How Surgeons Can Improve Outcomes of Revision ACL Reconstruction

    Outcomes of revision anterior cruciate ligament (ACL) reconstruction are known to be inferior to those of primary procedures, but little has been known about why this occurs – until now.

    New research from Washington University, St. Louis, Missouri, and Vanderbilt University Medical Center, Nashville, Tennessee, suggests that 2 important clinical decisions can significantly improve a patient’s chances of a experiencing a good outcome after revision surgery:

    • Opt for a transtibial surgical approach
    • Choose an inference screw for femoral and tibial fixation

    The research, presented at the American Orthopedic Society of Sports Medicine-Arthroscopy Association of North America Combined 2021 Annual Meeting, evaluated surgical factors typically associated with revision ACL reconstruction to determine which ones could influence patient outcomes at 6-year follow-up.

    The researchers enrolled more than 1200 patients who had undergone revision ACL reconstruction between 2006 and 2011. Data collected included:

    • Baseline demographics
    • Surgical technique and pathology
    • Patient-reported outcomes
      • International Knee Documentation Committee questionnaire (IKDC)
      • Knee injury and Osteoarthritis Outcome Score (KOOS)
      • Western Ontario and McMaster Universities Arthritis Index (WOMAC)
      • Marx activity rating score 

    Patients were followed for 6 years, and at the 6-year follow-up, data were obtained on 77% (949/1234) of the original patient cohort. The researchers found 3 significant drivers of poor outcomes among these patients, with femoral and tibial fixation being especially important.   

    • Using an interference screw for femoral fixation compared with a cross-pin resulted in significantly better outcomes in 6-year IKDC scores (OR=2.2; 95% CI=1.2, 3.8; p=0.008) and KOOS sports/rec and KOOS quality of life (QOL) subscales (OR range = 2.2-2.7; 95% CI=1.2, 3.8; P<0.001). 
    • Using an interference screw compared with a cross-pin also resulted in patients being 2.6 times less likely to have a subsequent surgery within the 6 years.
    • Using an interference screw for tibial fixation compared to any combination of tibial fixation techniques also resulted in significantly improved IKDC (OR=2.0; 95% CI=1.3, 2.9; P=0.001); KOOS pain, activities of daily living, and sports/rec subscales (OR range=1.5-1.6; 95% CI=1.0, 2.4; P<0.05); and WOMAC pain and stiffness subscales (OR range=1.5-1.8; 95% CI=1.0, 2.9; P<0.05).

    In addition, using a transtibial surgical approach compared with an anteromedial portal approach resulted in significantly improved KOOS pain and QOL subscales at 6 years (OR=1.5; 95% CI=1.02, 2.2; P<0.04).

    Patients whose surgeons had noted that the tibial tunnel aperture position was in the “optimum position” during revision surgery fared significantly worse in terms of IKDC, KOOS, and Marx activity levels than patients whose surgeons opted for either a blended new tunnel or noted that the previous tunnel had the same tunnel aperture but “compromised position”:

    • IKDC scores (OR=0.6; 95% CI=0.4, 0.8; P=0.003)
    • KOOS symptoms, pain, sports/rec, and QOL subscales (OR range=0.56-0.68; 95% CI=0.38, 0.47; P<0.05)
    • Marx activity levels (OR=0.20; 95% CI=0.07, 0.6; P=0.005)

    The research team noted other factors that affected outcomes, including lower baseline outcome scores, lower baseline activity level, being a smoker at the time of the revision, higher BMI, female gender, shorter time since the patient’s last ACL reconstruction, and having a previous ACL reconstruction on the contralateral side. All significantly increased the odds of reporting worse clinical outcomes at 6 years.

    “There are surgical variables that the physician can control at the time of an ACL revision which have the ability to modify clinical outcomes,” said Rick Wright, MD, from Vanderbilt University Medical Center.

    “Based on outcomes at 6 years, opting for a transtibial surgical approach and choosing an inference screw for femoral and tibial fixation will improve the patient’s odds of having a significantly better 6-year clinical outcome.”