Get Hip: An Introduction to Total Hip Replacement Surgery and Hip Implant Designs

Over the past 40 years, total hip replacement (THR) surgery—also known as total hip arthroplasty—has become commonplace in the United States and throughout the world. Although no surgery is without risk, the utility of THR to relieve pain and restore function among patients with damaged or degenerated hips and chronic pain is well accepted. There is a growing demand for the procedure, and this, along with rising costs and recent concerns about one form of hip implant design (the “metal-on-metal” variety), makes hip replacement an important technology to follow.

In 2009 alone, approximately 285,000 primary THR procedures were performed in the United States (HCUPnet “2009 Outcomes”), and the number keeps rising each year. The effects of an aging population seeking to retain an active lifestyle, the rise in obesity, and the increased application of THR to younger patients (e.g., individuals in their early 60s, as well as those in their 50s and sometimes younger) all contribute to the increasing demand, and growth over the next decades is expected to be substantial: By 2030, the number of primary THR procedures is projected to exceed 570,000 per year. Add to that the corresponding increases in revision surgeries, in which the hip prosthesis is replaced (most implants will last 20 years or more, but some require earlier replacement), and the effect on the healthcare system will be significant. Using these projections, researchers estimate that the Medicare bill for hip and knee replacements combined could approach $50 billion by 2030 (Kurtz et al. 2007, Wilson et al. 2008).

The financial impact of THR on individual hospitals and healthcare systems is likewise significant. One particular concern is that the cost of implants has greatly outpaced the rates of reimbursement. From 1991 to 2008, Medicare reimbursements for total joint replacements, including hips, rose only 27%, while the average selling price for hip implants rose 132% during a 10-year span within that period, 1996 to 2006 (Wilson et al. 2008). In some cases, the cost of the implant alone can exceed half of the expected reimbursement. Thus, healthcare facilities must manage this technology wisely.

This article serves as an introduction to help educate members of a facility’s value analysis committee about developments with the technology, and thereby to help inform purchasing decisions. Note that in some instances, complex clinical and technical concepts have been simplified to help provide readers with a basic understanding of the issues without overcomplicating the presentation.

The hip joint is a ball-and-socket joint formed by the spherical head of the femur, or thigh bone, fitting into the cup-shaped cavity of the acetabulum, or socket of the hip bone. Damage to the hip joint can develop over time—through disorders such as arthritis—or as the result of injury. When a severely damaged or diseased joint cannot be...