How to assess plantar reflex in a patient (pt) with a lower limb amputation?

Assessment of Plantar Reflex in Amputee Patients

In patients with lower limb amputation, the plantar reflex should be assessed by stroking the lateral border of the remaining foot, as this technique provides additional diagnostic value when the traditional plantar surface approach is not possible.

Anatomical Considerations in Amputees

When assessing the plantar reflex in a patient with lower limb amputation, several key anatomical considerations must be taken into account:

• Level of amputation: The assessment technique will vary depending on whether the amputation is:

  • Partial foot (transmetatarsal)
  • Below-knee (transtibial)
  • Above-knee (transfemoral)

• Remaining sensory pathways: Even in amputees, neurological assessment remains important as:

  • Plantar sensation is not a reliable indicator of long-term functional outcomes 1
  • Neurological status should not be viewed as an absolute criterion for decision-making in limb salvage 2

Modified Assessment Techniques

Primary Technique: Lateral Border Stimulation

• Stroke the lateral dorsal border of the foot (if partially preserved) 3
• This technique has been shown to provide additional diagnostic value in detecting pyramidal tract lesions
• Particularly valuable when the traditional plantar surface is not accessible due to amputation

Alternative Assessment Methods

When complete foot amputation has occurred:

1. Stump reflex assessment:

   • Assess for abnormal reflexes at the amputation site
   • Look for muscle contractions in the remaining limb segments

2. Contralateral limb assessment:

   • Always assess the plantar reflex in the non-amputated limb
   • Compare findings to establish baseline neurological status

3. Comprehensive neurological examination:

   • Assess muscle power, tone, and deep tendon reflexes in the remaining limb
   • Evaluate for other upper motor neuron signs (e.g., Hoffman's sign, hyperreflexia)

Clinical Significance and Documentation

The assessment of plantar reflex in amputees is important for:

• Neurological status monitoring: Detecting potential central nervous system pathology
• Rehabilitation planning: Informing physical therapy approaches
• Prosthetic fitting: Guiding appropriate prosthesis selection

When documenting findings:

• Clearly note the technique used for assessment
• Document the presence or absence of response
• Note any limitations in assessment due to the amputation

Special Considerations

• Phantom sensations: Patients may report sensations in the amputated limb - these should be documented but distinguished from actual reflex responses
• Experience matters: Research shows that more experienced clinicians need fewer tests to identify pyramidal syndromes 3
• Sensory recovery: Over 50% of patients with initially absent plantar sensation regain it within two years after limb salvage procedures 1

Importance in Amputation Decision-Making

The American Academy of Orthopaedic Surgeons specifically notes that:

• Absent plantar sensation at presentation should not be a major factor in treatment pathway decisions 2
• Multiple studies have shown that plantar examination at presentation is unreliable 2
• Neurologic deficit does not predictably affect functional recovery 2

This underscores the importance of comprehensive assessment rather than relying solely on plantar reflex findings when making clinical decisions about limb salvage versus amputation.

Remember that the assessment technique must be adapted to the specific anatomical situation of each patient, with the lateral border technique providing valuable additional information when traditional assessment is not possible.