Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA; Department of Orthopaedic Surgery, Newton-Wellesley Hospital, Newton, MA.
J Arthroplasty. 2020 Dec;35(12):3594-3600. doi: 10.1016/j.arth.2020.06.048. Epub 2020 Jun 24.
Spines with ankylosis or with a history of lumbosacral fusions have been collectively classified as rigid and unbalanced, and associated with an increased rate of dislocation after total hip arthroplasty (THA). It remains unknown whether the cause of spinal arthrodesis influences the dislocation rate.
A retrospective study was conducted from January 2000 to December 2017, with an institutional review board's approval to identify 2 cohorts with a history of THA: one with ankylosing spondylitis (AS) involving the lumbosacral spine and another cohort with a history of lumbosacral spinal fusion (SF). A chart review was performed to collect demographic and surgical variables. Lumbar lordosis angle (LLA), acetabular anteversion, and inclination angle measurements were taken for each patient. Kaplan-Meier survivorship curves were constructed and multivariable Cox regression was performed for analysis.
The AS and SF cohorts consisted of 142 and 135 patients, respectively. The SF group had a greater mean LLA (34.18°) than the AS group (21°). A total of 16 patients (11.85%) suffered from dislocation after primary elective THA in the SF group, whereas 4 patients (2.82%) in the AS group. After multivariable Cox regression analysis, increasing LLA and hips outside of the Lewinnek safe zone were found to be associated with a higher hazard of dislocation after THA.
We found that the degree of lumbar spine curvature is more associated with dislocation after THA than the history of SF itself; specifically, an increase in lumbar lordosis angle of 1º increases the probability of dislocation by 13% among AS and SF patients.
脊柱融合或有脊柱融合史的脊柱被归为僵硬和不平衡的脊柱，与全髋关节置换术后（THA）脱位率增加有关。目前尚不清楚脊柱融合的病因是否会影响脱位率。
本回顾性研究于 2000 年 1 月至 2017 年 12 月进行，获得机构审查委员会的批准，确定了有 THA 史的 2 个队列：一个是强直性脊柱炎（AS）累及腰骶部脊柱，另一个是有腰骶部脊柱融合史的队列（SF）。进行图表审查以收集人口统计学和手术变量。对每位患者进行腰椎前凸角（LLA）、髋臼前倾角和倾斜角测量。构建 Kaplan-Meier 生存曲线并进行多变量 Cox 回归分析。
AS 和 SF 队列分别包括 142 例和 135 例患者。SF 组的平均 LLA（34.18°）大于 AS 组（21°）。SF 组 16 例（11.85%）在初次择期 THA 后发生脱位，而 AS 组 4 例（2.82%）。多变量 Cox 回归分析后发现，LLA 增加和髋关节超出 Lewinnek 安全区与 THA 后脱位的风险增加相关。
我们发现，腰椎曲度的程度与 THA 后脱位的关系比 SF 史本身更密切；具体来说，AS 和 SF 患者的腰椎前凸角增加 1°，脱位的概率增加 13%。
