“When you perform ACL reconstruction surgery, you want to know how well patients function, what their activity level is, and if they’re at risk for developing arthritis,” said Dr. Spindler. “I really want to know what predicts ACL reconstruction failure or success so that we can improve our outcomes.”


Published 2/1/2008
Amy Kile

Brought to their knees: Improving ACL reconstruction

An OREF-funded study is changing the paradigm for success

Nearly 275,000 anterior cruciate ligament (ACL) reconstructions are performed in the United States each year. Hoping to improve patient outcomes, Kurt P. Spindler, MD, is leading a clinical follow-up study, initially funded by the Orthopaedic Research and Education Foundation (OREF), to assess what makes some reconstructed ACLs last longer than others.

Kurt P. Spindler, MD

Survey says
Adding to a database he had already developed as a fellow at Cleveland Clinic, Dr. Spindler collected prospective data from ACL reconstructions performed at Vanderbilt University Medical School and by Jack T. Andrish, MD, and Richard D. Parker, MD, at the Cleveland Clinic Foundation. With this data, Dr. Spindler applied for and received an OREF Prospective Clinical Research Grant in 2002.

The OREF grant provided the funding needed for the orthopaedists taking part in this study to contact patients 2 years after surgery. Patients were asked to respond to four standardized questionnaires designed to gather outcome data—the Short Form 36, which measures health-related quality of life for all medical disciplines; the Western Ontario MacMaster (WOMAC), which asks about pain, disability, and joint stiffness to evaluate pain and function in knees and hips affected by osteoarthritis; and the International Knee Documentation Committee (IKDC) and Knee Injury Outcome Osteoarthritis Score (KOOS) forms, which measure activity level.

Before the OREF study, Dr. Spindler said, the standard methods to measure ACL reconstruction were based on structural factors, such as knee stability, range of motion, and laxity. Dr. Spindler’s study relied on patients’ own evaluations of how their knees felt years after their procedures. In August 2005, The Journal of Bone and Joint Surgery (JBJS) published a paper on the study, highlighting validated questionnaires as a means to measure ACL reconstruction.

“Prior to the JBJS paper, everyone evaluated an ACL reconstruction by how stable the knee was,” Dr. Spindler said. “We changed the paradigm and said that measuring success with sports-specific evaluation forms was equally important to the patient. JBJS agreed and this is the kind of shift the OREF paper made. Now outcomes are measured by both knee stability and patient-reported outcomes.”

From Hondas to Ferraris
Based on the success of the OREF-funded study, Dr. Spindler established the Multicenter Orthopaedic Outcomes Network (MOON), a consortium of seven hospitals and universities throughout the United States, each of which adds ACL reconstruction outcome data to the database. In its first 3 years, members of MOON collected data on 1,600 patients, approaching a 90 percent follow-up rate.

After 4 years of collecting data and more than 2 years of writing grants, Dr. Spindler received, as the principal investigator, a $1.2 million National Institutes of Health (NIH) R01 grant to continue the MOON cohort study.

“When you perform ACL reconstruction surgery, you want to know how well patients function, what their activity level is, and if they’re at risk for developing arthritis,” said Dr. Spindler. “I really want to know what predicts ACL reconstruction failure or success so that we can improve our outcomes.”
Dr. Spindler examines a patient after an ACL reconstruction.

“Without OREF, there would have been no NIH grant,” said Dr. Spindler. “Think of the NIH as a car race. No one is going to give you a Ferrari to race at first. So you race Hondas for a while before you get good enough to race the big cars. OREF allows you to race safely and appropriately at your level, to build your skills set so that you have the opportunity to advance to the NIH, to get that Ferrari and win.”

The NIH funding will enable MOON members to use the four follow-up forms preoperatively as well as postoperatively. “When we follow up with the same measures years later, our results are more powerful because we’re able to control for their initial baseline account,” Dr. Spindler said.

The NIH funding also allowed the Vanderbilt Biostatistics Department, headed by Frank E. Harrell Jr., PhD, to customize the MOON affiliate database, and Robert S. Dittus, MD, MPH, of Vanderbilt’s Health Services Research Center, to provide epidemiologic support for it.

With the NIH funding, Dr. Spindler and the MOON affiliates can now take structural measurements—including laxity, function, and joint-space width measured by radiographs—on a randomized subset of patients that can act as a model for the whole group.

Satisfaction for both orthopaedists and patients
About 99 percent of MOON patients agree to participate in the cohort study. “I think that patients realize there’s a definite upside because results can improve ACL reconstruction for other people, and maybe for themselves,” Dr. Spindler said. “Data can be assessed to learn why some outcomes are better than others.”

For example, Dr. Spindler said, a poor outcome could be the result of the partial loss of the meniscus. If so, orthopaedists and engineers could develop a meniscus substitute to implant during ACL reconstruction. If data assessment shows other factors lead to poor outcomes, orthopaedists could counsel patients on helping their own recovery and maintaining their reconstructed ACL.

“We’re going to find out what factors determine poor ACL function and see if we can modify them to improve the outcome,” he said. “Perhaps people who gain 50 pounds are doomed after surgery, for example. Weight may be a big thing; I don’t know. That’s what this study will tell us.”

Follow-up data has already led the surgeons involved in MOON to conclude that the risk of tearing the graft in the reconstructed ACL is exactly the same as tearing the ACL in the same patient’s other knee and that body mass index, smoking status, arthritis on the medial femoral condyle, and preoperative activity level can predict how active a patient will be 2 years after ACL reconstruction.

The MOON cohort study could also directly benefit orthopaedists by changing insurance practices. “Good clinical research can not only help the patients but it can also help us, as physicians, show payors that we’ve improved the quality and the efficacy of what we do and, therefore, should be reimbursed,” said Dr. Spindler.

Amy Kile is a public relations specialist with OREF. She can be reached at kile@oref.org