[Return to Running (RTR) after Knee Joint Surgery: a Narrative Review]

The transition from purely time-based to criteria-based rehabilitation following knee joint surgery has led to the establishment of clinical and functional criteria for individual functions such as return to running. This narrative review aimed to extract recommended criteria from expert surveys and to present their predictive validity.

The authors conducted a literature search in PubMed. Studies were included that surveyed therapists and/or physicians on current practice for criteria-based return to running. In addition, an analysis was performed on studies that evaluated the validity of these criteria in clinical trials involving patients who had undergone knee surgery.

The literature search yielded data exclusively for patients who had undergone anterior cruciate ligament reconstruction. In the expert surveys, the postoperative period (≥12-16 weeks) was the most consistently reported criterion. Furthermore, clinical (pain, swelling) and functional (mobility, balance tests, dynamic control tests, quadriceps strength testing) criteria are frequently recommended but lack sufficient validation. In the few validation studies available, many of the proposed criteria and their cut-off values demonstrated insufficient predictive validity. Only clinical parameters (pain 0-2 on the numerical pain scale and swelling), a sufficient range of motion (0° extension, 130° flexion) and sufficient quadriceps strength (limb symmetry index >60% + 1.45-1.6 Nm/kg) appear to be meaningful.

Functional test batteries currently described in the literature and the corresponding target values for balance and jump testing should be viewed critically and require more rigorous evaluation in future studies. Until then, they do not provide valid guidelines for clinical decision-making regarding a safe return to running.