Session II - Basic Science


Thurs., 10/14/10 Basic Science, Paper #36, 4:34 pm OTA-2010

Unfocused Extracorporeal Shock Waves Induce Anabolic Responses in Osteoporotic Bone

Olav P. van der Jagt, MD1; J.H. Waarsing, PhD1; Nicole Kops, BS1; Wolfgang Schaden, MD2;
Victor A. De Ridder, MD3; Jan Verhaar, MD1; Harrie Weinans, PhD1;
1Erasmus MC, Rotterdam, The Netherlands;
2Traumacenter Meidling, Vienna, Austria;
3Sint Franciscus Hospital, Rotterdam, The Netherlands

Purpose: Current therapy for osteoporosis aims to reduce further bone loss using bisphosphonates. It was previously shown that nonosteoporotic rats treated with extracorporeal shock waves (ESW) had higher cortical and cancellous bone volumes and improved mechanical properties. In the current study, we examined the effects of unfocused ESW in osteoporotic rats. To explore the clinical value of ESW for patients who do or do not receive antiresorptives, rats were treated with or without a bisphosphonate.

Methods: Female Wistar rats received an ovariectomy. Two weeks after ovariectomy, one group received saline (n = 9) and another group received alendronate (n = 9). At 0 weeks, 1000 ESW were applied to one hind leg; the other was not treated and served as control. At 0, 2, 4, and 10 weeks after ESW, in vivo micro CT scans were made. Cancellous and cortical bone changes were analyzed. Furthermore, mechanical testing and histological analysis were performed. Paired t tests were used for statistical analyses.

Results: In saline-treated rats, ESW resulted in higher cancellous bone volume in cancellous bone at 2 weeks (P = 0.003), but not at 4 and 10 weeks (Fig. 1). ESW resulted in higher cortical volume at 2, 4, and 10 weeks with 3.2%, 5.5%, and 5.5%, respectively, more than the untreated control side (Fig. 2). In rats receiving alendronate, ESW resulted in higher cancellous bone volume at 2, 4, and 10 weeks (p = 0.002, p = 0.001, and p = 0.001, respectively) (Fig. 1). ESW resulted in higher cortical volume at 2, 4, and 10 weeks with 7%, 10.5%, and 12%, respectively, more than the untreated control side (Fig. 2). In both groups, ESW-treated legs showed significant higher maximal force at failure. Large areas of direct bone formation were observed at the cortex and around de novo bone niches in the marrow of ESW-treated legs. Intramedullary soft-tissue damage, but no periosteal or bone micro damage, was observed.

Fig. 1 Cancellous bone volume.

Fig. 2 Cortical bone volume

Conclusions: Unfocused ESW drastically increase cancellous and cortical bone volume and improve biomechanical properties. When shock-wave treatment is combined with an antiresorptive treatment, these beneficial effects are enhanced and retained. This study shows promising results for the use of ESW in the treatment of osteoporosis, but more research is needed to further investigate the biological responses and the safety for human therapy.


Alphabetical Disclosure Listing (292K PDF)

• The FDA has not cleared this drug and/or medical device for the use described in this presentation   (i.e., the drug or medical device is being discussed for an “off label” use).  ◆FDA information not available at time of printing. Δ OTA Grant.