Decrease in cystathionine-β-synthase in tendon tissue is an independent risk factor for rotator cuff retear following arthroscopic repair.

Background: Rotator cuff retear is a common complication after arthroscopic repair, and identifying its risk factors is crucial for improving treatment outcomes. The lack of hydrogen sulfide (HS) in the degenerative rotator cuff tendon may inhibit normal tendon-to-bone healing, as HS is a key regulator for stem cells to differentiate into chondrocytes rather than fibroblasts. This study was designed to investigate whether the expression level of HS synthases correlates with rotator cuff retear.

Methods: This prospective study included 163 patients with rotator cuff tears who underwent arthroscopic repair. Tendon tissues were collected intraoperatively and subjected to immunohistochemical staining for HS synthases, including cystathionine-β-synthase (CBS), cystathionine-γ-lyase, and 3-mercaptopyruvate. Multivariate regression and receiver operating characteristic analyses were used to examine the associations of rotator cuff retear with baseline characteristics, magnetic resonance imaging findings, and expression levels of HS synthases.

Results: Retear occurred in 29 patients (17.8%). The expression levels of CBS (r = -0.318, P < .001) and 3-mercaptopyruvate (r = -0.342, P < .001) were negatively correlated with age. Multivariate analysis identified older age (odds ratio = 1.11, P < .001) and lower CBS expression (odds ratio = 0.89, P < .001) as independent risk factors for retear. Receiver operating characteristic analysis showed that age >65 years and CBS expression <52.5 per 100 total cells were predictive of retear.

Conclusion: Older age and decreased CBS expression in tendon tissue are independent risk factors for rotator cuff retear after arthroscopic repair. Although these relationships are considered weak, they may invite more research into the topic.