Early Outcomes of Adolescent ACL Reconstruction With Hybrid Hamstring Tendon Autograft-Allograft Versus Hamstring Tendon Autograft Alone

Abstract

Background: Small-diameter semitendinosus-gracilis tendon autografts may be encountered intraoperatively during anterior cruciate ligament reconstruction (ACLR); these have been shown to be at increased risk of graft rupture. One option that surgeons have pursued to reduce the theoretical failure rate of these smaller-diameter grafts is augmenting them with allograft material, thereby forming a larger-diameter hybrid autograft-allograft construct. Purpose/Hypothesis: The purpose of this study was to compare outcomes in adolescent athletes of primary ACLR using a hybrid autologous hamstring tendon and soft tissue allograft construct versus ACLR using small-diameter hamstring tendon autograft. The hypothesis was that the hybrid hamstring autograft-allograft construct would provide superior short-term results. Study Design: Cohort study; Level of evidence, 3. Methods: We performed a retrospective analysis of 47 patients aged between 12 and 20 years who underwent hybrid graft ACLR (mean diameter, 9.1 mm) at a single institution. Electronic medical records including clinic notes, radiographic images, operative notes, and pathology reports were reviewed for study analysis. A control group of 64 patients who underwent small-diameter hamstring reconstruction (mean diameter, 7.1 mm) without allograft supplementation was compiled. Corresponding clinical, radiographic, and surgical characteristics were collected for the control group to allow for comparative analysis. Results: Mean follow-up was 2.7 years for the hybrid cohort and 2.3 years for the control group. Despite a significantly larger mean graft diameter in the hybrid group as compared with the control group ( P < .001), no significant difference in retear rate was seen between cohorts (hybrid, 9%; control, 13%; P = .554). Patients with hybrid anterior cruciate ligament constructs also underwent a comparable number of reoperations overall ( P = .838). Functionally, all patients with adequate follow-up returned to sports, with no significant difference in time to return to sports between the groups ( P = .213). Radiographically, hybrid graft constructs did not undergo a significantly larger degree of tunnel lysis ( P = .126). Conclusion: A cohort of adolescents with hybrid anterior cruciate ligament grafts was shown to have retear rates and overall clinical results comparable with those of a control group that received small-diameter hamstring tendon autografts alone.

Quadruple Hamstring Autograft Technique for Anterior Cruciate Ligament Reconstruction Reduces Allograft Augmentation

“…Rao and colleagues 11 in 2020 in another retrospective review of adult and adolescents found augmenting a hamstring autograft that is 8 mm or less with allograft showed no difference in overall reoperation, revision of ACL failure, or patient reported outcomes. Lastly, Heyworth and colleagues 10 in 2021 showed no difference in retear rates and clinical outcomes with augmented grafts in an adolescent group in a retrospective review.…”

“… 4 Studies assessing the use of allograft augmentation raise concerns for increased rates of graft rupture, particularly in adolescents; however, this is inconclusive in adults. 6 , 7 , 8 , 9 , 10 , 11 The purpose of this study was to assess the discrepancy in graft diameter between double- and quadruple-folded hamstring autografts and the need for allograft augmentation to obtain an adequate graft diameter during ACLR. It was hypothesized that quadruple-folded grafts would have a larger average diameter and reduced need for allograft augmentation.…”

No difference in revision risk between autologous hamstring graft less than 8 mm versus hybrid graft 8 mm or larger in anterior cruciate ligament reconstruction

“…However, due to iatrogenic suboptimal harvest or anatomical variation, the graft can be smaller than preferred [5]. While consensus on the minimum HA graft diameter needed to reduce the risk of graft failure is lacking [8], an inverse association between graft diameter and risk of failure and revision has been reported with most considering a diameter of ≥ 8 mm as the preferred minimum diameter [1, 9, 25]. There are several options for the surgeon when faced with a harvested HA with a diameter < 8 mm.…”

“…In contrast, Jacobs et al [10] compared HA (n = 46; average age 14.6) and HY (n = 42; average age 15) and found graft failure was significantly higher for HA (28.3%; mean diameter 7.8 mm) compared to HY (11.9%; mean diameter 9.9 mm) in their retrospective cohort study. More recently, Heyworth et al [8] found no differences between graft re‐tear rates in their retrospective review of HA (n = 64; average age 16.1) and HYs (n = 47, average age 15.8) with a re‐tear rate of 13% for HA (mean diameter 7.1 mm) and 9% for HY (mean diameter 9.1 mm).…”

No difference in postoperative efficacy and safety between autograft and allograft in anterior cruciate ligament reconstruction: a retrospective cohort study in 112 patients

“…Allograft is associated with some negative outcomes, including disease transmission (13), immune rejection (14), and a high risk of surgery failure (14). A hybrid graft combines allograft (tibialis posterior, tibialis anterior, gracilis tendon, or semitendinosus) with auto hamstring tendons to strengthen the autograft, resulting in a graft with a thicker diameter and a larger graft occupancy than that of autograft (15,16).…”