Not just quantity: Gluteus maximus muscle characteristics in able-bodied and SCI individuals e Implications for tissue viability pdf

Some individuals with spinal cord injury (SCI) remain pressureulcer (PU) free whilst others experience a recurring cycle of tissuebreakdown.Detailed analysis of gluteal muscle characteristics may provide insights to local tissueviability variability. The study hypothesis was that SCI individuals have alteredmuscle composition compared to able-bodied (AB).Materials: Ten AB and ten SCI received a supine pelvic CT scan, with contrast.Methods: Cross-sectional area (CSA) and overall muscle volume were derived using
image analysis. Gluteal muscle tissue type was classified at the S2/S3 sacral vertebraemidpoint, the superior greater trochanters margin (GT) and the inferior ischialtuberosities margin (IT) using the linear transformation Hounsfield Unit scale.
Results: SCI gluteal CSA was less than for AB throughout the muscle, with the greatestrelative atrophy at the IT (48%). Average AB gluteal volume was nearly doubleSCI. Eight SCI had over 20% infiltrative adipose tissue, three with over 50%. SCIgluteal CSA and intramuscular fat infiltration were significantly negatively correlated(p < 0.05). SCI IT axial slices showed less lean muscle and higher intramuscularfat infiltration than more proximally (p < 0.05).
Conclusion: SCI gluteal muscle characteristics were indicative of impaired tissueviability. SCI disuse muscle atrophy was anticipated; the analytic approach furtherindicated that intramuscular atrophy was not uniform. SCI muscle compositionshowed increased proportions of both low density muscle and adipose tissue. CTscan with contrast is effective for gluteal muscle characterization. Thisassessment technique may contribute to determination of personalized risk for PU development and other secondary complications.