Paper #69 - ISHA Annual Scientific Meeting 2016

Diabetics Undergoing Hip Arthroscopy More Frequently Demonstrate Femoral Head Chondromalacia

T. David Luo, MD, Winston-Salem, NC UNITED STATES
Alejandro Marquez-Lara, MD, Winston Salem, NC UNITED STATES
Sandeep Mannava, MD, PhD, Winston Salem, NC UNITED STATES
Austin Stone, MD, Winston Salem, NC UNITED STATES
Elizabeth A. Howse, MD, Walnut Creek, CA UNITED STATES
Allston J. Stubbs, MD, MBA, Winston Salem, NC UNITED STATES

Wake Forest Baptist Medical Center, Winston-Salem, NC, UNITED STATES

FDA Status Not Applicable

Summary: Hip chondral pathology is more prevalent in diabetics compared to a similar cohort of non-diabetic patients.

Abstract:
Introduction
Hip pain in patients with diabetes mellitus remains a challenge to diagnose and treat, and can be attributed to a variety of factors. Intra-articular chondral damage and neuropathic etiology may contribute to the diabetic patient’s pain symptoms. Few studies have reviewed the role of hip arthroscopy to diagnose and treat hip joint disease in the diabetic patient. We hypothesize that patients with diabetes and hip pain have greater degree of acetabular and femoral head chondromalacia at the time of hip arthroscopy compared to patients without diabetes.
Methods
In our institutional review board-approved study, we reviewed 413 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. Eleven diabetic patients were age-, sex- and BMI-matched to a control, non-diabetic cohort (n=310). Primary outcome variables were the acetabular and femoral head chondromalacia index (CMI), calculated as a product of the Outerbridge chondromalacia grade and surface area (mm2*severity).
Results
The diabetic and control groups were similar with respect to age (37.1 vs. 34.0, p=0.351), sex (64% female vs. 66% female, p=0.864), BMI (29.4 kg/m2 vs. 26.4 kg/m2, p=0.078), and operative side (64% right vs. 57% right, p=0.668). Both groups reported similar pain symptoms with respect to location; however a greater number of controls complained of radiculopathy (37% vs. 9%, p=0.013) while more diabetics complained of night pain (91% vs. 66%, p=0.023). 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. Radiographic lateral center-edge angle (41° vs. 31°, p=0.025) and anterior center-edge angle (39° vs. 34°, p=0.038) were greater in diabetics than controls. MRI and intraoperative findings indicated that more diabetics demonstrated evidence of femoral head chondromalacia compared to controls (57% vs. 8%, p=0.05; 100% vs. 71%, p<0.001, respectively). The correlation between diabetes and femoral head chondromalacia was positive (r=0.281, p<0.001). 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).
Discussion and Conclusion
Our results support our hypothesis that hip chondral pathology is more prevalent in diabetics compared to a similar cohort of non-diabetic patients. However, this difference did not translate to severity of the defect between the groups. Pre-clinical studies have demonstrated that elevated blood glucose levels adversely affect chondrocyte metabolism, leading to destruction of joint cartilage. The deficits in range of motion exhibited by diabetic patients 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.