Summary
Regarding graft maturation based on MRI evaluations, no significant differences were found in revision ACLR between BTB and double-bundle HT, although BTB maturation is significantly superior to that of HT in primary ACLR. BTB showed significantly better anterior knee stability than HT in both primary and revision ACLR, whereas no significant differences were observed in subjective or objective ev
Abstract
Purpose
The primary purpose of this study was to evaluate the magnetic resonance imaging (MRI) findings 2 years after anterior cruciate ligament reconstruction (ACLR) using tendon–bone autograft (BTB) or hamstring tendon autograft (HT) in primary or revision cases. Secondary purpose included clinical results from physical examination, including range of motion, Lachman test, pivot shift test, and knee anterior laxity evaluation, and the clinical score for subjective evaluations at 2 years after surgery in both groups (primary group / revision group).
Methods
Between 2014 and 2020, 100 patients received primary or revision ACLR were followed prospectively. Seventy-five patients with primary ACL injuries were divided into either the BTB group (n = 30) or HT group (n = 45). Twenty-five patients with revision case were divided into either the BTB group (n = 15) or HT group (n = 10). When using HT, an anatomical double-bundle ACLR was performed.
A total of 100 consecutive patients underwent ACLR performed by single surgeon. All participants underwent postoperative MRI evaluation 2 years postoperatively. The signal intensity (SI) characteristics of the reconstructed graft were evaluated using oblique axial proton density-weighted MR imaging (PDWI) perpendicular to the grafts. The signal/noise quotient (SNQ) was calculated to quantitatively determine the normalized SI. All measurements were performed at three separate visits. The evaluations were made by the same two investigators, and the average values were recorded. A lower SNQ value indicates less water content and theoretically better graft maturity. In the HT group, the anteromedial bundle (AMB) and posterolateral bundle (PLB) were evaluated respectively.
For clinical evaluation, the Lachman test, pivot shift test, KT-2000 evaluation, Lysholm score, and Knee injury and Osteoarthritis Outcome Score (KOOS) were used.
The inclusion criteria were as follows: (1) primary or revision ACLR, (2) use of BTB or HT for anatomical ACLR, (3) no history of injury to the contralateral knee. The exclusion criteria were as follows: (1) multiple ligament injuries (grade 3), (2) concomitant ipsilateral fracture around the knee, and (3) osteoarthritis.
Results
The mean MRI-SNQs were as follows: primary groups (BTB, 2.1 ± 0.5; AMB, 2.9 ± 0.9; and PLB, 4.1 ± 1.1) and revision groups (BTB, 3.6 ± 1.0.; AMB, 4.0 ± 1.2; and PLB, 4.8± 1.5). In the knee laxity evaluation, there were significant differences between BTB and HT in both primary (BTB: 0.9 ± 1.0 mm; HT: 2.0 ± 1.1 mm: p <0.01) and revision group (BTB: 2.2 ± 1.8 mm; HT: 2.6± 1.9 mm: p <0.05). No significant differences were detected in clinical scores between BTB and HT in both primary and revision cases.
Conclusion
Regarding graft maturation based on MRI evaluations, no significant differences were found in revision ACLR between BTB and double-bundle HT, although BTB maturation is significantly superior to that of HT in primary ACLR.
BTB showed significantly better anterior knee stability than HT in both primary and revision ACLR, whereas no significant differences were observed in subjective or objective evaluations over a minimum 2-year follow-up period.
For clinical relevance, the advantages of BTB may help clinicians decide on using the autograft option because significant differences were observed in MRI and knee anterior laxity evaluation between BTB and double-bundle HT in both primary and revision cases.