Better Clinicoradiological Results of BST-CarGel Treatment in Cartilage Repair Compared With Microfracture in Acetabular Chondral Defects at 2 Years

Abstract

Background: BST-CarGel (CarGel) is an injectable chitosan scaffold that is mixed with fresh, autologous blood and injected into the site of microfracture (MF) to physically stabilize clots and enhance cartilage repair. Purpose: To evaluate short-term clinicoradiological outcomes of patients treated arthroscopically for acetabular chondral defects with CarGel in conjunction with MF compared with those treated with MF alone. Study Design: Cohort study; Level of evidence, 3. Methods: All patients who underwent hip arthroscopy and received MF with or without CarGel for acetabular chondral defects between 2014 and 2018 with a minimum 2-year clinicoradiological follow-up were included. Intraoperative details, postoperative complications, and clinical outcome scores, including the international Hip Outcome Tool–33 (iHOT-33), Hip Outcome Score (HOS)–Activities of Daily Living (HOS-ADL), and Hip Outcome Score–Sports Profile, were analyzed. Serial plain radiographs were assessed independently by 2 blinded observers. A survival analysis was performed to identify the number of cases converted to total hip arthroplasty (THA) in both groups, which was correlated with the cartilage defect size at the time of surgery. Results: Eighty patients (54 CarGel and 26 MF) were evaluated, including 56 men (70%) and 48 right hips (60%). Three patients were lost to follow-up. There were no major adverse events in either group. The average defect size was 3.63 and 4.97 cm2 in MF and CarGel, respectively (P = .002). There was a statistically significant improvement in iHOT-33 (from 43.24 to 60.17 in MF and from 41.13 to 58.39 in CarGel) and HOS-ADL (from 62.25 to 76.75 in MF and from 44.69 to 79.16 in CarGel) scores. There was no difference between the 2 groups in the outcome scores after adjusting for covariates. Survival analysis showed 34.6% of MF cases and 5.9% of CarGel cases were converted to THA (P = .001). The mean defect size of the failure group was higher in CarGel than in MF (8.83 and 3.72 cm2, respectively). Mean joint space reduction was 1.41 mm in MF and 0.19 mm in CarGel (P < .001). Conclusion: Two-year clinicoradiological results were promising in these lesions that are difficult to treat. Arthroscopic treatment of chondral acetabular defects with CarGel demonstrated a significant decrease in progressive loss of joint space and conversion to THA compared with MF as an isolated procedure.