Tag Archive | Mark Miller

JBJS Classics: ACL Graft Strength and Stiffness

Each month during the coming year, OrthoBuzz will bring you a current commentary on a “classic” article from The Journal of Bone & Joint Surgery. These articles have been selected by the Editor-in-Chief and Deputy Editors of The Journal because of their long-standing significance to the orthopaedic community and the many citations they receive in the literature. Our OrthoBuzz commentators will highlight the impact that these JBJS articles have had on the practice of orthopaedics. Please feel free to join the conversation about these classics by clicking on the “Leave a Comment” button in the box to the left.

JBJS-Classics-logoIn the classic article, “Biomechanical analysis of human ligament grafts used in knee-ligament repairs and reconstructions” (J Bone Joint Surg Am 1984; 66:344–352), now 30 years old, Noyes and colleagues studied the mechanical properties of several anterior cruciate ligament (ACL) grafts that were used at that time. Using young donors, they found that the bone-patellar tendon-bone (BPTB) graft was the only graft studied that had a maximum load in excess of the native ACL. Many of the grafts they studied—including iliotibial tract, fascia lata, and quadriceps retinaculum—had exceedingly poor strengths, which is probably why they are no longer used.

Unfortunately, the authors did not double their hamstring grafts (as is commonly done clinically) for testing, and they also used 14-mm BPTB grafts, which are much wider than commonly used clinically, so some of their comparisons may have limited clinical applicability. The authors did note several limitations to their study, including that graft strength is only one of many factors for successful ACL reconstruction, that gripping was sometimes a problem during testing, and that they only performed uni-axial testing. Nevertheless, this article set the stage for critically analyzing graft choice based upon mechanical properties.

Subsequent studies, including those by Woo, Cooper, Howell, Brown, and others, now suggest that several grafts are available that are stronger and stiffer than the native ACL, including BPTB, quadrupled hamstring (strongest and stiffest of all grafts studied), quadriceps tendon, tibialis anterior tendon, and posterior tibial tendon:

Graft Type Ultimate Strength(N) Stiffness (KN/m)
Native ACL 2160 292
BPTB 2977 620
Quadrupled Hamstring 4590 861
Quadriceps Tendon 2352 463
Tibialis Anterior 3412 344
Posterior Tibialis 3391 302

Of course, many other ACL reconstruction controversies continue to be debated, including technique, fixation, and autograft vs. allograft. But graft strength and stiffness will continue to be one of many important factors for the ACL surgeon to consider, especially if future options such as ACL augmentation and the use of synthetics and biologics become available. We welcome comments from JBJS readers.

Mark D. Miller, MD

JBJS Deputy Editor for Sports Medicine

JBJS Website: #1 Among Orthopaedic Surgeons

According to the orthopaedic surgeon edition of Kantar Media’s Website Usage & Qualitative Evaluation study, JBJS.org ranks hands down as the #1 orthopaedic site that surgeons visit most often and spend the most time on. The Kantar study evaluates the opinions of orthopaedic surgeons on 29 professional websites, including 8 orthopaedic sites. Not only does JBJS.org rank number 1 among the other 7 orthopaedic sites in frequency of visits (4.7 times/month), the website ranks first among all 28 sites evaluated in terms of time per session (20.31 minutes). Additionally, JBJS.org ranks #1 in delivering quality clinical content and keeping surgeons informed of the latest practices and procedures. JBJS ties for first place in the category of information on drugs, devices, or professional services. Also noteworthy is the fact that JBJS Reviews, a new online review journal from JBJS launched in November 2013, has already taken over third place in time spent and number of site visits.

JBJS Webinar Series
JBJS has held multiple live webinar events on a wide variety of topics, and we are pleased to announce the expansion of the JBJS Webinar Series in 2014. Each webinar has proven to be a successful tool in educating, informing and engaging orthopaedic surgeons around the world. In 2014, JBJS is continuing this educational program through a new series of interactive online events.

Our webinars bring together groups of authors to present recently published scientific research and data, and they include commentary from guest experts. Live Q&A sessions follow the author and commentator presentations to provide the audience with the opportunity to further explore the concepts and data presented. Webinars continue to be available on-demand for several months after the event.

AVAILABLE ON-DEMAND (Previously Recorded Events)

Total Knee Arthroplasty Critical Decision Making: Socioeconomic and Clinical Considerations (June 10, 2014) – Moderated by Charles R. Clark, MD
Panelists/Authors: Kevin J. Bozic, MD and Thomas S. Thornhill, MD
Commentators: Daniel J. Berry, MD and Kevin Garvey, MD

Preventing Arthroplasty-Associated Venous Thromboembolism (VTE) (May 12, 2014) – Moderated by Thomas A. Einhorn, MD
Panelists/Authors: Clifford W. Colwell Jr, MD and John T. Schousboe, MD
Commentators: Vincent Pellegrini Jr, MD and Jay Lieberman, MD

Anterior Cruciate Ligament (ACL) Reconstruction (March 5, 2014) – Moderated by Mark Miller, MD
Panelists/Authors: Freddie Fu, MD and Christopher Kaeding, MD
Commentators: Brett Owens, MD and Darren L. Johnson, MD

Adhesive Capsulitis/Frozen Shoulder (December 2013) – Moderated by Andrew Green, MD
Presented in conjunction with the Journal of Orthopaedic & Sports Physical Therapy.
Panelists/Authors: George Murrell, MD, Martin J. Kelley, DPT, Jo Hannafin, MD, PhD, and Philip W. McClure, PT, PhD

Periprosthetic Joint Infection (October 2013) – Moderated by Charles R. Clark, MD
Panelists/Authors: Kevin J. Bozic, MD and Craig J. Della Valle, MD
Commentators: Javad Parvizi, MD, FRCS, and Geoffrey Tsaras, MD, MPH

Measuring Value in Orthopaedic Surgery (September 2013) – Moderated by James Herndon, MD
Panelist/Author: Kevin J. Bozic, MD
Commentators: David Jevsevar, MD and Jon J.P. Warner, MD
Editor, JBJS Reviews: Thomas A. Einhorn, MD

JBJS Webinar: Experts Call for Better Outcome Measures in ACL Studies

Changes in and current “best practices” for anterior cruciate ligament (ACL) reconstruction were the subject of a recent JBJS webinar that is available for free viewing until March 5, 2015.

The webinar focused on the procedural and outcome differences between nonanatomic transtibial tunnel drilling and more anatomic anteromedial portal drilling. Drs. Freddie Fu and Christopher Kaeding summarized their recent JBJS papers on ACL tunnel drilling, and Drs. Brett Owens and Darren Johnson commented on the authors’ findings. Dr. Mark Miller moderated the webinar.

One of several points the four ACL experts agreed upon during the webinar was the need for more objective outcome measures to help surgeons distinguish success from failure. For example, Dr. Fu argued for measuring outcomes with biomarkers and advanced imaging such as dynamic stereoradiography and 3-D computed tomography. As important as patient-centered outcomes are, Dr. Fu cited their subjectivity as a downside. “Getting back to sport in 6 months may not be so good if your ACL isn’t reconstructed anatomically,” he said.

Dr. Kaeding’s study found no KOOS-score differences between the two drilling techniques, but the transtibial group had a nearly 2.5-fold increased risk of subsequent ipsilateral knee surgery when compared to the anteromedial group. Commenting on that study, Dr. Johnson lauded the six-year follow-up and outcome metric of subsequent same-knee surgery. But he stressed that a combination of clinical outcomes–including patient satisfaction, knee stability, re-tear rates, and subsequent arthritis–would help surgeons make more informed decisions. He expressed hope that the patients in Dr. Kaeding’s study will continue to be followed so longer-term clinical data can been obtained.

To view the webinar in its entirety, free of charge, go to

https://vts.inxpo.com/Launch/QReg.htm?ShowKey=18001

You can also read a JBJS Reviews critical analysis of ACL tunnel placement here.