Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University Hospital, Philadelphia, PA; Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan.
Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University Hospital, Philadelphia, PA.
J Arthroplasty. 2020 Jun;35(6S):S268-S272. doi: 10.1016/j.arth.2020.02.059. Epub 2020 Mar 3.
We have previously reported the early clinical results of a modular-neck stem identifying an early 2-year revision rate of 13% due to neck-stem corrosion. This report updates our findings to a midterm mean follow-up of 5 years.
This is a consecutive retrospective review of 186 modular-neck hips in 175 patients with a mean follow-up period was 60.1 ± 22.9 months (range 24-100). We reviewed clinical findings, routine radiographs, detailed imaging (metal artifact reduction software-magnetic resonance imaging, ultrasound), and serum ion levels of cobalt and chromium. We performed a survival analysis with the endpoint defined as revision total hip arthroplasty due to neck-stem corrosion.
We revised 41 hips (22.0%) for neck-stem corrosion. Clinical symptoms (groin pain ± local swelling) were consistently present in those that came for revision. Mean serum cobalt ion levels increased as time passed in all patients. Detailed image findings showed that larger fluid collections and local soft tissue masses were seen predominately in symptomatic patients. However, 14% of patients who underwent revision did not have positive magnetic resonance imaging or ultrasound findings. The survival rate was 87% (95% confidence interval 81-92) at 3 years postoperatively and 72% (95% confidence interval 64-80) at 7 years postoperatively.
The revision rate for this modular-neck stem due to neck-stem corrosion at mid-term follow-up almost doubled in comparison to previous short-term results. It seems reasonable to consider clinical follow-up alone as symptoms, rather than blood testing for ion levels, seem to be the defining characteristic of failure.
我们之前报道了一种模块化颈干假体的早期临床结果，其 2 年翻修率因颈干腐蚀而高达 13%。本报告更新了中期平均随访 5 年的结果。
这是一项连续的回顾性研究，共纳入 175 例患者的 186 例模块化颈干髋关节，平均随访时间为 60.1±22.9 个月（范围 24-100 个月）。我们回顾了临床发现、常规 X 线片、详细影像学（磁共振成像采用金属伪影减少软件、超声）和钴、铬血清离子水平。我们采用生存分析，以因颈干腐蚀而进行全髋关节翻修为终点。
我们因颈干腐蚀而翻修了 41 髋（22.0%）。出现临床症状（腹股沟疼痛±局部肿胀）的患者均进行了翻修。所有患者的血清钴离子水平均随时间推移而升高。详细影像学发现，症状性患者中更常见大的积液和局部软组织肿块。然而，14%接受翻修的患者磁共振成像或超声检查未见阳性结果。术后 3 年的生存率为 87%（95%置信区间 81-92%），术后 7 年的生存率为 72%（95%置信区间 64-80%）。
与之前的短期结果相比，该模块化颈干假体在中期随访时因颈干腐蚀而进行翻修的比例几乎翻了一番。考虑到临床随访似乎更合理，因为症状而不是血清离子水平检测似乎是失败的特征。
