Hip and knee arthroplasty data for 80,000 procedures

The American Joint Replacement Registry (AJRR), a multistakeholder, not-for-profit organization that optimizes patient outcomes through collection of data on all primary and revision hip and knee replacement procedures in the United States, released its 2013 Annual Report on Hip and Knee Arthroplasty Data at the 2014 American Association of Hip and Knee Surgeons (AAHKS) Annual Meeting. This annual report is the first released by AJRR.

“We are pleased to be publishing our first comprehensive report characterizing 80,227 procedures,” said William J. Maloney, MD, chair of the AJRR board of directors. “This report covers the collection and analysis of data related to hip and knee replacement procedures that have taken place from when we began collecting data up until December 2013.”

As the only national joint replacement registry in the United States, AJRR collects data from nearly every state and a variety of participating institutions including community hospitals, academic medical centers, and large health systems. The report contains procedural data, component metrics, analysis, and AJRR accomplishments.

Reporting results
Of the total 80,277 procedures in the database, more than half (43,823) were submitted during 2013. These included more than 27,000 knee procedures and more than 16,000 hip procedures. More than 2,800 revision procedures were also reported (1,510 hip revision procedures and 1,367 knee revision procedures).

The mean age of patients whose procedures were reported in 2013 was 67.1 years. Patients who received hip procedures had a mean age slightly older than those who received knee procedures (67.6 years vs 66.7 years). According to registry data, more females than males received total joint replacements (59.6 percent vs. 40.4 percent).

Nearly two thirds of the reported procedures were total knee arthroplasties (TKA) (62 percent). Females received 61.8 percent of total knee procedures and 56 percent of total hip procedures reported.

Osteoarthritis was the most common reason for total hip arthroplasty (THA), accounting for 81.3 percent of all reported procedures. The second most common reason for THA was fracture of the neck of the femur, accounting for 11.7 percent of all reported procedures. Hip resurfacing procedures accounted for less than 1 percent of all hip procedures reported.

Osteoarthritis was also the most common reason for TKA, cited in 97.5 percent of reported procedures. More than 95 percent of reported knee procedures were TKAs.

For both THA and TKA, infection was the leading cause of early revision, accounting for 37.8 percent of all hip revisions and 45.7 percent of all knee revisions reported.

Component metrics
Nearly half (49.6 percent) of all THAs reported were cemented procedures. Based on a sample of approximately 2,000 hip procedures reported to the AJRR in 2013, most THAs used metal femoral heads with polyethylene liners (71.9 percent), followed by ceramic heads and polyethylene liners (27.9 percent). The most commonly used femoral head size was 36 mm in diameter.

With respect to TKAs, posterior-stabilized implants predominated, accounting for 59 percent of components reported. Cruciate-retaining designs were reported in 40 percent of cases. The most commonly used tibial bearing material was highly cross-linked polyethylene, despite the lack of longer term data to document improved performance. Three out of four reported TKAs had a highly cross-linked polyethylene component; the remainder were conventional polyethylene.

Looking to the future
The report also included preliminary 2014 accomplishments, including the AJRR’s selection by the Centers for Medicare & Medicaid Services as a qualified clinical data registry, a new reporting mechanism for the Physician Quality Reporting System. The component reference database information now includes more than 35,000 individual orthopaedic implants, augments, hardware, biologics, and cement.

Continued support and active participation from hospitals and surgeons will enable AJRR to remain successful. “We are thankful to the hospitals and surgeons who recognize the importance of a registry by making their surgical data available to AJRR,” said Dr. Maloney. “We will continue our diligence in building a significant national hip and knee arthroplasty registry.”