Novak Erik J, Silverstein Marc D, Bozic Kevin J
Department of Orthopaedic Surgery, University of California San Francisco, 500 Parnassus Avenue, MU 320W, San Francisco, CA 94143-0728, USA.
J Bone Joint Surg Am. 2007 Nov;89(11):2389-97. doi: 10.2106/JBJS.F.01109.
Total knee arthroplasty is one of the most clinically successful and cost-effective interventions in medicine. However, implant malalignment, especially in the coronal plane, is a common cause of early failure following total knee arthroplasty. Computer-assisted surgery has been employed during total knee arthroplasty to improve the precision of component alignment. The purpose of the present study was to evaluate the cost-effectiveness of computer-assisted surgery to determine whether the improved alignment achieved with computer navigation provides a sufficient decrease in failure rates and revisions to justify the added cost.
A decision-analysis model was used to estimate the cost-effectiveness of computer-assisted surgery in total knee arthroplasty. Model inputs, including costs, effectiveness, and clinical outcome probabilities, were obtained from a review of the literature. Sensitivity analyses were performed to evaluate the impact of component-alignment precision with use of computer-assisted and mechanical alignment guides, total knee arthroplasty failure rates secondary to malalignment, and costs of computer-assisted surgery systems on the cost-effectiveness of computer navigation in total knee arthroplasty.
Computer-assisted surgery is both more effective and more expensive than mechanical alignment systems. Given an additional cost of $1500 per operation, a 14% improvement in coronal alignment precision (within 3 degrees of neutral mechanical axis), and an elevenfold increase in revision rates at fifteen years with coronal malalignment (54% compared with 4.7%), the incremental cost of using computer-assisted surgery is $45,554 per quality-adjusted life-year gained. Cost-savings is achieved if the added cost of computer-assisted surgery is $629 or less per operation. Variability in published clinical outcomes, however, introduces uncertainty in determining the cost-effectiveness.
Computer-assisted surgery is potentially a cost-effective or cost-saving addition to total knee arthroplasty. However, the cost-effectiveness is sensitive to variability in the costs of computer navigation systems, the accuracy of alignment achieved with computer navigation, and the probability of revision total knee arthroplasty with malalignment.
全膝关节置换术是医学领域临床上最成功且性价比最高的干预措施之一。然而，植入物排列不齐，尤其是在冠状面，是全膝关节置换术后早期失败的常见原因。全膝关节置换术中已采用计算机辅助手术来提高假体排列的精度。本研究的目的是评估计算机辅助手术的成本效益，以确定计算机导航实现的更好排列是否能充分降低失败率和翻修率，从而证明增加的成本是合理的。
采用决策分析模型来估计计算机辅助手术在全膝关节置换术中的成本效益。模型输入，包括成本、有效性和临床结局概率，均来自对文献的综述。进行敏感性分析，以评估使用计算机辅助和机械对准导向装置时假体排列精度、排列不齐导致的全膝关节置换术失败率以及计算机辅助手术系统成本对计算机导航在全膝关节置换术中成本效益的影响。
计算机辅助手术比机械对准系统更有效但也更昂贵。假设每次手术额外成本为1500美元，冠状面排列精度提高14%（在中立机械轴3度范围内），且冠状面排列不齐时15年翻修率增加11倍（54%对比4.7%），那么每获得一个质量调整生命年，使用计算机辅助手术的增量成本为45554美元。如果计算机辅助手术每次手术的额外成本为629美元或更低，则可实现成本节约。然而，已发表的临床结局的变异性在确定成本效益时引入了不确定性。
计算机辅助手术可能是全膝关节置换术中一种具有成本效益或节省成本的补充手段。然而，成本效益对计算机导航系统成本的变异性、计算机导航实现的排列准确性以及排列不齐的全膝关节置换术翻修概率敏感。
