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ACL Reconstructions via Allografts
For articles focusing on graft-fixation devices, see ACL Reconstructions via Hamstring Autografts.
For a brief overview of knee anatomy, physiology, and biomechanics, please click here.
For articles specifically addressing the topic of revision ACL reconstructions, please see Revision Reconstructions: Factors behind ACL-Graft Failures, Outcomes. For articles focusing on ACL reconstruction in degenerate knees, please see ACL Reconstruction in the Arthritic Knee. Articles discussion the ACL-graft-choice process and comparing single- versus double-bundle ACL grafting can be found under Choosing a Knee-Ligament Graft. Allograft Update: The Current Status of Tissue Regulation, Procurement, Processing, and Sterilization (Basic Science Update), David R. McAllister et al.; American Journal of Sports Medicine, Baltimore; December 2007. This superb article, from authors who have spoken on this topic before, provides a comprehensive and penetratingly insightful overview of the infectious-disease-transmission concerns associated with allografts. It also provides insight into how various government organizations and tissue banks are addressing these concerns. The article delves into topics such as the different methods of graft sterilization, and discusses a series of well-publicized cases of fraud and negligence by disreputable tissue banks. It also highlights the advantages of correctly harvested and correctly processed allografts, as provided by reputable tissue banks. Sue Barber-Westin, a seasoned knee researcher, notes that there are five key areas any allograft knee-ligament-graft recipient should ask about: (1) Is the tissue bank accredited by the American Association of Tissue Banks and has it undergone recent inspection by the FDA? (2) Given that older donors translate into a greater risk of poor biomechanical graft quality, is the donor of age 45 or under? (3) What sterilization methods was the allograft subjected to (e.g. chemical, low-dose irradiation)? (4) Has the tissue bank had any problems, for example anything resulting in a recall of previous grafts? (5) What type of body tissue is the graft from, and what fixation method will be used? Will the fixation method reliably ensure that the graft is anchored along its length inside the tunnel, so as to avoid the "bungee-cord effect"? For a good discussion on the biomechanical shortfalls of the traditional single-bundle ACL graft, and for a good discussion on why dual-bundle ACL grafting is ultimately the way of the future (albeit there are some technical-logistical aspects that need to be addressed first, keeping in mind that double-bundle grafting increases the worries of surgeon error because this technique requires more bone-tunnel-drilling alignment finagling, and keeping in mind that incorrect bone-tunneling [hence surgeon error] is still the major cause of ACL-graft failure), please see the superb February 2007 article Effectiveness of Reconstruction of the Anterior Cruciate Ligament With Quadrupled Hamstrings and Bone-Patellar Tendon-Bone Autografts -- An In Vivo Study Comparing Tibial Internal-External Rotation, by Vasileios Chouliaras et al., in the Knee Biomechanics, Functional Anatomy of ACL and Other Ligaments Subsection, as well as the other articles linked to by that article. For a comprehensive overview of ACL-grafting techniques and pursuant considerations (including rehabilitation, graft ligamentization, potential problems, and other issues), please see the November 2005 article Clinical Sports Medicine Update: Treatment of Anterior Cruciate Ligament Injuries, Part 2, by Bruce Beynnon et al., in the ACL Reconstructions via Patellar-Tendon Autografts Subsection. For a comprehensive overview of all the major considerations pertaining to treatment of ACL injuries (including discussions of the impact of concomitant injuries, including damage to other ligaments as well as to articular cartilage and menisci), please see the October 2005 article Clinical Sports Medicine Update: Treatment of Anterior Cruciate Ligament Injuries, Part I, by Bruce D. Beynnon et al., in the ACL Reconstructions via Patellar-Tendon Autografts (includes also Quadriceps Tendon Autografts) Subsection. For insight into the issue of ACL graft type (allograft versus autograft, both patellar-tendon-sourced), please see the October 2005 article Anterior Cruciate Ligament Reconstruction in Patients Older Than 40 Years Allograft Versus Autograft Patellar Tendon, by Gene Barrett et al., in the ACL Injuries and Surgeries in Patients Over 40 Years of Age Subsection. For insight into the advantages of autografting over allografting, in particular with regards to patellar-tendon-type grafts, see the August 2005 article Clinical Comparison of the Tutoplast Allograft and Autologous Patellar Tendon (Bone–Patellar Tendon–Bone) for the Reconstruction of the Anterior Cruciate Ligament: 2- and 6-Year Results, by Ottmar Gorschewsky et al., in the Choosing a Knee-Ligament Graft Subsection. For insight into the issue of bone-tunnel widening/enlargement and its relation to contact pressure, please see the April 2005 article Contact pressure in anterior cruciate ligament bone tunnels: Comparison of endoscopic and two-incision technique, by Hiroyuki Segawa et al., in the ACL Reconstructions via Soft-Tissue (e.g. Hamstring) Autografts Subsection. The Biomechanical Effects of Low-Dose Irradiation on Bone–Patellar Tendon–Bone Allografts, Andrew R. Curran et al.; American Journal of Sports Medicine, Baltimore; July 2004, Vol 26/5, p.1131-1135. Comments: This study shows that irradiating (using ionizing radiation) an allograft (cadaver graft) results in diminished strength and increased likelihood of graft failure. The typical amount used in North America is between 1 and 2.5 Mrad (megarads), despite the fact that about 3.5 megarads are needed in order to reliably destroy the DNA of an extremely worrisome pathogen such as the AIDS virus. Unfortunately, the reduced radiation dose, while unreliable in terms of disinfection, is still enough to detrimentally affect the structure and stregth of the graft. For penetrating insight into the functional anatomy and biomechanics/kinematics of natural versus reconstructed ACLs, be sure to read the pair of current-concepts articles by F.H. Fu: Current Trends in Anterior Cruciate Ligament Reconstruction; Part 1: Biology and Biomechanics of Reconstruction, and Current Trends in Anterior Cruciate Ligament Reconstruction; Part 2: Operative Procedures and Clinical Correlations , in the ACL Reconstruction via Patellar-Tendon Autografting Subsection. Reconstruction of the Anterior and Posterior Cruciate Ligaments After Knee Dislocation Results Using Fresh-Frozen Nonirradiated Allografts, Daniel C. Wascher; American Journal of Sports Medicine, Baltimore; Mar/Apr 1999, Vol 27/2, p. 189. Comments: Wascher et al. describe a series of cases in which allografts were used to reconstruct knees in which both cruciate ligaments were fully torn. They achieved good results, but noted that regainment of completely "normal" knee function, especially given the severe injuries of these knees, was difficult to attain. It was noted that promptly-performed reconstructions (e.g. within 3 months of the injury) yielded results superior to those of delayed reconstructions. (The reason for the three-month time limit is because in a chronically ACL-deficient knee, the secondary restraints [most notably the posterolateral structures] tend to stretch out over a period of months and years. This means that a knee which has been ACL-deficient for an extended period of time will be more loose overall than a knee which incurred the exact same injury six weeks ago. [Similar concerns apply in the case of PCL deficiencies.] Because allografts take roughly twice as long to ligamentize as autografts, allografts are likely to stretch out and fail if used in an extremely loose knee. For such chronically deficient knees, the most reliable option is always the patellar-tendon autograft, due to the presence of bone plugs at both ends. No other graft option brings the security and fast ligamentization provided by bone-plug-to-bone-tunnel healing at both ends of the graft.) Reconstruction of the Lateral Collateral Ligament of the Knee With Patellar Tendon Allograft Report of a New Technique in Combined Ligament Injuries, Harrison A. Latimer; American Journal of Sports Medicine, Baltimore; Sep/Oct 1998, Vol 26/5, p. 656. Comments: Latimer et al. describe allograft reconstruction of knee injuries involving the posterolateral complex (which is generally defined as including the LCL and two minor ligaments). The article provides a good overview of the medium-term success rate of LCL allografting, and provides insight into allografting in general. The authors also review previous research findings on this topic. For insight into the use of patellar-tendon allografting (not autografting) in the context of degenerate (osteoarthritic) or otherwise articular-cartilage-compromised knees, please see Arthroscopic-Assisted Allograft Anterior Cruciate Ligament Reconstruction in Patients With Symptomatic Arthrosis, also by Noyes and Barber-Westin, in the ACL Reconstruction in the Arthritic Knee Subsection. For insight into the treatment of combined ACL-MCL tearing injuries, please see Anterior cruciate ligament-medial collateral ligament injury: Nonoperative management of medial collateral ligament tears with anterior cruciate ligament reconstruction: A preliminary report, by Shelbourne and Porter, and also The Treatment of Acute Combined Ruptures of the Anterior Cruciate and Medial Ligaments of the Knee, by Noyes and Barber-Westin, in the Injuries Involving the MCL and Treatment Thereof Subsection. Click here to return to the Main Entrance Page of the Knee Library.
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