From the Department of Orthopaedic Surgery, University of California Los Angeles, Los Angeles, CA.
J Am Acad Orthop Surg Glob Res Rev. 2022 Aug 11;6(8). doi: 10.5435/JAAOSGlobal-D-22-00082. eCollection 2022 Aug 1.
Modular knee arthrodesis (MKU) is a salvage treatment for recurrent periprosthetic joint infection (PJI) or PJI associated with notable bone loss. Reimplantation endoprosthetic reconstruction (REI) is an option in patients with MKU who have PJI clearance but are not satisfied with pain or functional outcomes with MKU. The purpose of this study was to evaluate the outcomes of MKU to REI conversion.
This was a single-center retrospective cohort study of 56 patients who underwent MKU to REI from 2010 to 2019. All patients were staged according to the McPherson staging system. An infecting organism was documented based on pre-MKU aspiration or intraoperative cultures at the time of MKU. Rate ratios were calculated for relevant patient factors. Rate ratios were calculated using Poisson regression with a log link.
The mean REI patient age was 67 years, most of the patients were McPherson B hosts (62.5%) with a type 2 (46.4%) or type 3 (51.8%) limb score, and all PJI were chronic. The most common infecting organisms at the time of MKU were Staphylococcus epidermidis (23.2%) and Staphylococcus aureus (23.2%, MSSA 14.3%, MRSA 8.9%). The mean time from MKU to REI was 220 days. An 8.9% REI index hospitalization complication rate and a 21.4% overall complication rate (excluding reinfection) were observed. Sixty-seven percent of the patients remained infection-free at an average follow-up of 37 months, among those there was 96.4% implant survivorship. No notable association was observed between index PJI organism or McPherson staging and REI failure secondary to PJI.
Approximately two thirds of patients who undergo conversion from MKU to REI have infection-free survival at the midterm follow-up. An index infecting organism and a McPherson host type do not seem to be markedly associated with reinfection risk. These findings help guide expectations of PJI MKU conversion to REI.
模块化膝关节融合术（MKU）是治疗复发性假体周围关节感染（PJI）或 PJI 伴明显骨质丢失的挽救性治疗方法。对于 MKU 后 PJI 清除但对 MKU 的疼痛或功能结果不满意的患者，可选择再植入式假体重建（REI）。本研究旨在评估 MKU 转为 REI 的结果。
这是一项 2010 年至 2019 年间对 56 例接受 MKU 转为 REI 的患者进行的单中心回顾性队列研究。所有患者均根据 McPherson 分期系统分期。根据术前 MKU 抽吸或术中 MKU 时的培养物记录感染病原体。计算相关患者因素的率比。使用泊松回归和对数链接计算率比。
REI 患者的平均年龄为 67 岁，大多数患者为 McPherson B 宿主（62.5%），肢体评分类型 2（46.4%）或类型 3（51.8%），所有 PJI 均为慢性。MKU 时最常见的感染病原体是表皮葡萄球菌（23.2%）和金黄色葡萄球菌（23.2%，MSSA 14.3%，MRSA 8.9%）。从 MKU 到 REI 的平均时间为 220 天。观察到 8.9%的 REI 指数住院并发症发生率和 21.4%的总并发症发生率（不包括再感染）。在平均 37 个月的随访中，67%的患者保持无感染，其中 96.4%的植入物存活率。在 REI 因 PJI 而失败的患者中，未观察到指数 PJI 病原体或 McPherson 分期与感染之间存在显著相关性。
大约三分之二接受 MKU 转为 REI 的患者在中期随访时无感染生存。感染病原体和 McPherson 宿主类型似乎与再感染风险无明显关联。这些发现有助于指导对 PJI MKU 转为 REI 的期望。
