Researcher(s)
- London Downing, Exercise Science, Delaware State University
Faculty Mentor(s)
- Karin Silbernagel, Physical Therapy, University of Delaware
Abstract
Background: Bone-patellar-tendon-bone (BPTB) autograft is a method of anterior cruciate ligament reconstruction (ACLR) where the central third of the patellar tendon (PT) is harvested. After graft harvest, the tendon retains healthy tissue in the medial and lateral portions, with a central gap between them. Despite only the central portion being removed, all regions are altered. The purpose was to compare graft-site PT structure between 1 and 3 months after ACLR with BPTB graft.
Materials and Methods: Participants included 15 females and 19 males (age [mean±SD] = 19.7±10.1 years, BMI = 24.8±3.1 kg/m2) 1.3±0.3 and 3.4±0.3 months post-ACLR with BPTB. Short-axis images at 50% length of the patellar tendon were taken using B-mode ultrasound with participants supine in 30º of knee flexion. The total, medial, and lateral cross-sectional areas (CSA, cm2) of the patellar tendon, and the width of the central gap (mm) at 25, 50, and 75% of tendon depth were measured. Values used for analyses were the average gap width and the proportion (%) of healthy tendon ([(medial + lateral CSA)/total CSA]X100). Paired t-test was used for statistical analysis.
Results: Average gap width increased from 1-month (mean±SD = 3.36±0.60 mm) to 3-months (4.23±1.54 mm, p = 0.005) after ACLR, while the proportion of healthy tendon decreased from 1 (61.8±6.8%) to 3-months (57.7±8.1%, p = 0.04).
Conclusion From 1- to 3-months after surgery, graft-site tendon gap-width increases while the proportion of healthy tissue decreases. These findings add to the body of evidence detailing changes that occur throughout ACLR recovery. Future studies should investigate how these measures relate to other tendon metrics, including stiffness, viscosity, and neovascularization, as well as functional recovery like range of motion, strength, and pain. As the prevalence of diagnostic ultrasound in the clinical setting increases, these measures have the potential to provide insight into healing trajectory.