2015 ISAKOS Biennial Congress ePoster #1212

Increased Risk of Revision After Anterior Cruciate Ligament Reconstruction With Bone-Patellar Tendon-Bone Allograft Compared to Bone-Patellar Tendon-Bone Autograft

Gregory B. Maletis, MD, Baldwin Park, CA UNITED STATES
Jason Chen, MA, San Diego, CA UNITED STATES
Maria CS. Inacio, PhD, San Diego, CA UNITED STATES
Tad T Funahashi, MD, Newport Beach, CA UNITED STATES

Kaiser Permanente Surgical Outcomes and Analysis, San Diego, California, USA

FDA Status Not Applicable

Summary: A 4.5 times higher risk of revision was seen with bone-patellar tendon-bone allograft compared to bone-patellar tendon-bone autograft, but whether the tissue is irradiated with either high or low dose radiation, or is not processed at all makes little difference in the risk of revision.

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Abstract:

Introduction

The use of allograft tissue for anterior cruciate ligament reconstruction (ACLR) remains controversial. Numerous meta-analysis and systematic reviews of smaller clinical studies have not found differences between autograft and allograft outcomes but large registry studies have shown an increased risk of revision with allograft tissue. The purpose of this study was to compare the risk of aseptic revision between bone-patellar tendon-bone (BPTB) autografts and BPTB allografts.

Methods

A retrospective cohort study of prospectively collected data was conducted using an US ACLR Registry. A cohort of primary unilateral ACLR cases reconstructed with BPTB autografts and BPTB allografts was identified. Aseptic revision was the end point of the study. Type of graft and allograft processing methods (non-processed, <1.8Mrads, >1.8 MRads irradiation) were the exposures of interest evaluated. Age (<22 and >22 years-old) was evaluated as an effect modifier. All analyses were adjusted for age, gender, and race. Kaplan-Meier curves and Cox proportional hazard models were employed. Hazard ratios (HR), 95% confidence intervals (CI) are provided.

Results

The BPTB cohort had 5586 cases, 3783 (67.7%) were male, 2359 (42.2%) were White, 1029 (18.4%) cases used allograft (non-processed =160,<1.8MRads =543, >1.8MRads = 300) and 4557 (81.6%) cases used autograft. The median age was 34.9 years-old (interquartile range (IQR) 25.4-44.0) for allograft cases and 22.0 years-old (IQR 17.6-30.0) for autograft cases. The 2 year and 5 year graft survival for patients <22 years of age was 86.9% and 82.5% for allografts, and 97% and 94.9% for autografts respectively. The BPTB allografts had a significantly higher adjusted risk of revision than BPTB autografts (HR: 4.54, 95%CI 3.03-6.79, p<0.001). This higher risk of revision was consistent with all allograft processing methods when compared to autografts and was also consistently higher in patients with allografts regardless of age.

Conclusions

The five year graft survival for BPTB autografts was 94.9% compared to only 82.5% for BPTB allografts. When BPTB allograft tissue is used for an ACL reconstruction, one can expect a 4.54 times higher risk of revision than if BPTB autograft is used. Whether the tissue is irradiated with either high or low dose radiation, or is not processed at all, makes little difference in the risk of revision. Surgeons and patients need to be aware of the increased risks of revision when BPTB allograft is used for reconstruction.