Introduction
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 performed
Method
Fifteen patients have had a MACI since July 2004. Ten patients have a five 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 – 6.0cm2).
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 years. An MRI scan was performed at all time intervals. Biopsies were taken at 3 – 5 years in all patients.
Results
All outcome scores show a significant improvement post MACI. VAS pain scores improve with time. Other outcome scores improve for up to two years then are maintained or slightly decrease.
There is one failure to date thus survival is 93%.
MRI showed restoration of repair tissue with a mean fill of 90% at 3years and 79% at 5 years. 11/14 patients have persisting subchondral oedema which is a concern, 3/14 are developing bone cysts.
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
Medium term results are reasonable. Outcome scores plateau at two years. Ongoing oedema post MACI is a concern. At rearthroscopy 80% of grafts are soft and 73% of biopsies show fibrocartilage.