TMT Arthritis

1. Clinical Overview

Summary

Arthritis of the Tarsometatarsal (TMT) joints, also known as Midfoot Arthritis, is a common cause of dorsal foot pain and difficulty wearing shoes. It primarily affects the 2nd and 3rd TMT joints (the rigid "Keystone" of the foot), often as a sequela of old Lisfranc injuries or primary degeneration. A hallmark sign is the formation of a large dorsal osteophyte known as the "100 Dollar Bump" (or "Saddle Bone"), which rubs against laces. [1,2]

The tarsometatarsal complex consists of five joints between the three cuneiforms and cuboid proximally, and the five metatarsal bases distally. The middle column (2nd and 3rd TMT joints) experiences the highest mechanical stress and demonstrates minimal physiological motion, making it most susceptible to degenerative changes. [3,4]

Treatment emphasizes stiff-soled shoes to minimize midfoot stress. Surgery involves fusion (arthrodesis) of the medial and middle columns, while the lateral column (4th/5th) is usually preserved to maintain foot accommodation. Arthrodesis provides reliable pain relief with fusion rates exceeding 90% and high patient satisfaction scores. [5,6]

Key Facts

• The Column Theory: [7]
  • Medial Column (1st Ray): Mobile. Essential for shock absorption. Approximately 10mm of sagittal motion.
  • Middle Column (2nd/3rd Rays): Extremely rigid. The "Keystone". Most prone to primary OA. Less than 2mm sagittal motion.
  • Lateral Column (4th/5th Rays): Mobile. Essential for uneven ground. Approximately 10mm sagittal motion.
• The "100 Dollar Bump": Midfoot bossing (osteophytes) creates a prominence. It's called the $100 bump because patients can no longer wear inexpensive shoes; they require expensive, custom-fit footwear.
• Fusion Rule: You can fuse the 1st, 2nd, and 3rd TMT joints with impunity (they don't move much anyway). NEVER fuse the 4th and 5th if possible—it leads to a stiff, painful lateral foot and stress fractures. [8,9]

Clinical Pearls

"Lace Pain": The most specific historical clue. "My foot hurts right where I tie my shoelaces."

"Piano Key Test": Provocative maneuver. Hold the hindfoot and stress individual metatarsals up and down. Pain localizes the specific arthritic joint.

"Charcot Mimic": In a diabetic patient with new midfoot swelling/pain, this is Charcot Neuroarthropathy (active phase) until proven otherwise. Do not inject steroids!

"Weightbearing Films Essential": Non-weightbearing radiographs may underestimate the severity of joint collapse and malalignment. Always obtain standing views. [10]

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2. Epidemiology

Demographics

• Age: Typically > 50 years for primary osteoarthritis. [1]
• History: Often remote trauma (dropped object, sprain 20 years ago). Post-traumatic arthritis may occur at any age following Lisfranc injury. [2]
• Population: Females > Males (possibly related to high heels and narrow shoe wear). [11]
• Prevalence: Midfoot arthritis accounts for approximately 13% of all foot and ankle arthritis cases requiring surgical intervention. [12]

Risk Factors

• Previous Lisfranc injury: Most significant risk factor for post-traumatic TMT arthritis. Even subtle Lisfranc injuries can lead to progressive degeneration. [2,13]
• Pes planus (flatfoot): Increased mechanical stress on midfoot joints. [14]
• Inflammatory arthropathies: Rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis.
• Obesity: Increased mechanical load.
• Diabetes mellitus: Associated with Charcot neuroarthropathy.
• Occupational: Prolonged standing, manual labor, military service.

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3. Pathophysiology

Anatomy

• Joints: [7,15]
  • 1st TMT (Medial Cuneiform - 1st Metatarsal).
  • 2nd TMT (Middle Cuneiform - 2nd Metatarsal). Defined by the "Mortise" (recessed between cuneiforms).
  • 3rd TMT (Lateral Cuneiform - 3rd Metatarsal).
  • 4th TMT (Cuboid - 4th Metatarsal).
  • 5th TMT (Cuboid - 5th Metatarsal).
• Sagittal Motion: [7]
  • 1st Ray: 10mm.
  • 2nd Ray: 0.6mm (Rigid).
  • 3rd Ray: 1.6mm.
  • 4th/5th Rays: 10mm (Mobile).
• Ligamentous Stability: The Lisfranc ligament (from medial cuneiform to 2nd metatarsal base) is the primary stabilizer of the TMT complex. Additional dorsal, plantar, and interosseous ligaments provide stability. [13]

The Stress Riser Concept

The 2nd TMT joint acts as the fulcrum of the foot lever. The 2nd metatarsal is recessed into the mortise formed by the three cuneiforms, creating a "Roman arch" configuration that distributes load. However, this keystone position concentrates forces during gait, explaining why primary osteoarthritis is most common at the 2nd TMT joint. [3,4]

During push-off phase of gait, approximately 60% of body weight is transmitted through the midfoot, with peak pressures occurring at the 2nd TMT joint. This repetitive loading leads to cartilage degeneration over time. [16]

Degenerative Cascade

1. Cartilage Wear: Initial proteoglycan loss and collagen disruption.
2. Subchondral Sclerosis: Bone responds to increased stress with increased density.
3. Osteophyte Formation: Dorsal osteophytes develop as the body attempts to increase surface area and distribute load. The "100 Dollar Bump" is the clinical manifestation.
4. Joint Space Collapse: Progressive narrowing leads to bone-on-bone contact.
5. Deformity: Loss of arch height, abduction of forefoot, secondary deformities in adjacent joints. [1,17]

Post-Traumatic Arthritis

Following Lisfranc injuries, even anatomic reduction may not prevent arthritis. Cartilage damage at the time of injury, residual instability, and altered biomechanics all contribute to accelerated degeneration. Studies show 50-94% of patients develop post-traumatic arthritis within 5-10 years following Lisfranc injury. [2,13]

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4. Clinical Presentation

Symptoms

• Pain: Dorsal midfoot pain. Aching quality. Worse with first steps (start-up pain) and after prolonged standing or walking. [1]
• Bossing: Hard bony lump on top of the foot causing pressure symptoms.
• Shoe Wear: Difficulty fitting into slip-ons, boots, or laced shoes. Patients report needing to buy shoes one size larger.
• Activity Limitation: Difficulty with uneven ground, stairs, prolonged walking.
• Stiffness: Particularly after rest. Improves with gentle activity (mechanical symptoms).

Signs

• Visual Inspection:
  • Dorsal exostosis (palpable and visible prominence).
  • Flatfoot deformity (if navicular or Lisfranc ligaments have failed).
  • Forefoot abduction (increased angle between hindfoot and forefoot).
  • Callus formation under metatarsal heads (transfer metatarsalgia).
• Palpation:
  • Point tenderness directly over the affected TMT joints.
  • Palpable osteophytes dorsally.
  • Warmth suggests inflammatory phase or Charcot.
• Range of Motion:
  • Reduced midfoot motion (normally minimal).
  • Pain on pronation/abduction of forefoot.
• Special Tests: [18]
  • Piano Key Test: Stabilize hindfoot, dorsiflex/plantarflex individual metatarsals. Pain and hypermobility indicate arthritic joint.
  • TMT Compression Test: Compress forefoot against midfoot. Pain localizes arthritis.
  • Single Limb Stance: Inability to perform single-leg heel raise suggests significant midfoot instability.

Differential Diagnosis

• Charcot Neuroarthropathy: Diabetic patient, acute swelling, warmth, erythema, rocker-bottom deformity. [19]
• Midfoot Tendinopathy: Tibialis posterior, peroneus longus. More diffuse pain, reproducible with tendon loading.
• Navicular Stress Fracture: Athletes, point tenderness over navicular, positive "N spot."
• Lisfranc Sprain: Acute injury, normal radiographs, ligamentous tenderness.
• Morton's Neuroma: Interdigital pain, Mulder's click, neurogenic symptoms.
• Plantar Fasciitis: Plantar heel pain, worse with first steps.
• Inflammatory Arthropathy: Bilateral, systemic symptoms, laboratory markers.

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5. Investigations

Imaging

X-Ray (Weight Bearing) - First Line [10,20]

• AP View:
  • Joint space narrowing (gold standard: less than 2mm).
  • Subchondral sclerosis.
  • Osteophyte formation.
  • Alignment: assess for abduction deformity (increased 1st-2nd intermetatarsal angle).
  • Loss of parallel alignment between medial cuneiform and 2nd metatarsal.
• Lateral View:
  • Dorsal osteophytes (beaking).
  • Sag of the longitudinal arch (reduced talo-first metatarsal angle).
  • Joint space assessment.
  • Plantar gapping (sign of instability).
• Oblique View:
  • Better visualization of 3rd, 4th, 5th TMT joints.
  • Intercuneiform arthritis.

Critical Point: Non-weightbearing radiographs are inadequate. The deformity and joint collapse are often only apparent under load. [10]

CT Scan - Gold Standard for Surgical Planning [21]

• Indications:
  • Pre-operative planning to determine exactly which joints require fusion.
  • Assessment of intercuneiform and naviculocuneiform involvement.
  • Evaluation of bone quality for fixation planning.
  • Detection of subtle fractures or loose bodies.
• Protocol: Axial cuts with coronal and sagittal reconstructions. Weightbearing CT (if available) provides superior assessment of alignment.
• Key Findings:
  • Precise determination of arthritic joints (not all five TMT joints may be involved).
  • Cystic changes suggesting advanced disease.
  • Degree of deformity for corrective planning.

MRI - Limited Role

• Indications:
  • Suspected Charcot (bone marrow edema, fragmentation).
  • Evaluation of soft tissue masses.
  • Ligamentous injury assessment (acute Lisfranc sprain).
• Findings:
  • Bone marrow edema suggests active inflammation.
  • Synovitis, joint effusion.
  • Ligament discontinuity or thickening.

Nuclear Medicine - Specific Indications

• Bone Scan (Tc-99m MDP): Increased uptake in arthritic joints. Useful for identifying occult pathology or differentiating between multiple pain generators.
• White Cell Scan: If infection suspected (diabetic foot, post-operative).

Diagnostic Injection [22]

• Essential Tool: If X-rays show diffuse disease but pain is localized, fluoroscopic-guided injection determines which joints to fuse.
• Technique:
  • 1-2 mL local anesthetic (0.5% bupivacaine) + steroid (40mg methylprednisolone).
  • Inject specific joint under fluoroscopic guidance.
  • Patient ambulates immediately and reports pain relief.
• Interpretation:

  • 80% pain relief confirms that joint as primary pain generator.

  • Partial relief suggests multiple joints involved.
  • No relief suggests alternative diagnosis.
• Therapeutic Effect: 3-6 months pain relief in 60-70% of patients. May be repeated but generally limited to 3 injections per year.

Laboratory Studies - Selective Use

• Inflammatory Markers: ESR, CRP if inflammatory arthropathy suspected.
• Rheumatoid Factor, Anti-CCP: If rheumatoid arthritis suspected.
• Uric Acid: If gout suspected (rare in TMT joints).
• HbA1c: In diabetic patients to assess control and Charcot risk.

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6. Management Algorithm

                  MIDFOOT PAIN
                        ↓
              X-RAY: TMT ARTHRITIS
             ┌──────────┴──────────┐
         COLUMN 1/2/3            COLUMN 4/5
              ↓                       ↓
        CONSERVATIVE            CONSERVATIVE
    (Stiff Sole / NSAID)        (Wide Shoe)
              ↓                       ↓
         Trial 3-6 months         Trial 3-6 months
              ↓                       ↓
           FAILED?                 FAILED?
              ↓                       ↓
      Diagnostic Injection      Diagnostic Injection
              ↓                       ↓
         Confirms Joint?         Confirms Joint?
              ↓                       ↓
           FUSION               RESECTION
       (Arthrodesis)         (Interposition Arthroplasty)
              ↓                       ↓
      Plates vs Screws         Remove Joint Surfaces
         Bone Graft            Insert Spacer (Tendon)

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7. Management: Conservative

First-Line Treatment (3-6 Months Trial) [1,23]

Footwear Modification

• Stiff Soles: Carbon fiber insert or hiking boots. The goal is to stop the midfoot from bending (acting as a lever) during push-off, thus reducing stress on arthritic joints.
• Rocker Bottom: External rocker sole rolls the foot forward, bypassing the midfoot hinge. Reduces TMT joint motion by approximately 40%.
• Wide Toe Box: Accommodates forefoot abduction and reduces pressure.
• Cushioned Insoles: Absorbs shock, though evidence is limited for pain reduction.
• Custom Orthotics: Semi-rigid arch support may help redistribute pressure away from painful joints. Success rate approximately 50-60% for symptom relief.

Lacing Technique

• Skip Lacing: Skip eyelets over the prominent dorsal bump to reduce direct pressure on osteophytes.
• Elastic Laces: Allow shoe to expand during walking.

Pharmacological

• NSAIDs: First-line analgesics. Oral (ibuprofen 400mg TDS, naproxen 500mg BD) or topical (diclofenac gel).
• Acetaminophen: Alternative for patients who cannot tolerate NSAIDs.
• Topical Capsaicin: May provide modest relief.
• Note: No role for disease-modifying agents in primary osteoarthritis (unlike inflammatory arthropathies).

Activity Modification

• Avoid high-impact activities (running, jumping).
• Low-impact alternatives: swimming, cycling.
• Weight loss if obese (reduces mechanical load).

Physical Therapy

• Goals: Maintain ankle and hindfoot ROM, strengthen intrinsic foot muscles, improve proprioception.
• Modalities: Ultrasound, iontophoresis (limited evidence).
• Gait Training: Optimize walking mechanics to reduce midfoot stress.

Second-Line: Injections [22,24]

• Indications: Failed conservative measures for 3+ months, not ready for surgery, diagnostic uncertainty.
• Technique: Fluoroscopic-guided corticosteroid injection (40mg methylprednisolone + 1mL 0.5% bupivacaine).
• Efficacy: 60-70% report significant pain relief. Duration 3-6 months on average.
• Frequency: Maximum 3 injections per year (risk of cartilage damage with repeated injections).
• Contraindications: Active infection, diabetes with poor control (relative), Charcot foot.

Outcome of Conservative Treatment

Success rates (defined as adequate symptom control to avoid surgery) range from 40-60% at 2 years. Predictors of conservative success include mild radiographic changes, isolated joint involvement, and patient willingness to modify footwear permanently. [1,23]

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8. Management: Surgical

Indications for Surgery [5,6,25]

• Failure of conservative treatment for minimum 3-6 months.
• Persistent pain limiting activities of daily living.
• Progressive deformity.
• Patient willing to accept surgical risks and rehabilitation.

1. Arthrodesis (Fusion) - Gold Standard [5,6,26]

Indications

• Painful arthritis of medial/middle columns (1st, 2nd, 3rd) failing conservative care.
• Post-traumatic arthritis following Lisfranc injury.
• Advanced degenerative disease with deformity.

Surgical Technique

• Approach:
  • Two dorsal longitudinal incisions (between 1st/2nd and 3rd/4th metatarsals).
  • Identify and protect neurovascular structures (dorsalis pedis artery, deep peroneal nerve).
  • Incise joint capsules, expose articular surfaces.
• Joint Preparation:
  • Remove all articular cartilage down to bleeding subchondral bone using curettes, osteotomes, or burr.
  • Remove dorsal osteophytes (improves shoe fit and wound closure).
  • Correct deformity: restore arch height, correct abduction, achieve neutral alignment.
  • Prepare "fish-scale" bleeding bone surfaces to maximize fusion surface area.
• Fixation Options: [27,28]
  • Dorsal Plates: Provide superior construct stiffness, allow compression. Risk of prominence and irritation (10-15% require removal).
  • Compression Screws: Interfragmentary compression, lower profile. Cannulated screws over guidewires for precision. Typically 3.5mm or 4.0mm cortical screws.
  • Hybrid Construct: Combination of plate + screw provides maximal stability. Current gold standard for complex cases.
  • Locking Plates: In osteopenic bone or revision cases.
• Bone Graft: [29]
  • Indications: Large joint gaps, revision surgery, osteoporosis, smoking.
  • Autograft: Calcaneus (local), iliac crest (if large volume needed). Gold standard.
  • Allograft: Cancellous chips. Osteoinductive but less effective than autograft.
  • Bone Graft Substitutes: Calcium phosphate, BMP (off-label use). Mixed evidence.

Post-Operative Protocol

• Immobilization: Below-knee cast or boot, non-weightbearing for 6 weeks.
• Protected Weightbearing: Weeks 6-12, progressive weightbearing in boot.
• Full Weightbearing: 12 weeks if radiographic union evident.
• Return to Activity: 4-6 months for full unrestricted activity.

Outcomes [5,6,30]

• Fusion Rate: 85-95% overall. Higher with rigid fixation and bone graft.
• Pain Relief: 80-90% report significant improvement in pain scores (VAS reduction > 50%).
• Patient Satisfaction: 75-85% satisfied or very satisfied.
• Functional Scores: AOFAS midfoot score improves from average 45 pre-op to 75 post-op.
• Return to Work: 85-90% return to previous employment, though manual laborers may require job modification.

2. Exostectomy (Bump Removal) - Limited Role [31]

Indications

• Pain is primarily from shoe pressure on dorsal osteophyte.
• Minimal deep joint pain on examination.
• Well-preserved joint space on imaging.
• Patient refuses arthrodesis.

Procedure

• Simple shaving of dorsal exostosis through small incision.
• Preserve joint capsule integrity.
• Smooth bone edges.

Outcomes

• Short-term relief in 60-70%.
• Does NOT treat underlying arthritis.
• Progressive symptoms likely over 3-5 years.
• May serve as bridge to eventual fusion.

3. Interposition Arthroplasty - Lateral Column Only [8,9,32]

Indications

• 4th and 5th TMT joints arthritis.
• Isolated lateral column disease.

Rationale

Fusing the lateral column (4th/5th TMT joints) causes a rigid lateral foot, leading to stiffness, pain on uneven ground, and stress fractures of the lateral metatarsals. Resection arthroplasty maintains motion while relieving pain. [8,9]

Technique

• Remove articular surfaces of 4th and/or 5th TMT joints.
• Create 2-3mm gap.
• Interpose spacer:
  • Tendon (extensor digitorum brevis).
  • Joint capsule.
  • Commercial spacer (silicone, pyrocarbon - less common).
• Close capsule to stabilize spacer.

Outcomes [32]

• 70-80% good to excellent pain relief.
• Maintained lateral column motion.
• Lower satisfaction than medial/middle column fusion.
• Revision rate approximately 15-20%.

4. Revision Surgery - Complex Cases

Indications

• Non-union despite adequate conservative trial (> 6 months).
• Painful malunion with deformity.
• Hardware failure or prominence.

Technique

• Remove previous hardware.
• Excise non-union fibrous tissue.
• Refresh bone surfaces.
• Consider bone graft (autograft preferred).
• Rigid fixation (often hybrid construct).
• Consider biological augmentation (BMP - off-label).

Outcomes

• Fusion rate 70-85% (lower than primary).
• Higher complication rate.
• Longer immobilization typically required.

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9. Complications

Non-Union [29,33]

• Incidence: 5-15% overall. Higher in smokers (up to 25%), diabetics, osteoporosis.
• Risk Factors:
  • Smoking (most significant modifiable factor).
  • Diabetes mellitus.
  • NSAIDs in early post-operative period.
  • Inadequate fixation.
  • Poor bone quality.
  • Patient non-compliance with weightbearing restrictions.
• Diagnosis: Persistent pain beyond 3-4 months, lack of bridging bone on CT scan at 6 months.
• Management:
  • Observation if asymptomatic (20-30% of radiographic non-unions are painless).
  • Revision fusion if symptomatic: debride fibrous tissue, bone graft, rigid fixation.

Malunion/Malalignment

• Incidence: 5-10%.
• Manifestations: Loss of arch height, forefoot abduction, transfer metatarsalgia.
• Prevention: Intraoperative fluoroscopy, provisional fixation before final compression.
• Management: Corrective osteotomy and re-fusion if symptomatic.

Nerve Injury

• Deep Peroneal Nerve: [34]
  • Runs directly over 1st and 2nd TMT joints, between EHL and EDL tendons.
  • Injury causes numbness in first webspace (no motor deficit at this level).
  • Incidence: 2-5%.
  • Usually neurapraxia resolving over 3-6 months.
• Superficial Peroneal Nerve: Risk with lateral incisions. Dorsal foot numbness.
• Prevention: Careful dissection, identify nerve branches before retraction, minimize prolonged retraction.

Vascular Injury

• Dorsalis Pedis Artery: Runs with deep peroneal nerve. Pulsatile bleeding if injured.
• Management: Direct repair, ligation if necessary (collateral circulation usually adequate).

Prominent Hardware [35]

• Incidence: 10-15% with dorsal plating.
• Symptoms: Palpable hardware, shoe pressure, pain.
• Management: Elective removal once union confirmed (minimum 12 months).

Adjacent Joint Arthritis

• Incidence: 10-20% over 5-10 years.
• Commonly Affected: Naviculocuneiform, intercuneiform, metatarsophalangeal joints.
• Mechanism: Altered biomechanics after fusion shifts stress to adjacent joints.
• Management: Conservative measures; fusion extension if necessary.

Infection

• Superficial: 2-5%. Treat with antibiotics, wound care.
• Deep/Hardware: 1-2%. May require hardware removal and prolonged antibiotics.
• Higher Risk: Diabetes, immunosuppression, smoking.

Complex Regional Pain Syndrome (CRPS)

• Incidence: 1-2%.
• Diagnosis: Budapest criteria - pain disproportionate to injury, sensory/vasomotor/sudomotor changes.
• Management: Early mobilization, physiotherapy, pharmacotherapy (gabapentin, duloxetine), sympathetic blocks.

Stress Fractures - Lateral Column Fusion

• Incidence: 15-25% if 4th/5th TMT joints fused. [8,9]
• Location: 4th or 5th metatarsal shaft.
• Mechanism: Loss of lateral column mobility creates rigid lever, overloading metatarsal shafts.
• Prevention: AVOID fusing lateral column if possible.

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10. Evidence & Guidelines

Fixation: Plates vs Screws [27,28]

Landmark Study - Comparative Biomechanics: Compression screws provide higher compressive forces at the fusion site (average 300N vs 150N for plates alone). However, dorsal plates provide superior construct stiffness against dorsiflexion and plantarflexion moments. A hybrid construct (dorsal plate + interfragmentary screw) combines advantages and is biomechanically strongest. [27]

Clinical Outcomes: Randomized trial comparing screws alone vs plates alone vs hybrid fixation showed no difference in fusion rates (all > 90%) but hybrid fixation had lowest pain scores at 3 months. Hardware removal rates were highest for plates (18%) vs screws (6%). [28]

Current Recommendation: Isolated joint: compression screws adequate. Multiple joints or osteoporotic bone: consider hybrid fixation. Patient counseling regarding potential hardware removal with plates.

Lateral Column (4th and 5th) Management [8,9,32]

Shawen et al Study: Case series of 24 patients with 4th/5th TMT fusion showed 58% poor outcomes, with complaints of lateral foot stiffness, pain on uneven ground, and inability to perform previous activities. Six patients (25%) developed lateral metatarsal stress fractures. Comparison group with resection arthroplasty had 75% good outcomes. [8]

Biomechanical Studies: Cadaveric studies demonstrate that 4th/5th TMT fusion reduces lateral column motion by 85%, increasing stress on 4th/5th metatarsal shafts by 60%. Resection arthroplasty maintains 70% of normal lateral column motion. [9]

Current Recommendation: Isolated medial/middle column arthritis: fuse 1st/2nd/3rd, preserve 4th/5th. Isolated lateral column arthritis: resection arthroplasty preferred over fusion. Pan-midfoot arthritis: individualized decision, but preserve lateral column when possible.

Bone Graft in TMT Fusion [29]

Systematic Review: Analysis of 32 studies (1,247 patients) showed fusion rates of 92% with bone graft vs 87% without (p=0.04). Benefit most pronounced in smokers (fusion rate 78% with graft vs 58% without) and revision cases. Autograft superior to allograft (94% vs 88% fusion). [29]

Current Recommendation: Bone graft not mandatory for primary fusion in healthy non-smokers with good bone quality. Consider autograft for: smoking, diabetes, osteoporosis, revision surgery, large joint gaps (> 3mm).

Outcomes After TMT Arthrodesis [5,6,30]

Long-term Follow-up Studies: Five-year outcomes after TMT arthrodesis show sustained pain relief (80% VAS improvement maintained), though 20% develop adjacent joint arthritis requiring treatment. Patient satisfaction remains high (82% would undergo surgery again). Return to high-impact sports is limited (30% return to running), but low-impact activities are well tolerated. [30]

Prognostic Factors for Success:

• Non-smoker: OR 3.2 (95% CI 1.8-5.7)
• Single joint involvement: OR 2.4 (95% CI 1.3-4.5)
• No workers' compensation: OR 2.8 (95% CI 1.5-5.2)
• Age less than 60 years: OR 1.9 (95% CI 1.1-3.4)

Conservative Treatment Evidence [23,24]

Rocker Sole Biomechanics: Gait analysis studies demonstrate that rocker-bottom sole modification reduces TMT joint motion by 35-45% and decreases peak plantar pressure under midfoot by 30%. Clinical correlation shows 55% of patients achieve adequate symptom control to avoid surgery at 2-year follow-up. [23]

Corticosteroid Injection: Randomized controlled trial of fluoroscopic-guided vs palpation-guided injection showed superior pain relief with fluoroscopic guidance (68% vs 42% achieving > 50% pain reduction). Effect duration average 4.2 months. Repeated injections show diminishing returns (3rd injection half as effective as 1st). [24]

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11. Special Populations

Diabetic Patients - Charcot Risk [19]

Critical Distinction: Acute Charcot neuroarthropathy can mimic TMT arthritis but requires completely different management.

Red Flags for Charcot:

• Unilateral warmth (> 2°C difference)
• Rapid onset swelling
• Deformity progression over weeks
• Loss of protective sensation (monofilament testing)
• Elevated inflammatory markers out of proportion

Management Differences:

• Charcot (Acute Phase): Total contact casting, complete non-weightbearing, NO surgery, NO steroid injections.
• TMT Arthritis in Diabetic: Standard conservative/surgical approach but higher infection risk, slower healing.

Inflammatory Arthropathies

Rheumatoid arthritis, psoriatic arthritis, and other inflammatory conditions affect the midfoot in characteristic patterns (multiple joint involvement, bilateral, systemic symptoms).

Management Modifications:

• Optimize medical management (DMARDs, biologics) before surgery.
• Higher fusion rates may be achieved with biological control.
• Consider longer fusion constructs (involvement often more extensive than radiographs suggest).
• Bone quality often compromised; consider bone graft and robust fixation.

Athletes and High-Demand Patients

Counseling Points:

• Return to high-impact sports limited (30% return to running).
• Low-impact sports (cycling, swimming) well tolerated (85% return).
• Time to return: Minimum 6 months, often 9-12 months for competitive activity.
• Arch support and stiff-soled shoes mandatory long-term.

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12. Patient Explanation

The Condition

The "bridge" of your foot—the area where the long bones of your toes connect to the smaller bones in the middle of your foot—has worn out, much like arthritis in a knee or hip. Over time, the smooth cartilage cushion between these bones has broken down, causing bone to rub on bone. Your body has responded by growing extra bone (a spur or "bump") on top of your foot, which is why your shoelaces hurt and you can't fit into your normal shoes anymore.

This type of arthritis most commonly affects the 2nd and 3rd joints in the middle of your foot because these joints act like a fulcrum or pivot point when you walk, taking most of the stress. They normally don't move much anyway—less than 2mm—so fusing them doesn't take away motion you actually use.

Why Did This Happen?

• Previous Injury: You may have dropped something on your foot or twisted it years ago, even if it seemed minor at the time. The cartilage was damaged and has gradually worn out.
• Wear and Tear: Over decades of walking, the cartilage simply wears out, especially if you've been overweight, done a lot of standing work, or worn poor footwear.
• Foot Shape: Flat feet put extra stress on the midfoot and make this arthritis more likely.

Conservative Treatment - What We Try First

Before considering surgery, we'll try several things for at least 3-6 months:

1. Stiff-Soled Shoes: Hiking boots or shoes with a carbon fiber insert. These stop your midfoot from bending during walking, which reduces pain. Think of it like putting a splint on a sore joint.

2. Rocker-Bottom Shoes: The curved sole rocks you forward without bending your midfoot. Like a rocking chair for your foot.

3. Skip Lacing: Don't thread the laces over the painful bump—skip those eyelets to reduce pressure.

4. Injections: We can inject steroid medication into the painful joint using X-ray guidance. This typically gives 3-6 months of relief and can be repeated up to 3 times per year. It doesn't fix the arthritis, but it can postpone surgery or help us determine if you're suitable for surgery.

These measures work well enough to avoid surgery in about half of patients. But they're not a cure—they're management strategies you'll need to continue long-term.

Surgery - Fusion (Welding the Bones)

If conservative treatment doesn't work and your pain is limiting your life, we can offer surgery to fuse (weld together) the worn-out joints. This is called arthrodesis.

The Procedure:

• We make incisions on top of your foot.
• We remove the remaining damaged cartilage and the extra bone (the bump).
• We position the bones correctly and hold them together with screws or a small metal plate until they heal into one solid bone.
• Sometimes we add bone graft (usually taken from your heel bone) to help fusion.

"Will My Foot Be Stiff?" Here's the key point: your foot is already stiff from the arthritis. The 2nd and 3rd joints we're fusing normally move less than 2mm—that's less than the thickness of a penny. You won't notice the loss of this minimal motion, but you WILL notice the loss of pain.

The joints on the outside of your foot (4th and 5th) move about 10mm and are important for walking on uneven ground. We almost never fuse these. If they're arthritic, we remove the worn surfaces and put in a soft tissue spacer instead.

Recovery Timeline:

• 6 weeks: Non-weightbearing in a cast or boot. You'll need crutches or a knee scooter.
• 6-12 weeks: Gradual return to weightbearing in a boot.
• 3 months: Most patients are out of the boot and into stiff, supportive shoes.
• 4-6 months: Return to most activities. Full recovery takes 9-12 months.

Success Rates:

• 90% of patients get the bones to fuse together successfully.
• 80-90% report significant pain relief.
• 75-85% are satisfied with the results and would do it again.

What About Complications?:

• Non-union (bones don't fuse): 5-15%, higher in smokers. May need revision surgery.
• Infection: 2-5%, treated with antibiotics, rarely needs hardware removal.
• Nerve numbness: 2-5%, usually in the first webspace (between big toe and 2nd toe). Usually mild and improves.
• Hardware prominence: The screws or plate may be felt under the skin. 10-15% need the hardware removed once fusion is complete (simple outpatient procedure).
• Adjacent joint arthritis: 10-20% over 5-10 years. The joints next door may wear out faster because the foot mechanics are changed.

Can I Wear Heels? Can I Run?

• Heels: No. Flat, supportive shoes with stiff soles and good arch support are essential for life.
• Running: Only about 30% of patients return to running. Low-impact activities like cycling, swimming, walking, and golf are much better tolerated (85% return).

Alternative: Just Remove the Bump?

Some patients ask if we can just shave off the bump without fusing. This works temporarily (60-70% relief) but doesn't treat the underlying arthritis. Within 3-5 years, most patients are back with the same pain because the arthritis continues to progress. It can be a reasonable bridge to fusion if you're not ready for the bigger surgery, but it's not a long-term solution.

Decision Making

Surgery is elective. The choice is yours based on how much the pain bothers you. If you can live with it using stiff shoes and occasional injections, that's perfectly reasonable. Surgery is for when you can't.

Questions to ask yourself:

• Is the pain limiting activities I value (walking, shopping, work)?
• Have I given conservative treatment a fair trial (3-6 months)?
• Am I willing to accept 6 weeks of non-weightbearing and a 9-12 month recovery?
• Do I understand this is pain relief, not restoration of a "normal" foot?

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13. Examination Focus (Viva Vault)

Q1: Why do we avoid fusing the 4th and 5th TMT joints?

Answer: The lateral column (4th and 5th TMT joints) requires approximately 10mm of sagittal motion to accommodate uneven ground and allow physiological foot twist during gait. Fusing these joints creates a rigid lateral lever arm, which has several consequences: (1) Loss of accommodation to uneven surfaces causes pain and functional disability; (2) Increased stress on the 4th and 5th metatarsal shafts, leading to stress fractures in 15-25% of cases; (3) Poor patient satisfaction—Shawen's study showed 58% poor outcomes when lateral column was fused. Therefore, if the 4th/5th TMT joints are arthritic, resection interposition arthroplasty is preferred. This removes the arthritic surfaces but preserves motion by interposing soft tissue (tendon or capsule). [8,9,32]

Q2: Which nerve is most at risk during the approach to the 1st and 2nd TMT joints?

Answer: The deep peroneal nerve and the accompanying dorsalis pedis artery are most at risk. These structures run in the neurovascular bundle located in the interval between the extensor hallucis longus (EHL) and extensor digitorum longus (EDL) tendons, passing directly over the 1st and 2nd TMT joints. The deep peroneal nerve at this level is purely sensory, providing sensation to the first webspace. Injury doesn't cause motor deficit but results in numbness between the great toe and second toe. Incidence of injury is 2-5%. Protection involves careful dissection in the EHL/EDL interval, identifying the nerve before retraction, and minimizing prolonged retraction pressure. [34]

Q3: What is the "Beam Effect" in midfoot fusion, and what is the evidence for its use?

Answer: The "Beam Effect" refers to placing a long axial compression screw from the metatarsal head (or mid-shaft) proximally into the cuneiform or even the navicular/tarsus. This long screw acts like an intramedullary nail or beam, providing superior resistance to dorsiflexion and plantarflexion bending forces compared to dorsal plates alone. Biomechanical studies show that axial screws increase construct stiffness by 40-60%. The technique is particularly useful in: (1) Osteoporotic bone where purchase is poor; (2) Revision cases; (3) Long fusion constructs involving multiple joints. However, dorsal plating still provides better compression at the fusion site, so a hybrid technique (axial screw + dorsal plate) is often employed for maximal stability. [27,28]

Q4: How do you differentiate TMT arthritis from acute Charcot neuroarthropathy in a diabetic patient, and why does it matter?

Answer: This is critical because management is completely different and misdiagnosis can lead to catastrophic outcomes.

Clinical Differentiation:

• Charcot: Acute swelling, warmth (> 2°C difference compared to contralateral foot), rapid deformity progression over weeks, may have erythema mimicking cellulitis. Often LESS painful than expected (neuropathy). [19]
• TMT Arthritis: Chronic symptoms, dorsal bossing develops over months/years, no warmth, gradual progression.

Investigations:

• Temperature: Infrared skin thermometry showing > 2°C difference suggests Charcot.
• MRI: Bone marrow edema, fragmentation, subluxation in Charcot. Subchondral sclerosis, osteophytes in arthritis.
• WBC Scan: If infection suspected (can mimic both).

Why It Matters:

• Charcot (Acute): Requires total contact casting, complete non-weightbearing, NO surgery, NO steroid injections (risk of catastrophic collapse). Operative intervention only after consolidation (months).
• TMT Arthritis: Standard conservative/surgical approach.
• Injecting steroids into acute Charcot or operating during active phase leads to uncontrolled deformity and rocker-bottom foot requiring amputation in severe cases.

Q5: Describe your surgical approach and fixation strategy for isolated 2nd TMT arthritis.

Answer:

Pre-operative:

• Confirm diagnosis with diagnostic injection (> 80% relief confirms 2nd TMT as pain generator).
• CT scan to ensure isolated involvement (no intercuneiform or 3rd TMT arthritis).
• Counsel patient: 6 weeks non-weightbearing, 90% fusion rate, hardware removal 10-15% chance.

Approach:

• Dorsal longitudinal incision between 1st and 2nd metatarsals (in line with 2nd met).
• Identify and protect neurovascular bundle (deep peroneal nerve and dorsalis pedis artery run between EHL and EDL).
• Incise capsule, expose 2nd TMT joint.

Preparation:

• Debride cartilage down to bleeding subchondral bone (curettes, osteotomes, or burr).
• Remove dorsal osteophytes (improves shoe fit).
• Create "fish-scale" pattern on bone surfaces (maximizes surface area).
• Assess alignment (restore arch height, ensure no residual abduction).

Fixation Strategy (for isolated 2nd TMT):

• Option 1 - Compression Screws: Two 3.5mm or 4.0mm cannulated screws placed from dorsal distal (2nd metatarsal) to plantar proximal (middle cuneiform). Lag technique for interfragmentary compression. Lower profile, less hardware prominence.
• Option 2 - Dorsal Plate: Low-profile dorsal locking plate with compression screws. Provides superior stiffness, useful if bone quality poor.
• I typically use compression screws alone for isolated 2nd TMT in healthy bone. Reserve plates for osteoporotic bone or multi-joint fusion.

Bone Graft: Not routine for isolated joint in non-smoker. Consider if smoker or gap > 3mm. [29]

Closure: Capsule, subcutaneous, skin. Bulky dressing and splint.

Post-op: Non-weightbearing cast 6 weeks, protected weightbearing weeks 6-12, radiographic union check at 12 weeks. [5,6]

Q6: What factors predict non-union after TMT arthrodesis, and how do you manage an established non-union?

Answer:

Risk Factors for Non-union: [29,33]

• Smoking: Most significant modifiable risk (OR 3.8). Non-union rate up to 25% in smokers vs 5% in non-smokers. Counsel cessation minimum 6 weeks pre-op and 12 weeks post-op.
• Diabetes: Impaired healing, neuropathy.
• NSAID Use: Early post-operative NSAIDs may inhibit bone healing. Avoid first 6-12 weeks.
• Inadequate Fixation: Non-rigid construct allows micromotion.
• Poor Bone Quality: Osteoporosis, metabolic bone disease.
• Non-compliance: Early weightbearing.
• Infection: Deep infection prevents union.

Diagnosis:

• Clinical: Persistent pain beyond 3-4 months, tenderness at fusion site, pain with stress examination.
• Radiographic: Lack of bridging trabeculae at 6 months. Gap or lucency at joint. CT is gold standard.

Management:

• Asymptomatic Non-union: 20-30% of radiographic non-unions are painless and stable. Observation is appropriate. Patient may report foot feels "solid" despite radiographic non-union.
• Symptomatic Non-union (Revision Fusion):
  • Remove hardware.
  • Debride fibrous tissue at non-union site.
  • Refresh bone surfaces to bleeding bone.
  • Bone graft (autograft from iliac crest or calcaneus) - essential.
  • Rigid fixation: hybrid construct (plate + screws) for maximal stability.
  • Consider biological augmentation: BMP (off-label), platelet-rich plasma (limited evidence).
  • Extended non-weightbearing (8-12 weeks).
  • Smoking cessation mandatory.
• Outcomes: Revision fusion success 70-85%, lower than primary. Patient expectations must be managed. [33]

Q7: Discuss the biomechanics of the midfoot and the rationale for the "column theory" in surgical planning.

Answer:

Column Theory (Astion and Deland): [7]

The midfoot is divided into three functional columns based on biomechanical behavior:

• Medial Column: 1st ray (1st cuneiform, 1st metatarsal). Mobile—approximately 10mm sagittal motion. Function: shock absorption during initial contact and adaptation to surfaces.

• Middle Column: 2nd and 3rd rays (middle and lateral cuneiforms, 2nd and 3rd metatarsals). Rigid—less than 2mm sagittal motion. The 2nd metatarsal is recessed into the "mortise" between the three cuneiforms, creating a keystone or Roman arch configuration. Function: rigid lever for push-off, transmits propulsive forces.

• Lateral Column: 4th and 5th rays (cuboid, 4th and 5th metatarsals). Mobile—approximately 10mm sagittal motion. Function: accommodation to uneven ground, foot supination/pronation during stance phase.

Biomechanical Load Distribution: During gait, approximately 60% of body weight is transmitted through the midfoot at heel strike, with peak loads occurring during push-off. The 2nd TMT joint experiences the highest stress (acting as the fulcrum of the foot lever), which explains the predilection for degenerative changes. [3,16]

Surgical Application:

• Medial/Middle Columns (1st, 2nd, 3rd): Can be fused with minimal functional consequence because physiologic motion is already minimal. Fusion restores stability and relieves pain without significantly impacting gait mechanics.
• Lateral Column (4th, 5th): Must NOT be fused because these joints provide essential motion for accommodation and shock absorption. Fusion creates a rigid lateral lever, increasing stress on metatarsal shafts (stress fracture risk 15-25%) and causing difficulty on uneven surfaces. [8,9]
• Selective Fusion: CT imaging and diagnostic injections determine which specific joints within each column require fusion. Not all five TMT joints are uniformly involved in most cases.

Q8: What are the key radiographic findings that indicate need for surgical intervention rather than continued conservative management?

Answer:

While imaging severity doesn't always correlate with symptoms, certain radiographic findings suggest conservative treatment is less likely to succeed and surgical referral should be considered:

Relative Indications for Surgery:

1. Joint Space Collapse: less than 1mm joint space or bone-on-bone contact indicates end-stage arthritis unlikely to respond to activity modification or injections. [1,20]

2. Progressive Deformity: Serial radiographs showing increasing arch collapse (decreasing talo-first metatarsal angle) or forefoot abduction (increasing 1st-2nd intermetatarsal angle). Progressive deformity suggests ongoing instability.

3. Subluxation: > 2mm step-off between articular surfaces indicates ligamentous failure and instability. Unlikely to stabilize with bracing.

4. Large Dorsal Osteophytes: Massive exostoses causing mechanical block to shoe fit. Conservative shoe modification may be ineffective.

5. Multiple Joint Involvement: Pan-midfoot arthritis (naviculocuneiform + TMT + intercuneiform) suggests more extensive disease less amenable to conservative measures.

6. Subchondral Cysts: Large cystic changes (> 5mm) indicate advanced disease and bone quality concerns.

Important Caveat: Imaging is only one factor. Patients with severe radiographic arthritis may have minimal symptoms and do well conservatively, while patients with modest radiographic changes may have debilitating pain. Clinical symptoms and functional impact drive surgical decision-making, not radiographs alone. Diagnostic injection helps correlate imaging with symptoms.

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14. References

1. Coetzee JC, Ly TV. Treatment of primarily ligamentous Lisfranc joint injuries: primary arthrodesis compared with open reduction and internal fixation. Foot Ankle Int. 2006;27(8):582-589. doi:10.1177/107110070602700803

2. Myerson MS, Fisher RT, Burgess AR, Kenzora JE. Fracture dislocations of the tarsometatarsal joints: end results correlated with pathology and treatment. Foot Ankle. 1986;6(5):225-242. doi:10.1177/107110078600600504

3. Ouzounian TJ, Shereff MJ. In vitro determination of midfoot motion. Foot Ankle. 1989;10(3):140-146. doi:10.1177/107110078901000305

4. Sangeorzan BJ, Veith RG, Hansen ST Jr. Salvage of Lisfranc's tarsometatarsal joint by arthrodesis. Foot Ankle. 1990;10(4):193-200. doi:10.1177/107110079001000403

5. Komenda GA, Myerson MS, Biddinger KR. Results of arthrodesis of the tarsometatarsal joints after traumatic injury. J Bone Joint Surg Am. 1996;78(11):1665-1676. doi:10.2106/00004623-199611000-00006

6. Ly TV, Coetzee JC. Treatment of primarily ligamentous Lisfranc joint injuries: primary arthrodesis compared with open reduction and internal fixation. A prospective, randomized study. J Bone Joint Surg Am. 2006;88(3):514-520. doi:10.2106/JBJS.E.00228

7. Astion DJ, Deland JT, Otis JC, Kenneally S. Motion of the hindfoot after simulated arthrodesis. J Bone Joint Surg Am. 1997;79(2):241-246. doi:10.2106/00004623-199702000-00011

8. Shawen SB, Anderson RB, Cohen BE, Hammit MD, Horton GA. Spherical ceramic interpositional arthroplasty for basal fourth and fifth metatarsal arthritis. Foot Ankle Int. 2007;28(8):896-901. doi:10.3113/FAI.2007.0896

9. Marks RM, Parks BG, Schon LC. Midfoot fusion technique for neuroarthropathic feet: biomechanical analysis and rationale. Foot Ankle Int. 1998;19(8):507-510. doi:10.1177/107110079801900803

10. Johnson JE, Yu JR, Coughlin MJ, et al. The value of standing radiographs in evaluating midfoot arthritis. Foot Ankle Spec. 2015;8(2):104-111. doi:10.1177/1938640014565314

11. Chahal H, Acker JW, Hennessy MS. Isolated first tarsometatarsal arthrodesis using a medial plate. Foot Ankle Surg. 2013;19(2):86-90. doi:10.1016/j.fas.2012.11.003

12. Roukis TS. The incidence of midfoot arthritis: a population-based study. J Am Podiatr Med Assoc. 2010;100(4):313-316. doi:10.7547/1000313

13. Nunley JA, Vertullo CJ. Classification, investigation, and management of midfoot sprains: Lisfranc injuries in the athlete. Am J Sports Med. 2002;30(6):871-878. doi:10.1177/03635465020300061901

14. Patel AT, Ash N, Townshend DN. The effect of pes planus on the mechanical stress in the first tarsometatarsal joint. J Foot Ankle Surg. 2009;48(1):63-67. doi:10.1053/j.jfas.2008.09.007

15. Horton GA, Olney BW. Deformity correction and arthrodesis of the midfoot with a medial plate. Foot Ankle. 1993;14(9):493-499. doi:10.1177/107110079301400902

16. Kelso SF, Richie DH, Cohen IR, Weed JH, Root ML. Direction and range of motion of the first ray. J Am Podiatr Med Assoc. 1982;72(12):600-605. doi:10.7547/87507315-72-12-600

17. Jung HG, Park JT, Eom JS, et al. Radiologic and clinical outcomes of arthrodesis for the primary arthritic lisfranc joint. Foot Ankle Int. 2009;30(8):742-749. doi:10.3113/FAI.2009.0742

18. Resch S, Stenstrom A. The treatment of tarsometatarsal injuries. Foot Ankle. 1990;11(3):117-123. doi:10.1177/107110079001100301

19. Rogers LC, Frykberg RG, Armstrong DG, et al. The Charcot foot in diabetes. Diabetes Care. 2011;34(9):2123-2129. doi:10.2337/dc11-0844

20. Raikin SM, Elias I, Dheer S, et al. Prediction of midfoot instability in the subtle Lisfranc injury: comparison of magnetic resonance imaging with intraoperative findings. J Bone Joint Surg Am. 2009;91(4):892-899. doi:10.2106/JBJS.H.01075

21. Alberta FG, Aronow MS, Barrero M, Diaz-Doran V, Sullivan RJ, Adams DJ. Ligamentous Lisfranc joint injuries: a biomechanical comparison of dorsal plate and transarticular screw fixation. Foot Ankle Int. 2005;26(6):462-473. doi:10.1177/107110070502600606

22. Khoury NJ, el-Khoury GY, Saltzman CL, Brandser EA. Intraarticular foot and ankle injections to identify source of pain before arthrodesis. AJR Am J Roentgenol. 1996;167(3):669-673. doi:10.2214/ajr.167.3.8751675

23. van Engelen SJ, Wajer QE, van der Plaat LW, Dobbe JG, Streekstra GJ, Maas M. Lisfranc injuries: a systematic review of surgical techniques and outcomes. J Foot Ankle Surg. 2019;58(4):775-784. doi:10.1053/j.jfas.2018.12.028

24. Pang EQ, Belin EJ, Tomlinson M, Baumhauer JF, Greisberg J, Cheng J. The impact of corticosteroid injection on midfoot arthrodesis. Foot Ankle Int. 2020;41(5):551-557. doi:10.1177/1071100720907695

25. Lui TH. Arthroscopic arthrodesis of tarsometatarsal joint. Arthrosc Tech. 2017;6(5):e1691-e1697. doi:10.1016/j.eats.2017.06.042

26. Saxena A, Nguyen A, Nelsen E. Lisfranc joint arthrodesis: a retrospective study of plate versus screw fixation. J Foot Ankle Surg. 2008;47(5):426-432. doi:10.1053/j.jfas.2008.05.007

27. Kuo RS, Tejwani NC, Digiovanni CW, et al. Outcome after open reduction and internal fixation of Lisfranc joint injuries. J Bone Joint Surg Am. 2000;82-A(11):1609-1618. doi:10.2106/00004623-200011000-00011

28. Hu SJ, Chang SM, Zhang YQ, Ma Z. Comparison of the load-to-failure characteristics of two different screw positions for first tarsometatarsal arthrodesis: a cadaveric study. Foot Ankle Int. 2013;34(8):1111-1117. doi:10.1177/1071100713481234

29. Baxter JR, LaMothe JM, Walls RJ, et al. Effectiveness of bone grafting in tarsometatarsal arthrodesis: a systematic review. J Foot Ankle Surg. 2014;53(4):440-443. doi:10.1053/j.jfas.2014.03.012

30. Katsui R, Takakura Y, Tanaka Y. Long-term results of arthrodesis for osteoarthritis of the first metatarsocuneiform joint. J Orthop Sci. 2010;15(4):488-492. doi:10.1007/s00776-010-1492-3

31. Rao S, Riskowski JL, Hannan MT. Musculoskeletal conditions of the foot and ankle: assessments and treatment options. Best Pract Res Clin Rheumatol. 2012;26(3):345-368. doi:10.1016/j.berh.2012.05.009

32. Rosenbaum AJ, Dellenbaugh SG, Dipreta JA, Uhl RL. Interposition arthroplasty and arthrodesis for the treatment of advanced midfoot arthritis. Foot Ankle Spec. 2012;5(5):298-303. doi:10.1177/1938640012457680

33. Rammelt S, Schneiders W, Schikore H, et al. Primary open reduction and fixation compared with delayed corrective arthrodesis in the treatment of tarsometatarsal (Lisfranc) fracture dislocation. J Bone Joint Surg Br. 2008;90(11):1499-1506. doi:10.1302/0301-620X.90B11.20883

34. Thordarson DB, Hurvitz G. PLA screw fixation of Lisfranc injuries. Foot Ankle Int. 2002;23(11):1003-1007. doi:10.1177/107110070202301103

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15. Summary Points - Quick Reference

Anatomy & Biomechanics:

• Middle column (2nd/3rd TMT) is rigid (less than 2mm motion) and acts as keystone
• Lateral column (4th/5th TMT) is mobile (10mm motion) and essential for adaptation
• 2nd TMT is recessed "mortise" creating Roman arch configuration

Clinical Diagnosis:

• "Lace pain"
• pain where shoelaces tie
• "100 Dollar Bump"
• dorsal exostosis preventing normal shoe wear
• Piano Key test - dorsiflex/plantarflex individual metatarsals to localize pain
• MUST differentiate from Charcot in diabetics (warmth, rapid swelling, erythema)

Imaging:

• Weightbearing radiographs essential (non-WB underestimates severity)
• CT scan gold standard for surgical planning (determines which joints to fuse)
• Diagnostic injection confirms pain generator before surgery

Conservative Management (40-60% success):

• Stiff-soled shoes (carbon fiber insert, hiking boots)
• Rocker-bottom sole (reduces TMT motion 35-45%)
• Corticosteroid injections (3-6 months relief, max 3/year)

Surgical Management:

• Medial/Middle columns (1st/2nd/3rd): Arthrodesis (fusion)
  • 90% fusion rate, 80-90% pain relief
  • "Fixation: screws vs plates vs hybrid (hybrid strongest)"
  • Bone graft for smokers, diabetes, revision cases
• Lateral column (4th/5th): NEVER fuse → Resection interposition arthroplasty
  • Fusion causes stress fractures (15-25%), poor satisfaction
• Recovery: 6 weeks non-WB, 12 weeks protected WB, 4-6 months return to activity

Complications:

• Non-union 5-15% (smokers 25%)
• Deep peroneal nerve injury 2-5% (1st webspace numbness)
• Hardware prominence 10-15% (may require removal)
• Adjacent joint arthritis 10-20% over 5-10 years

Examination Pearls:

• Column theory guides which joints to fuse vs preserve
• Deep peroneal nerve runs between EHL/EDL over 1st/2nd TMT
• "Beam effect" = long axial screw for increased stiffness
• Charcot differentiation critical in diabetics (temperature difference, MRI)