Summary
Patients with a pre-operative ALL injury have a higher failure rate than patients without an ALL injury after single bundle ACL reconstruction
Abstract
Background
Isolated reconstruction of the anterior cruciate ligament (ACL) does not reestablish the normal knee biomechanics in cases of associated injuries to the anterolateral structures. Short-term studies have already demonstrated that a documented ALL tear may lead to worse functional outcomes and higher failure rate compared to patients with no anterolateral abnormality.
Purpose
To evaluate the clinical outcomes and failure rate of ACL reconstruction in patients with and without ALL injury diagnosed using magnetic resonance imaging with a minimum five year follow up.
Study design: Cohort study; Level of evidence, 2.
Methods
A prospective cohort of patients with acute ACL injury was divided into 2 groups based on the presence (ALL group) or absence (no-ALL group) of ALL injury on preoperative magnetic resonance imaging scans. Both groups underwent anatomic reconstruction of the ACL with autologous hamstring tendon grafts. The Lysholm and subjective IKDC scores (International Knee Documentation Committee), KT-1000 arthrometer and pivot-shift test results, reconstruction failure rate, incidence of contralateral ACL injury, presence of associated meniscal injury, and presence of knee hyperextension were evaluated. Only patients with a minimum of five years follow up were evaluated. The evaluation at 5 year follow up was also compared with the same patient’s evaluation at 2 years follow up.
Results
A total of 156 patients were evaluated at five-year follow up. Postoperative mean ± SD follow-up was 70.9 ± 6.9 and 72.3 ± 8.6 months for the ALL and no-ALL groups, respectively. No significant differences were found between the groups in terms of age, sex, knee hyperextension, duration of injury before reconstruction, follow-up time, or associated meniscal injuries. In the preoperative evaluation, the pivot-shift grade and the KT-1000 arthrometer values were similar. In the postoperative evaluation, patients in the no-ALL group had a lower reconstruction failure rate (14.3% vs 4.6%; P = .049) and better clinical outcomes according to the Lysholm scores (85.0 ± 10.3 vs 92.3 ± 6.3; P < .0001). There was no postoperative difference in the subjective IKDC, in the KT-1000 or in the pivot-shift results. Patients in the ALL group also presented a worsening of the knee instability from two to five years according to the KT-1000 (2.4 +/- 1.6 vc 2.8 +/- 1.4; p=0.038). Patients in the no-ALL group presented no differences in outcomes from two to five years follow up.
Conclusion
Combined ACL and ALL injuries were associated with significantly less favorable outcomes than were isolated ACL injuries at a minimum follow-up of 5 years after ACL reconstruction. Patients with concomitant ALL injury showed a higher rerupture rate and worse functional scores. Also, knee stability tends to worsen from 2 to 5 years in cases of associated ALL injury.