Kelly Mackenzie, Chen Antonia F, Ryan Sean P, Working Zachary M, De Ayushmita, Mullen Kyle, Porter Kimberly R, Kagan Ryland
Department of Orthopaedics and Rehabilitation, Oregon Health and Science University, Portland, OR, USA.
Department of Orthopaedics, Brigham and Women's Hospital, Boston, MA, USA.
Clin Orthop Relat Res. 2024 Aug 1;482(8):1485-1493. doi: 10.1097/CORR.0000000000002985. Epub 2024 Feb 6.
Periprosthetic femur fracture is a known complication after THA. The associated risk of cementless femoral component design for periprosthetic femur fracture in a registry population of patients older than 65 years has yet to be clearly identified.
QUESTIONS/PURPOSES: (1) Is femoral stem geometry associated with the risk of periprosthetic femur fracture after cementless THA? (2) Is the presence or absence of a collar on cementless femoral implant designs associated with the risk of periprosthetic femur fracture after THA?
We analyzed American Joint Replacement Registry data from 2012 to March 2020. Unique to this registry is the high use of cementless femoral stems in patients 65 years and older. We identified 266,040 primary cementless THAs during the study period in patients with a diagnosis of osteoarthritis and surgeries linked to supplemental Centers for Medicare and Medicaid data where available. Patient demographics, procedure dates, and reoperation for periprosthetic femur fracture with revision or open reduction and internal fixation were recorded. The main analysis was performed comparing the Kheir and Chen classification: 42% (112,231 of 266,040) were single-wedge, 22% (57,758 of 266,040) were double-wedge, and 24% (62,983 of 266,040) were gradual taper/metadiaphyseal-filling cementless femoral components, which yielded a total of 232,972 primary cementless THAs. An additional analysis compared cementless stems with collars (20% [47,376 of 232,972]) with those with collarless designs (80% [185,596 of 232,972]). A Cox proportional hazard regression analysis with the competing risk of death was used to evaluate the association of design and fracture risk while adjusting for potential confounders.
After controlling for the potentially confounding variables of age, sex, geographic region, osteoporosis or osteopenia diagnosis, hospital volume, and the competing risk of death, we found that compared with gradual taper/metadiaphyseal-filling stems, single-wedge designs were associated with a greater risk of periprosthetic femur fracture (HR 2.9 [95% confidence interval (CI) 2.2 to 3.9]; p < 0. 001). Compared with gradual taper/metadiaphyseal-filling stems, double-wedge designs showed an increased risk of periprosthetic femur fracture (HR 3.0 [95% CI 2.2 to 4.0]; p < 0. 001). Collarless stems showed an increased risk of periprosthetic fracture compared with collared stems (HR 7.8 [95% CI 4.1 to 15]; p < 0. 001).
If cementless femoral fixation is used for THA in patients 65 years or older, surgeons should consider using gradual taper/metadiaphyseal-filling and collared stem designs because they are associated with a lower risk of periprosthetic femur fracture. Future investigations should compare gradual taper/metadiaphyseal-filling and collared cementless designs with cemented fixation in this population.
Level III, therapeutic study.
人工关节置换术后股骨假体周围骨折是一种已知的并发症。在年龄大于65岁的登记患者群体中，非骨水泥型股骨假体设计与股骨假体周围骨折的相关风险尚未明确。
问题/目的：（1）非骨水泥型全髋关节置换术后，股骨干几何形状与股骨假体周围骨折风险是否相关？（2）非骨水泥型股骨假体设计中有无领圈与全髋关节置换术后股骨假体周围骨折风险是否相关？
我们分析了2012年至2020年3月的美国关节置换登记数据。该登记的独特之处在于65岁及以上患者中大量使用非骨水泥型股骨干。在研究期间，我们在诊断为骨关节炎且手术与补充医疗保险和医疗补助数据相关联的患者中，识别出266,040例初次非骨水泥型全髋关节置换术。记录患者人口统计学资料、手术日期以及因股骨假体周围骨折进行翻修或切开复位内固定的再次手术情况。主要分析是比较凯尔和陈的分类：42%（266,040例中的112,231例）为单楔型，22%（266,040例中的57,758例）为双楔型，24%（266,040例中的62,983例）为渐缩/干骺端填充型非骨水泥型股骨假体组件，总计232,972例初次非骨水泥型全髋关节置换术。另一项分析比较了有领圈的非骨水泥型股骨干（20% [232,972例中的47,376例]）与无领圈设计的股骨干（80% [232,972例中的185,596例]）。采用带有死亡竞争风险的Cox比例风险回归分析来评估设计与骨折风险之间的关联，同时对潜在混杂因素进行校正。
在控制了年龄、性别、地理区域、骨质疏松或骨质减少诊断、医院规模以及死亡竞争风险等潜在混杂变量后，我们发现，与渐缩/干骺端填充型股骨干相比，单楔型设计与股骨假体周围骨折风险更高相关（风险比2.9 [95%置信区间（CI）为2.2至3.9]；p < 0.001）。与渐缩/干骺端填充型股骨干相比，双楔型设计显示股骨假体周围骨折风险增加（风险比3.0 [95% CI为 2.2至4.0]；p < 0.001）。与有领圈的股骨干相比，无领圈的股骨干显示假体周围骨折风险增加（风险比7.8 [95% CI为4.1至15]；p < 0.001）。
如果在65岁及以上患者的全髋关节置换术中使用非骨水泥型股骨固定，外科医生应考虑使用渐缩/干骺端填充型和有领圈的股骨干设计，因为它们与股骨假体周围骨折风险较低相关。未来的研究应比较该人群中渐缩/干骺端填充型和有领圈的非骨水泥型设计与骨水泥固定的情况。
三级，治疗性研究。
