Researchers Publish Study on Shoulder Replacement Materials

Woman's shoulders in sports outfit

A study by Shannon R. Carpenter, Ivan Urits, and Anand M. Murthi, MD, Department of Orthopaedic Surgery, MedStar Union Memorial Hospital, titled “Porous metals and alternate bearing surfaces in shoulder arthroplasty,” was published in Current Reviews in Musculoskeletal Medicine. In this study, the authors examined the long-term effects of innovative materials used in shoulder replacements.

As a method for relieving joint pain, shoulder replacements are less common than knee or hip replacements. Approximately 53,000 people undergo shoulder arthroplasty each year in the United States to relieve joint pain caused by various types of arthritis, fractures, or rotator cuff tears.

Of the complications suffered by patients who undergo shoulder arthroplasty, 24% are caused by glenoid loosening, which may be caused by the implant designs. This study focused on innovative materials used in the creation of new prostheses. Currently, prostheses are primarily made of a combination of metals and polyethylene (plastic) components. The researchers found that the prosthesis design needs to be conducive to growth to increase the body’s acceptance of the materials and thus increase longevity in the patient.

The team determined that using porous materials, such as porous tantalum or titanium, may increase the longevity of the prosthesis in patients. One effect of this new technology is the allowance for possible biological ingrowth into the porous material. These materials may provide increased duration of fixation compared with previous implant designs. The study examined the use of two types of porous materials, but because limited literature is available on the options, more study is required before either option can be endorsed.

Studies have shown that in both knee and hip replacements, modifications to the materials used in the creation of the prosthesis can extend the life of the prosthesis. The researchers recognize that other elements are in play in each case, and that more research is needed to determine the best combination of materials for optimal outcomes and longevity of the prosthesis. Increases in the life of the prosthesis affect patient outcomes, as a higher-quality or modified prosthesis will work better with the body and decrease the need for future surgery to repair or replace the joint.

Current Reviews in Musculoskeletal Medicine, 2016. DOI: 10.1007/s12178-016-9319-x