Background: Traumatic chondral lesions of the knee are common in football and rugby players. The diagnosis is often confirmed by arthroscopy which can be therapeutic by performing microfracture. Prospective information about the clinical results after microfracture is still limited.
Aim: To evaluate the short-term outcome of microfractured lesions in professional football ad rugby players in terms of healing and ability to return to play.
Methods: Twenty-four consecutive professional male players with isolated full-thickness articular cartilage defects on weight-bearing surface of femoral condyles were treated with microfracture. Clinical assessment of healing was done at three, six, 12 and at 18 months by using modified Cincinnati subjective and objective functional scoring. All 24 subjects were periodically scanned by 3-Tesla MRI on the day of the clinical evaluations and scored by the Henderson MRI classification for cartilage healing. A second look arthroscopy was carried out in 10 players five to seven months after surgery to evaluate lesion healing by using ICRS scoring system. This was done due to presence of discrepancy between a "normal" MRI and persistent clinical symptoms.
Results: This study showed that 83.3% of players' resume full training between five to seven months (mean: 6.2) after microfracture of full-thickness chondral lesions of weight-bearing surface of the knee. Function and MRI knee scores of the 24 subjects gradually improved over 18 months, and showed good correlation in assessing healing after microfracture at six, 12 and 18 months (r2 = 0.993, 0.986 and 0.993, respectively) however, the second look arthroscopy score proved to have stronger strength of association with function score than MRI score.
Conclusion: We confirmed that microfracture is a safe and effective procedure in treating isolated traumatic chondral lesions of the load-bearing areas of the knee. Healing as defined by subjective symptoms and evaluated by MRI and a modified knee function score occurred between 5 to 7 months in most cases, which is a reasonable absence period for the majority of players to resume their normal sports activity without risking contracts and careers. MRI correlated well with the functional knee score, but neither of these methods were totally reliable in confirming healing at the defect site. Arthroscopic probing is therefore still the gold standard in our view. From a strict scientific stand point an untreated control group would be valuable to demonstrate that microfracture does not just mirror the natural course of healing.