Body-Weight Changes and Physical Activity After Anterior Cruciate Ligament Reconstruction

Recovery after anterior cruciate ligament reconstruction (ACLR) can lead to weight gain and reduced physical activity (PA), potentially increasing long-term health risks. Understanding the relationship between PA patterns and weight changes after ACLR is essential for optimizing rehabilitation strategies.

To examine the relationship between PA patterns and weight changes in the first 6 months after ACLR. We hypothesized that lower PA levels and longer sedentary time would predict greater weight gain.

Case series.

Academic hospital and private sports medicine clinic.

A total of 61 individuals (34 females, 27 males; age range, 13-35 years, body mass index < 35) who underwent primary ACLR was included. All participants received an autograft, could have undergone a concomitant meniscal repair, and had no extended weightbearing restrictions.

Body weight was measured preoperatively and at 10.4 ± 2.4 weeks (early phase) and 26.9 ± 2.6 weeks (midphase) after ACLR. We assessed PA levels, including daily steps, moderate to vigorous PA (MVPA), and sedentary behavior, using accelerometry. A 2-way mixed (time × sex) analysis of variance was used to analyze weight changes, and logistic regressions were used to evaluate whether early- and midphase PA levels, age, and sex predicted weight gain (≥5%) after ACLR.

Males gained more weight (3.4 ± 4.6 kg; P < .001) than females (1.1 ± 2.9 kg; P = .03). Logistic regression models for all PA levels predicted a gain of ≥5% body weight at early (daily steps: ${\text{χ}}_3^2$ = 11.231, P = .01; daily MVPA: ${\text{χ}}_3^2$ = 12.843, P = .005; and daily sedentary behavior: ${\text{χ}}_3^2$ = 10.794, P = .01) and midphase (daily steps: ${\text{χ}}_3^2$ = 10.320, P = .02; daily MVPA: ${\text{χ}}_3^2$ = 12.451, P = .006; and daily sedentary behavior: ${\text{χ}}_3^2$ = 10.003, P = .02). Males had 5.407 to 10.025 times higher odds of ≥5% weight gain than females. However, PA, sedentary behavior, and age did not predict weight gain.

Weight gain is common 6 months after ACLR, with males experiencing greater increases than females. Although PA and sedentary behavior did not predict weight changes, incorporating targeted weight-management strategies, including nutritional and metabolic health interventions, into ACLR rehabilitation may help optimize recovery.