in inexperienced hands — troughing in 35%, rotational malunion in 30%, early recurrence in 25%, and 45% dissatisfied at one year. It defines the learning curve and makes troughing the signature preventable complication.
The SCARF osteotomy for the correction of hallux valgus deformities
Clinical and radiographic outcomes of the scarf osteotomy for hallux valgus correction at intermediate follow-up.
Scarf osteotomy for hallux valgus deformity: an intermediate followup of clinical and radiographic outcomes
An intermediate follow-up of the clinical and radiographic outcomes of the scarf osteotomy in adult hallux valgus.
Equivalent correction in scarf and chevron osteotomy in moderate and severe hallux valgus: a randomized controlled trial
Randomised trial of 136 feet (115 patients) to scarf (66) versus chevron (70). No significant difference in HVA, IMA or DMAA correction in mild-to-moderate deformity; recurrent MTP subluxation was the main cause of insufficient correction in both groups (7 scarf, 5 chevron). Choice should follow deformity magnitude and surgeon experience, not an assumption that the scarf is inherently superior.
The Scarf osteotomy with minimally invasive lateral release for treatment of hallux valgus deformity: intermediate and long-term results
93 feet followed for a mean of 124 months (over 10 years). Median AOFAS improved from 57 to 95; HVA, IMA, DMAA and sesamoid position all significantly corrected, but recurrence (HVA at least 20 degrees) reached 30% at long-term follow-up, with higher final HVA linked to more pain. Counsel that roughly one in three may show radiographic recurrence by 10 years even with good initial correction.
Outcomes after scarf osteotomy for treatment of adult hallux valgus deformity
Outcomes after the scarf osteotomy for adult hallux valgus at intermediate follow-up.
Surgery for the correction of hallux valgus: minimum five-year results with a validated patient-reported outcome tool and regression analysis
Minimum five-year results after hallux valgus surgery using a validated patient-reported outcome tool, with regression analysis of the predictors of outcome.
Long-term follow-up of a randomized controlled trial comparing scarf to chevron osteotomy in hallux valgus correction
14-year follow-up of the randomised scarf-versus-chevron cohort (73 feet). Radiographic recurrence was high and similar in both groups (28/37 chevron, 27/36 scarf), with no difference in pain, AOFAS, SF-36 or MOXFQ; reoperation of the same toe was rare. At 14 years neither technique is superior in preventing recurrence.