Background 

The use of the direct anterior approach, a muscle-sparing technique for THA, has increased over the years; however, this approach is associated with longer procedure times and a more expensive direct cost. Furthermore, studies have shown a higher revision rate in the early stages of the learning curve. Whether the clinical advantages of the direct anterior compared with the posterior approach—such as less soft tissue damage, decreased short-term postoperative pain, a lower dislocation rate, decreased length of stay in the hospital, and higher likelihood of being discharged home—outweigh the higher cost is still debatable. Determining the cost-effectiveness of the approach may inform its utility and justify its use at various stages of the learning curve.

Questions/purposes 

We used a Markov modeling approach to ask: (1) Is the direct anterior approach more likely to be a cost-effective approach than the posterior approach over the long-term for more experienced or higher volume hip surgeons? (2) How many procedures does a surgeon need to perform for the direct anterior approach to be a cost-effective choice?

Methods 

A Markov model was created with three health states (well-functioning THA, revision THA, and death) to compare the cost-effectiveness of the direct anterior approach with that of the posterior approach in five scenarios: surgeons who performed one to 15, 16 to 30, 31 to 50, 51 to 100, and more than 100 direct anterior THAs during a 6-year span. Procedure costs (not charges), dislocation costs, and fracture costs were derived from published reports, and model was run using two different cost differentials between the direct anterior and posterior approaches (USD 219 and USD 1800, respectively). The lower cost was calculated as the total cost differential minus pharmaceutical and implant costs to account for differences in implant use and physician preference regarding postoperative pain management. The USD 1800 cost differential incorporated pharmaceutical and implant costs. Probabilities were derived from systematic review of the evidence as well as from the Australian Orthopaedic Association National Joint Replacement Registry. Utilities were estimated from best available literature and disutilities associated with dislocation and fracture were incorporated into the model. Quality of life was expressed in quality-adjusted life years (QALYs), which are calculated by multiplying the utility of a health state (ranging from 0 to 1) by the duration of time in that health state. The primary outcome measure was the incremental cost-effectiveness ratio, or the change in costs divided by the change in QALYs when the direct anterior approach was used for THA. USD 100,000 per quality-adjusted life years was used as a threshold for willingness to pay. One-way and probabilistic sensitivity analyses were performed for the scenario in which the direct anterior approach is cost-effective to further account for uncertainty in model inputs.

Results 

At a cost differential of USD 219 (95% CI 175 to 263), the direct anterior approach was associated with lower cost and higher effectiveness compared with the posterior approach for surgeons with an experience level of more than 100 operations during a 6-year span. At a cost differential of USD 1800 (95% CI 1440 to 2160), the direct anterior approach remained a cost-effective strategy for surgeons who performed more than 100 operations. At both cost differentials, the direct anterior approach was not cost-effective for surgeons who performed fewer than 100 operations. One-way sensitivity analyses revealed the model to be the most sensitive to fluctuations in the utility of revision THA, probability of revision after the posterior approach THA, probability of dislocation after the posterior approach THA, fluctuations in the probability of dislocation after direct anterior THA, cost of direct anterior THA, and probability of intraoperative fracture with the direct anterior approach. At the cost differential of USD 219 and for surgeons with a surgical experience level of more than 100 direct anterior operations, the direct anterior approach was still the cost-effective strategy for the entire range of values.

Conclusion 

For high-volume hip surgeons, defined here as surgeons who perform more than 100 procedures during a 6-year span, the direct anterior approach may be a cost-effective strategy within the limitations imposed by our analysis. For lower volume hip surgeons, performing a more familiar approach appears to be more cost-effective.

中文翻译：

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直接前路入路全髋关节置换术是否具有成本效益？马尔可夫分析

背景 

直接前路入路（一种保留肌肉的 THA 技术）的使用多年来有所增加。然而，这种方法的手术时间较长，直接成本也较高。此外，研究表明在学习曲线的早期阶段复习率较高。与后路相比，直接前路入路的临床优势（例如软组织损伤更少、术后短期疼痛减轻、脱位率更低、住院时间缩短以及出院回家的可能性更高）是否胜过较高的成本仍然值得商榷。确定该方法的成本效益可以告知其效用并证明其在学习曲线的各个阶段的使用的合理性。

问题/目的 

我们使用马尔可夫建模方法来询问：（1）对于经验丰富或业务量较大的髋关节外科医生来说，从长远来看，直接前路入路是​​否比后路入路更有成本效益？(2) 外科医生需要进行多少次手术才能使直接前路入路成为一种经济有效的选择？

方法 

创建了包含三种健康状态（功能良好的 THA、翻修 THA 和死亡）的马尔可夫模型，以比较五种情况下直接前路入路与后路入路的成本效益：执行 1 至 15、16 次手术的外科医生6 年期间，进行了 30 次、31 次至 50 次、51 次至 100 次以及超过 100 次直接前路 THA。手术成本（不是收费）、脱位成本和骨折成本来自已发表的报告，模型使用直接前路和后路入路之间的两种不同成本差异（分别为 219 美元和 1800 美元）运行。较低的成本计算为总成本差减去药物和植入成本，以考虑植入物使用和医生对术后疼痛管理的偏好的差异。1800 美元的成本差异包括药物和植入成本。概率来自对证据的系统审查以及澳大利亚骨科协会国家关节置换登记处。效用是根据最佳可用文献估计的，与脱位和骨折相关的负效用已纳入模型中。生活质量以质量调整生命年 (QALY) 表示，其计算方法是将健康状态的效用（范围从 0 到 1）乘以该健康状态的持续时间。主要结果指标是增量成本效益比，即采用直接前路入路进行 THA 时，成本变化除以 QALY 变化。每个质量调整生命年 100,000 美元被用作支付意愿的门槛。针对直接前向方法具有成本效益的场景进行了单向和概率敏感性分析，以进一步解释模型输入的不确定性。

结果 

成本差异为 219 美元（95% CI 175 至 263），对于在 6 年期间拥有超过 100 例手术经验的外科医生来说，与后路入路相比，直接前路入路具有更低的成本和更高的有效性。成本差异为 1800 美元（95% CI 1440 至 2160），对于进行超过 100 例手术的外科医生来说，直接前路仍然是一种具有成本效益的策略。在这两种成本差异下，对于进行少于 100 例手术的外科医生来说，直接前路入路并不具有成本效益。单向敏感性分析显示，该模型对翻修 THA 效用、后路 THA 后翻修概率、后路 THA 后脱位概率、直接前路 THA 后脱位概率的波动最为敏感。 、直接前路 THA 的费用以及直接前路手术中发生骨折的概率。成本差异为 219 美元，对于手术经验水平超过 100 例直接前路手术的外科医生来说，直接前路入路仍然是整个价值范围内具有成本效益的策略。

结论 

对于高手术量髋关节外科医生（此处定义为在 6 年时间内执行 100 多次手术的外科医生）来说，在我们分析所施加的限制内，直接前路入路可能是一种具有成本效益的策略。对于手术量较小的髋关节外科医生来说，采用更熟悉的方法似乎更具成本效益。