Summary

This study defined the PASS threshold value for the subjective IKDC and Lysholm as 67.9 and 80. Predictor of achieving PASS was low intensity trauma. Modern surgical techniques after multiligament knee injuries allow return to work without modification in most cases dependent on the work heaviness. Return to low-intensity sports was feasible for patients practicing regular activity before injury.

Abstract

Multi-ligament knee injuries have a significant functional impact for the patient. Parameters such as Patient Acceptable Symptom Status (PASS) are new measures to assess patient satisfaction and improve interpretation of patient-reported outcomes measurements (PROMs). In addition to the subjective scores, assessment of return to activity is an important issue.
The primary purpose of this study was to determine the PASS threshold value for the subjective IKDC and Lysholm scores after multiligament reconstruction with a minimum follow-up of 12 months. The secondary objectives were to determine the predictive factors for achieving this value, to assess impact on professional activity according to heaviness and on return to sport.
A retrospective, single-center analysis was conducted on patients treated for knee dislocation (07/2008-12/2019). 42 patients were assessed with a follow up compliance of 85.7%. All patients had knee ligament repair and/or reconstruction with allograft and autograft according to treatment algorithm. Clinical data and postoperative complications were collected at the last follow-up consultation. IKDC subjective knee and Lysholm scores were performed. PASS threshold value was calculated using an anchoring method. Multivariate logistic regressions were conducted to determine predictors of achieving PASS. A self-questionnaire was given to the patient to assess impact on work and sports. Activities were classified according to Tegner scale.
With a mean follow-up of 4.8 years, 78.6% of the patients reported satisfactory symptom status. No significant difference was observed between patients who answered "yes" and those who answered "no" to the PASS question showed. Expect for PROMs, IKDC was 75.2 points for patients who answered "yes" to PASS question versus 61.4 for those who answered no (p = 0.003) and a mean Lysholm score of 86.2 points versus 71.6 (p=0.002). The PASS cutoff for the cohort was defined at 67.9 for the IKDC and 80 for the Lysholm score. A multivariate logistic regression according to the achievement of this threshold value defined that low-intensity trauma was a predictor of achieving this value for the subjective IKDC (Odds Ratio 10.507, 95% CI 1.074 to 102.839, p=0.043). 34 patients (81%) had returned to work without job modification, 7 (16.7%) patients required job adjustment and 1 (2.4%) patient was classified as invalid. Patients in light work group returned to work significantly more without modification than heavy work group (p =0.038). Pre-injury, 30 (71.4%) patients were practicing sports. At the last follow-up, 25 (59.5%) patients were involved in sports. 25/30 (83.3%) patients practicing sports had resumed sports but at a lower level before the injury (Tegner: before injury 5.2 vs after reconstruction 4.4; p= 0.014)
This study defined the PASS threshold value for the subjective IKDC and Lysholm as 67.9 and 80, with a minimum follow-up of one year. Predictor of achieving PASS for subjective IKDC score was low intensity trauma. Modern surgical techniques after multiligament knee injuries allow return to work without modification in most cases. However, this remains dependent on the work heaviness. Furthermore, return to low-intensity sports was feasible for patients practicing regular activity before injury.