Abstract
Objectives:
Quadriceps tendon autograft has gained popularity in the high-risk adolescent population based on consistent graft size and biomechanical properties, with some studies citing lower graft failure rates as compared to hamstring and patellar tendon autografts in comparable populations. The purpose of this study was to assess the midterm outcomes of all-soft tissue quadriceps tendon autograft ACL reconstruction in adolescent patients, including ACL graft tear, contralateral ACL tear, and complications.
Methods:
A prospective single-center study was performed of all patients less than 19 years of age who underwent transphyseal or conventional ACL reconstruction with an all-soft tissue quadriceps tendon autograft with treatment of concomitant meniscal and chondral pathology from 1/1/2019 – 6/30/2022. Patients requiring multiligament knee reconstruction were excluded. Patients were treated with post-operative bracing in hyperextension until sufficient quadriceps control was obtained. A standard physical therapy protocol was utilized, emphasizing early terminal knee extension and return to sports no sooner than 9-months post-operatively pending appropriate strength and mechanics at 6-month functional testing. Patient reported outcome scores were obtained annually. The primary study outcomes were ACL graft tear, contralateral ACL injury, and surgical complications.
Results:
480 patients were enrolled in the study, and 397 patients (83%) had minimum 2-year follow-up and were included in analysis. Mean patient age was 15.7 years (range 10 – 18 years) and 54% were female. Physes were open in 95 patients (24%) and the mean growth remaining based on left hand bone age was 1.2 years. Mean graft size was 9.2 femoral side (range 7.5 – 11.5) and 9.0 tibial side (range 7 – 11.5). Mean clinical follow-up was 34 months.
There were 36 ACL graft tears (9%) and 28 (7%) contralateral ACL tears. Rate of ACL graft injury was greater in males (13%) vs females (7%), (OR 2.2, 95% CI 1.09, 4.53). Among male patients 16 years, 13% sustained an ACL graft tear vs 5% in males >16 years (OR 2.7, 95% CI 1.1, 6.3). There was a 10% ACL graft tear rate in female patients 15 years vs 4% in females >15 years (OR 2.4, 95% CI 0.76-7.66). Females represented 35% of ACL graft tears, yet 75% of contralateral ACL tears. The odds of a female sustaining a contralateral ACL tear was 1.7 times greater than an ACL graft tear (95% CI 0.8, 3.5). Complications requiring reoperation included arthrofibrosis (14 patients, 4%), meniscus tear (2%), and infection (1%).
Conclusions:
ACL graft tear occurred in 9% of adolescent patients within 3 years after quadriceps tendon autograft ACL reconstruction. Risk of ACL graft tear was significantly greater in males as compared to females and in male patients with a chronologic age 16 years as compared to those >16 years. There was a 7% rate of contralateral ACL injury in the study, nearly the same as rate of ACL graft tear. Female patients had an increased risk of contralateral ACL tear as compared to ACL graft tear. Rates of reoperation for complications, including arthrofibrosis were low.