***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: Six heterogeneous trials were identified with 442 participants. Methodological flaws of the included trials included incomplete follow-up and inadequate reporting of outcomes. Three trials compared ACI versus mosaicplasty. One reported statistically significant results in favour of ACI at one year in the numbers of people with 'good' or 'excellent' functional results. Conversely, another trial found significant improvement for the mosaicplasty group when assessed using one functional scoring system at two years, but no statistically significant differences based on two other scoring systems. A third trial found no difference between ACI and mosaicplasty, 10 months on average after the surgery. There was no statistically significant difference in functional outcomes at two years in a single trial comparing ACI with microfracture nor in the functional results at 18 months of a single trial comparing characterised chondrocyte implantation versus microfracture. However, the results at 36 months for this trial seemed to indicate better functional results for characterised chondrocyte implantation compared with those for microfracture. The sixth trial comparing matrix-guided ACI versus microfracture found significantly better results for functional outcomes at two year follow-up in the MACI group. There is insufficient evidence to draw conclusions on the use of ACI for treating full thickness articular cartilage defects in the knee. Further good quality randomised controlled trials with long-term functional outcomes are required.
Output:

This review includes six small randomised controlled trials that compared ACI with either mosaicplasty or microfracture. Although there are some promising results for ACI compared with microfracture from one trial, the evidence from two other trials testing the same comparison did not confirm these. None of the other three trials testing different comparisons provided conclusive evidence in favour of ACI, although the longer-term results suggest that the results for some types of ACI may improve over time. The review identified several ongoing trials that should help to provide evidence to inform on the use of ACI in the future. Meanwhile, there is insufficient evidence to draw conclusions on the use of ACI.