Autograft-Only and Allograft-Augmented Hamstring Autograft Have Similar Failure Rates After Anterior Cruciate Ligament Reconstruction

PurposeSurgeons generally consider the donor age as a factor that negatively influences the quality of allograft used in anterior cruciate ligament (ACL) reconstruction, however, the available evidence does not clearly support this statement. The purpose of the study was to investigate if donor age influences the biomechanical properties of allografts used in ACL reconstruction.MethodsA comprehensive literature search was conducted for all relevant articles using MEDLINE (PubMed), Scopus, and Cochrane Collaboration Library, according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis. Studies including the analysis of the correlation between biomechanical properties of the allografts and donor age were selected. The role of donor age was labelled as ‘none’ if absent, ‘higher’ or ‘lower’ if the properties were higher or lower in older specimens with respect to younger. The correlation was defined as ‘weak’ or ‘strong’ according to each study definition.ResultsNo conflicting role of donor age was reported for modulus of elasticity, load to failure, strain, stiffness and displacement. The only parameters where the significant results were consistent were the tensile strength and the stress (low or moderate correlations). When considering the tested samples with a donor's age <65 years, a significant role of age was reported in only four out of 13 groups of graft tested (patellar tendon, fascia lata, anterior tibialis tendon and posterior tibialis tendon).ConclusionThe current literature did not allow to state that the donor age negatively influences the biomechanical properties of allografts, making it impossible to identify a clear age cut‐off value to exclude them from ACL reconstruction procedures.Level of EvidenceLevel IV, systematic review.

Section: Discussionmentioning

confidence: 99%

Donor age has no relevant role in biomechanical properties of allografts used in anterior cruciate ligament (ACL) reconstruction: A systematic review

Grassi,

Agostinone,

Di Paolo

et al. 2024

“…The diameter of the ACL graft varies depending on the type used. An 8-mm diameter for the single-bundle ACL graft was selected, representing the minimum acceptable diameter for commonly used grafts such as the semitendinosus and gracilis tendons [1]. However, thinner grafts are occasionally utilised in practice.…”

Section: Methodsmentioning

confidence: 99%

Smith machine squats pose high risk to ACL graft integrity after the ACL reconstruction and conventional squats are a safer alternative

Kotiuk,

Ziółek,

Kostrub

et al. 2024

PurposeThe purpose of this study was to evaluate the impact of squats after the anterior cruciate ligament (ACL) reconstruction on the ACL graft, considering new data on biomechanics, posterior tibial slope (PTS) and anterolateral ligament (ALL).MethodsUtilising finite element analysis on the new 14‐component knee joint model, we have evaluated stresses on the knee elements separately for the knee with a native double‐bundle ACL and with a single‐bundle ACL graft for the 5° and 14° PTS variants during both conventional and Smith machine horizontal squats.ResultsReplacing a native ACL with a single‐bundle graft causes an overstrain on the graft compared to the intact ACL under all conditions. Stresses on the ACL, ACL graft and ALL are much higher during the Smith machine squats compared to the conventional ones. The stress on the menisci is 3.6–4.9 times higher with conventional squats. PTS at the squats' lowest point minimally affects ACL stress but impacts menisci.ConclusionsThe single‐bundle ACL reconstruction (ACLR) does not reproduce the biomechanics of the native ACL and increases stresses in most knee joint elements, according to the current study. Conventional squats are relatively safe for the ACL graft at their lowest point. Passing the half‐squat position is the most dangerous point. Smith machine horizontal squats produce stress on the ACL graft several times higher than its estimated breaking load and dangerous stress levels on the ALL. During the rehabilitation following ACLR, it is advisable to prioritise the conventional squats over Smith machine squats until ligamentisation is complete.Level of EvidenceLevel III.

Hamstring autografts demonstrate either similar or inferior outcomes to quadriceps or bone–patellar tendon–bone autografts in revision anterior cruciate ligament reconstruction: A systematic review of comparative studies

Vivekanantha,

Kahlon,

Hassan

et al. 2024

PurposeTo evaluate the clinical outcomes in patients undergoing revision anterior cruciate ligament reconstruction (r‐ACLR) using hamstring tendon (HT) autografts with those using either quadriceps tendon (QT) or bone–patellar tendon–bone (BPTB) autografts or allografts.MethodsThree databases were searched on 8 August 2023. The authors adhered to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) and Revised Assessment of Multiple Systematic Reviews (R‐AMSTAR) guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, surgical details, patient‐reported outcome measures (PROMs), rates of instability, failure and return to sport (RTS) were extracted.ResultsEleven studies comprising 859 patients were included in this review. Five studies compared HT and QT autografts. One study each reported greater IKDC scores (p = 0.04) and Tegner scores (p = 0.04) in the QT group, while one study each reported higher anterior translation (p = 0.04), rates of positive pivot shift (p = 0.03) and rates of failure (p = 0.03) in the HT group. Six studies compared HT and BPTB autografts with one study each reporting greater Lysholm scores (p = 0.02) and less side‐to‐side anterior laxity (p < 0.01) in the BPTB group. Two studies compared HT autografts with allografts with only one study reporting a faster time to RTS in the HT group than the allograft group (p < 0.001). All other comparisons were not significant.ConclusionsHT autografts result in either similar or inferior outcomes in r‐ACLR when compared to QT or BPTB autograft options. Allografts resulted in similar outcomes to HT autografts apart from greater time to RTS for r‐ACLR.Level of EvidenceLevel III.