Purpose: To compare clinical results and MR images of different arthroscopic techniques used in our hospital (mosaic-plasty, microfractures, fixation or excision and curettage).

Materials and methods: This was a retrospective study of 40 cases of knee ostochondritis in adolescent patients operated in our hospital between 1992 and 2005 assessed by location, sex, surgical technique and MRI.

Results: Mean age at surgery was 16 years of age. The most frequent location was the medial condyle. The right knee was involved in 74% of cases. Mosaic-plasty was carried out in 26% of cases, microfractures in 42%, excision and curettage in 26% and fragment osteosynthesis in 6%. Mean follow-up was 7 years and in the microfracture group there were 25% poor results and 75% excellent results. The results were poor in 100% of the group that underwent fragment osteosynthesis. In the excision and curettage group there were 50% good results and 50% excellent results. In the mosaic-plasty group there were excellent results in 100% of the patients. The MRI showed incorporation and a normal profile of the subchondral surface in all the patients of the group that underwent mosaic-plasty. In the group of patients with microfractures there was cartilage in the microfractured area in 75% of the patients. In fragment osteosynthesis there was MRI evidence of non-union in 100% of cases. In the excision and curettage group there was only partial regeneration in 100% of cases.

Conclusions: In comparison with the other techniques described, better outcomes are seen when mosaic-plasty is the treatment used in advanced stages of knee osteochondritis in adolescent patients.