Bischel Oliver E, Suda Arnold J, Böhm Paul M, Bormann Therese, Jäger Sebastian, Seeger Jörn B
Berufsgenossenschaftliche Unfallklinik Ludwigshafen, Ludwig-Guttmann-Str. 13, 67071 Ludwigshafen, Germany.
AUVA-Unfallkrankenhaus Salzburg, Dr.-Franz-Rehrl-Platz 5, 5010 Salzburg, Austria.
Bioengineering (Basel). 2023 Mar 8;10(3):341. doi: 10.3390/bioengineering10030341.
Modularity in revision THA (RTHA) has become accepted during the last three decades. Nevertheless, specific risks of modularity of current revision devices such as breakage of taper junctions occur during follow-up. Data reporting failure rates are predominantly given by the manufacturers but independent data acquisition is missing so far.
QUESTIONS/PURPOSES: 1. What time-related risk of breakage of taper junction between neck and body of an established modular revision device can be expected in a consecutive single institutional series and a mid-term follow-up? 2. Are there specific factors influencing breakage in this cohort?
A retrospective analysis was performed of a consecutive series of 89 cases after femoral revision using a tapered modular revision stem. Mean follow-up period was 7.1 (range: 3.0-13.7) years. Breakage of stem as failure criteria of the implant was investigated with a Kaplan-Meier analysis.
Breakage of taper junctions occurred in four patients during follow-up showing a time-depending implant survival of 94.2 (95% CI: 88.6-100%) after 13.7 years. Implant survival of stems with lateralized necks of 87.4 (95% CI: 75.6-100%) after 13.7 years was significantly lower compared to the standard offset variant with 100% after 13.5 years (log rank test = 0.0283). Chi square test also revealed a significantly higher risk of breakage of lateralized necks compared to standard offset pieces ( = 0.0141). Three of four patients were obese with a mean BMI of 37.9 kg/m. Grade of obesity (grade 1 or higher) had significant influence on risk of breakage. Survival of the implant was significantly lower in obese patients with at least grade 1 obesity compared to patients with a BMI < 30 kg/m (82.9 (95% CI: 64.9-100%) after 11.6 years vs. 98.4 (95% CI: 95.3-100%) after 13.7 years; log-rank = 0.0327).
Cumulative risk for failure of taper junctions was high in this consecutive single institutional cohort and may further increase during follow-up. As independent data acquisition in registries is missing, failure rate may be higher than reported data of the manufacturers. The use of lateralized offset necks in obese patients of at least grade 1 obesity showed a significantly higher risk of breakage. The use of monobloc revision devices may be an option, but randomized control trials are currently missing to establish standardized treatment protocols considering individual risks for both monobloc and/or modular implants.
在过去三十年中，翻修全髋关节置换术（RTHA）中的模块化已被广泛接受。然而，目前翻修器械的模块化存在特定风险，如在随访期间锥度连接部位会出现断裂。报道的故障率主要由制造商提供，但目前仍缺乏独立的数据采集。
问题/目的：1. 在一个连续的单机构系列研究和中期随访中，对于一种成熟的模块化翻修器械，其颈部与主体之间的锥度连接部位预计会有怎样的与时间相关的断裂风险？2. 在该队列中是否存在影响断裂的特定因素？
对89例使用锥形模块化翻修柄进行股骨翻修的连续病例进行回顾性分析。平均随访期为7.1年（范围：3.0 - 13.7年）。采用Kaplan - Meier分析，以柄的断裂作为植入物失败的标准进行研究。
随访期间有4例患者出现锥度连接部位断裂，13.7年后植入物的累计生存率为94.2%（95%CI：88.6 - 100%）。13.7年后，颈部外偏的柄的植入物生存率为87.4%（95%CI：75.6 - 100%），与13.5年后标准偏移型为100%相比显著更低（对数秩检验 = 0.0283）。卡方检验也显示，与标准偏移型部件相比，颈部外偏型的断裂风险显著更高（ = 0.0141）。4例患者中有3例肥胖，平均体重指数（BMI）为37.9kg/m²。肥胖程度（1级或更高）对断裂风险有显著影响。与BMI < 30kg/m²的患者相比，至少1级肥胖的肥胖患者植入物的生存率显著更低（11.6年后为82.9%（95%CI：64.9 - 100%），而13.7年后为98.4%（95%CI：95.3 - 100%）；对数秩检验 = 0.0327）。
在这个连续的单机构队列中，锥度连接部位失败的累积风险较高，且在随访期间可能会进一步增加。由于登记处缺乏独立的数据采集，故障率可能高于制造商报告的数据。在至少1级肥胖的肥胖患者中使用颈部外偏的偏移型颈部显示出显著更高的断裂风险。使用一体式翻修器械可能是一种选择，但目前缺乏随机对照试验来建立考虑一体式和/或模块化植入物个体风险的标准化治疗方案。
