Comparison of chondral defects in diabetic patients and matched controls undergoing hip arthroscopy

Abstract

Purpose To review the role of hip arthroscopy to diagnose and assess intraoperative hip pathology in diabetic patients compared to matched nondiabetic patients. Methods In our institutional review board-approved study, we retrospectively reviewed 791 consecutive hip arthroscopies performed by a single surgeon between 2010 and 2015. Patients under 18 years of age or who had previous ipsilateral hip surgery were excluded, leaving 321 patients who met inclusion criteria. Eleven diabetic patients were matched by age, sex, and body mass index to a control, nondiabetic group ( n = 310). Clinical symptoms, preoperative evaluations, radiographic and intraoperative findings were compared. Primary outcomes included the acetabular and femoral head chondromalacia index (CMI), calculated as a product of the Outerbridge chondromalacia grade and surface area (mm 2 *severity). Results On physical exam, diabetics had significantly less terminal hip flexion (83° vs. 92°, P = 0.011) and internal rotation (0.5° vs. 6.4°, P > 0.001) on the operative side compared to controls. More diabetics demonstrated evidence of femoral head chondromalacia compared to controls (57% vs. 8%, P = 0.05; 100% vs. 71%, P > 0.001, respectively) on MRI and intraoperative findings. Acetabular chondromalacia prevalence and grade were similar between the groups on operative findings. Acetabular (369 vs. 389, P = 0.842) and femoral head CMI (510 vs. 354, P = 0.081) did not vary significantly between diabetics and controls. Femoral head CMI positively correlated with acetabular CMI ( r = 0.398, P > 0.001). Conclusions Hip chondral pathology is more prevalent in diabetics compared to a similar group of nondiabetic patients. However, this difference did not translate to severity of the defect between the groups. The deficits in range of motion exhibited by diabetic patients may be due to pincer-type impingement but also suggest soft tissue involvement about the hip joint. Further, histological and molecular studies may better delineate the pathologic process that leads to hip pain in diabetic patients.