Ten-year results from the UK National Ligament Registry: Patient characteristics and factors predicting nonresponders for completion of outcome scores

Abstract

Purpose: The aim of this study was to report the demographic and mechanism of injury data in the UK National Ligament Registry (NLR) at 10 years and determine factors leading to poor compliance with completion of Patient-Reported Outcome Scores (PROMs).

Methods: A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary anterior cruciate ligament reconstruction (ACLR) were included. Patient demographics, mechanism of injury and patient compliance with completing PROMs were analysed. Patient characteristics were further analysed in relation to compliance with completing the different PROMs at the predefined time points. Patients were identified as nonresponders if they had not completed either 1- or 2-year postoperative Knee injury and Osteoarthritis Outcome Score (KOOS).

Results: A total of 17,492 patients were included in this study. The average age for patients undergoing ACLR between 2013 and 2022 was 29.4 (SD, 10.3). Seventy percent were men and 30% women. Football was the most common activity associated with an ACL injury. Patient compliance with recording PROMs was 55% preoperatively and 37%, 32% and 24% at 1-, 2- and 5-year postoperative follow-up, respectively. Nonresponders represented 54% of eligible patients. Multivariate analyses showed that sex, age, smoking, time interval between injury and surgery and low socioeconomic status were associated with low compliance with postoperative PROM completion (p < 0.001).

Conclusion: This study reports the demographic characteristics for patients on the NLR since 2013. Male sex, young age, increased waiting time between injury and surgery, smoking and lower socioeconomic class were predictors of low compliance with completion of postoperative PROMs on the UK NLR. Understanding the factors that affect patient compliance with PROMs improves our ability to provide targeted interventions and information to specific patient populations with the aim of enhancing inclusiveness and representation of population in the registry.

Level of evidence: Level III.

Keywords: ACL reconstruction; KOOS; National Ligament Registry; PROMs; anterior cruciate ligament.