2015 ISAKOS Biennial Congress ePoster #1389

Anterior Cruciate Ligament Reconstruction: Age Related Risk Factors for Revision

Gregory B. Maletis, MD, Baldwin Park, CA UNITED STATES
Jason Chen, MA, San Diego, CA UNITED STATES
Maria CS. Inacio, PhD, San Diego, CA UNITED STATES
Tad T Funahashi, MD, Newport Beach, CA UNITED STATES
Kaiser Baldwin Park, Baldwin Park, CA, USA

FDA Status Not Applicable

Summary: In patients <21 years of age, a higher risk of revision is seen in males, patients reconstructed with allograft or hamstring autografts, BMI < 30, and whites.

Abstract:

Introduction

It is not clear if the risk of revision ACLR and factors associated with revision are similar for patients throughout their lifetimes. The purpose was to study age related risk factors for revision after ACLR.

Methods

A retrospective cohort study of prospectively collected data from a US institutional anterior cruciate ligament reconstruction registry (ACLRR) between 02/2005 - 06/2013 was conducted. All primary, single ligament injury, ACLR cases were included. Using age at time of surgery, the cohort was stratified into 4 groups: <21, 21-30, 31-40, and >40. Aseptic revision was the main endpoint of the study. Gender, race, body mass index (BMI), and graft type were assessed as potential risk factors for revision within each age group using a multivariable Cox regression model (hazard ratios (HRs) and 95% confidence intervals (CI) are provided).

Results

21,304 primary ACLR patients were included, of whom 13,385 (62.8%) were male, 8,274 (39.4%) had a BMI < 30kg/m2, and 10,318 (48.4%) were White. There were 8,671 (41%) ACLRs performed with allografts, 6,823 (32.2%) with hamstring autografts, 5,260 (24.8%) with bone-patellar tendon-bone (BPTB) autografts. 7,026 (33%) patients were <21, 5,762 (27%) between 21-30, 4,656 (22%) between 31-40, and 3,860 (18%) were >40 years of age. The revision-free survival rate at 5 years was highest in the >40 age group, 98.1% (95% CI 97.2 to 98.6), and was lowest in the <21 age group, 90.9% (95% CI 89.8 - 91.8). In patients <21, after adjusting for the other covariates, females had a 0.76 times (95% CI 0.61 - 0.93) lower risk of aseptic revision than males. Patients with BMI between 30-34 kg/m2 (HR=0.75, 95% CI 0.59 -0.95) and those with a BMI>=35 kg/m2(HR=0.49,95% CI 0.34- 0.70) had a lower risk of revision than patients with BMI<30 kg/m2. Black patients <21 had a 0.55 times (95% CI 0.36 - 0.85) lower risk than white patients. Differences in gender, BMI, and race were not found in older age groups. Within all of the younger age groups (< 40), patients with allografts were at a higher risk for revision than patients with BPTB autografts (HR= 2.69, 2.35, 3.04 for <21, 21-30, and 31-40 respectively). Within the <21 age group, patients with hamstring autografts were found to have a 1.61 times (95% CI 1.20 - 2.17) higher risk of revision than patients with BPTB autografts. Differences were not identified in older age group patients.

Conclusion

Younger patients are at greater risk for revision ACLR. In patients <21 years of age, a lower risk of revision was noted in females, patients with BMI >=30kg/m2 compared to BMI <30kg/m2, and blacks compared to whites. A higher risk of revision was identified in patients <21 years of age who underwent reconstruction with hamstring autografts compared to BPTB autografts. Patients <21, 21-30, and 30-40 years old all had a higher risk of revision when allografts were used compared to BPTB autografts. Age related risk factors are important for surgeons and patients to understand when planning ACLR surgery.