Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are the two of the most common orthopedic procedures performed in the U.S.A. Excellent outcomes have been documented that demonstrates improvement in daily living for millions of patients.
With each passing day, new TKA and THA implants are introduced and claim to be more “anatomic” and longer-lasting, without specific evidence for these claims. The financial incentives for these new generation implants are clear. The orthopedic industry has gone from a six billion dollar market in 1995 to seventeen billion dollars in 2005 to 35 billion dollars in revenue in 2014.1,2 The market is expected to grow to 42 billion in 2019.2 These are combined total revenues from the 5 major implant companies. The average implant cost ranged from $1797 to $12,093 per procedure.1
However, the data supporting the use of these new generation implants is sparse. The Charnley hip (invented in the 1960s) has demonstrated a 10-year and 25-year survivorship data at 95% and 78% respectively.3 The first generation Insall total knee, which was implanted in the 1970s, has a 10-year and 15-year survivorship at 96% and 91% respectively.4
In comparison, newer third generation total knee arthroplasty systems currently have 8-year survivorship data of 97%, demonstrating minimal difference. 5 Mobile-bearing total knee systems were invented in hopes of reducing wear and reducing revision surgery, especially in the young patient. While these implants come at increased costs, short-term data has demonstrated no difference in clinical outcome including revisions for stiffness, implant-related issues, and bearing dislocation are slightly higher in mobile-bearing cohorts.6
New systems in both THA and TKA have been invented in hopes of improving implant survivorship as well as clinical outcomes. Without the availability of convincing data, it becomes hard to justify the increased expense of newer implants. There is a potential that these newer implants have improved clinical outcomes (with regards to patient satisfaction and function), however, outcomes have not been documented. To justify the use of newer and more expensive implants, patient-reported outcomes (PROs) could be used to demonstrated superior efficacy and function for the patient. Regardless of survivorship of the implant or radiographs, a “patient-centric” view should be taken for a procedure that is hoping to improve the quality of life of a patient.
- Gomez, P. F. & Morcuende, J. A. A historical and economic perspective on Sir John Charnley, Chas F. Thackray Limited, and the early arthoplasty industry. Iowa Orthop. J. 25, 30–37 (2005).
- Advanced Orthopedic Technologies, Implants and Regenerative Products. (2014). at <http://www.reportlinker.com/p096659-summary/Advanced-Orthopedic-Technologies-Implants-and-Regenerative-Products.html>
- Berry, D. J., Harmsen, W. S., Cabanela, M. E. & Morrey, B. F. Twenty-five-year survivorship of two thousand consecutive primary Charnley total hip replacements: factors affecting survivorship of acetabular and femoral components. J. Bone Joint Surg. Am. 84-A, 171–177 (2002).
- Scuderi, G. R., Insall, J. N., Windsor, R. E. & Moran, M. C. Survivorship of cemented knee replacements. J. Bone Joint Surg. Br. 71, 798–803 (1989).
- Bozic, K. J. et al. Implant survivorship and complication rates after total knee arthroplasty with a third-generation cemented system: 5 to 8 years followup. Clin. Orthop. 117–124 (2005).
- Aglietti, P., Baldini, A., Buzzi, R., Lup, D. & De Luca, L. Comparison of mobile-bearing and fixed-bearing total knee arthroplasty: a prospective randomized study. J. Arthroplasty 20, 145–153 (2005).