Histological Evidence of Intrinsic Muscle Degeneration in Compression Ulnar Neuropathy

Purpose We investigated the histological characteristics of the tissues in the intrinsic hand muscles of patients with compressive ulnar neuropathy (CUN) to determine how the compromised nerve influences the target muscle. Methods In total, 83 patients underwent surgery for CUN in our institution between March 2015 and August 2017. Of these, 45 patients who met our inclusion/exclusion criteria were initially included in this study. Basic demographic data including age, sex, hand dominance, duration of symptoms, bone mineral density, and clinical stage were evaluated. During the ulnar nerve decompression surgery, a biopsy of the ipsilateral adductor pollicis was performed. Using the biopsy samples, we analyzed the tissue composition and degree of degeneration, and investigated the association with demographic factors and clinical status. Results The ratio of muscle/connective tissue/fat was 62.62 ± 8.27%/23.44 ± 4.10%/14.16 ± 6.68% in the affected muscle. The ratio was different than that of samples taken from control groups. In samples containing muscle fibers, although the total fat content remained low, fat was consistently concentrated at the fascicular borders, between fascicles (perifascicular fat, 62.3 ± 18.2% of fascicles), and within fascicles (intrafascicular fat, 35.6 ± 11.8% of fascicles). The proportion of centrally nucleated muscle fibers was also significantly elevated (5.58 ± 4.25%; P
Source: Annals of Plastic Surgery - Category: Cosmetic Surgery Tags: Peripheral Nerve Surgery and Research Source Type: research