Application of pulsed electromagnetic fields after microfractures to the knee: a mid-term study

Purpose: Pulsed electromagnetic fields (PEMFs) may improve clinical outcomes following microfractures and prevent their decline over time. Methods: Sixty-eight patients who underwent partial medial meniscectomy and microfractures to the medial femoral condyle for management of grade III–IV cartilage lesions were randomly divided into two groups using a block randomization procedure. After surgery, 34 patients underwent PEMFs application in the I-ONE group; 34 patients underwent placebo treatment in the placebo group. All patients had the same postoperative rehabilitation protocol. Sixty patients (28 in the I-ONE group, 32 in the placebo group) were assessed at an intermediate follow-up of two years and a minimum follow-up of five years after surgery. Results: The two groups were homogeneous. There was a significant improvement from baseline to the last minimum follow up of two years. At two years, IKDC and Lysholm and Constant scores were significantly improved compared to baseline in both groups with no significant inter-group differences. At the last follow up (minimum five years), clinical and functional outcomes were decreased in both the groups, with significant better outcomes in the I-ONE group. At five years, the percentage of patients still active at the same level they were pre-operatively was greater in the I-ONE group (82 % vs 68 %, P = 0.28). At radiographic assessment, at the latest evaluation, six patients (21.4 %) in the I-ONE group and nine (28.1 %) in the placebo group demonstrated grade I–II degenerative changes according to Fairbank grading system (Χ = 0.36, P = 0.55). Conclusions: PEMFs application can improve the effectiveness of microfracture in the long term.