Rate of Conversion to Matrix-Induced Autologous Chondrocyte Implantation After a Biopsy: A Multisurgeon Study

Nicholas Pasic; Hannah L Bradsell; Andres Barandiaran; Avi S Robinson; Brian J Cole; Armando F Vidal; Rachel M Frank

doi:10.1177/23259671231160732

Rate of Conversion to Matrix-Induced Autologous Chondrocyte Implantation After a Biopsy: A Multisurgeon Study

Orthop J Sports Med. 2023 May 9;11(5):23259671231160732. doi: 10.1177/23259671231160732. eCollection 2023 May.

Authors

Nicholas Pasic¹, Hannah L Bradsell¹, Andres Barandiaran¹, Avi S Robinson¹, Brian J Cole², Armando F Vidal³, Rachel M Frank¹

Affiliations

¹ Division of Sports Medicine and Shoulder Surgery, Department of Orthopedics, University of Colorado School of Medicine, Aurora, Colorado, USA.
² Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Illinois, USA.
³ The Steadman Clinic, Vail, Colorado, USA.

Abstract

Background: Autologous chondrocyte implantation (ACI) and matrix-induced autologous chondrocyte implantation (MACI) are performed to treat focal chondral defects (FCDs); both are 2-step procedures involving a biopsy, followed by transplantation. There is little published research evaluating ACI/MACI in patients who undergo a biopsy alone.

Purpose: To determine (1) the value of ACI/MACI cartilage biopsies and concomitant procedures in patients with FCDs of the knee and (2) the conversion rate to cartilage transplantation as well as the rate of reoperation.

Study design: Case series; Level of evidence, 4.

Methods: A retrospective review was performed of 46 patients (63% female) who underwent a MACI (or ACI) biopsy between January 2013 and January 2018. Preoperative data, intraoperative data, and postoperative outcomes were assessed at a minimum of 2 years after the biopsy. The conversion rate from a biopsy to transplantation and the reoperation rate were calculated and analyzed.

Results: Among the 46 patients included, 17 (37.0%) underwent subsequent surgery, with only 12 undergoing cartilage restoration surgery, for an overall transplantation rate of 26.1%. Of these 12 patients, 9 underwent MACI/ACI, 2 underwent osteochondral allograft transplantation (OCA), and 1 underwent particulated juvenile articular cartilage implantation at 7.2 ± 7.5 months after the biopsy. The reoperation rate was 16.7% (1 patient after MACI/ACI and 1 patient after OCA) at 13.5 ± 2.3 months after transplantation.

Conclusion: Arthroscopic surgery with debridement, chondroplasty, loose body removal, meniscectomy/meniscal repair, and other treatment approaches of knee compartment abnormalities at the time of a biopsy appeared to be sufficient in improving function and reducing pain in patients with knee FCDs.

Keywords: autologous chondrocyte implantation (ACI); cartilage restoration; cartilage transplant; focal chondral defect; matrix-induced autologous chondrocyte implantation (MACI).