title: Histopathologic evaluation of passive stabilizers in shoulder instability.
abstract: BACKGROUND
  The macroscopic pathomorphology in recurrent shoulder instability has been described. However, less is known regarding the histopathologic details of the affected structures. This study evaluates different histopathologic stages of shoulder instability by assessing biopsy specimens of static stabilizers for possible correlations with clinical parameters. Our hypothesis was that clinical parameters of shoulder instability correlate with histopathologic findings.
  
  
  METHODS
  Passive shoulder stabilizers (labrum, anterior bundle of the inferior glenohumeral ligament) were biopsied during arthroscopic shoulder stabilization. Samples were submitted to immunohistochemistry, in situ hybridization, and blinded evaluation. Clinical data, comprising age (<30 years or ≥30 years), total number of dislocations (1, 2-3, or >3), and period since initial dislocation (<6 months, 6 months to 6 years, or >6 years), were tested for statistical correlation with the following histopathologic parameters: inflammation, lipomatous changes, vascular proliferation, tissue fragmentation, and cellularity.
  
  
  RESULTS
  Standardized biopsies were performed in 30 consecutive patients (4 women and 26 men; mean age, 32.6 years) with anterior shoulder instability. Microscopic evaluation showed only small variations in histologic changes among all samples. Only limited variations in cell density, matrix swelling, and collagen fiber disruptions were found. Immunohistochemical analysis showed a similar expression of decorin in all samples. Clinical parameters (age, total number of dislocations, and period since initial dislocation) were statistically independent from histopathologic parameters (inflammation, lipomatous changes, vascular proliferation, tissue fragmentation, and cellularity). No correlation was found in patients with 1 dislocation versus those with more than 1 dislocation.
  
  
  CONCLUSIONS
  In contrast to macroscopic findings among different grades of shoulder instability, this study detected no correlation between clinical items (age, total number of dislocations, and period since initial dislocation) and histopathologic parameters. These clinical items seem to be independent from the tissue status of static stabilizers of the shoulder.
authors.affiliation: Center for Musculoskeletal Surgery ,Charité-Universitaetsmedizin Berlin, Berlin, Germany. stephan.pauly@charite.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Pauly
authors.forename: Lars
authors.initials: L
authors.lastname: Morawietz
authors.forename: David
authors.initials: D
authors.lastname: Krüger
authors.forename: Patrick
authors.initials: P
authors.lastname: Strube
authors.forename: Markus
authors.initials: M
authors.lastname: Scheibel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001182:Arthroscopy; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000473:pathology* / Q000601:surgery; D008023:Ligaments, Articular / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012785:Shoulder Joint / Q000473:pathology* / Q000601:surgery; D055815:Young Adult