Effects of Estrogen-Deficient State on Rotator Cuff Healing:

Background:Rotator cuff retears after surgical repair are a concern, despite advances in operative techniques, but few studies have investigated the effects of the estrogen-deficient state on tendon-to-bone healing at the repair site.Purpose:We evaluated the effect of the estrogen-deficient state on tendon-to-bone healing after rotator cuff repair in an ovariectomized rat model.Study Design:Controlled laboratory study.Methods:Female Sprague Dawley rats underwent detachment and immediate repair of the supraspinatus tendon. Surgery was performed in 24 rats at 4.5 weeks of age 17 weeks after ovariectomy (OVX group) and in 24 age-matched control rats without ovariectomy (control group). Animals were sacrificed at 2, 4, 8, and 12 weeks after surgery for biomechanical and histological evaluations of reattachment. Bone mineral density (BMD) at the insertion site and cancellous bone in the humeral head was assessed by micro–computed tomography.Results:BMD was significantly lower both at the insertion site and in ...