Hammer Toes

Hammer Toe is the most common lesser toe deformity, accounting for approximately 80% of all lesser toe pathology. It predominantly affects the 2nd toe due to its length (often longest ray) and relationship with hallux valgus.

Epidemiology

• Prevalence: 2-20% of adult population
• Gender: Women affected 4-5x more than men (footwear)
• Age: Peak 40-60 years
• Location: 2nd toe in 80% of cases
• Bilateral: 40% have bilateral involvement

Anatomy

• PIPJ: Proximal interphalangeal joint - site of primary deformity
• Flexors: FDL (flexor digitorum longus), FDB (flexor digitorum brevis)
• Extensors: EDL (extensor digitorum longus), EDB (extensor digitorum brevis)
• Intrinsics: Interossei, lumbricals - flex MTPJ, extend IPJs

Pathophysiology

• Muscle Imbalance: FDL/FDB overpull relative to extensors
• Intrinsic Weakness: Loss of intrinsic function → PIPJ flexion
• Shoe Wear: Tight toe box → toe flexion adaptation
• Hallux Valgus: 2nd toe crowded, forced to flex
• Inflammatory Arthritis: Joint destruction, subluxation

Aetiology

• Footwear: High heels, narrow toe box - most common
• Hallux Valgus: Associated in 50-75% of cases
• Long 2nd Metatarsal: Increased pressure
• Inflammatory Arthritis: RA, psoriatic
• Neurological: Diabetic neuropathy, CMT, CVA (usually claw)
• Trauma: Compartment syndrome, crush injury

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History

• Pain: Dorsal PIPJ (shoe rubbing), tip of toe, under metatarsal head
• Callus/Corn: Dorsal PIPJ, tip of toe, interdigital
• Cosmesis: Crooked toe appearance
• Shoe Wear: Difficulty finding comfortable shoes
• Progression: Initially flexible → becomes rigid over time
• Hallux: Associated bunion symptoms

Physical Examination

Examination Technique

1. Standing Assessment

   • Observe toe position weight-bearing
   • Check for associated hallux valgus
   • Assess arch, hindfoot alignment

2. Seated Examination

   • Flexibility Test: Most critical exam finding
     • Plantarflex ankle (relaxes FDL)
     • Attempt to correct PIPJ deformity
     • If corrects = Flexible
     • If fixed = Rigid

3. MTPJ Assessment

   • Drawer Test: Grasp toe, attempt to sublux proximally
   • Positive = MTPJ instability (plantar plate injury)
   • Assess MTPJ ROM

4. Callus/Skin

   • Dorsal PIPJ: From shoe pressure
   • Tip of toe: From ground contact
   • Interdigital: From adjacent toe pressure

5. Neurovascular

   • Capillary refill
   • Sensation (diabetic neuropathy common)

Classification Systems

Differential Diagnosis

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The passive flexibility test — correcting the PIPJ with the ankle plantarflexed to relax the FDL — tells you whether the interphalangeal contracture is fixed. The push-up test (Kelikian push-up test) answers a different, complementary question that the topic's own MCQ material relies on: is the deformity being driven from the MTPJ, and will it reduce when the forefoot is loaded?

• Technique: with the patient seated, the examiner pushes upward (dorsally) on the plantar aspect of the metatarsal head, simulating weight-bearing and toe-off, and watches the toe.
• Interpretation: a flexible/dynamic deformity realigns — the toe straightens as the MTPJ is reduced, indicating the interphalangeal posture is secondary to MTPJ position, so soft-tissue balancing (with metatarsal-level correction where the MTPJ is unstable) can realign it. A toe that fails to correct on push-up has a fixed interphalangeal contracture requiring bony PIPJ correction (resection arthroplasty or arthrodesis).
• Putting the tests together: combined with the plantarflexion flexibility test and the dorsal drawer test for MTPJ stability, the push-up test localises the deformity (isolated PIPJ versus MTPJ-driven) and grades its rigidity — exactly what selects soft-tissue versus bony surgery and decides whether a Weil osteotomy is needed. Formal plantar plate grading and repair are developed under plantar plate insufficiency.

Imaging

Weight-Bearing Radiographs:

• AP View: MTPJ alignment, subluxation, joint space
• Oblique View: PIPJ deformity, osteophytes
• Lateral View: Degree of flexion, PIPJ arthritis

Radiographic Assessment

• MTPJ subluxation (proximal phalanx displaced dorsally)
• PIPJ joint destruction/arthritis
• Associated hallux valgus angle
• Metatarsal length assessment
• Bone quality (inflammatory arthritis)

Special Investigations

• HbA1c: If diabetic neuropathy suspected
• Inflammatory Markers: ESR, CRP if inflammatory arthritis
• Nerve Conduction Studies: If neurological cause suspected (CMT)

Surgical Complications

Prevention Strategies

• Conservative bone resection: Avoid over-resection at PIPJ
• Arthrodesis over arthroplasty: More stable correction for rigid deformities
• Address MTPJ: Weil osteotomy if subluxed
• K-wire care: Clean pin sites, adequate duration (3-4 weeks)
• Patient selection: Avoid surgery in poorly controlled diabetics

Immediate Postoperative Period (0-2 Weeks)

Early Recovery Phase (2-6 Weeks)

Late Recovery Phase (6-12 Weeks)

• Footwear transition: Gradual return to regular shoes (wide toe box initially)
• Swelling: Toe swelling may persist 3-6 months - normal finding
• Return to activities: Low-impact exercise at 6-8 weeks, sports at 10-12 weeks
• Final assessment: Evaluate alignment and ROM at 12 weeks

Complications and Management

Expected Outcomes

Factors Affecting Outcome

• Positive: Flexible deformity, isolated PIPJ, no MTPJ involvement
• Negative: Rigid deformity, MTPJ subluxation, inflammatory arthritis, diabetic

Return to Activity

• Walking: 2-4 weeks post-op
• Driving: 4-6 weeks
• Dress Shoes: 6-8 weeks
• Sports: 8-12 weeks
• Final Result: 6-12 months

Global Epidemiology

Lesser-toe deformities are among the most common forefoot complaints worldwide. Population studies report hammer/claw/mallet toes in a substantial minority of adults, rising steeply with age and strongly female-predominant (footwear and a longer second ray are the dominant drivers). Prevalence is higher in older, shod populations and lower in habitually barefoot communities, supporting footwear as a key modifiable factor. Hallux valgus coexists in the majority of symptomatic second-toe deformities.

Side-by-Side Guidance

There is no single international registry for lesser-toe surgery; comparative evidence comes from case series, the Jay/Malay fixation RCT, and large pooled fixation reviews rather than from arthroplasty-style joint registries.

High- vs Limited-Resource Practice Variation

• High-resource settings: Day-case surgery; growing use of intramedullary fusion implants despite cost and hardware-failure data favouring K-wires; frequent combined bunion + lesser-toe correction.
• Limited-resource settings: Percutaneous K-wire fixation and FDL tenotomy/transfer predominate (low cost, reliable); emphasis on footwear modification and offloading where surgical access is limited.
• Diabetic / neuropathic populations: Worldwide, the threshold for elective bony surgery is raised because of impaired healing; offloading, accommodative footwear and ulcer prevention take priority.

Hammer, claw and mallet toes are the visible endpoint of a dynamic imbalance between the extrinsic (long) tendons and the intrinsic muscles of the foot. Three classic pathomechanical patterns, long described in the podiatric and orthopaedic literature, explain how that imbalance arises and predict the foot type that accompanies it:

• Flexor stabilisation — the commonest mechanism behind the acquired hammer toe. In a pronated or flatfoot foot the long and short flexors (FDL/FDB) fire earlier and for longer during stance to try to stabilise an unstable forefoot, overpowering the intrinsics. The unopposed flexors buckle the PIPJ, producing the hammer toe (often with an adductovarus lesser toe). This is the pattern to expect in the flexible, footwear-driven patient with hallux valgus.
• Extensor substitution — occurs during swing phase when the extensor digitorum longus (EDL) is over-recruited to help a weak tibialis anterior dorsiflex the ankle. The EDL overpowers the lumbricals and hyperextends the MTPJ; the toe then buckles at the interphalangeal joints. It is associated with a high-arched (cavus) foot and produces a claw-type posture with prominent MTPJ dorsiflexion.
• Flexor substitution — the least common. When the triceps surae is weak, the deep flexors, tibialis posterior and peroneus longus substitute for push-off; the flexors again overpower the intrinsics and claw the toes. It is seen in the supinated/cavus foot.

Recognising the pattern matters because it points to the underlying driver. A flexible flexor-stabilisation hammer toe responds well to flexor balancing (FDL tenotomy or Girdlestone-Taylor transfer), whereas an extensor- or flexor-substitution (cavus) pattern warns that an unaddressed hindfoot or cavus deformity, and often a neurological cause, will drive recurrence if the toe is treated in isolation — here the toe is the symptom, not the disease.

• Arthroplasty vs arthrodesis for rigid deformity — Arthrodesis offers a more stable, lower-recurrence construct but at the cost of a stiff toe and a non-union risk; resection arthroplasty preserves some motion but is more prone to recurrence and floating toe. No high-quality RCT directly settles the choice, so selection remains driven by patient age, activity and surgeon preference.
• Intramedullary implants vs K-wire — The single RCT favours implants for fusion rate and patient-reported scores, yet pooled reviews show higher hardware-failure rates and a 640-894x cost premium with no clear complication benefit. Whether the avoided pin-tract morbidity justifies the cost is unresolved.
• When to address the MTPJ / plantar plate — There is debate over whether all crossover and instability-driven deformities need formal plantar plate repair, or whether a Weil osteotomy with soft-tissue balancing alone suffices. The Coughlin-Nery staging is increasingly used to guide this, but thresholds vary.
• Floating toe is partly unavoidable — Even with meticulous technique, floating toe occurs in a meaningful proportion after Weil osteotomy and plantar plate work; its true preventability and the best salvage remain uncertain.
• Role of percutaneous (minimally invasive) techniques — Percutaneous flexor tenotomy and minimally invasive osteotomies are expanding, but long-term comparative data against open correction are still limited.

Hammer toe is the most common lesser toe deformity, characterized by PIPJ flexion with neutral DIPJ and MTPJ, affecting the 2nd toe in 80% of cases due to hallux valgus pressure and intrinsic muscle imbalance. The flexibility test (plantarflex ankle to relax FDL) is the critical examination determining surgical approach: flexible deformities respond to soft tissue procedures (FDL tenotomy, Girdlestone-Taylor transfer), while rigid deformities require bone surgery (PIPJ arthroplasty or arthrodesis). Always assess MTPJ stability with drawer test, as subluxation requires concurrent Weil osteotomy. Surgical correction achieves 80-90% good outcomes with proper deformity classification and procedure selection.