Hwang KR, Murrell GA, Millar NL, Bonar F, Lam P, Walton JR. Advanced glycation end products in idiopathic frozen shoulders.
J Shoulder Elbow Surg 2016;
25:981-8. [PMID:
26776943 PMCID:
PMC5402873 DOI:
10.1016/j.jse.2015.10.015]
[Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 10/07/2015] [Accepted: 10/18/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND
The pathophysiologic mechanisms behind proliferation of fibroblasts and deposition of dense collagen matrix in idiopathic frozen shoulder remain unclear. Accumulation of advanced glycation end products (AGEs) with cross-linking and stabilization of collagen has been hypothesized to contribute to this pathophysiologic process. This study investigated whether the immunoreactivity of AGEs is higher in patients with idiopathic frozen shoulder than in the control groups.
METHODS
Shoulder capsule samples were collected from 8 patients with idiopathic frozen shoulder, 6 with unstable shoulders (control 1), and 8 with rotator cuff tears (control 2). The samples were hematoxylin and eosin stained and analyzed by immunohistochemistry using antibodies against AGEs. Immunoreactivities were rated in a blinded fashion from none (0) to strong (3). Immunohistochemical distribution within the capsule was noted.
RESULTS
Frozen shoulder patients had greater frequency and severity of self-reported pain (P = .02) than rotator cuff tear patients and more restricted range of motion in all planes (P < .05) than patients of the instability and rotator cuff tear groups. Hematoxylin and eosin-stained capsular tissue from frozen shoulder showed fibroblastic proliferation, increased numbers of adipocytes, and increased subsynovial vascularity. Immunoreactivity of AGEs was stronger in frozen shoulder capsules (2.8) than in instability (0.3; P = .0001) and rotator cuff tear (1.1; P = .016) capsules.
CONCLUSION
This study highlights a potential role for AGEs in the pathogenesis of frozen shoulder. The overexpression of AGEs may explain the fibroblastic proliferation and deposition of collagen matrix in idiopathic frozen shoulder.
LEVEL OF EVIDENCE
Basic Science Study; Histology.
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