PURPOSE OF THE STUDY: Bone remodeling and osteolysis around total hip prostheses, with its inevitable corollary, prosthesis loosening, remains a difficult problem in orthopedic surgery. Alendronate (bisphosphonate) has proven its efficacy for the treatment of osteoporosis of the lumbar spine and femoral neck. A few in vitro studies have pointed out its inhibiting effect on particle-induced osteolysis. In vivo, one study has demonstrated its usefulness in preventing osteolysis around non-cemented total hip arthroplasties (THA). The purpose of this work was to study the efficacy of this agent for the prevention of changes in peri-prosthetic bone mineral density (BMD) after primary THA. MATERIAL AND METHODS: The study series included 38 patients with degenerative hip disease who underwent THA. The patients were randomized in double-blind fashion to two treatment arms: 10 alendronate and 600 mg calcium per day for 2 years (20 patients) or placebo and 600 mg calcium per day for 2 years (18 patients). Conventional x-rays and x-ray biphotonic absorptiometry (DPX) was performed on day four postop and at 3, 6, 12, and 24 months postop. The periprosthetic zones described by Grüen were used for analysis. RESULTS:DPX demonstrated a significant reduction in BMD in all patients included in the study. The bone loss was the same in both groups during the early postoperative period reaching maximum loss at 3 months. Differences were observed after this time. In the placebo group, bone loss reached a plateau at 6 months then BMD started to increase progressively, reaching 12.7% bone loss at 2 years follow-up (p<0.002). In the alendronate group, there was no plateau, BMD increased continuously starting from three months and reached 6.857% bone loss at 2 years (p<0.003). DISCUSSION: Administration of alendronate led to a significant reduction in peri-prosthetic bone loss at 2 years follow-up. These results are the first to our knowledge demonstrating the beneficial effect in vivo of alendronate on bone behavior around cemented THAs. CONCLUSION: This beneficial effect observed in vivo should be confirmed in further studies including a larger number of patients and longer follow-up. The action of alendronate could facilitate and even retard revision surgery by preserving bone stock.
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PURPOSE OF THE STUDY: Bone remodeling and osteolysis around total hip prostheses, with its inevitable corollary, prosthesis loosening, remains a difficult problem in orthopedic surgery. Alendronate (bisphosphonate) has proven its efficacy for the treatment of osteoporosis of the lumbar spine and femoral neck. A few in vitro studies have pointed out its inhibiting effect on particle-induced osteolysis. In vivo, one study has demonstrated its usefulness in preventing osteolysis around non-cemented total hip arthroplasties (THA). The purpose of this work was to study the efficacy of this agent for the prevention of changes in peri-prosthetic bone mineral density (BMD) after primary THA. MATERIAL AND METHODS: The study series included 38 patients with degenerative hip disease who underwent THA. The patients were randomized in double-blind fashion to two treatment arms: 10 alendronate and 600 mg calcium per day for 2 years (20 patients) or placebo and 600 mg calcium per day for 2 years (18 patients). Conventional x-rays and x-ray biphotonic absorptiometry (DPX) was performed on day four postop and at 3, 6, 12, and 24 months postop. The periprosthetic zones described by Grüen were used for analysis. RESULTS:DPX demonstrated a significant reduction in BMD in all patients included in the study. The bone loss was the same in both groups during the early postoperative period reaching maximum loss at 3 months. Differences were observed after this time. In the placebo group, bone loss reached a plateau at 6 months then BMD started to increase progressively, reaching 12.7% bone loss at 2 years follow-up (p<0.002). In the alendronate group, there was no plateau, BMD increased continuously starting from three months and reached 6.857% bone loss at 2 years (p<0.003). DISCUSSION: Administration of alendronate led to a significant reduction in peri-prosthetic bone loss at 2 years follow-up. These results are the first to our knowledge demonstrating the beneficial effect in vivo of alendronate on bone behavior around cemented THAs. CONCLUSION: This beneficial effect observed in vivo should be confirmed in further studies including a larger number of patients and longer follow-up. The action of alendronate could facilitate and even retard revision surgery by preserving bone stock.
Authors: C Neuerburg; R Schmidmaier; S Schilling; C Kammerlander; W Böcker; W Mutschler; U Stumpf Journal: Unfallchirurg Date: 2015-11 Impact factor: 1.000