Polyurethane synthetic scaffold for meniscal regeneration: prospective clinical study at 3 years’ follow-up

Objectives: A new polyurethane meniscal scaffold has been introduced in the clinical practice. The better properties compared to previous devices should resist to the high knee forces and therefore give more chondroprotection. Aim of this study is to evaluate its safety and clinical efficacy to treat partial meniscal loss at 3 years’ follow-up. Methods: 18 patients (11 males, 7 females, mean age 45 years) affected by a partial loss of meniscal substance, either medial or lateral (13 and 5, respectively), associated with pain and/or swelling were treated with this implant and evaluated yearly up to 36 months. Eleven patients also underwent concurrent procedures involving cartilage treatment or osteotomies. One patient had a reinjury playing competitive soccer after the 12 months evaluation and was excluded from the subsequent analysis. Patients were prospectively evaluated through IKDC objective and subjective, and Tegner scores. Furthermore, MRI evaluation of the treated knees was performed. Results: A statistically significant increase in all the clinical parameters considered was registered. IKDC subjective score improved from 47.3 ± 17.5 to 72.9 ± 13.9 (p\0.0005) at 1 year, result confirmed at 2 and 3 years’ follow-up. The IKDC objective score confirmed this trend, increasing from 61 % of normal/nearly normal knees at basal evaluation to 94 % at 3 years of follow-up (p = 0.01). Tegner score also showed a significant increase from the pre-operative level (median value 2, range 1–5) to final evaluation (median value 3, range 2–5; p = 0.005), albeit not reaching the pre-injury level. MRI evaluation detected a good morphology but still present hyper-intensity in all scaffolds. Conclusions: The implantation of this novel polyurethane scaffold proved to be safe and potentially effective for partial meniscal loss, with promising clinical and MRI results at short-term follow-up. Further high-quality studies at longer follow-up could better evaluate the clinical outcome and joint protection effect.