Department of Orthopaedic Surgery, Yokohama City University School of Medicine, Yokohama, Japan.
J Bone Joint Surg Am. 2011 Jul 6;93(13):1203-9. doi: 10.2106/JBJS.I.01714.
Several previous studies have demonstrated that bone mineral density loss around femoral implants is common, particularly in the proximal part of the femur, soon after total hip arthroplasty. The purpose of the present study was to compare the effects of alendronate and alfacalcidol on bone mineral density loss around the femoral implant and in the lumbar spine after total hip arthroplasty.
The present study included sixty patients with osteoarthritis of the hip who had undergone a primary cementless total hip arthroplasty. We assigned these individuals to treatment with alendronate (n = 20), alfacalcidol (n = 18), or no medication (n = 22). Periprosthetic and lumbar spine bone mineral density was measured one week after surgery, and biochemical markers (bone-specific alkaline phosphatase and serum N-terminal telopeptides of type-1 collagen) were measured before surgery as a reference baseline. Subsequent measurements were performed at twelve, twenty-four, and forty-eight weeks after surgery. The periprosthetic measurement area in the femur was defined as Regions 1 to 7, which are consecutively located around the implant from the greater trochanter to the lesser trochanter and calcar.
Bone mineral density in the alendronate group was maintained in all regions. In the alfacalcidol and no-medication groups, bone mineral density in Region 7 was lower than in Regions 3 to 6 throughout the study period (p < 0.0001 as a result of repeated measures analysis of variance). Bone mineral density in the lumbar spine in the alendronate and alfacalcidol groups was higher than in the no-medication group at forty-eight weeks. The serum level of N-terminal telopeptides of type-1 collagen in the alendronate group was lower than that in the no-medication group throughout the study period (p = 0.003, 0.02 and 0.005).
Alendronate prevented bone mineral density loss around femoral implants, particularly in Region 7 (calcar), but alfacalcidol did not show any effects in any regions. However, bone mineral density losses in the lumbar spine were effectively prevented by either alendronate or alfacalcidol.
多项先前的研究表明，全髋关节置换术后股骨假体周围的骨密度丢失很常见，尤其是在股骨近端。本研究的目的是比较阿仑膦酸钠和阿尔法骨化醇对全髋关节置换术后股骨假体周围和腰椎骨密度丢失的影响。
本研究纳入了 60 例接受初次非骨水泥全髋关节置换术的髋关节骨关节炎患者。我们将这些患者分为阿仑膦酸钠组（n=20）、阿尔法骨化醇组（n=18）和无药物组（n=22）。术后一周测量假体周围和腰椎骨密度，术前测量生化标志物（骨碱性磷酸酶和血清 1 型胶原氨基端肽）作为参考基线。术后 12、24 和 48 周进行后续测量。股骨假体周围测量区域定义为 1 至 7 区，它们依次位于假体周围，从大转子到小转子和股骨颈。
阿仑膦酸钠组的骨密度在所有区域均得到维持。在阿尔法骨化醇组和无药物组中，整个研究期间 7 区的骨密度均低于 3 至 6 区（重复测量方差分析结果为 p<0.0001）。48 周时，阿仑膦酸钠组和阿尔法骨化醇组的腰椎骨密度均高于无药物组。阿仑膦酸钠组的血清 1 型胶原氨基端肽水平在整个研究期间均低于无药物组（p=0.003、0.02 和 0.005）。
阿仑膦酸钠预防了股骨假体周围的骨密度丢失，特别是在 7 区（股骨颈），但阿尔法骨化醇在任何区域均未显示出任何效果。然而，阿仑膦酸钠和阿尔法骨化醇均有效地预防了腰椎骨密度丢失。
