Bucholz Robert W
Department of Orthopaedic Surgery, University of Texas Southwestern Medical School, Dallas 75390-8883, USA.
Clin Orthop Relat Res. 2002 Feb(395):44-52. doi: 10.1097/00003086-200202000-00006.
An estimated 500,000 to 600,000 bone grafting procedures are done annually in the United States. Approximately (1/2) of these surgeries involve spinal arthrodesis whereas 35% to 40% are used for general orthopaedic applications. Synthetic bone graft substitutes currently represent only 10% of the bone graft market, but their share is increasing as experience and confidence in their use are accrued. Despite 15 to 20 years of clinical experience with various synthetic substitutes, there have been few welldesigned, controlled clinical trials of these implants. Synthetic bone graft substitutes consist of hydroxyapatite, tricalcium phosphate, calcium sulfate, or a combination of these minerals. Their fabrication technique, crystallinity, pore dimensions, mechanical properties, and resorption rate vary. All synthetic porous substitutes share numerous advantages over autografts and allografts including their unlimited supply, easy sterilization, and storage. However, the degree to which the substitute provides an osteoconductive structural framework or matrix for new bone ingrowth differs among implants. Disadvantages of ceramic implants include brittle handling properties, variable rates of resorption, poor performance in diaphyseal defects, and potentially adverse effects on normal bone remodeling. These inherent weaknesses have refocused their primary use to bone graft extenders and carriers for pharmaceuticals. The composition, histologic features, indications, and clinical experience of several of the synthetic bone graft substitutes approved for orthopaedic use in the United States are reviewed.
在美国，每年估计进行50万至60万例骨移植手术。其中约一半的手术涉及脊柱融合术，而35%至40%用于一般骨科应用。合成骨移植替代品目前仅占骨移植市场的10%，但随着对其使用经验的积累和信心的增强，其份额正在增加。尽管对各种合成替代品已有15至20年的临床经验，但针对这些植入物的精心设计、对照的临床试验却很少。合成骨移植替代品由羟基磷灰石、磷酸三钙、硫酸钙或这些矿物质的组合组成。它们的制造技术、结晶度、孔隙尺寸、机械性能和吸收率各不相同。所有合成多孔替代品相对于自体骨移植和异体骨移植都具有许多优点，包括供应无限、易于灭菌和储存。然而，不同植入物在为新骨生长提供骨传导结构框架或基质的程度上存在差异。陶瓷植入物的缺点包括处理易碎、吸收率可变、在骨干缺损中性能不佳以及对正常骨重塑可能产生不利影响。这些固有弱点使其主要用途重新聚焦于骨移植扩展剂和药物载体。本文综述了美国批准用于骨科的几种合成骨移植替代品的成分、组织学特征、适应症和临床经验。
