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. 2024 Aug 9;12(8):23259671241254115.
doi: 10.1177/23259671241254115. eCollection 2024 Aug.

Outcomes of ACL Reconstruction Utilizing Supercritical CO2-Sterilized Allografts

John E Farey  1 , Lucy J Salmon  1   2 , Justin P Roe  1   3 , Vivianne Russell  1 , Keran Sundaraj  1 , Leo A Pinczewski  1   2
Affiliations

Outcomes of ACL Reconstruction Utilizing Supercritical CO2-Sterilized Allografts

John E Farey et al. Orthop J Sports Med. .

Abstract

Background: Allograft tendons are perceived to have a high ACL graft failure rate in primary anterior cruciate ligament (ACL) reconstruction (ACLR). Historical series may be biased by graft processing methods that degrade the biomechanical properties of donor tendons such as irradiation. Supercritical carbon dioxide (SCCO2) is a validated method of terminally sterilizing biomaterials at physiological temperatures without irradiation, but in vivo use of SCCO2-processed tendon allografts for primary ACLR has not been reported to date.

Hypothesis: ACLR with SCCO2 allografts would result in acceptable failure rates, subjective knee scores, and clinical evaluation at 2 years postoperatively.

Study design: Case series; Level of evidence, 4.

Methods: Patients underwent primary ACLR with terminally sterilized SCCO2-processed human gracilis, peroneus longus, semitendinosus, tibialis anterior, and tibialis posterior tendon allografts. Patient demographics were collected, along with tendon donor age and sex. At 1 year postoperatively, subjective International Knee Documentation Committee (IKDC) and ACL-Return to Sport After Injury (ACL-RSI) scores were collected, as well as clinical evaluation. At 2 years postoperatively, the IKDC and ACL-RSI scores were repeated, and return to sports and further knee injuries were recorded.

Results: A total of 144 patients with a medianage of 26 (IQR 14) years formed the study group. Patients were predominately male (58%). The loss to follow-up rate was 8% (n = 12). The mean age of allograft tendon donors was 37 (range 17-58) years, and the majority were male (83%). The mean allograft diameter was 8.9 ± 1.0 mm. At 2 years, ACL graft failureoccurred in 5% (n = 7). All graft failureswere in patients aged ≤25 years (P = .007). Neither donor age (≤40 or >40 years) nor donor sex was associated with graft failure (P > .05). The median IKDC subjective score was 95 and ACL-RSI score was 75. There were no revisions for sepsis within the first 2 years postoperatively.

Conclusion: SCCO2 processing of allograft tendons demonstrated satisfactory clinical and patient-reported outcomes at 24 months postoperatively in a consecutive series of patients with primary ACLR, with similar ACL graft failure rates and subjective knee scores compared with those reported in published series of hamstring tendon autograft and fresh frozen nonirradiated allograft.

Keywords: ACL; allograft; carbon dioxide; chromatography; knee; ligament; supercritical fluid.

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Conflict of interest statement

One or more of the authors has declared the following potential conflict of interest or source of funding: L.A.P. has received IP royalties from Australian Biotechnologies, stock and stock options from Australian Biotechnologies, research support from the Australian Orthopaedic Association, research support from the Friends of the Mater Foundation, IP royalties from Signature Orthopaedics, and research support from Smith+Nephew. J.P.R. has received research support from 360 MedCare, Smith+Nephew, and the Friends of the Mater Foundation. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Figures

Figure 1.
Figure 1.
Distribution of allograft type.
Figure 2.
Figure 2.
Distribution of allograft donor age.
Figure 3.
Figure 3.
Distribution of Anterior Cruciate Ligament–Return to Sport After Injury (ACL-RSI) score at 2 years.
Figure 4.
Figure 4.
Distribution of reported activity level at 2 years. IKDC, International Knee Documentation Committee.
Figure 5.
Figure 5.
Distribution of International Knee Documentation Committee (IKDC) subgroup grades at 1 year.
Figure 6.
Figure 6.
International Knee Documentation Committee ligament grades at 1 year. Manual Max: Manual Maximum testing on KT1000 arthrometer.
See this image and copyright information in PMC

References

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