Hammer Toes

Basics

Hammer toes are classified as a form of lesser toe (digits 2–5) deformities.

Description

  • Plantar flexion deformity of the proximal interphalangeal joint (PIPJ) with varying degrees of hyperextension of the metatarsophalangeal (MTP) and distal interphalangeal (DIP) joints (1). Occurs primarily in sagittal plane.
  • Can be flexible, semirigid, or fixed:
    • Flexible: Passively correctable to neutral position
    • Semirigid: Partially correctable to neutral position
    • Fixed: Not passively correctable to neutral position

Epidemiology

Most common deformity of lesser toes, typically affecting only one or two digits; 2nd toe most commonly involved

Incidence

  • Undefined with limited data
  • Can range from 1–20%
  • Increases with age, duration of deformity (from flexible to rigid)

Prevalence

  • More common in women than men (2):
    • Female predominance from 2.5:1 to 9:1, depending on age group
  • Blacks more affected than whites (2)

Risk Factors

  • Pes cavus and planus
  • Hallux valgus
  • Metatarsus adductus
  • Ankle equinus
  • Neuromuscular disease (rare)
  • Trauma
  • Improperly fitted shoes (e.g., with narrow toe box) and/or hosiery
  • Abnormal metatarsal and/or digit length
  • Inflammatory joint disease (e.g., rheumatoid arthritis)
  • Connective tissue disease
  • Diabetes mellitus

Genetics

  • Specific genetic markers not identified
  • Seen more frequently in families

General Prevention

  • No documented means of prevention
  • Modification of shoewear using pressure dispersive devices improves pain (1).
  • Foot orthoses modulate biomechanical dysfunction and muscular imbalance, thereby preventing progression (2)
  • Control of predisposing factors (e.g., inflammatory joint disease) may slow progression

Pathophysiology

  • Any biomechanical dysfunction that results in loss of function of extensor digitorum longus (EDL) tendon at PIPJ and the flexor digitorum longus (FDL) tendon at the MTP joint. The intrinsic muscles sublux dorsally as the MTP hyperextends. This results in plantar flexion of the PIPJ and hyperextension of the MTP joint (2).
  • Specific pathomechanics vary by etiology
    • Toe length discrepancy or narrow toe box induces PIPJ flexion by forcing digit to accommodate shoewear. May also lead to MTP joint synovitis secondary to overuse, with elongation of plantar plate and MTP joint hyperextension.
    • Rheumatoid arthritis causes MTP joint destruction and resultant subluxation

Etiology

  • Congenital
  • Acquired:
    • Any condition that compromises intra-articular and periarticular tissues, such as 2nd ray longer than 1st, inflammatory joint disease, improper fitting shoes, and trauma (1)
      • Damage to joint capsule, collateral ligaments, or synovia leads to unstable PIPJ or MTP joint.

Commonly Associated Conditions

  • Hallux valgus
  • Cavus foot
  • Metatarsus adductus
  • Dorsal callus

Start with the tape under the toes, with the sticky side up. Gently wrap the tape under the big toe (or the toe next to the hammer toe), then over the hammer toe, and then under the next toe and over to the toe you started with. This forces the hammer toe into a normal position. This does not straighten the toe permanently.

Diagnosis

History and physical exam often sufficient for diagnosis of hammer toes. Additional testing available to exclude other conditions

History

  • Location, duration, severity, and rate of progression of foot deformity (3)[C]
  • Type, location, duration of pain
    • Patients often relate sensation of lump on plantar aspect of MTP joint.
  • Degree of functional impairment
  • Factors that improve and exacerbate the condition
  • Type of footwear and hosiery worn
  • Peripheral neurological symptoms
  • Any prior treatment rendered

Physical Exam

  • Note MTP joint hyperextension, PIPJ flexion, and DIPJ extension.
  • Observe any adjacent toe deformities (e.g., hallux valgus, flexion contractures).
  • Assess degree of flexibility and reducibility of deformity in both weightbearing and nonweightbearing positions (2)[C].
  • Note any hyperkeratosis over the joint, ulcers, clavi (dorsal PIPJ, metatarsal head), adventitious bursa, erythema, or skin breakdown (2).
  • Palpate for pain over dorsal aspect of PIPJ or MTP joint.
  • Drawer test of MTP joint
  • Palpate webspaces to exclude interdigital neuroma.
  • Neurovascular evaluation (e.g., pulses, sensation, muscle bulk)

Diagnostic Tests & Interpretation

Lab

Initial lab tests

  • Not required unless clinically indicated to rule out suspected metabolic or inflammatory arthropathies (2)[C]
    • Rheumatoid factor, ANA, HLA-B27 serologies for inflammatory disease

Imaging

Initial approach

Weightbearing x-rays of affected foot in anterior-posterior (AP), lateral, and oblique views (2)[C]

  • AP view superior for assessing MTP subluxation or dislocation
  • Lateral view best for evaluation of gross hammer toe deformity

Follow-Up & Special Considerations

MRI or bone scan if suspect osteomyelitis

Diagnostic Procedures/Surgery

  • Nerve conduction studies or EMG if suspect neurologic disorder
  • Doppler or plethysmography if impaired circulation and surgery is considered
  • Computerized weightbearing pressure testing indicated only in setting of neuromuscular deficiencies of toes

Pathological Findings

Histologic evaluation typically not necessary before treatment

Differential Diagnosis

Hammer toe: Hyperextension of the MTP and DIP joints and plantar flexion of the PIP joint

  • Claw toe: Dorsiflexion of MTP joint and plantar flexion of the DIP joint
  • Mallet toe: Fixed or flexible deformity of the distal interphalangeal (DIP) joint of the toe
  • Overlapping 5th toe
  • Interdigital neuroma
  • Plantar plate rupture
  • Nonspecific synovitis of MTP joint
  • Exostosis
  • Arthritis (e.g., rheumatoid, psoriatic)
  • Fracture

Most common deformity of lesser toes, typically affecting only one or two digits; 2nd toe most commonly involved

Treatment

Goal of treatment is to reduce or relieve symptoms so that patients may return to their normal activity level. Management includes surgical and nonsurgical interventions. Mild cases, however, may not require treatment.

Medication

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Indicated if adequate pain relief achievable nonsurgically or patient is poor surgical candidate

First Line

  • Nonsteroidal anti-inflammatory drugs (NSAIDs) may be helpful in managing symptoms of pain, as well as soft tissue and joint inflammation.
  • Contraindications: Gastrointestinal bleeding or active intracranial bleed; thrombocytopenia; coagulation defects; necrotizing enterocolitis; significant renal dysfunction

Second Line

Anti-inflammatory (cortisone) injectables if local inflammation or bursitis exists (1)[C]

Additional Treatment

General Measures

Nonsurgical (conservative) treatment includes:

  • Shoe modifications, such as wider and/or deeper toe box, may be used to accommodate the deformity and decrease the pressure over osseous prominences. Avoid high-heeled shoes (2)[C].
  • Toe sleeve or orthodigital padding of the hammer toe prominence (4)[C]
  • Hammer toe straightening orthotics or taping to reduce flexible deformities
  • Debridement of hyperkeratotic lesions is effective in reducing symptoms. Topical keratolytics may be helpful (2)[C].
  • Shoe orthotics may be used to control abnormal biomechanical influences.
  • Physical therapy for stretching and strengthening of the toes may help to preserve flexibility.

Issues for Referral

If nonsurgical (conservative) treatment is unsuccessful and/or impractical or patient has combined deformity of MTP joint, PIPJ, and/or DIPJ, then patient may be referred to an orthopedic surgeon or surgical podiatrist for surgical interventions.

Surgery/Other Procedures

  • Surgical procedures for the correction of hammer toes rely on the degree and flexibility of the contracture(s) and the related abnormalities that exist.
  • Surgical interventions for flexible hammer toes include (1,4)[C]:
    • PIPJ arthroplasty (most common)
    • Flexor tendon lengthening/flexor tenotomy
    • Extensor tendon lengthening/tenotomy/MTP joint capsulotomy
    • Exostosectomy
    • Implant arthroplasty
  • Surgical interventions for semirigid/rigid hammer toes include (1,4)[C]:
    • PIPJ resection arthroplasty or arthrodesis
    • Girdlestone-Taylor flexor-to-extensor transfer
    • Metatarsal shortening (Weil osteotomy)
    • Exostosectomy
    • Diaphysectomy of the proximal phalanx (less common)
    • Middle phalangectomy (less common)
    • Soft tissue releases/lengthening
  • Procedures may be performed as isolated operations or in conjunction with other procedures
  • Contraindications for surgery: Active infection, inadequate vascular supply, and desire for cosmesis alone

Ongoing Care

Follow-Up Recommendations

  • Radiographs should be taken immediately following surgery or at the first postoperative visit. Subsequent x-rays may be taken as needed.
  • Full weightbearing in a postoperative (surgical) shoe or other device is indicated based on the procedure(s) performed and on the individual patient.
  • Elevate the foot above nose to minimize swelling, which can lead to pain and delay wound healing.
  • Return to regular shoewear depends on the postoperative course.
  • Role and efficacy of postoperative physical therapy (3 times per week for 2–3 weeks) unclear

Patient Monitoring

In the absence of complications, the patient should be seen initially within the 1st week following the procedure(s). Frequency of subsequent visits is determined based on the procedure(s) performed and the postoperative course.

Patient Education

  • Patients should be aware of mild to moderate swelling and plantar foot discomfort that may persist for many (1–6) months after surgery and may limit footwear options until resolved.
  • MTP joint and PIPJ may remain stiff for extended period of time.
  • “Molding” of the operative toe (assumes shape of adjacent toes)
  • Encourage patients to wear shoes of adequate size with rounded or squared toe box in future.

Prognosis

  • Nonoperative (conservative) treatment usually alleviates pain; however, the deformity may progress despite diligent care.
  • Surgical treatment of flexible hammer toe deformity reliably corrects the deformity and alleviates pain. Recurrence and progression are common, especially if the patient resumes wearing improperly fitted shoes.
  • Surgical treatment of fixed hammer toe deformity provides reliable deformity correction and pain relief. Recurrence is uncommon.

Complications

  • Common complications specific to digital surgery include, but are not limited to, the following:
    • Persistent edema
    • Recurrence of deformity
    • Residual pain
    • Excessive stiffness
    • Metatarsalgia
  • Less common complications include the following:
    • Numbness (e.g., digital nerve palsy)
    • Flail toe
    • Symptomatic osseous regrowth
    • Malposition of toe
    • Malunion/nonunion
    • Infection
    • Vascular impairment (e.g., toe ischemia, gangrene)

References

1. Academy of Ambulatory Foot and Ankle Surgery: Hammertoe Syndrome. National Guideline Clearinghouse. 2003.

2. Clinical Practice Guideline Forefoot Disorders Panel of the American College of Foot and Ankle Surgeons: Diagnosis and Treatment of Forefoot Disorders. Section 1: Digital Deformities. The Journal of Foot & Ankle Surgery. 2009;48(2):230–8.

3. Schrier JC, Verheyen CC, Louwerens JW. Definitions of hammer toe and claw toe: an evaluation of the literature. J Am Podiatr Med Assoc. 2009;99:194–7.

4. Smith BW, Coughlin MJ et al. Disorders of the lesser toes. Sports Med Arthrosc. 2009;17:167–74.

Additional Reading

Miller JM, Blacklidge DK, Ferdowsian V, Collman DR et al. Chevron arthrodesis of the interphalangeal joint for hammertoe correction. J Foot Ankle Surg. 2010;49:194–6.

O’Kane C, Kilmartin T. Review of proximal interphalangeal joint excisional arthroplasty for the correction of second hammer toe deformity in 100 cases. Foot Ankle Int. 2005;26:320–5.

Pietrzak WS, Lessek TP, Perns SV. A bioabsorbable fixation implant for use in proximal interphalangeal joint (hammer toe) arthrodesis: biomechanical testing in a synthetic bone substrate. J Foot Ankle Surg. 2006;45:288–94.

See Also (Topic, Algorithm, Electronic Media Element)

Algorithm: Foot Pain

Codes

ICD9

  • 735.4 Other hammer toe (acquired)
  • 755.66 Other congenital anomalies of toes

Snomed

  • 122481008 hammer toe (disorder)
  • 45636002 acquired hallux malleus (disorder)
  • 85280007 congenital hammer toe (disorder)

Clinical Pearls

  • Hammer toe is plantar flexion deformity of PIPJ.
  • Patients may complain of pain at the PIPJ or MTP joint.
  • Perform a careful inspection and examination of foot, especially PIPJ and MTP joint.
  • Initial management of hammer toe deformity consists of conservative therapy; however, if unsuccessful, surgical interventions are indicated.
  • Well-fitting shoewear is vital to minimizing recurrence after treatment.

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