title: The effect of myofibroblasts and corticosteroid injections in adhesive capsulitis.
abstract: OBJECTIVE
  Adhesive capsulitis is a condition that results in restricted glenohumeral motion. Fibroblasts have been implicated in the disease process; however, their role as a contractile element in the development of fibrosis and capsular contracture is not well understood. We hypothesized (1) that myofibroblast prevalence in capsular biopsy specimens from patients with adhesive capsulitis would be increased compared with controls and (2) that patients treated with an intra-articular injection of corticosteroid would have fewer myofibroblasts.
  
  
  METHODS
  The study prospectively enrolled 20 consecutive patients with adhesive capsulitis scheduled for capsular release and matched controls. Tissue samples were collected from the posterior and anterior capsule for histomorphologic and immunohistologic analyses. Identical sectioning and preparation was performed in 14 additional adhesive capsulitis specimens from patients who had not received corticosteroid injections.
  
  
  RESULTS
  Patients with adhesive capsulitis not treated with preoperative corticosteroid demonstrated more histologic evidence of fibromatosis, synovial hyperplasia, and an increase in positive staining for α-smooth muscle actin than patients who had received intra-articular injections of steroid. No specimens obtained from control patients demonstrated positive staining for α-smooth muscle actin.
  
  
  CONCLUSIONS
  There was a higher prevalence of myofibroblast staining in patients with adhesive capsulitis, implicating activation of the myofibroblast in the pathophysiology of capsular contracture. Intra-articular steroid injection decreases the presence and amount of fibromatosis, vascular hyperplasia, fibrosis, and the presence of fibroblasts staining for α-smooth muscle actin. This supports the use of steroid injections to alter the disease process by decreasing the pathologic changes found in the capsular tissue.
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Iowa Sports Medicine Center, Iowa City, IA, USA. Electronic address: carolyn-hettrich@uiowa.edu.
authors.forename: Carolyn M
authors.initials: CM
authors.lastname: Hettrich
authors.affiliation: Laboratory for Soft Tissue Research, Hospital for Special Surgery, New York, NY, USA.
authors.forename: Edward F
authors.initials: EF
authors.lastname: DiCarlo
authors.affiliation: Laboratory for Soft Tissue Research, Hospital for Special Surgery, New York, NY, USA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Faryniarz
authors.affiliation: Laboratory for Soft Tissue Research, Hospital for Special Surgery, New York, NY, USA.
authors.forename: Katherine B
authors.initials: KB
authors.lastname: Vadasdi
authors.affiliation: Laboratory for Soft Tissue Research, Hospital for Special Surgery, New York, NY, USA.
authors.forename: Riley
authors.initials: R
authors.lastname: Williams
authors.affiliation: Laboratory for Soft Tissue Research, Hospital for Special Surgery, New York, NY, USA.
authors.forename: Jo A
authors.initials: JA
authors.lastname: Hannafin
mesh_terms: D000328:Adult; D000368:Aged; D002062:Bursitis / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D016022:Case-Control Studies; D005260:Female; D005355:Fibrosis; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D007270:Injections, Intra-Articular; D057913:Joint Capsule Release; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage*; D008875:Middle Aged; D058628:Myofibroblasts / Q000502:physiology*; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology; D012785:Shoulder Joint / Q000502:physiology
chemical_list: D005938:Glucocorticoids; D008775:Methylprednisolone
keywords: Adhesive capsulitis; corticosteroid injection; fibrosis; frozen shoulder; myofibroblast; synovial hyperplasia