Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Claw Toes

Basics
Description
The term claw toes describes a hyperextension deformity of the MTP joint of the lesser toes with flexion deformity of the PIP joint .
 
General Prevention
Use of appropriate shoe wear (wide shoes with a high toe box) can prevent the development of claw toes in many cases.
 
Epidemiology
Incidence
  • Increases with advancing age
  • Occurs more frequently in females than males.
Genetics
Patients with a hereditary motor sensory neuropathy as the cause of claw toes may have an autosomal dominant pattern of transmission.
 
Pathophysiology
  • The most common cause is an imbalance between the intrinsic and extrinsic muscles of the foot.
    • Concurrent contracture of the long flexors and extensors of the toes without any balancing force from the intrinsic muscles
  • Typically occurs secondary to underlying neurogenic or inflammatory conditions that lead to imbalance of the toe musculature and attenuation of the passive ligament restraints of the joints
  • Can be idiopathic
  • Causative factors:
    • Tight shoe wear
    • Hallux valgus
    • Inflammatory arthropathy
    • Neuropathy
    • Diabetes mellitus
    • Hereditary sensorimotor neuropathies
    • Neuromuscular disease
    • Spasticity disorders
    • Compartment syndrome
Diagnosis
Signs and Symptoms
  • Dorsal prominence of the PIP joint of the lesser toes
  • Callosities and irritation of the overlying skin
  • Pain over the dorsum of the toe or under the ball of the foot (metatarsalgia)
  • Difficulty with shoe wear
History
  • Patients may complain of unacceptable cosmetic appearance, difficulty with shoe wear, or a painful bursa over the dorsum of the PIP joint.
  • With hyperextension of the MTP joint, the plantar fat pad subluxates distally and causes painful plantar calluses and possible ulcerations in insensate feet.
Physical Exam
  • Often occurs in multiple adjacent digits, as well as bilaterally
  • Often associated with cavus foot deformity
  • The clinician should:
    • Manipulate the joints to determine whether the deformity is rigid or flexible
    • Perform a thorough neuromuscular exam
    • Test sensation of the foot
Imaging
Plain radiographs show subluxation of the MTP joints and flexion deformity of the PIP joint.
 
Differential Diagnosis
  • Other conditions have similar signs and symptoms but are not associated with hyperextension of the MTP joints:
    • Hammer toes
    • Mallet toes
Treatment
General Measures
  • A Budin splint may help correct flexible deformities.
  • Silicone padding covering the toes may pad the symptomatic areas.
  • Cushioned insoles can protect from painful metatarsalgia.
  • Wide shoes with a high toe box can avoid painful rubbing of the claw toes.
Geriatric Considerations
  • This condition is very common in elderly females.
  • If morbidities such as diabetes or peripheral vascular disease coexist, surgical management should be a last resort.
Pediatric Considerations
Congenital curly toes may be present at birth and may require tendon releases at an early age.
 
Surgery
  • For flexible deformities, a flexor-to-extensor tendon transfer can be performed to straighten the claw toe.
  • Rigid deformities require release of the contracted MTP capsule and collateral ligaments, and extensor tendon release or lengthening.
  • Claw toes with dislocation of the MTP joint are treated with oblique distal metatarsal osteotomy to achieve bony shortening and reduce the MTP joint  .
  • Rigid PIP joint contractures are corrected with partial phalangectomy or PIP joint fusion.
Follow-up
Issues for Referral
  • Persistent pain not relieved by nonoperative care:
    • Inability to wear shoes
    • Overlying skin ulceration or impending ulceration in patients with neuropathy
Prognosis
Claw toes usually are progressive, worsening in pain and deformity over time.
 
Complications
  • Complications of surgical treatment include:
    • Stiffness
    • Wound infection
    • Persistent pain
    • Failure to correct deformity adequately
    • Recurrence of deformity
Miscellaneous
Codes
ICD9-CM
735.5 Claw toe
 
Patient Teaching
  • Many splints and pads can be obtained at local drugstores in the foot care section.
  • Medical supply stores may have a wider selection of orthoses.
Prevention
Avoidance of narrow, tight-fitting shoes is the best way to prevent the development of claw toes.
 
FAQ
Q: What differentiates claw toes from hammer toes?
A: Claw toes involve flexion contractures of the distal and PIP joints along with hyperextension of the MTP joint. Hammer toes involve isolated PIP flexion deformity.

Q: What is the most common underlying etiology of claw toes?
A: Neurologic disorders cause atrophy or weakness of the intrinsic muscles of the foot. These conditions lead to relative imbalance between the intrinsic and extrinsic muscles, leading in turn to flexion deformities of the IP joints and hyperextension of the MTP joint. Claw toes commonly are seen in conditions such as diabetes (neuropathy), spinal disorders, stroke, paralysis, and spasticity disorders, and in hereditary motor sensory neuropathies such as Charcot-Marie-Tooth disease.

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