Loop Length Change of an Adjustable-Length Femoral Cortical Suspension Device in Anatomic Rectangular Tunnel Anterior Cruciate Ligament Reconstruction With a Bone–Patellar Tendon–Bone Graft and Associated Clinical Outcomes

Abstract

To evaluate loop length changes of an adjustable femoral cortical suspensory fixation device and assess the clinical results after anatomic rectangular tunnel anterior cruciate ligament (ART-ACL) reconstruction with a bone-tendon-bone (BTB) graft. The study included 50 patients who underwent ART-ACL reconstruction with a BTB graft fixed using the adjustable-length device BTB TightRope for femoral fixation between July 2013 and December 2014. Computed tomography examinations were performed at 1 and 12weeks after the surgery. Loop length was measured in the reconstructed plane just parallel to the femoral tunnel, including the bone plug and the button. Measurement was performed thrice, and the mean value was used. Loop length change was defined as the difference in loop length between 1 and 12weeks after the surgery. A paired t test was conducted with the effect size for statistical analysis. At 2years postoperatively, clinical evaluations, including subjective and objective assessments, were performed. The mean loop lengths at 1 and 12weeks were 25.77 ± 3.88mm and 25.81 ± 3.89mm, respectively, with a significant difference (P= .01). However, the effect size was 0.01, suggesting that the difference was not meaningful. The mean individual loop length change was 0.04 ± 0.13mm. All individual loop length changes were within the measurement error range. At 2years postoperatively, 49 patients (98%) were graded as normal or nearly normal according to the International Knee Documentation Committee form. The mean side-to-side difference in anterior laxity at manual maximum force was 0.2 ± 0.5mm. The loop length change of an adjustable-length femoral cortical suspension device was negligible after ART-ACL reconstruction with a BTB graft. This ART-ACL reconstruction with a BTB graft using an adjustable-length device could safely provide sufficient stability to the operated knee. Level Ⅳ, therapeutic case series.