February 9, 2012 - Smith & Nephew (NYSE:SNN;LSE:SN), the global medical technology business, today announced the results of a new study for its BIRMINGHAM HIP◊ Resurfacing (BHR) System. The study, carried out at the request of the FDA, followed the progress of the first 400 BHR patients in the United Kingdom and found that after 10 years, 99% were either satisfied or extremely satisfied with their BHR procedure.
“These results further exemplify why the BHR Hip is unlike any other metal-on-metal implant,” says John Soto, Senior Vice President for Smith & Nephew's Global Hip Franchise. “Not only does the BHR Hip offer all the advantages of hip resurfacing, including bone-conservation, greater range of motion and decreased risk of dislocation, but it does so while maintaining implant survivorship rates that are on par with, or in some patient populations even better than, traditional total hip replacement which has long been considered the most successful orthopaedic surgical procedure for relieving chronic pain.”
In addition to patient satisfaction, the 10-year BHR data showed:
- The Oswestry Modified Harris Hip Score (OMHHS) averaged 92.5 points - demonstrating excellent long-term clinical implant function. 1
- The implant survival rate according to the Kaplan-Meier analysis was 95.9% - well exceeding the 10-year survivorship threshold of 90% for implants as established by the National Institute for Health and Clinical Science (NICE) 2
- A radiographic success rate of 99.7% was observed by independent radiographic review.
Recently, several metal-on-metal hip implants have been taken off the market by other device companies due to higher than expected failure rates and increasing patient safety concerns. The latest results show that the BHR Hip stands apart from these and many other metal-on-metal resurfacing devices. Key features of the BHR Hip that contribute to this success include its distinctive metallurgy and its sophisticated design geometry.
The BHR Hip has a distinctive metallurgy heritage which goes back more than 30 years and includes first-generation metal-on-metal materials. In particular, the BHR Hip is produced using the “As Cast” process which maintains the quantity and quality of carbides in the metal and thereby creates a metal with high wear resistance.
Additionally, the BHR Hip's design geometry replicates the natural hip's ability to pull the body's own joint fluids into the space between the ball and socket.
Much like the lubricating barrier in a healthy hip, BHR's geometry creates a natural fluid layer between the femoral head and the cup that the two metal surfaces glide across during physical activity. Without this lubrication, higher metal wear occurs and the likelihood of premature failure increases.
“The fact is that the BHR Hip is not like other metal-on-metal hip implants,” adds Soto. “It really is in a class all its own - it's safe and effective, and is the best choice for the right patient.”
The 10-year study sample, carried out at the request of the FDA, was comprised of patients implanted by the primary investigator and BHR design surgeon Derek McMinn, MD FRCS of The McMinn Centre in Birmingham, England. The study included 258 males and 142 females who were implanted either unilaterally or bilaterally and had an average age of 53.2 years (range: 23-84 years).
1Harris Hip Score is a tool for the evaluation of how a patient is doing after their hip is replaced. Based on a total of 100 points possible, each question (pain, function, functional activity and physical exam) is awarded a certain number of points based on how it is answered. The score is reported as 90-100 for excellent results, 80-89 for good results, 70-79 for fair results, 60-69 for poor. Any score below 60 is considered a failed result
2National Institute for Clinical Excellence (NICE): Guidance for the Selection of Prostheses for Total Hip Replacement, 2000