Paper #IV-1

DO BISPHOSPHONATES REDUCE PERI-PROSTHETIC BONE LOSS AFTER TOTAL JOINT ARTHROPLASTY? A META-ANALYSIS

Sohail S. Bajammal, MB ChB

Hamilton, ON

Co-Authors

Mohit Bhandari, MD, MSc, 

Gordon H. Guyatt, MD, MSc,

Lauren Griffith, MSc,

Jason W. Busse, DC, MSc,

Holger Schunemann, MD, PhD

Thomas A. Einhorn, MD

Introduction

Periprosthetic bone loss is responsible for the majority of cases of implant failure after total joint arthroplasty. Our aim was to determine the effect of bisphosphonates on periprosthetic bone mineral density (BMD, g/cm2) after total joint arthroplasty.

Method

We conducted computerized searches using OVID databases to November 2003 for randomized controlled trials evaluating the effects of bisphosphonates on periprosthetic BMD in patients undergoing primary total joint arthroplasty. Computerized searches of the archives of AAOS Annual Meetings 1989-2003 were also conducted. Additional strategies to identify articles included a hand search of the bibliographies of relevant articles and direct contact with the authors.

Results

Of 386 citations initially identified, 9 citations met our eligibility criteria. The total number of randomized controlled trials was 6 (5 published and 1 abstract). The pooled sample size was 290 patients. Less periprosthetic bone loss occurred in the intervention group compared to the control group at the following follow-up intervals: 3 months (n=128, Weighted Mean Difference (WMD): 3.3%, 95% Confidence Interval (CI): 1.9-4.7, p<0.01); 6 months (n=224, WMD: 4.5%, CI: 1.6-7.4, p<0.001); and 12 months (n=173, WMD: 4.2%, CI: 1.5-6.9, p=0.03). Tests of heterogeneity revealed greater maintenance of BMD in cemented arthroplasty than in uncemented arthroplasty (WMD: 7.5%, CI: 4.3-10.7 versus WMD: 2.1%, CI: 0.61-3.6, respectively, p<0.001) at 12 months follow up.

Conclusion

Bisphosphonates have a beneficial effect on maintaining periprosthetic bone stock compared to control after total joint arthroplasty. Whether this increase in BMD results in improved fixation and longevity of prosthetic components remains unanswered.