A study on the diagnosis of early postoperative infection following primary total knee arthroplasty co-authored by Midwest Orthopaedics at Rush joint replacement surgeon Dr. Craig Della Valle has garnered the Mark Coventry Award Paper from The Knee Society.

Dr. Della Valle authored the study with Hany S. Bedair, M.D., who did his fellowship training at Rush in the joint replacement section and is now at the Massachusetts General Hospital in Boston. Co-authors of the paper include: Nicholas Ting, B.A.; Christina Jacovides, B.A.; Arjun Saxena, M.D.; Mario Moric, M.S.; and Javad Parvizi, M.D. The award will be presented at the 2010 Knee Society/American Association of Hip and Knee Surgeons meeting March 13, 2010, at the Morial Convention Center, New Orleans, Louisiana.

"Kudos to Hany and Craig for their world-class research," says Dr. Joshua Jacobs, Chairman, Department of Orthopaedic Surgery, Rush University Medical Center. "Rush's award-winning studies in the diagnosis and management of the infected total knee arthroplasty patient complement numerous other clinical and basic science research programs in total joint replacement, sports medicine, spine surgery, hand/upper extremity surgery and orthopaedic oncology."

The study, entitled Diagnosis of Early Post-Operative Infection following Primary Total Knee Arthroplasty: The Utility of Synovial Fluid Cell Count and Differential, evaluated the utility of the synovial white blood cell count (WBC), differential, C reactive protein (CRP), and erythrocyte sedimentation rate in diagnosing infection in the first six weeks following primary total knee arthroplasty.

"While there has been much written on the diagnosis of the chronically infected knee replacement, this study is unique in that it assists the clinician in the diagnosis of infection in the early postoperative period," says Dr. Della Valle. "Diagnosis within the first few weeks is particularly challenging as normal postoperative pain and swelling can make it difficult to identify an infection that requires surgical management. Specifically, our work has shown that using traditional cut-off values for commonly used laboratory tests such as the synovial fluid white blood cell count may lead to unnecessary surgical intervention. Based on our data we have outlined modified optimal cut-off values that are extremely accurate in the early postoperative period."

A multi-surgeon, multi-institution consecutive series of 11,964 primary TKAs from Rush University Medical Center and Thomas Jefferson University in Philadelphia was reviewed for knee aspirations performed within six weeks of TKA. Infection was diagnosed based on positive cultures or gross purulence. Infected and non-infected knees were compared to determine the utility of synovial WBC in identifying infection early post-operatively.

"Based upon the observations of this study, we would recommend the use of the synovial white blood cell count as the single best predictor of periprosthetic knee infection in the early postoperative period," says Dr. Della Valle.

About The Knee Society

Founded in 1983, the purposes of The Knee Society include:

• To advance the knowledge of the knee joint in health and disease.
• To provide an appropriate educational setting that will maintain the highest level of professional standards in order to promote continuous advancement in professional knowledge and improved treatment of disorders of the knee.
• To create an optimum environment to enhance education, research and treatment of arthritis of the knee joint.
• To promote and maintain professional standards to provide the best care to patients with arthritic disorders of the knee joint.

For more information about The Knee Society, visit www.kneesociety.org.