Are Chondrocytes Overlying Cam Morphology Suitable for Therapeutic Use?

Abstract

Objectives:Cam-type femoroacetabular impingement (FAI) results in extra bone and cartilage on the anterolateral femoral head-neck junction, causing abnormal contact between the femur and the acetabulum. We investigated whether chondrocytes isolated from cam lesions in FAI patients are metabolically similar to normal chondrocytes and therefore a potential option for therapeutic use via autologous implantation.Methods:Cam cartilage was obtained intraoperatively from 7 human patients with cam lesions (Alpha angle > 60 degrees) (4 arthroscopy, 2 arthroplasty, and 1 periacetabular osteotomy). Healthy femoral and acetabular articular cartilage was obtained from 8 Yucatan minipig hips for comparison. Chondrocytes were extracted from the cartilage then cultured at a high density for up to 1 week. Mitochondrial stress testing procedures (with 2 mM oligomycin, 2.5 mM carbonyl cyanide p-trifluoromethoxy-phenylhydrazone (FCCP), 2 mM rotenone, 5 mM antimycin A) for determination of the chondrocytes basal and maximal respiration were performed.Results:No significant differences in basal (p = 0.73) or maximum (p = 0.40) respiration were found when comparing chondrocytes from cam lesions to normal porcine articular chondrocytes. There was a significant difference in maximum respiration when comparing chondrocytes from cam lesions in patients who underwent a total hip arthroplasty to chondrocytes from other cam lesions (p = 0.007).Conclusion:Basal and maximum respiration in chondrocytes from cartilage overlying cam lesions suggests a similar level of respiration to healthy articular chondrocytes. Given the importance of mitochondria to cartilage homeostasis, this study supports that chondrocytes overlying non-arthritic femoral cam lesions may be a novel source of healthy chondrocytes.