title: More histologic and ultrastructural degenerative signs in the subscapularis tendon and the joint capsule in male patients with shoulder impingement.
abstract: OBJECTIVE
  The purpose of the present study was to analyze biopsy samples from the subscapularis tendon and from the joint capsule from male patients with shoulder impingement syndrome (SAIS) and compare them with samples from male patients with post-traumatic recurrent shoulder instability. The hypothesis of the study was that patients with SAIS would have more histologic and ultrastructural degenerative changes in their subscapularis tendon and joint capsule than patients with post-traumatic recurrent shoulder instability.
  
  
  METHODS
  Male patients scheduled for surgery, with either subacromial decompression or Bankart reconstruction, were included. Four biopsies from each patient were obtained from the capsule and four from the subscapularis tendon during arthroscopic surgery. The histologic characteristics and the presence of glycosaminoglycans were assessed using the light microscope, and the ultrastructure was assessed using a transmission electron microscope.
  
  
  RESULTS
  Eight patients, median age 53 (45-74) years (p < 0.0001), were included in the impingement group, and 12 patients, median age 27 (22-48) years, were included in the instability group. The histologic assessment revealed significantly higher cellularity and total degeneration score in the capsule (p = 0.016 and p = 0.014 respectively) in patients with subacromial impingement compared with the instability patients. The corresponding finding was not made for the subscapularis tendon. The ultrastructural evaluation revealed that the instability patients had more fibrils with a large diameter (indicating less degeneration) in both the subscapularis tendon and the capsule compared with the impingement patients (p < 0.0001).
  
  
  CONCLUSIONS
  Male patients with subacromial impingement have more histologic and ultrastructural degenerative changes in their shoulder compared with patients with post-traumatic recurrent shoulder instability.
  
  
  CONCLUSIONS
  It appears that in patients with subacromial impingement, the whole shoulder joint is affected and not only the subacromial space. It is the opinion of the authors that intra-articular therapeutic injections could be tried more often in these patients.
  
  
  METHODS
  III.
authors.affiliation: Department of Orthopedics, NU-Hospital Group Trollhättan/Uddevalla, Uddevalla Sjukhus, 451, Uddevalla, Sweden. stefanos.farfaras@vgregion.se.|Gothenburg University-Sahlgrenska Academy, Gothenburg, Sweden. stefanos.farfaras@vgregion.se.
authors.forename: Stefanos
authors.identifier: http://orcid.org/0000-0001-6466-3776
authors.initials: S
authors.lastname: Farfaras
authors.affiliation: Department of Orthopedics, NU-Hospital Group Trollhättan/Uddevalla, Uddevalla Sjukhus, 451, Uddevalla, Sweden.
authors.forename: Lars Erik
authors.initials: LE
authors.lastname: Ejerhed
authors.affiliation: Department of Orthopedics, NU-Hospital Group Trollhättan/Uddevalla, Uddevalla Sjukhus, 451, Uddevalla, Sweden.|Gothenburg University-Sahlgrenska Academy, Gothenburg, Sweden.
authors.forename: Erling K
authors.initials: EK
authors.lastname: Hallström
authors.affiliation: Division of Clinical Research Center, Department of Laboratory Medicine, Karolinska Institute Stockholm, Stockholm, Sweden.
authors.forename: Kjell
authors.initials: K
authors.lastname: Hultenby
authors.affiliation: Bone and Joint Research Group, Department of Orthopedics, Institute of Clinical Medicine, University Hospital North Norway, The Arctic University of Norway, Tromsø, Norway.
authors.forename: Khaled
authors.initials: K
authors.lastname: Meknas
authors.affiliation: Department of Clinical Science, Karolinska Institute, Stockholm, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Movin
authors.affiliation: Division of Pathology, Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden.
authors.forename: Nikos
authors.initials: N
authors.lastname: Papadogiannakis
authors.affiliation: Department of Orthopedics, NU-Hospital Group Trollhättan/Uddevalla, Uddevalla Sjukhus, 451, Uddevalla, Sweden.|Gothenburg University-Sahlgrenska Academy, Gothenburg, Sweden.
authors.forename: Jüri-Toomas
authors.initials: JT
authors.lastname: Kartus
mesh_terms: D000328:Adult; D000368:Aged; D001182:Arthroscopy; D001706:Biopsy; D006025:Glycosaminoglycans / Q000032:analysis; D006801:Humans; D017746:Joint Capsule / Q000737:chemistry / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D007593:Joint Instability / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D012008:Recurrence; D017006:Rotator Cuff / Q000737:chemistry / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D012782:Shoulder / Q000473:pathology / Q000601:surgery; D019534:Shoulder Impingement Syndrome / Q000473:pathology* / Q000601:surgery; D012785:Shoulder Joint / Q000737:chemistry / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D013710:Tendons / Q000737:chemistry / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D014947:Wounds and Injuries / Q000150:complications; D055815:Young Adult
chemical_list: D006025:Glycosaminoglycans
keywords: Biopsy; Degeneration; Shoulder instability; Shoulder joint capsule; Subacromial impingement; Subscapularis tendon