PRIMARY FROZEN SHOULDER, THE UNTOLD STORY!

Abstract

The purpose of the study was to test the hypothesis that cellular mechanisms of fibroblasts derived from primary frozen shoulder (PFS) exhibit similar activity in terms of contraction, response to cytokine transforming growth factor-beta1 (TGF beta1) and mechanical stimulation similar to that generated by fibroblasts derived from Dupuytren’s disease. Frozen shoulder has been postulated to be Dupuytren’s disease of the shoulder with an association inferred since 1936. Primary explant cultures of fibroblasts from seven patients with PFS and five control patients were obtained using standard tissue culture techniques. Fibroblasts were seeded in 3-D collagen constructs and contraction force generated over 24 hours measured using a culture force monitor (CFM) in real time. Increasing concentrations of TGF-beta1 were added to cell seeded gels and force generated measured using the CFM over 24 hours. These mechanical output data were statistically compared to data available from Dupuytren’s disease. Compared to Dupuytren’s fibroblasts, PFS fibroblasts showed a statistically reduced ability to contract a 3-D collagen gel over 24 hours (p< 0.01). In Dupuytren’s disease, fibroblasts derived from nodules and cords generate peak forces of 140 dynes and 110 dynes respectively, while PFS fibroblasts generated peak force of 8 dynes The response to TGF-beta1 stimulation, which has been shown to enhance peak force contraction in Dupuytren’s fibroblasts had no effect on PFS fibroblasts and this was statistically significant (p< 0.01). These data suggest intrinsic differences in cellular activity and mechanisms between Dupuytren’s and Primary Frozen Shoulder even though clinically they both manifest with a contracted extracellular matrix affecting function and requiring surgical intervention. This may explain increased post surgical recurrence in Dupuytren’s as compared to Primary Frozen Shoulder release.