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Updated: Dec 6, 2025
Athymic Rat Model for Evaluation of Engineered Anterior Cruciate Ligament Grafts
Published on: March 26, 2015
Xenograft for anterior cruciate ligament reconstruction was associated with high graft processing infection
Willem Van Der Merwe1, Martin Lind2, Peter Faunø2
1Sport Science Institute of S. Africa, Cape Town, South Africa.
Purpose:
To evaluate clinical ad radiological outcomes of anterior cruciate ligament (ACL) reconstruction with an immunochemically modified porcine patellar tendon xenograft controlled against human Achilles tendon allograft at 24-month minimum follow-up.
Methods:
66 patients undergoing arthroscopic ACL reconstruction were randomized into 2 groups: 34 allografts and 32 xenografts treated to attenuate the host immune response. Follow-up was 24-month minimum. Anterior knee stability was measured as KT - 1000 side-to-side laxity difference (respect to the contralateral healthy knee). Functional performance was assessed by one-legged hop test. Objective manual pivot-shift test and subjective (IKDC, Tegner and SF-36) outcomes were collected. MRI and standard X-Ray were performed.
Results:
61 subjects (32 allograft, 29 xenograft) were evaluated at 12 and 24 months. Six of the subjects in xenograft group (20.6%) got an infection attributed to a water-based pathogen graft contamination in processing. Intention-to-treat analysis (using the last observation carried forward imputation method) revealed higher KT - 1000 laxity in xenograft group at 24-month follow-up (P = .042). Also pivot-shift was higher in xenograft group at 12-month (P = .015) and 24-month follow-up (P = .038). Per-protocol analysis (missing/contaminated subjects excluded) did not revealed clinical differences between groups. Tibial tunnel widening in the allograft group was low, whereas xenograft tunnel widening was within the expected range of 20-35% as reported in the literature. No immunological reactivity was associated to xenograft group.
Conclusions:
High infection rate (20.6%) was reported in xenograft group. Both groups of patients achieved comparable clinical outcomes if missing/contaminated subjects are excluded. Improved harvesting/processing treatments in future studies using xenografts for ACL reconstruction are needed to reduce infection rate, otherwise xenograft should not be used in ACL reconstruction.
Level Of Evidence:
Multicenter and double-blinded Randomized Controlled Clinical Trial, Level I.
