Nationally Recognized, Groundbreaking Research on Improving Total Knee Replacement (TKR) Outcomes

Research taking place at UMass Memorial Medical Center - 3/20/2009 - FOR IMMEDIATE RELEASE Contact: Marketing and Communications Department
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WORCESTER, MA, March 20, 2009 - Thanks to the work of David Ayers, MD, and Patricia Franklin, MD, tens of thousands of future TKR patients could enjoy significantly improved functional outcomes.

TKR is a surgical procedure in which an artificial joint or prothesis replaces a damaged knee joint to relieve pain, often caused by osteoarthritis, and improve physical function and mobility. More than 300,000 TKRs are performed every year in the United States and experts predict this number will increase 525 percent by the year 2030.

Following up on initial research they undertook at SUNY Upstate Medical Center Syracuse in 2000, Drs. Ayers and Franklin discovered through careful analysis of a national TKR database of more than 16,000 cases that although 98 percent of patients reported excellent pain relief at 12 months post surgery, wide variability in physical function and patient activity existed. Importantly, two-thirds of patients reported much better than average improvement in function at one year after surgery. However, one-third of patients lagged behind in functional gain. Through additional analysis, Drs. Ayers, Franklin and colleagues were able to identify specific characteristics of these patients at-risk for less functional improvement.

Combinations of these characteristics, including older age, higher body mass index, poor quadriceps muscle strength and poor emotional health, can put a patient at risk for sub-optimal functional gains.

“This was an important breakthrough. If we identify TKR patients at-risk for less than optimal functional outcomes pre-operatively,” explained Dr. Ayers. “we can theoretically, develop individualized clinical pathways for these patients and provide more resources and support to address their needs and improve their functional outcomes postoperatively.”

In fact, this is now being done on a research basis at the UMass Memorial Arthritis and Total Joint Replacement Center for patients at-risk for less than optimal functional outcomes.

Drs. Ayers and Franklin’s leading-edge research and its enormous potential to improve functional outcomes for tens of thousands of TKR patients worldwide has been recognized nationally. Last year, The Knee Society, a national organization comprised of leading orthopedic surgeons, awarded Drs. Ayers, Franklin and two of their colleagues its prestigious Chitranjan Ranawat Award for the year’s greatest contribution to advancing professional knowledge to improve the treatment of knee disorders.

The researchers also received a $1.7 million National Institute of Health (NIH) grant to conduct a prospective randomized study to test one method to improve function and outcomes after TKR for osteoarthritis. Showing how unique this research is and how highly the NIH views its future promise, the UMass Memorial Arthritis and Total Joint Replacement Center is the only center in the United States to be selected for such a TKR grant.

Faculty Members Involved in Research Projects


David Ayers, MD   (link to research page)

Research focus

  • Radiostereometric (RSA) Imaging of Hip Prostheses and Spine Fusion
  • Total Knee Replacement (TKR) (in collaboration with Dr P. Franklin)
Radiostereometric analysis (RSA) provides precise and reproducible measurement of femoral head penetration and is a reliable tool for early prediction of long-term clinical success among total joint replacement patients. Dr Ayers is particularly interested in the following issues:

  • Ultra high molecular weight polyethylene (UHMWPE) wear debris-induced osteolysis may be the leading cause of total hip arthroplasty (THA) implant failure occurring after the early postoperative period. Measurement of femoral head penetration as an indicator of acetabular liner wear provides an in vivo marker of early periprosthetic osteolysis.

  • The initial stability of a cementless femoral stem is an important predictor of the clinical success of the total hip replacement (THR).  Tapered cementless stems have proven to successfully relieve pain and restore function at intermediate clinical follow-up.

Patricia Franklin, MD, MBA, MPH    (link to research page)

 Research focus

  • Total Knee Replacement (TKR)
  • Outcomes Research
Dr Frankin is Director of Clinical and Outcomes Research and a member of the core faculty of the PhD in Clinical and Population Health Research. She has extensive experience in the analysis and interpretation of clinical and outcome data and is particularly interested in post-total joint replacement functional gains. With her colleagues, she has conducted a series of funded studies to evaluate the contribution of the patient’s physical and emotional health and daily activity to long-term function after total knee replacement (TKR), Medicare’s highest volume procedure. She currently serves as Principal Investigator on an NIH-funded RO1 to design and evaluate a program to enhance patient adherence to optimal levels of home exercise and physical activity in the TKR rehabilitation period. Dr. Franklin’s eHealth research includes a multi-site RCT testing the efficacy of brief emails to facilitate diet and physical activity change (funded by the Robert Wood Johnson Foundation Health e-Technologies Initiative). Recently the RWJF funded her team to transform population data into web-based outcome prediction tools that will allow patients and physicians to anticipate individualized functional gains after TKR. She is also collaborating in the development of technology for patients to monitor and trend pain and function in personal and electronic health records. While her research focuses on patients with advanced knee arthritis and TKR, each of these eHealth interventions can be extrapolated to self-care in the aging adult.

 

Paul Fanning, PhD    (link to research page)

Research focus 
  • The Mechanical Regulation of Biological Mediators of Cartilage and Joint Destruction in Osteoarthritis
  • Mechanical Models of Arthritis

Currently in the U.S., musculoskeletal conditions are the leading cause of disability.  Joint diseases account for 50% of all chronic conditions in the elderly.  Worldwide, OA is only the 6th leading cause of years of life lost to ill health.  The burden of musculoskeletal disease, both in terms of human illness and heath care costs is projected to widen significantly by the year 2030.  The aging of the U.S. population is expected to produce an additional 21 million individuals in the 65-and-over age group, representing a 20% increase over current demographics.  Surprisingly, despite the wealth of clinical data on OA, surgical treatment which culminates in total joint replacement, remains the most effective therapy for progressive OA.  Relatively little is known about the basic biology of OA especially how mechanical wear, the major hallmark of OA, influences fundamental biological control mechanisms in chondrocytes, the cells that populate cartilage.  

Recently, through the use of specially-designed mechanical compression devices, we have found that chondrocytes respond to increasing mechanical loading signals much as other tissues respond to increasing concentrations of hormones or growth factors by activating 3 distinct MAPK signaling pathways, including the so-called ‘stress-activated’ protein kinase pathways.  This finding not only opens the way for further research into what actions these signaling pathways have on specific genes involved in OA but also provides an opportunity to intervene with pathway-selective MAPK inhibitors in the treatment of OA.


Marci Jones, MD   


Jie Song, PhD    (link to research page)

Research focus
 
  • Synthetic extracellular matrix analogs for guiding the repair and regeneration of musculoskeletal tissues
With a growing and aging population, the demand for synthetic grafts assisting the repair and reconstruction of musculoskeletal tissue defects induced by trauma, aging, cancer and metabolic diseases is quickly rising. Our lab is interested in designing synthetic extracellular matrix (ECM) analogs capable of promoting the repair or guiding the regeneration of musculoskeletal tissues. These synthetic constructs are also programmed with unique physical properties to facilitate surgical handling (e.g. deployable, elastic, injectable) and proper in vivo degradation characteristics.