Claw Toes

Claw Toe is a complex triplanar deformity involving hyperextension of the MTP joint with flexion contractures of both the PIP and DIP joints. Unlike hammer toe (PIP flexion only) or mallet toe (DIP flexion only), claw toe affects ALL THREE joints simultaneously.

Epidemiology

• Prevalence: 2-20% of adult population (varies by age)
• Gender: No significant gender predominance (unlike hammer toe)
• Age: Can occur at any age depending on etiology
• Bilateral: 60-80% bilateral (suggests systemic cause)
• Association: 80% have underlying neurological condition or cavus foot

Key Distinctions

Claw vs Hammer vs Mallet:

• Claw: MTP extension + PIP flexion + DIP flexion (all 3 joints)
• Hammer: PIP flexion only (neutral MTP, neutral/extended DIP)
• Mallet: DIP flexion only (neutral MTP, neutral PIP)

The presence of MTP hyperextension is pathognomonic for claw toe and suggests intrinsic muscle dysfunction.

Normal Intrinsic Muscle Function

The intrinsic muscles of the foot (lumbricals and interossei) are critical for balanced toe function:

Biomechanical Basis of Claw Deformity

Normal Balance:

• Intrinsics: Flex MTP, extend PIP/DIP
• Extrinsic flexors (FDL/FDB): Flex PIP/DIP
• Extrinsic extensors (EDL/EDB): Extend MTP
• Balance maintains neutral toe position

Intrinsic Muscle Weakness/Paralysis:

When intrinsics are weak or absent, extrinsic muscles dominate:

1. EDL unopposed → MTP HYPEREXTENSION
2. FDL/FDB unopposed → PIP and DIP FLEXION
3. Loss of stabilization → progressive deformity
4. Weight-bearing forces → drive MTP into more extension

Etiology Categories

History

Physical Examination

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Imaging

Radiographic Measurements

Special Investigations

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The topic names floating toe as the most common complication (10-20% after PIP arthroplasty, and the "most common" in the MCQ) but never explains why it happens, how to prevent it, or how to treat a symptomatic one. A floating toe sits elevated off the ground with no pulp purchase, so it cannot help grip or share load.

• Why it happens. The toe floats when its plantar-flexing / ground-purchase force at the MTP is lost or overpowered by a dorsal force:
  • PIP resection arthroplasty shortens the toe and disrupts the flexor and plantar-plate purchase, so the toe loses the plantarflexion that holds the pulp down.
  • An over-tight FDL-to-EDL transfer pulls the toe into too much MTP flexion-correction and dorsiflexion, lifting the tip.
  • A Weil osteotomy translates the metatarsal head plantarward and proximally, which shifts the intrinsic (interosseous/lumbrical) tendons dorsal to the MTP axis of rotation - the intrinsics then act as MTP extensors instead of flexors, producing a dorsal contracture and a floating toe (the classic Weil pitfall).
• How to prevent it. Resect minimal bone, tension the transfer so the toe rests plantigrade with the ankle neutral (not over-corrected), preserve or repair the plantar plate, limit Weil shortening and avoid excessive plantar translation, and stabilise the MTP (temporary K-wire) while it heals.
• How to treat a symptomatic floating toe. Most are asymptomatic and observed. A symptomatic one is addressed by flexor tenodesis / FDL transfer to restore plantar pull, plantar plate reefing, MTP capsular release of the dorsal contracture, or, if a Weil has malpositioned the head, a corrective (e.g. more proximal / less plantar) revision.

The topic's own evidence and vivas lean heavily on percutaneous flexor tenotomy - it has a dedicated EvidenceCard (Rasmussen: 93% of ulcerated toes healed), a diabetic-ulcer viva, and it appears in the guidelines and controversies - yet the surgical-technique section (Girdlestone-Taylor, PIP arthroplasty, arthrodesis, adjuncts) never describes this minimal, limb-sparing operation.

• The indication. A flexible claw or hammer toe with a tip-of-toe (apex) ulcer or impending ulcer, classically in a diabetic neuropathic (or neuroischaemic) foot - the setting where a formal open reconstruction or arthrodesis carries unacceptable wound and vascular risk.
• The procedure. A percutaneous stab on the plantar surface just proximal to the flexion crease divides the FDL and FDB tendons; the flexible toe then straightens and the tip lifts off the ground, offloading the apex. It is done under local anaesthetic, needs no fixation, and the incision heals by itself.
• Why it works and its evidence. Releasing the deforming flexor pull lets the neuropathic toe sit plantigrade so the ulcer offloads and heals (Rasmussen: 93% healed, median 21 days, no infections or amputations), and prophylactic tenotomy of an at-risk toe prevents ulceration. It is explicitly a limb-sparing alternative to amputation in the poorly-vascularised foot.
• The limits. It only works while the toe is flexible - a rigid contracture will not correct with tenotomy alone and needs PIP arthrodesis (or resection) as elsewhere in this topic; and dividing the flexors can leave a small floating-toe tendency, usually well tolerated in this population.

Immediate Postoperative Period (0-2 Weeks)

Early Healing Phase (2-6 Weeks)

Late Healing Phase (6-12 Weeks)

Long-Term Management (3-12 Months)

• Swelling may persist 3-6 months
• Numbness around surgical site gradually improves
• Shoe modifications as needed
• Monitor for recurrence or adjacent toe deformity
• Annual follow-up if neurological condition

Primary Prevention

Secondary Prevention

Postoperative Recurrence Prevention:

• Address underlying neurological or biomechanical cause
• Proper footwear long-term
• Intrinsic muscle strengthening exercises
• Regular monitoring of adjacent toes
• Revision surgery if recurrence occurs

Prognosis

Global Epidemiology

• Diabetes burden: ~537 million adults live with diabetes worldwide (IDF, 2021); distal symmetrical polyneuropathy develops in roughly 30-50% over time and is a leading driver of acquired claw toe and plantar pressure redistribution.
• Charcot-Marie-Tooth disease: prevalence ~1 in 2,500 globally - the commonest inherited neuropathy and the classic cause of bilateral, progressive claw toes with cavovarus feet.
• Lesser-toe deformity: prevalence rises steeply with age; population foot studies report clawing/hammering in a substantial minority of older adults, more in women (footwear and hallux valgus association) but with no sex bias in neurological claw toe.
• Resource-setting variation: in high-resource settings deformity is often elective/cosmetic-driven; in limited-resource settings the same deformity more often presents late with ulceration, infection or osteomyelitis because of delayed access and barefoot/ill-fitting footwear.

Side-by-Side Guidance

There is no implant registry specific to lesser-toe surgery; outcome data derive from case series (see Evidence Base) rather than national arthroplasty registries such as NJR/AJRR/AOANJRR. Intramedullary IP fusion implants are tracked only through device-surveillance schemes, not joint registries.

Practice Variation

• High-resource: day-case surgery, intramedullary headless implants, MRI-confirmed plantar plate repair, formal gait/neuromuscular work-up.
• Limited-resource: emphasis on footwear, callus care and simple K-wire arthrodesis or percutaneous flexor tenotomy; earlier resort to amputation when ulceration is neglected or vascular supply is poor.

• Arthroplasty vs arthrodesis for rigid PIP deformity: arthrodesis gives more reliable alignment and lower recurrence but at the cost of a stiff toe and a small nonunion rate; resection arthroplasty is quicker and easier to revise but has a higher floating-toe and recurrence rate. Robust comparative (Level I) data are lacking.
• K-wire vs intramedullary implant for IP fusion: newer buried intramedullary devices avoid pin-tract infection and external wires, but high-quality evidence of superior fusion or function over the cheap, familiar K-wire remains limited, and implants add cost.
• Does the plantar plate always need formal repair? For MTPJ instability driving a claw/crossover toe, some advocate anatomic dorsal plantar plate repair with Weil osteotomy, while others argue a Weil osteotomy plus flexor transfer alone restores enough stability - the marginal benefit of suturing an often-attenuated plate is debated.
• Prophylactic surgery in the neuropathic foot: percutaneous flexor tenotomy can heal and prevent tip-of-toe ulcers, but how widely to apply prophylactic tenotomy in asymptomatic at-risk diabetic claw toes is unsettled.
• Extent of cavus correction: how aggressively to correct the hindfoot at the index operation (osteotomy/tendon transfer) versus staging it remains a judgement call, balanced against recurrence risk if the cavus driver is left untreated.

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