We describe a novel single stage arthroscopic repair procedure for articular cartilage defect in the knee. The aim of the study was to evaluate the clinical and radiological outcomes at two years.

The pre-clinical study involved two groups of New Zealand rabbits, treated with microfracture alone and microfracture combined with fibrin gel and concentrated bone marrow aspirate cells (BMAC) application. New cartilage from both groups was studied with histological staining, immunohistochemistry and electron microscopy. The fibrin gel-BMAC group scored better than the microfracture group on all counts.

This is a prospective study of 30 patients with symptomatic ICRS grade III/IV chondral defects, ranging from 2–8 cm², which were assessed clinically and radiologically. The surgical procedure involved debridement of the lesion, microfracture and arthroscopic application of concentrated BMAC with fibrin gel under CO₂ insufflation. Patients underwent morphological MRI, quantitative T2*-mapping and d-GEMRIC scan. Clinical assessment was carried out using the Lysholm, IKDC and KOOS scores while radiological assessment used the MOCART score.

At 2 year follow-up, Lysholm score was 80.1, as compared to 50.8 pre-operatively (p < 0.05). KOOS (symptomatic) was 92.1, as compared to 65.7 pre-operatively. IKDC (subjective) was 83, up from 39 preoperatively. The mean T2* relaxation-times for the repair tissue and native cartilage were 29.1 and 29.9 respectively. Average MOCART score for all lesions was 72.

Our technique shows encouraging clinical and radiological results. The morphological MRI shows good cartilage defect filling and the biochemical MRI (T2*-mapping) suggests hyaline like repair tissue.