Department of Orthopaedic Surgery and Traumatology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Nielsine Nielsens Vej 5, Staircase 6, 2. Floor, Copenhagen, NV, 2400, Denmark.
Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark.
BMC Musculoskelet Disord. 2024 Feb 9;25(1):119. doi: 10.1186/s12891-024-07237-z.
Several factors might be associated with risk of dislocating following uncemented hemiarthroplasty (HA) due to femoral neck fracture (FNF). Current evidence is limited with great variance in reported incidence of dislocation (1-15%). Aim of this study was to identify the cumulative incidence of first-time dislocation following HA and to identify the associated risk factors.
We performed a retrospective cohort study of patients receiving an HA (BFX Biomet stem, posterior approach) at Copenhagen University Hospital, Bispebjerg, in 2010-2016. Patients were followed until death or end of study (dec 2018). Dislocation was identified by code extraction from the Danish National Patient Registry. Variables included in the multivariate model were defined pre-analysis to include: age, sex and variables with a p-value < 0.1 in univariate analysis. A regression model was fitted for 90 days dislocation as the assumption of proportional hazard rate (HR) was not met here after.
We identified 772 stems (some patients occurred with both right and left hip) and 58 stems suffered 90 dislocations during the observation period, resulting in a 7% (CI 5-9) incidence of dislocation 90 days after index surgery. 55 of the 58 stems (95%) experienced the first dislocation within 90 days after surgery. Only absence of dementia was identified as an independent protective factor in the cause-specific model (HR 0.46 (CI 0.23-0.89)) resulting in a 2.4-fold cumulative risk of experiencing a dislocation in case of dementia. Several other variables such as age, sex, various medical conditions, surgery delay and surgical experience were eliminated as statistical risk factors. We found a decrease in survival probability for patients who experienced a dislocation during follow-up.
The incidence of first-time dislocation of HA (BFX Biomet stem, posterior approach) in patients with a hip fracture is found to be 7% 90 days after surgery. Due to the non-existing attribution bias, we claim it to be the true incidence. Dementia was among several variables identified as the only risk factor for dislocation. In perspective, we may consider treating patients with dementia by other methods than HA e.g., HA with cement or with a more constrained solution. Also, a surgical approach that reduce the risk of dislocation should be considered.
多种因素可能与股骨颈骨折（FNF）后非骨水泥半髋关节置换术后脱位风险相关。目前的证据有限，脱位的报告发生率差异很大（1-15%）。本研究的目的是确定初次髋关节置换术后脱位的累积发生率，并确定相关的危险因素。
我们对 2010 年至 2016 年在哥本哈根大学医院比斯加夫医院接受髋关节置换术（BFX Biomet 柄，后路）的患者进行了回顾性队列研究。患者随访至死亡或研究结束（2018 年 12 月）。脱位通过从丹麦国家患者登记处提取代码来确定。多变量模型中包含的变量在分析前定义，包括：年龄、性别和单变量分析中 p 值<0.1 的变量。由于此处不符合比例风险率（HR）的假设，因此为 90 天脱位拟合了回归模型。
我们确定了 772 个柄（一些患者同时发生右侧和左侧髋关节），58 个柄在观察期间发生了 90 次脱位，在指数手术后 90 天的脱位发生率为 7%（CI 5-9）。58 个柄中的 55 个（95%）在手术后 90 天内首次发生脱位。只有没有痴呆被确定为特定原因模型中的独立保护因素（HR 0.46（CI 0.23-0.89）），这导致在患有痴呆的情况下，脱位的累积风险增加 2.4 倍。其他一些变量，如年龄、性别、各种医疗条件、手术延迟和手术经验，被排除为统计学危险因素。我们发现，在随访期间发生脱位的患者的生存概率下降。
髋关节骨折患者初次髋关节置换术后脱位的发生率为手术后 90 天 7%。由于不存在归因偏倚，我们认为这是真实的发生率。痴呆是确定的脱位的唯一危险因素之一。从这个角度来看，我们可以考虑通过其他方法治疗痴呆患者，而不是髋关节置换术，例如使用水泥或更具约束性的解决方案的髋关节置换术。此外，还应考虑采用降低脱位风险的手术方法。
