Tuesday, December 13, 2011

Bisphosphonates Increase Joint Replacement Survival

BACKGROUND: In the United Kingdom in 2009, there were 71,527 total primary arthroplasties of the knee and 64,772 of the hip, which is an overall rate of just over 2 knee or hip replacement surgeries per 1000 population. Revision surgery isn't nearly as effective as primary joint replacement surgery of the hip or knee, and therefore it is important to work to improve the success rates of primary surgery. Bisphosphonates are pharmaceuticals commonly used for osteoporosis, and are theorized to be helpful in the post-op management after hip or knee replacement surgery (arthroplasties). The antiresorptive properties on osteoclast activity that bisphosphonates have potentially could increase bone strength and healing after joint replacement surgery.

METHODS: A study looking at the use of bisphosphonate usage in people in the U.K. undergoing knee or hip replacement therapy was recently published in the British Medical Journal. The primary outcome looked at was implant survival time. They identified over 40,000 people with primary total arthroplasty of the hip or knee and tracked the clinical outcomes.

RESULTS: After 5 years, just over 1% of the patients required revision surgery. Patients taking bisphosphonates had about half the rate of revision surgery. To prevent one revision surgery, the researchers estimated that just over 100 patients would have to take bisphosphonates to avoid one revision at five years. The time to revision surgery was found to be about twice as long in patients taking bisphosphonates.

CONCLUSIONS: bisphosphonate appears to be helpful after joint replacement surgery, nearly doubling the time to revision surgery when repeat surgery is necessary. Further studies are required for confirmation before widespread use is recommended.

COMMENT: A primary question raised by this research is whether or not it is worth it for 100 people to take a pharmaceutical for 5 years in order to avoid one revision surgery. The side-effects from 500 person-years of taking bisphosphonates was not fully addressed in this article. I suspect that ultimately bisphosphonate therapy will prove beneficial as they also appear to be useful in the treatment of osteoporosis, which affects many people who require joint replacement surgery.


Association between bisphosphonate use and implant survival after primary total arthroplasty of the knee or hip: population based retrospective cohort study. Prieto-Alhambra D, Javaid MK, Judge A, Murray D, Carr A, Cooper C, Arden NK. BMJ. 2011 Dec 6;343:d7222. doi: 10.1136/bmj.d7222.

Treatment of Osteoarthritic Change in the Hip: Joint Preservation or Joint Replacement? Sofue M, Endo N (Eds). Springer; 1 edition (January 12, 2007).

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