Determining the Substantial Clinical Benefit Values for Patient-Reported Outcome Scores After Primary ACL Reconstruction

Young-Sik Jeon; Ja-Woon Lee; Soo-Hyun Kim; Sang-Gyun Kim; Young-Ha Kim; Ji Hoon Bae

doi:10.1177/23259671221091795

Determining the Substantial Clinical Benefit Values for Patient-Reported Outcome Scores After Primary ACL Reconstruction

Orthop J Sports Med. 2022 May 5;10(5):23259671221091795. doi: 10.1177/23259671221091795. eCollection 2022 May.

Authors

Young-Sik Jeon¹, Ja-Woon Lee², Soo-Hyun Kim³, Sang-Gyun Kim⁴, Young-Ha Kim¹, Ji Hoon Bae¹

Affiliations

¹ Department of Orthopedic Surgery, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
² Department of Orthopedic Surgery, Armed Forces Capital Hospital, Seongnam, Republic of Korea.
³ Department of Orthopedic Surgery, Naval Maritime Medical Center, Jinju, Republic of Korea.
⁴ Department of Orthopedic Surgery, National Medical Center, Seoul, Republic of Korea.

Abstract

Background: Little is known about the threshold of patient-reported outcomes (PROs) at which patients perceive to have attained a substantial clinical benefit (SCB) after anterior cruciate ligament reconstruction (ACLR).

Purpose: To determine the SCB value of PROs 1 year after ACLR in the general population and to determine factors that predict SCB attainment.

Study design: Case series; Level of evidence, 4.

Methods: The Lysholm, International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC-SKF), Tegner, and Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scores were examined postoperatively in 88 patients who underwent ACLR. At the 12-month follow-up visit, the patients answered 2 independent anchor questions about daily discomfort and functional recovery. Receiver operating characteristic (ROC) curve analysis was used to differentiate PRO scores between patients who responded as having no difficulty versus some difficulty with daily knee discomfort (anchor question 1) and between patients with substantial recovery versus nonsubstantial recovery of knee function (anchor question 2). The area under the ROC curve (AUC) was calculated to assess reliability, and the differences between the AUC values were compared. Multivariate logistic regression analyses were performed to determine predictors affecting SCB attainment.

Results: There were 76 patients enrolled in this study. The 12-month Lysholm, IKDC-SKF, Tegner, and ACL-RSI scores that corresponded to the SCB were 88.0, 85.1, 6.5, and 64.2 for anchor question 1 and 84.5, 77.7, 5.5, and 57.1 for anchor question 2, respectively. The AUC values obtained from the ROC curve analyses showed acceptable to excellent reliability (anchor question 1: Lysholm, 0.90; IKDC-SKF, 0.86; Tegner, 0.71; ACL-RSI, 0.92; anchor question 2: Lysholm, 0.80; IKDC-SKF, 0.90; Tegner, 0.82; ACL-RSI, 0.82) and were all statistically significant (P < .001 to P = .028). For all PROs, younger age (Odds Ratio (OR), 0.88-0.94; P < .001 to P = .027) and greater muscle strength (OR, 1.03-1.07; P < .001 to P = .023) were predictive factors of SCB attainment.

Conclusion: The postoperative Lysholm, IKDC-SKF, Tegner, and ACL-RSI scores showed acceptable to excellent reliability in predicting the SCB after ACLR in the general population. Age at surgery and thigh muscle strength influenced SCB attainment for all PROs.

Keywords: anterior cruciate ligament reconstruction; general population; patient-reported outcome; significant clinical benefit.