The Impact of “High-Risk” Sports in Knee Replacement Patients

At the recent meeting of the American Academy of Orthopaedic Surgeons, a study was presented where survivorship of total knee replacements in patients who participated in certain “high-risk” sports was compared to those who did not participate in such activities.1

In this study, a group of 1500 patients that received the identical prosthesis were asked if they participated in certain high-risk activities. These are activities which place excessive load on the implant such as basketball, soccer or football. Within this group, 218 were identified as having participated in such “high-risk” sports. These patients were then “matched” against a control group so other factors such as BMI, age and sex could be eliminated.

What the researchers discovered was somewhat contrary to conventional wisdom. At roughly 7.5 years after surgery, the high-risk group had slightly superior function and slightly lower rates of failure (loosening, wear of the implant etc) compared to the control group. As stated in the study, “At a mean follow-up time of 7.5 years after modern condylar TKA in 218 patients no significant differences in implant durability could be demonstrated between those involved in not-recommended sports activities compared to matched controls.” Only time will tell if differences in implant longevity over longer periods will become apparent, so further study is warranted. Nonetheless, as increasingly younger and more active patients elect to have total knee replacement surgery, the limits on total knee replacement design and longevity will be tested and questioned.

References
1 Parratte S, Lynn Dahm DL, Stuart MJ, Pagnano MW, Berry DJ, Does Participation in Not-recommended Sports Impact Total Knee Arthroplasty Durability, AAOS Annual Meeting Podium Presentation, 2010

Mobile Bearing Knee Replacement Offers no Benefits vs. Fixed Bearing

In a previous posting 1, the question was raised as to which is better, fixed or mobile bearing . In the end, the answer was not very clear. But in the view of one implant manufacture, the choice is simple: fixed bearing.

In a recent press release, a major U.S. Orthopedic implant company (Stryker Corporation) has decided not to offer their mobile bearing knee replacement in the U.S. market. Although the company has executed a clinical trial in an effort to gain FDA approval for the device, data gathered during the study has demonstrated no clinical advantages for the mobile bearing knee compared to a comparable fixed bearing design.

The company also cited higher costs and higher revision rates for mobile bearings as further reasons why the mobile bearing design will not be pursued in the U.S. market.

The original press release can be found here:
http://www.prnewswire.com/news-releases/us-ide-study-indicates-mobile-bearing-knees-offer-no-clinical-advantages-over-fixed-bearing-knees-86866577.html

More on Stryker can be found here:
http://www.stryker.com/en-us/products/Orthopaedics/KneeReplacement/index.htm

1 Is One Really Better? Fixed vs. Mobile Bearing Knee replacement

Total Knee Replacement

, which is also known as Total Knee Arthroplasty, is a surgical procedure where:

  • The worn ends of the bones which make up the knee joint are resurfaced with metal and plastic implants
  • The alignment of the bones of the knee is restored so that the weight which passes through the knee is normally distributed.

Further Reading on Total Knee Replacement:

Knee Replacement Surgery Overview

Knee Replacement Complications

Minimally Invasive Knee Replacement

Computer Assisted Knee Replacement