Hospital For Special Surgery Awarded Patent For New Glenoid Component For Shoulder Prosthesis Design

The U.S. Patent Office has awarded a patent to the Hospital for Special Surgery for a new type of shoulder joint prosthesis design for the glenoid component aimed at improving stability while maintaining fixation. The new design, the subject of US Patent 6,875,234, issued on April 5, 2005, is designed to reduce the risk of future dislocation or artificial shoulder component loosening, two common problems with existing products. However, clinical research still needs to be conducted to show the complete benefits of this new patented design.

"Approximately 20,000 total shoulder replacement surgeries are performed annually in the U.S. with the volume growing at 5% a year due to the increasingly active lives led by aging members of America's post World War II baby boom generation," said Joseph Lipman, managing director of HSS Ventures, an affiliate of the Hospital for Special Surgery focused on product development, technology licensing and venture investing in orthopedics and rheumatology. Mr. Lipman is the director of joint development at Hospital for Special Surgery.

Shoulder joint replacements are composed of two parts, humeral and glenoid, which function in a ball-in-socket manner like other joints in the body. Finding the right design to optimize movement and minimize wear over time has been a challenge in the past. Prior designs sometimes have been associated with instability and component loosening over time, the leading complication of total shoulder arthroplasty (replacement), according to a Journal of Bone and Joint Surgery paper, entitled, "Complications of Total Shoulder Replacement Arthroplasty," written by Michael Wirth and Charles Rockwood in 1996.

The HSS-patented design involves the glenoid component and features two radii of curvature, decreasing the likelihood of dislocation, a problem seen in current designs on the market. The design can be used with the various materials used in replacement shoulders, including metal or polyethylene.