Chondral regeneration in femoroacetabular lesions is favoured using peripheral blood stem cells with hyaluronan‐based scaffold and micro‐drilling: A prospective cohort study

Purpose To determine whether intra‐articular injections of peripheral blood stem cells (PBSC) with hyaluronan (HA)‐based scaffold improve articular cartilage regeneration in chondral injuries caused by mixed‐femoroacetabular impingement syndrome (FAIS) over a period longer than 24 months post‐hip arthroscopy. Methods In this prospective cohort study, patients with mixed‐FAIS and chondral injury ≥ IIIB according to the International Cartilage Regeneration and Joint Preservation Society grade or III/IV of Konan/Haddad classification underwent intra‐articular injection of PBSC with an HA‐based scaffold and micro‐drillings during hip arthroscopy. The degree of chondral repair was measured at baseline and 5 years using the International Cartilage Repair Society morphologic score system (MSS) as the primary outcome. Pain was measured at baseline and 5 years using the Visual Analogue Scale for Pain (VAS Pain), and hip functionality was measured at baseline (presurgery), 6 months, 1 year, and 5 years using the Hip Outcome Score (HOS). The largest diameter of injury, median follow‐up, side effects, complications, and improvements were described. T‐test, ANOVA with multiple comparisons, and statistical power were estimated. Results From initially 34 cases, 25 patients were enrolled. The median follow‐up was 5.1 ± 0.3 years. One patient (4%) reported a few side effects with filgrastim administration. No infection, tumours, or synovitis was reported. The largest diameters in zones two, three, and four were 12.4 ± 3.1 mm (n = 8), 13.5 ± 2.8 mm (n = 14), and 11.4 ± 1.9 mm (n = 3), respectively. Ninety‐two percent (23/25) of patients improved their outcomes. The MSS and HOS increased from 3.8 ± 1.1 to 9.6 ± 1.5 pts (p