Viability of chondrocytes harvested during treatment of hip femoroacetabular impingement.

PURPOSE

This study aimed to collect tissue overlying a CAM deformity for subsequent cell culture and chondrocyte expression as a proof of concept of clinical feasibility for autologous cell-based cartilage restoration in the hip.

METHODS

IRB approval was obtained to collect otherwise-discarded tissues from patients undergoing surgical management of labral tears and FAI. The collected tissue was exposed to collagenase type II for 16-24 h for chondrocyte isolation. Isolated cells were counted and seeded onto T-25 flasks in DMEM supplemented with 10% FBS. Media was changed every three days until > 90% confluency. At confluency, cells were counted and seeded onto a T-175 flask representing passage one. At second confluency, cells were counted again; if the total did not surpass 20,000,000 cells based on the minimum number needed for cell-based treatments, they were seeded onto two T-175 flasks representing passage two. Cells were not expanded beyond passage two based on the goal of phenotype maintenance.

RESULTS

Mean weight of collected tissues was 209.69 ± 78.09 mg (median = 202 mg). 41 of 55 samples reached > 20,000,000 cells at a mean of 33.98 ± 13.06 days (median = 30 days). Mean initial cell seeding of successful expansions was 1,116,871.79 ± 2,271,995.77 cells (median = 340,000 cells). Of samples that failed to reach threshold, five did not have sufficient cells following chondrocyte isolation to establish culture, and nine did not progress toward confluency for passage one. There were no significant differences in patient age (p =.988) or sex (p =.537) between successful versus unsuccessful expansions. There was a significant difference in patient BMI (p <.001) between successful versus unsuccessful expansions.

CONCLUSIONS

74.5% of tissue samples reached the minimum threshold (20 million cells), indicating successful expansions that may be sufficient for use in hip preservation procedures involving cell-based cartilage restoration. These findings support the viability of chondrocytes harvested from tissue overlying CAM deformities, and the feasibility of utilizing the tissue in subsequent autologous chondrocyte implantation procedures.