Significant New Antimicrobial Coating From Penn and MIT
What happens when a large animal orthopedic surgeon pairs up with researchers from MIT? Antimicrobial magic. Ever since he started building the translational research program in orthopedic trauma and sports medicine at the University of Pennsylvania School of Veterinary Medicine New Bolton Center, Thomas P Schaer, VMD has engaged in cross-disciplinary collaboration to address periprosthetic or device-associated infections. He tells OTW, “My colleagues and I took our antimicrobial technology and escalated its application from the laboratory bench to the next stage of translational validation. We did so by functionalizing the surfaces of commercially available off-the-shelf trauma products (fracture plates) with antimicrobial properties.”
Dr. Schaer, who will be a delegate for the upcoming International Consensus Meeting on Periprosthetic Joint Infection in August 2013, says, “I began this work after observing the devastating consequences of implant infection in long bone fracture repairs in horses. I approached Dr. Alexander Klibanov at MIT, and together we started the translation of an antimicrobial coating that was developed in his laboratory. Here is the critical point: veterinarians are trained to approach treatment from a frugal perspective because in many cases, exorbitant costs are a nonstarter. So, we knew how to design a coating that would be simple and inexpensive (something that is increasingly important in human medicine). In the Comparative Orthopedic Research Laboratory (CORL) at New Bolton Center, we have evaluated surface modifiers for orthopedic implants that target surgical site infection in humans; some were potent, complex chemical surface modifications, while others were very simple coatings that can easily be applied at the time of surgery.”
“One of the notable things about this work is that often, early stage technologies rest on solid basic findings, yet the successful and often arduous translation into clinically relevant models has yet to be completed. I am pleased that we were able to evaluate both the safety and efficacy of this technology in a clinically relevant large animal infected fracture healing model.”
“Specifically, we demonstrated that the presence of a N, N-dodecyl, methyl-PEI coating on the surface of a metal implant was effective in eliminating the clinical signs of infection in-vivo in a large animal infection model. It was also exciting to find that the coated plates supported bone healing even in the presence of significant bacterial contamination and completely prevented biofilm formation. We are currently designing the next phase for the translation of this technology into human and veterinary clinical patients, and are reaching out to interested industrial partners.”
New Study Says 98% of TKA Patients Get Back to Work
Total joint surgeons to insurers and the government: our surgeries DO make a difference in quality of life! Adolph V. Lombardi, Jr., M.D., F.A.C.S. is president of Joint Implant Surgeons, Inc. in New Albany, Ohio. He is on the threshold of publishing his new work on total joint patients and return to work. Dr. Lombardi tells OTW, “The patient population for total joint surgery continues to be younger individuals, so my colleagues and I decided to look at the literature on return to work. We found that most of the existing articles were written on patients over 60 years of age. We looked at people who were working prior to knee replacement and people who had undergone a total knee from 1-5 years ago. Using an independent survey center, our team explored five high volume practices in the U.S. and obtained 661 participants, whose average age was 54. We found that 75% of the participants had been employed three months prior to surgery, and of those, 98% went back to work after surgery…and 89% successfully returned to the same job. We used U.S. Department of Labor definitions: sedentary, light work, heavy work, very heavy work. Prior to surgery, physical demand categories of the patients’ jobs were sedentary 12%, light 10%, medium 24%, heavy 24%, and very heavy 30%. The return to work rate for those employed during the 3 months prior to surgery by physical demand category was sedentary 95%, light 91%, medium 100%, heavy 98%, and very heavy 97%. We were truly pleased by these results; and for the patients; of course, there is a certain amount personal satisfaction they get from going back to work and continuing to earn an income for their families. We often hear that we aren’t doing much for patients’ quality of life, so it is important to share this data with insurers and government officials.”
80% of THR, TKR Patients Report Better Sexual Function
Bravely going where few orthopedic researchers have gone, a team of surgeons from New York have found that total hip (THR) or total knee replacement (TKR) surgery improves sexual function in 80% of patients. José A. Rodriquez, M.D. is an orthopedic surgeon and chief, Center for Joint Preservation and Reconstruction at Lenox Hill Hospital in New York. Asked why he chose to explore this topic, Dr. Rodriguez told OTW, “When I was training a woman in her late twenties came in with severe arthritis of the hip; she asked for a hip replacement. The senior surgeon told her that she was too young and he began to leave the room. Then he heard her crying. She told him that it was not just the physical pain that was affecting her life, but the lack of intimacy. She was concerned that her marriage would fail. He listened…and he did the operation. Many people feel awkward discussing this topic, and it’s hard to quantify the unhappiness that pain with intimacy can cause.”
“I began addressing this issue with my patients when appropriate. It is a delicate subject, so I would say something along the lines of, ‘You may return to activities as your body feels comfortable, including exercise or intimacy.’ Patients would often see that as an opening and would then ask me intimacy-related questions. I then took the issues they raised and created a questionnaire. I had patients rate the different aspects of their lives before surgery, six months later, and one year later; we used a completely blinded format so that patients felt comfortable telling the truth. We asked how the arthritis affects their self-esteem, general well-being, and sexual self-image. We mailed 392 questionnaires out and received 103 in return.”
“We found that 57% of participants felt that arthritis had affected their self-esteem; 68% felt that their self-esteem had improved after surgery, and 72% were able to perform household chores and activities of daily living. There were separate questions on sexuality that included questions about frequency, duration, occurrence of orgasm, and libido. We found that 59% of participants felt that the frequency was diminished because of the arthritis; 12% had a decline in sexual function after surgery—of those more than half were worried about damaging the implant—which may be a misconception that can be addressed with discussion.”
“While most orthopedic surgeons are aware that these issues exist, whether they feel comfortable talking about them is another thing entirely. At least with these results we have something concrete to say. We can tell patients, for example, ‘This is the likelihood of your sexual activity increasing after surgery.’ What patient wouldn’t want to hear that?”
Obesity Increases Costs in TKA
There are more and more obese patients undergoing total knee arthroplasty, so it’s more critical than ever that we know the costs involved. Hilal Maradit Kremers, M.D. is associate professor of epidemiology at Mayo Clinic in Minnesota, and holds appointments in the departments of health sciences research and orthopedics. She gave OTW details on her new study, “The Effect Of Obesity On Direct Medical Costs In Total Knee Arthroplasty.” Dr. Kremers: “We examined 8, 129 patients who had undergone 6, 475 primary and 1, 654 revision TKA procedures at a large U.S. medical center over an eight year period. Our goal was to examine the effect of obesity on length of hospital stay and direct medical costs. We calculated direct medical costs using standardized, inflation-adjusted costs for services and procedures billed during hospitalization and the 90-day window.”
“One dramatic finding was how the prevalence of obesity has increased so much in such a short period of time. The prevalence of obesity in knee patients increased from 50% in 2000 to 60% in 2008. Obese patients have a lot of comorbidities and a higher risk of complications. Thus we asked, ‘Does obesity increase costs because of the comorbidities?’ We accounted for the comorbidities and the complications and found that obesity was still associated with higher costs.”
“The bottom line is that obesity is associated with longer hospital stays and costs in TKA. If one considers this from a population perspective, as opposed to an individual patient perspective, you’re talking about an enormous financial burden…it’s only $200 for Mr. X’s surgery, but multiply that by the huge number of obese patients undergoing surgery these days, and it’s obvious that this is a real problem.”
