A Prospective Outcome, MRI and Biospy Study of MACI Cartilage Transplantation

Abstract

Objectives:MACI has been performed by one surgeon. in New Zealand in patients who have failed a microfracture procedure A prospective study with outcome scores, serial MRI’s and biopsies has been performedMethod:Fifteen patients have had a MACI since July 2004. All patients have a five year follow up, four a ten year follow up. No patients have been lost to follow up. The mean age is 34 (range 25-45). The mean defect size is 3.76 cm2 (range 2.2 – 6.0 cm2). VAS pain, KOOS score, IKDC subjective score, WOMAC score, SF 36 & Tegner Activity score were collected by a research assistant preoperatively and at 6 months, 1, 2, 3 5 and 10 years. An MRI scan was performed at all time intervals. Biopsies were taken at 3 – 5 years in all patients.Results:All outcome scores and VAS pain scores show a significant improvement post MACI up to two years, a plateau to five years the deteroriation at ten years. There are two failure to date thus survival is 87% at a mean of 8 years. MRI showed restoration of repair tissue with a mean fill of 90% at 2years, 72% at 5 years and 49% at ten years and all patients at ten years had a full thickness defect 86% of patients had bone oedema at 5 years, 100% at 10 years 28% had bone cysts at 5 years, 100% at 10 years All patients have had MACI biopsies. Eleven biopsies show fibrocartilage and four show hyaline like cartilage. Eleven have a normal ICRS arthroscopic score, three a nearly normal score and one abnormal score however 80% have a softer MACI graft than surrounding articular cartilage.Conclusion:Outcome scores are reasonable but are deterioating at 10 years Serial MRI’s show significant graft deterioration, increasing bone oedema and bone cyst formation At rearthroscopy 80% of grafts are soft and 73% of biopsies show fibrocartilage. MACI post microfracture is not the long term solution for isolated chondral defects.