Baseline predictors of health-related quality of life after anterior cruciate ligament reconstruction: a longitudinal analysis of a multicenter cohort at two and six years

Abstract

Background: Limited information exists regarding predictors of general quality of life following anterior cruciate ligament (ACL) reconstruction with up to six-year follow-up. We hypothesized that certain variables evaluated at the time of ACL reconstruction will predict the general quality of life as measured by the Short Form-36 (SF-36).

Methods: All unilateral ACL reconstructions from 2002 to 2004 in patients currently enrolled in a prospective multicenter cohort were evaluated. Patients preoperatively completed the SF-36 validated outcome instrument. Surgeons documented intra-articular pathological conditions and treatment, as well as the ACL reconstruction surgical technique. At baseline and at a minimum of two and six years postoperatively, patients completed the SF-36. Longitudinal analysis was performed for the two-year and six-year end points.

Results: Of the initial 1512 subjects, at least one follow-up questionnaire was obtained from 1411 subjects (93%). The cohort was 44% female, and the median patient age at enrollment was twenty-three years. The mean scores were 41.9 points for the Physical Component Summary (PCS) and 51.7 points for the Mental Component Summary (MCS) at baseline, 53.6 points for the PCS and 52.0 points for the MCS at two years, and 54.0 points for the PCS and 52.4 points for the MCS at six years. Significant predictors of a higher PCS score were a higher baseline PCS score, younger age, lower baseline body mass index, having >50% of the lateral meniscus excised, or having no treatment done on a lateral meniscal tear. In contrast, significant predictors of a lower PCS score were a shorter follow-up time since surgery, revision ACL reconstruction, smoking at baseline, fewer years of education, and chondromalacia of the lateral tibial plateau. The mean utility gained at six years after ACL reconstruction was 5.3 quality-adjusted life years (QALYs).

Conclusions: Large improvements in the PCS (with an effect size of 1.2) were noted at two years and were maintained at six years after ACL reconstruction. Lower education and smoking were significant predictors of lower PCS and MCS scores. ACL reconstruction resulted in a relatively high gain of QALYs.

Fig. 1

Flow diagram of subject enrollment. PCL = posterior cruciate ligament, LCL = lateral cruciate ligament, and MCL = medial cruciate ligament.

Fig. 2

Normative-based scoring of the SF-36 profile. t0 = baseline, t2 = two-year follow-up, and t6 = six-year follow-up.

Fig. 3

Relative proportion of variance accounted for by each term, combined across physical domains. LTP = lateral tibial plateau, MFC = medial femoral condyle, ACLR = ACL reconstruction, LFC = lateral femoral condyle, MTP = medial tibial plateau, and df = degrees of freedom.

Fig. 4

Relative proportion of variance accounted for by each term, combined across mental domains. MFC = medial femoral condyle, LTP = lateral tibial plateau, LFC = lateral femoral condyle, MTP = medial tibial plateau, ACLR = ACL reconstruction, and df = degrees of freedom.