Percutaneous inside-out meniscal repair without a posterior safety incision: clinical outcomes and safety profile

Meniscal repair has increasingly replaced meniscectomy because of its superior long-term clinical outcomes and protective effects against osteoarthritis. The inside-out technique is widely considered the gold standard due to its strong biomechanical fixation and versatility. However, the conventional technique requires a posteromedial or posterolateral safety incision to protect neurovascular structures, which increases surgical invasiveness and technical complexity. This study aimed to evaluate the clinical and MRI outcomes of a percutaneous modification of the inside-out technique that eliminates the need for a formal posterior safety incision. This retrospective cohort study included 61 patients who underwent isolated meniscal repair using the percutaneous inside-out technique between January 2022 and January 2023 with a minimum follow-up of 24 months. Clinical and radiological outcomes were evaluated using magnetic resonance imaging (MRI), International Knee Documentation Committee (IKDC) and Lysholm scores, McMurray testing, and neurological examination. Postoperative MRI demonstrated complete healing in 62.3% and partial healing in 9.8% of patients, yielding an overall healing rate of 72.1%. Functional success was achieved in 90.2% of patients according to IKDC scores and 88.5% according to Lysholm scores, with a combined success rate of 77.0%. Neurological complications occurred in 9.8% of patients and were not associated with the stab incision site. Higher Lysholm scores, non-smoking status, left-sided surgery, longitudinal or horizontal tear patterns, and a negative postoperative McMurray test were identified as independent predictors of MRI healing. Conversely, higher IKDC scores showed an inverse association with MRI healing grades. ROC analysis demonstrated that the Lysholm score had good discriminative ability for detecting neurological deficits (AUC = 0.767; cut-off = 91; sensitivity = 83.3%, specificity = 69.1%). The percutaneous inside-out technique demonstrated favorable clinical and MRI outcomes while avoiding the need for a formal posterior safety incision. This approach may represent a reliable and minimally invasive alternative to conventional inside-out meniscal repair techniques.