Bunionette Deformity (Tailor's Bunion)

Coughlin Classification (Standard System)

The Coughlin classification divides bunionette deformities into three types based on radiographic location of the structural abnormality. This classification directly guides surgical decision-making.

Fallat Classification (Alternative System)

An alternative classification system (less commonly used):

• Type I: Lateral deviation of fifth MT head
• Type II: Lateral bowing of fifth MT shaft
• Type III: Enlargement of fifth MT head

Similar concept to Coughlin but different type numbering. Coughlin classification is more widely accepted and used in exam settings.

Radiographic Measurements

Other measurements:

• Fifth metatarsal head width: Increased in Type I deformity
• Metatarsal head position: Relationship to fourth MT head, degree of lateral prominence
• Declination angle: Sagittal plane alignment (lateral view)

These measurements are essential for surgical planning and classification.

Conservative Management (First-Line)

All patients should undergo adequate conservative trial before considering surgery.

Indications for conservative management:

• Mild to moderate symptoms
• Patient unwilling or medically unfit for surgery
• First presentation without previous conservative attempts
• Recommended trial period: 3-6 months minimum

Orthotic management:

• Custom foot orthoses with lateral posting
• Metatarsal pads to redistribute forefoot pressure away from fifth MT
• Arch support for concurrent pes planus if present
• Important: Orthoses improve symptoms but do not correct structural deformity

Activity modification:

• Reduce high-impact activities during symptomatic periods
• Cross-training with low-impact alternatives (swimming, cycling)
• Proper footwear for all activities
• Weight loss if obese (reduces forefoot loading)

Medications:

• NSAIDs for acute inflammatory episodes
• Topical anti-inflammatory preparations
• Acetaminophen for pain management (if NSAIDs contraindicated)

Physical therapy:

• Stretching exercises for foot and ankle
• Intrinsic foot muscle strengthening
• Gait training and biomechanical optimization
• Ice application for acute flares

Corticosteroid injection:

• Into bursa over fifth MT head
• May provide temporary relief (weeks to months)
• Risk of skin atrophy, depigmentation with superficial injection
• Not recommended as definitive treatment
• Useful for diagnostic confirmation

Outcomes of conservative management:

• Symptom improvement in 40-60% with appropriate shoe modification
• Most effective in mild deformity with primarily extrinsic shoe pressure
• Limited benefit for significant structural deformity
• Does not prevent progression of bony deformity
• Many patients eventually require surgical correction

Conservative management remains the first-line approach for all bunionette patients.

Surgical Management

Indications for surgery:

• Symptomatic bunionette despite adequate conservative trial (minimum 3-6 months)
• Pain significantly interfering with desired activities or footwear
• Progressive deformity causing increasing symptoms
• Recurrent skin breakdown, ulceration, or chronic bursitis
• Cosmetic concerns (relative indication - patient must understand risks and realistic expectations)

Contraindications:

Absolute contraindications:

• Active infection in surgical field
• Severe peripheral vascular disease with critical limb ischemia
• Unrealistic patient expectations or poor understanding
• Medical instability precluding elective surgery

Relative contraindications:

• Mild symptoms adequately managed conservatively
• Poor expected compliance with post-operative restrictions
• Active inflammatory arthropathy (may require modified approach)
• Significant medical comorbidities increasing perioperative risk
• Occupation requiring immediate return to unprotected weight-bearing

Careful patient selection is essential for optimal surgical outcomes.

Lateral Condylectomy for Type I Bunionette

Indications:

• Type I deformity (isolated lateral condyle enlargement)
• Normal 4-5 IM angle (under 8 degrees)
• No significant lateral deviation of fifth toe
• Minimal or no shaft bowing

Surgical principle:

• Remove prominent lateral bone without shortening metatarsal
• Preserve joint articular surface and MTP stability
• Minimal disruption of normal biomechanics
• Simplest procedure but highest recurrence rate (15-25%)

Setup:

• Supine position
• Ankle tourniquet (250 mmHg)
• Image intensifier available (C-arm)
• Standard small fragment orthopedic instruments
• Microsagittal saw

Step-by-step technique:

1. Incision:

   • Dorsolateral longitudinal incision centered over fifth MT head (3-4 cm length)
   • Can be straight or gently curvilinear
   • Protect dorsal sensory nerve branches (sural nerve distribution)

2. Exposure:

   • Identify and carefully protect neurovascular bundles
   • Longitudinal capsulotomy over lateral aspect of MT head
   • Subperiosteal reflection of capsule to expose lateral eminence
   • Define extent of bony prominence requiring resection

3. Osteotomy:

   • Use microsagittal saw or osteotome
   • Remove lateral eminence parallel to lateral metatarsal shaft
   • Extent: from dorsal cortex to plantar cortex
   • Remove only the prominent portion - avoid entering MTP joint articular surface
   • Resection should leave smooth lateral contour matching normal shaft

4. Bone smoothing:

   • Use rongeur or power burr to smooth all bony edges
   • Remove any remaining prominences or sharp corners
   • Palpate to ensure no residual lateral projection

5. Optional medial displacement:

   • If significant residual lateral prominence after condylectomy alone
   • Perform small chevron-type osteotomy at MT head-neck junction
   • Medial displacement 2-3 mm maximum
   • K-wire fixation (0.062 inch) if unstable

6. Capsule management:

   • Excise any redundant capsule if large chronic bursa present
   • Capsulorrhaphy with absorbable suture (3-0 or 4-0)
   • Consider medial capsular reef to help realign fifth toe position

7. Closure:

   • Meticulous layered closure
   • Subcutaneous tissue with 3-0 absorbable suture
   • Skin with 4-0 absorbable subcuticular or non-absorbable interrupted
   • Soft compressive dressing maintaining corrected fifth toe alignment

Technical pearls:

• Remove adequate bone to eliminate prominence but avoid excessive resection
• Stay lateral to MTP joint margin - preserve articular cartilage
• Smooth all edges meticulously to prevent recurrent bony prominences
• Consider intraoperative fluoroscopy to confirm adequate but not excessive resection
• Protect plantar lateral neurovascular bundle (most at risk)

Pitfalls to avoid:

• Inadequate bone removal leads to residual prominence and recurrence
• Excessive bone removal causes MT head instability and transfer metatarsalgia
• Violation of articular surface leads to post-operative degenerative arthritis
• Neurovascular injury (especially plantar lateral digital nerve to fifth toe)

Post-operative management:

• Post-operative shoe (rigid sole, open toe) for 2-4 weeks
• Weight-bearing as tolerated immediately
• Elevation and ice for first 72 hours
• ROM exercises start day 2-3 to prevent stiffness
• Return to normal wide toe box shoes at 4-6 weeks
• Full unrestricted activity at 6-8 weeks
• Radiographs at 6 weeks to assess bone healing

Expected outcomes:

• Success rate: 65-80% (lower than osteotomy procedures)
• Recurrence rate: 15-25% (highest of all bunionette procedures)
• Best results in true Type I deformity without structural IMA increase
• Patient satisfaction: 70-85%

This procedure concludes the lateral condylectomy technique for Type I bunionette deformity.

Distal Chevron Osteotomy for Type II Bunionette

Indications:

• Type II deformity (lateral shaft bowing)
• Normal or mild increased 4-5 IM angle (under 10-13 degrees)
• Apex of deformity at distal metatarsal or MT head-neck junction
• Desire to maintain metatarsal length
• Good bone quality for fixation

Surgical principle:

• V-shaped osteotomy allows medial displacement of MT head
• Corrects lateral prominence from shaft bowing
• Inherently stable design
• Maintains metatarsal length
• Allows early mobilization with rigid fixation

Setup:

• Supine position
• Ankle tourniquet
• Image intensifier (C-arm) essential
• Small fragment instruments, microsagittal saw
• 2.0 mm or 2.7 mm cannulated screw set or K-wires

Step-by-step technique:

1. Approach:

   • Dorsolateral longitudinal incision over fifth MT head-neck junction (4 cm)
   • Protect sural nerve branches (dorsal and lateral cutaneous nerves)
   • Longitudinal capsulotomy exposing lateral MT head and neck
   • Subperiosteal elevation of capsule and periosteum

2. Planning the chevron cut:

   • Mark apex at center of MT head with marking pen or K-wire
   • Plan V-shaped osteotomy in coronal plane
   • Standard angle: 60 degrees (30 degrees each limb from longitudinal axis)
   • Dorsal and plantar arms of equal length

3. Chevron osteotomy execution:

   • Use microsagittal saw with narrow blade
   • Carefully protect plantar soft tissues during plantar arm cut
   • First arm: dorsal-distal to plantar-proximal
   • Second arm: plantar-distal to dorsal-proximal
   • Complete both cuts meeting at apex
   • Ensure cuts are through-and-through but avoid soft tissue damage

4. Displacement:

   • Medially displace capital (head) fragment 3-5 mm
   • Ensure congruent bone-to-bone contact
   • Check alignment with image intensifier
   • Avoid excessive displacement (causes shortening and transfer metatarsalgia)

5. Fixation:

   • Preferred: Single 2.0 mm or 2.7 mm cannulated lag screw
     • Insert guide wire from dorsal-lateral to plantar-medial across osteotomy
     • Confirm position with fluoroscopy (AP and lateral views)
     • Measure, drill, countersink, insert screw
     • Screw head should be buried beneath lateral cortex
   • Alternative: Two 0.062 inch K-wires divergent pattern
     • Cross both cortices for stability
     • Bend and cut outside skin (remove at 6 weeks)

6. Lateral eminence management:

   • Remove any residual lateral prominence (lateral condylectomy)
   • Smooth all osteotomy edges with rongeur or burr
   • Ensure no sharp corners or bony projections remain

7. Capsular closure:

   • Repair capsule with 3-0 or 4-0 absorbable suture
   • Consider medial capsular reef if fifth toe valgus present
   • Avoid over-tightening (can restrict ROM)

8. Wound closure:

   • Layered closure: subcutaneous then skin
   • Soft dressing maintaining alignment
   • Compressive but not constrictive

Technical pearls:

• Standard 60-degree chevron provides excellent stability
• Can modify angle for more (acute angle) or less (obtuse angle) correction potential
• Fluoroscopy essential - confirm osteotomy position and fixation in two planes
• Remove lateral condyle after displacement if residual bump present
• Lag screw technique provides superior stability over K-wires
• Avoid shortening more than 2-3 mm total (measure pre-op and post-op length)

Pitfalls to avoid:

• Excessive medial displacement (over 5 mm) causes shortening
• Inadequate displacement leaves residual lateral prominence
• Saw blade injury to plantar soft tissues during plantar arm cut
• Malrotation of head fragment (check alignment carefully)
• Screw penetration into MTP joint (confirm on lateral fluoroscopy)

Post-operative protocol:

• Post-operative shoe (rigid sole) for 6 weeks
• Protected weight-bearing weeks 0-2, then progressive weight-bearing
• ROM exercises begin week 2 (gentle active and passive)
• Radiographs at 2 weeks and 6 weeks
• Return to normal wide shoes at 6-8 weeks once union confirmed
• Full unrestricted activity at 10-12 weeks
• Hardware removal rarely needed (only if symptomatic)

Expected outcomes:

• Success rate: 85-90%
• Patient satisfaction: 85-92%
• Recurrence rate: 5-10% (much lower than condylectomy)
• Predictable correction of lateral deviation
• Low complication rate
• Union rate: over 95%

This completes the distal chevron osteotomy technique for Type II bunionette.

Proximal Oblique Osteotomy for Type III Bunionette

Indications:

• Type III deformity (increased 4-5 IM angle over 8-10 degrees)
• Splay foot with pathologic divergence of fourth and fifth metatarsals
• Apex of deformity at metatarsal base or TMT joint
• Need for significant IMA correction (distal procedures inadequate)

Surgical principle:

• Correct increased 4-5 IM angle at proximal metatarsal (apex of deformity)
• Greater correction potential than distal procedures for IMA reduction
• Addresses structural cause of lateral forefoot splay
• Requires rigid fixation (less inherent stability than distal osteotomies)

Setup:

• Supine position
• Ankle tourniquet
• Image intensifier essential for this procedure
• Small fragment instruments, microsagittal saw
• 2.0 mm or 2.7 mm screw fixation set (two screws recommended)

Step-by-step technique:

1. Incision:

   • Dorsolateral incision over proximal fifth metatarsal (4-5 cm length)
   • Centered 1-3 cm distal to fifth MT base
   • Protect sural nerve and its branches carefully
   • Extensile incision may be needed for adequate exposure

2. Exposure:

   • Subperiosteal exposure of proximal metatarsal shaft
   • Identify and protect peroneus brevis tendon insertion (at MT base)
   • Minimal soft tissue stripping to preserve blood supply
   • Clear periosteum only where osteotomy planned

3. Osteotomy planning:

   • Mark osteotomy site 1-2 cm distal to MT base
   • Oblique orientation: dorsal-distal to plantar-proximal
   • Angle typically 45-60 degrees from horizontal
   • This orientation allows medial displacement and rotation

4. Osteotomy execution:

   • Use microsagittal saw
   • Oblique cut from dorsal-distal to plantar-proximal
   • Protect soft tissues, especially plantar structures
   • Complete osteotomy but maintain some soft tissue hinge if possible

5. Correction maneuver:

   • Medially displace distal fragment
   • Rotate to correct 4-5 IM angle (close down the intermetatarsal space)
   • Check with image intensifier (aim for IMA under 8 degrees)
   • May achieve 3-5 mm of lateral correction per mm of medial displacement
   • Ensure adequate bone-to-bone contact for healing

6. Fixation:

   • Preferred: Two 2.0 mm or 2.7 mm lag screws
     • First screw: perpendicular to osteotomy for compression
     • Second screw: oblique for rotational stability
     • Confirm position with AP and lateral fluoroscopy
   • Alternative: Single screw plus K-wire, or mini-plate
   • Rigid fixation essential for early mobilization and union

7. Verification:

   • Confirm 4-5 IMA corrected to under 8 degrees on fluoroscopy
   • Check no shortening or malrotation of fifth MT
   • Ensure smooth lateral contour without residual prominence
   • May perform distal lateral condylectomy if needed

8. Closure:

   • Periosteal closure with absorbable suture if possible (improves healing)
   • Layered soft tissue closure
   • Skin closure with absorbable or non-absorbable suture
   • Compressive dressing

Technical pearls:

• Proximal osteotomy provides superior IMA correction compared to distal procedures
• Oblique cut orientation allows both translation and rotation
• Two-screw fixation significantly more stable than single screw
• Protect peroneus brevis insertion at fifth MT base (important lateral stabilizer)
• Monitor for potential fifth MT base stress fracture post-operatively (rare)

Pitfalls to avoid:

• Insufficient IMA correction (undercorrection) leads to recurrence
• Excessive medial displacement causes fifth MT to cross under fourth MT
• Inadequate fixation results in loss of correction or nonunion
• Extensive soft tissue stripping impairs blood supply and healing
• Injury to peroneus brevis tendon

Post-operative protocol:

• Post-operative shoe or walking boot for 6-8 weeks
• Non-weight-bearing or toe-touch weight-bearing for 2-3 weeks (more conservative than distal osteotomy due to proximal location)
• Progressive weight-bearing weeks 3-6 as tolerated
• Serial radiographs at 2 weeks, 6 weeks, and 12 weeks
• Return to normal shoes once radiographic union confirmed (typically 8-10 weeks)
• Full unrestricted activity at 12-16 weeks
• Longer recovery than distal procedures

Expected outcomes:

• Success rate: 80-85%
• Better IMA correction than distal procedures (can correct 5-8 degrees)
• Nonunion risk: 5-8% (higher than distal osteotomy)
• Transfer metatarsalgia: 8-10%
• Patient satisfaction: 80-85%
• Recurrence: 5-10% if adequate correction achieved

This concludes the proximal oblique osteotomy technique for Type III bunionette deformity.

Oblique Shaft (Diaphyseal) Osteotomy for Combination Deformity

Indications:

• Combination deformity (Type II plus Type III - most common clinical scenario)
• Both lateral shaft bowing AND increased 4-5 IM angle present
• Desire to address multiple components with single osteotomy
• Avoidance of staged or multiple procedures

Surgical principle:

• Single oblique osteotomy through mid-shaft addresses both shaft bowing and IMA increase
• Greater correction potential than isolated distal osteotomy
• Single procedure more efficient than combined distal and proximal osteotomies
• Requires careful pre-operative planning to determine optimal osteotomy location and angle

Advantages over other procedures:

• Addresses both Type II (bowing) and Type III (IMA) components
• Single incision and osteotomy site
• Versatile - can customize cut orientation for individual deformity
• Good correction potential for moderate to severe deformity

Disadvantages:

• Technically more demanding
• Less inherent stability than chevron
• Requires meticulous fixation
• Longer healing time than distal procedures

Surgical technique (key steps):

1. Incision:

   • Dorsolateral longitudinal incision over mid-shaft fifth metatarsal (5-6 cm)
   • Centered at planned osteotomy site (mid-shaft or junction of middle and proximal thirds)

2. Osteotomy:

   • Oblique osteotomy orientation: distal-dorsal to proximal-plantar
   • Angle typically 45-60 degrees from metatarsal long axis
   • Location determines what can be corrected (more proximal = better IMA correction)

3. Correction:

   • Medial translation of distal fragment (corrects IMA)
   • Rotation of distal fragment (straightens lateral bow)
   • May shorten 2-3 mm if needed to achieve bone contact

4. Fixation:

   • Two or three screws (2.7 mm) in lag fashion
   • Alternative: mini-plate (dorsal or lateral application)
   • Rigid fixation essential

5. Post-operative:

   • Protected weight-bearing for 4-6 weeks
   • Boot or post-operative shoe for 6-8 weeks
   • Progressive return to activity weeks 8-12

Outcomes:

• Success rate: 85-90% for appropriate combination deformities
• Recurrence: 5-10%
• Nonunion: 5-7% (intermediate between distal and proximal)

This technique is advanced and typically reserved for experienced foot and ankle surgeons managing complex combination bunionette deformities.