Novel Interlinked Suspensory Fixation Technique Demonstrates Excellent Biomechanics and Improves Patient Outcomes in...

Introduction Quadriceps tendon (QT) autografts are a versatile option for primary anterior cruciate ligament reconstruction (ACLR) due to low donor site morbidity, favorable biomechanical properties, and reliable clinical outcomes. Suspensory loop fixation techniques have been described for QT graft preparation; however, concerns regarding graft strength and construct stability persist. This study aims to evaluate the biomechanical strength and report clinical outcomes of a novel interlinked adjustable loop suspensory (IAL) fixation technique for all-soft tissue QT autograft preparation for ACLR. Methods   This study combined controlled laboratory biomechanical testing with retrospective clinical case series. Strengthening the Reporting of Observation Studies in Epidemiology (STROBE) guidelines for cohort studies were followed. QT tendon grafts were harvested from fresh-frozen cadaveric knee specimens and trimmed to a diameter of 9.5 mm and length of 75 mm. Grafts were prepared following the IAL technique. All grafts underwent cyclic loading of 50-250 N for 2,000 cycles at 1 Hz, followed by ultimate load to failure testing (ULTF) at a displacement rate of 0.33 mm/s. Elongation under cyclic loading, ULTF, and mode of failure were recorded. Clinical data were collected for patients undergoing primary ACLR with this graft preparation, with or without concomitant meniscus treatment. Patient-reported outcome measures (PROMs) and range of motion (ROM) data were retrospectively collected from the medical record. Results  Five QT grafts underwent biomechanical testing. The mean elongation was 4.16±0.42 mm over 2000 cycles, with minimal additional elongation between cycles 1000 and 2000 (0.09±0.01 mm). Mean ULTF was 1251.41±134.78 N. Graft failure occurred at the suture-tendon interface, with two grafts breaking at the loop and three demonstrating suture tail slippages. Thirty-three skeletally mature patients were included in this study. All patients demonstrated significant and clinically meaningful improvements in pain and functional outcomes at two-year follow up, and flexion and extension ROM at the six-month follow-up. Two (6.1%) patients had recurrent ipsilateral ACL tears due to re-injury; none of the patients experienced graft failure. Conclusion  This novel interlinked adjustable-loop QT graft preparation demonstrates promising biomechanical characteristics and satisfactory early clinical outcomes, supporting its use as an effective preparation technique for all-soft tissue QT autografts in ACLR.