Patient Acceptable Symptom State Thresholds for the Lysholm Knee Scoring Scale in Patients After Anterior Cruciate Ligament Reconstruction.

Background: Patient-reported outcome measures are used to evaluate the functional status and assess the results after a medical intervention. For anterior cruciate ligament (ACL) reconstruction, the Lysholm scale is one of the most commonly used scales. The Patient Acceptable Symptom State (PASS) defines cutoff values for any patient-reported outcome measure, beyond which patients consider they have achieved an acceptable result. The PASS threshold for the Lysholm scale in patients undergoing ACL reconstruction has not yet been defined in the literature. Purpose: To define the thresholds of the PASS for the Lysholm scale in patients who have undergone ACL reconstruction with a follow-up of 2 to 5 years. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Patients who underwent isolated ACL reconstruction completed a survey during their last follow-up visit that included the Lysholm scale. All patients were asked to rate their satisfaction with their current health state by answering the following question: "Considering all the activities you perform as part of your normal daily life, your level of pain, and your degree of difficulty, if you were to remain in your current condition over the next few months, would you consider your current health state satisfactory?" Pre-, intra-, and postoperative variables were evaluated, and cutoff points for the Lysholm scale were established to discriminate the PASS using receiver operating characteristic (ROC) curves. Results: In total, 378 patients who underwent isolated ACL reconstruction with a mean follow-up of 35.8 ± 12.6 months were evaluated. Of these patients, 43 (11.4%) reported not being satisfied (PASS-No), while 335 patients (88.6%) reported being satisfied (PASS-Yes) after the procedure. The ROC curve identified a cutoff point of 85.0 points on the Lysholm scale (79.1% sensitivity, 90.7% specificity). Factors associated with failure to achieve the PASS threshold included greater preoperative knee hyperextension, postoperative residual pivot shift, new injuries, and subsequent ACL revision or meniscal surgeries on the operated knee. Conclusion: The PASS threshold for the Lysholm scale was 85.0 points for patients who had undergone ACL reconstruction, with a mean follow-up of 3 years. By establishing threshold values for the PASS, this study provides valuable insight to aid in the interpretation of the Lysholm scale in the clinical practice of ACL surgeons.