Characterization of primary chondrocytes harvested from hips with femoroacetabular impingement

Acetabular chondral lesions are common in patients with femoroacetabular impingement (FAI) syndrome. The aim of this study was (1) to evaluate the proliferation potential of primary human chondrocytes (hC) derived from both acetabular and femoral site and (2) to validate cellular differentiation during three-dimensional (3D) cultivation as a prerequisite for autologous matrix-assisted cartilage regeneration of the hip joint.

hC were isolated from cartilage samples obtained from N = 6 patients during offset reconstruction. Proteoglycan content was assessed by Safranin-O staining. Proliferation and cell viability were quantified by microscopic cell counting and Trypan Blue exclusion. Messenger ribonucleic acid (mRNA) expression levels of collagen type 1 and 2, aggrecan (ACAN), and interleukin-1β (IL-1β) genes were assessed upon monolayer cultivation, after 48 h/4-10°C - transport simulation and after 14 days of 3D hydrogel cultivation.

Primary hC from acetabular and femoral damaged sites were viable. No significant intergroup differences were observed concerning cell viability (>95%) after monolayer cultivation and transport simulation. Harvest yields from acetabular and femoral cartilage samples were comparable to that known from knee joints (mean ± standard deviation (SD), 13.4 × 10(6) ± 5 × 10(6) cells per culture vs 20 × 10(6) cells). Redifferentiation was induced during 3D hydrogel cultivation as observed by increased levels of collagen II (1000-fold) and ACAN (10-fold) gene vs monolayer cultivation (P < 0.001).

hC derived from damaged acetabular and femoral site are qualified for autologous matrix-assisted cartilage transplantation paving the way for cell-based cartilage regeneration in FAI patients.