TY - JOUR
T1 - Enhancement of periprosthetic bone quality with topical hydroxyapatite-bisphosphonate composite
AU - Suratwala, Sanjeev J.
AU - Cho, Samuel K.
AU - Van Raalte, Jonathan J.
AU - Sang, Hyun Park
AU - Sung, Wook Seo
AU - Chang, Seong Sil
AU - Gardner, Thomas R.
AU - Lee, Francis Young In
N1 - Funding Information:
In support of their research for or preparation of this work, one or more of the authors received, in any one year, outside funding or grants in excess of $10,000 from Stryker, the National Institutes of Health (grant 1R01EB006834) and from the Orthopaedic Research and Education Foundation (OREF). Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. A commercial entity (Stryker) paid or directed in any one year, or agreed to pay or direct, benefits in excess of $10,000 to a research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which one or more of the authors, or a member of his or her immediate family, is affiliated or associated.
PY - 2008/10/1
Y1 - 2008/10/1
N2 - Background: Implant loosening is associated with inflammatory bone loss induced by ultra-high molecular weight polyethylene wear debris. We hypothesized that a hydroxyapatite-bisphosphonate composite improves periprosthetic bone quality and osseous integration of an intramedullary implant even in the presence of ultra-highmolecular weight polyethylene particles in an experimental rat femur model. Methods: A preliminary in vitro study determined the optimal concentration of zoledronate (50 mM) that would maximally decrease osteoclasts without harming osteoblasts. Hydroxyapatite-coated intramedullary nails were implanted bilaterally in the femora of sixteen rats (the control group), and hydroxyapatite-zoledronate-coated nails were implanted bilaterally in the femora of sixteen rats (the experimental group). Ultra-high molecular weight polyethylene particles were introduced into the femoral canal before implantation. Eight rats fromeach group were killed at six weeks, and the remaining rats were killed at six months. Periprosthetic bone mass was analyzed by dual x-ray absorptiometry and microcomputed tomography. Osseous integration was examined by biomechanical testing of pullout strength. Results: Themean bone area (and standard deviation) inthe periprostheticbone regionwas significantly greater (p<0.0001) in the hydroxyapatite-zoledronate group (2.388 ± 0.960mm2) than in the control group (0.933 ± 0.571 mm 2). This difference was larger in the six-week group than in the six-month group (p = 0.03). The average peak pullout force for the treated femora (241.0 ± 95.1 N) was significantly greater (p < 0.0001) than that for the controls (55.6 ± 49.0 N). This difference was similar in the six-week and six-month groups. The energy required for nail pullout was significantly greater (p < 0.0001) for the treated femora (521.6 ± 293.8 N-mm) than for the controls (142.2 ± 152.1 N-mm). This difference in energy to pullout was similar in the six-week and six-month groups. Regression analysis demonstrated a high correlation between periprosthetic bone mass and peak pullout force for both the six-week (r = 0.766, p = 0.0005) and six-month (r = 0.838, p < 0.0001) groups. Conclusions: Surface modification of implants with hydroxyapatite-zoledronate improves periprosthetic bone quality and osseous integration. Clinical Relevance: Hydroxyapatite-based site-specific delivery of bisphosphonates may be one way of reducing ultrahigh molecular weight polyethylene wear particle-induced periprosthetic osteolysis and implant loosening.
AB - Background: Implant loosening is associated with inflammatory bone loss induced by ultra-high molecular weight polyethylene wear debris. We hypothesized that a hydroxyapatite-bisphosphonate composite improves periprosthetic bone quality and osseous integration of an intramedullary implant even in the presence of ultra-highmolecular weight polyethylene particles in an experimental rat femur model. Methods: A preliminary in vitro study determined the optimal concentration of zoledronate (50 mM) that would maximally decrease osteoclasts without harming osteoblasts. Hydroxyapatite-coated intramedullary nails were implanted bilaterally in the femora of sixteen rats (the control group), and hydroxyapatite-zoledronate-coated nails were implanted bilaterally in the femora of sixteen rats (the experimental group). Ultra-high molecular weight polyethylene particles were introduced into the femoral canal before implantation. Eight rats fromeach group were killed at six weeks, and the remaining rats were killed at six months. Periprosthetic bone mass was analyzed by dual x-ray absorptiometry and microcomputed tomography. Osseous integration was examined by biomechanical testing of pullout strength. Results: Themean bone area (and standard deviation) inthe periprostheticbone regionwas significantly greater (p<0.0001) in the hydroxyapatite-zoledronate group (2.388 ± 0.960mm2) than in the control group (0.933 ± 0.571 mm 2). This difference was larger in the six-week group than in the six-month group (p = 0.03). The average peak pullout force for the treated femora (241.0 ± 95.1 N) was significantly greater (p < 0.0001) than that for the controls (55.6 ± 49.0 N). This difference was similar in the six-week and six-month groups. The energy required for nail pullout was significantly greater (p < 0.0001) for the treated femora (521.6 ± 293.8 N-mm) than for the controls (142.2 ± 152.1 N-mm). This difference in energy to pullout was similar in the six-week and six-month groups. Regression analysis demonstrated a high correlation between periprosthetic bone mass and peak pullout force for both the six-week (r = 0.766, p = 0.0005) and six-month (r = 0.838, p < 0.0001) groups. Conclusions: Surface modification of implants with hydroxyapatite-zoledronate improves periprosthetic bone quality and osseous integration. Clinical Relevance: Hydroxyapatite-based site-specific delivery of bisphosphonates may be one way of reducing ultrahigh molecular weight polyethylene wear particle-induced periprosthetic osteolysis and implant loosening.
UR - https://www.scopus.com/pages/publications/53549110250
U2 - 10.2106/JBJS.G.00409
DO - 10.2106/JBJS.G.00409
M3 - Article
C2 - 18829917
AN - SCOPUS:53549110250
SN - 0021-9355
VL - 90
SP - 2189
EP - 2196
JO - Journal of Bone and Joint Surgery
JF - Journal of Bone and Joint Surgery
IS - 10
ER -