Affiliations: [a] Graduate School of Biomedical Engineering, University of New South Wales, Sydney, Australia | [b] Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA | [c] Department of Mechanical & Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA | [d] Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, OH, USA
Correspondence:
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Corresponding author: Melissa L. Knothe Tate, Paul Trainor Chair of Biomedical Engineering, Graduate School of Biomedical Engineering, University of New South Wales, 509 Samuels Building, 2052 Sydney NSW, Australia. Tel.: +612 93853924; Fax: +612 96632108; E-mail: [email protected].
Abstract: Background:Normal “wear and tear” of bones during weight bearing activity creates microdamage that triggers bone to heal itself. Objective:A controlled laboratory study was carried out to determine the effect of lithotripsy on bone apposition and resorption in osteopenic, hind-limb suspended, aged rats compared to age-matched controls allowed normal weight bearing (cage) activity. Methods:First, we tested the feasibility of using a clinical lithotripsy device, designed for treatment of kidney stones, to create microdamage in bone. In a second step, we tested the hypothesis that microdamage induced through lithotripsy treatment increases bone apposition in aged rats. In a third step, we exposed osteopenic, aged rats to lithotripsy to evaluate the effectiveness of lithotripsy in counteracting bone loss due to simulated disuse. Results:Both in aged, weight bearing as well as aged, osteopenic rats, we showed that lithotripsy effectively increases the area of bone apposition along the periosteal and endosteal surfaces. While new bone apposition concentrates in areas of lithotripsy treatment in aged bone of weight bearing rats, new bone apposition extends beyond the immediate treatment site (to the contralateral limb) of osteopenic animals. Furthermore, bone resorption decreases in osteopenic (hindlimb suspended) and aged rat femora treated with lithotripsy, compared to baseline and hindlimb suspended controls. This decrease in resorption is not observed in the contralateral limb of osteopenic animals. Conclusion:Taken as a whole, lithotripsy may offer a viable treatment method for disuse osteopenia or osteoporosis, particularly for aging individuals or for those who are limited in their weight bearing activities.
Keywords: Aging, bone, osteopenia, lithotripsy, translational research
