Predictors of Activity Level 2 Years after Anterior Cruciate Ligament Reconstruction (ACLR)

Abstract

Objective ACL deficient subjects are at risk of knee injury with cutting and pivoting activities; in accord, ACL reconstructions (ACLR) are performed to restore stability to allow for return to cutting and pivoting activities. The Marx activity level is a validated patient-reported measure to quantify the amount and frequency of running, cutting, decelerating, and pivoting performed. Our objective was to quantify activity level 2 yrs after ACLR and identify explanatory variables measured at baseline (demographics, concomitant meniscal/articular cartilage injuries and their treatment) associated with activity level at short-term follow-up (2 yrs). Methods In 2002, the multicenter consortium began enrolling subjects undergoing ACLR at six recruitment sites. This ongoing multicenter cohort study targets follow-up at 2, 6, and 10 years. The current study reports two-year follow-up of subjects enrolled in 2002. Participants in the multicenter ACLR cohort completed a series of validated, patient-oriented questionnaires that included activity level assessment. Follow-up questionnaires were collected by mail between 1/01/04 and 6/01/05 to assess changes. Measurement of intraarticular pathology, techniques of ACLR, and secondary procedures were recorded at baseline by participating surgeons. Multivariable proportional odds ordinal logistic regression was used to assess predictors of activity level after adjusting for baseline patient characteristics. Interquartile range (IQR) odds ratios (OR) are given for continuous variables, IQROR demonstrate the effect of increasing a baseline variable from its first quartile to its third quartile. The fitted model that used OR to specify predicted probabilities of exceeding any activity level was translated into predicted mean activity level and is presented in a nomogram for more interpretability. Results Of the 446 subjects that underwent unilateral ACLR, follow-up was obtained on 393 (88%). The cohort is 56% male, median age 23 yrs. Median and IQR activity level was 12 (8–16) at baseline, and declined to 9 (3–13) at follow-up. After controlling for other baseline factors such as age, marital and student status, contralateral knee status, sport and competition level, and articular cartilage/meniscal injuries, the following factors were predictors of activity level at 2-year follow-up. High baseline activity level was associated with higher activity at 2 yrs (IQROR=3.8, 95% CI=2.0–7.4, p<0.0001), and lower baseline BMI (IQROR=1.37, 95% CI=1.04–1.82, p=0.027). The following baseline factors were associated with lower activity: female gender (OR=0.60, 95% CI=0.39–0.91, p=0.015); smoking within 6 months (IQROR=0.55, 95% CI=0.33–0.92, p=0.023); and revision ACLR (IQROR=0.41, CI=0.20–0.83, p=0.014). Conclusions (1) The proportion of subjects returning to the same or higher level of activity two years after ACLR was 45%, and evaluation of post treatment activity levels should control for patients’ preoperative activity since this is a strong predictor of future activity. (2) Assum...

Return to sport following anterior cruciate ligament reconstruction

“…Despite many reports of successful outcomes following ACL reconstruction, recent reports have suggested that the rates of return to sport may not match the success of this surgery as measured by other factors [2,4,5,10,13,19,25,31,44]. This discrepancy raises many issues and the purpose of this article is to explore return to sport following ACL reconstruction from a number of perspectives.…”

“…Dunn et al tried to quantify some of these factors [13]. They found that a higher pre-injury activity level was the strongest predictor of return to sport at two years after ACL reconstruction, while female gender, a higher body mass index (BMI) and smoking in the first six months prior to surgery were associated with a lower rate of return to sport.…”

What Can the First 2 Months Tell Us About Outcomes After Anterior Cruciate Ligament Reconstruction?

“…Traditionally, patients have been studied preoperatively and several months after surgery to determine the effects of ACLR. 2,4,6,12,21,24,25,39,40 This leads one to question the influence that early postoperative stages of recovery have on self-reported outcomes. Our results showed significant associations between patients' subjective IKDC scores during the first 2 months postoperatively and the !12-month IKDC score.…”

“…11 Though controversy lingers, substantial research has been conducted on specific surgical procedures, various graft options, and rehabilitation protocols in an attempt to identify prognostic risk factors and modifiable predictors to improve self-reported outcomes after ACLR. 12,13 Although multiple authors have evaluated various factors related to returning individuals to their prior level of function, research identifying the effectiveness of early postoperative measures on self-reported outcomes after ACLR is lacking. Several self-efficacy studies have provided compelling evidence that a large number of patients are unable to return to their prior level of function in spite of an apparently successful surgery and rehabilitation.…”

“…Higher BMI scores might predict lower self-reported outcomes scores. 12,13 Also, the odds of successful outcomes are 0.35 times lower for persons over the traditional threshold for obesity (BMI ! 30 kg/m 2 ).…”