Spinal Pathology and Muscle Morphologies with Chronic Low Back Pain and Lower Limb Amputation

Area of Science:

• Biomedical Engineering
• Orthopedics
• Rehabilitation Medicine

Background:

• Low back pain (LBP) is a prevalent issue for individuals with lower limb amputation (LLA), significantly impacting their quality of life and functional capacity.
• Understanding the underlying pathophysiological mechanisms of LBP in this population is crucial for developing effective interventions.

Purpose of the Study:

• To compare lumbar spine pathologies and muscle morphologies in individuals with LBP, both with and without LLA.
• To investigate potential differences in spinal health and muscle composition between these groups.

Main Methods:

• Retrospective analysis of electronic medical records for Service members with and without LLA seeking care for LBP.
• Matched cohorts (n=15 each) with and without unilateral transtibial LLA were selected.
• Lumbar spine parameters (lordosis angle, spondylolysis, facet arthrosis, Pfirrmann grades, Modic changes) and muscle morphology (area, intramuscular fat) were assessed via imaging.

Main Results:

• Individuals with LLA exhibited a larger lordosis angle (P=0.01) and higher prevalence of spondylolysis (P=0.008; 40%) compared to controls.
• While lumbar muscle area was comparable, intramuscular fat content was significantly greater in the LLA group (P≤0.05).
• Facet arthrosis prevalence was similar between groups (P=0.3), and intramuscular fat did not correlate with Pfirrmann grades (P>0.15).

Conclusions:

• Despite similar lumbar muscle size, individuals with unilateral LLA may have an increased predisposition to symptomatic spondylolisthesis and intramuscular fat accumulation.
• These findings suggest potential long-term spinal health implications for individuals with LLA.
• Targeted surgical or rehabilitation interventions may be beneficial in mitigating LBP-related disability and improving function in this population.