Tillander Jonatan, Hagberg Kerstin, Berlin Örjan, Hagberg Lars, Brånemark Rickard
Department of Infectious Diseases, Institution of Biomedicine, University of Gothenburg, Gothenburg, 416 45, Sweden.
Department of Orthopaedics, University of Gothenburg, Gothenburg, Sweden.
Clin Orthop Relat Res. 2017 Dec;475(12):3100-3108. doi: 10.1007/s11999-017-5507-2. Epub 2017 Sep 22.
Percutaneous anchoring of femoral amputation prostheses using osseointegrating titanium implants has been in use for more than 25 years. The method offers considerable advantages in daily life compared with conventional socket prostheses, however long-term success might be jeopardized by implant-associated infection, especially osteomyelitis, but the long-term risk of this complication is unknown.
QUESTIONS/PURPOSES: (1) To quantify the risk of osteomyelitis, (2) to characterize the clinical effect of osteomyelitis (including risk of implant extraction and impairments to function), and (3) to determine whether common patient factors (age, sex, body weight, diabetes, and implant component replacements) are associated with osteomyelitis in patients with transfemoral amputations treated with osseointegrated titanium implants.
We retrospectively analyzed our first 96 patients receiving femoral implants (102 implants; mean implant time, 95 months) treated at our center between 1990 and 2010 for osteomyelitis. Six patients were lost to followup. The reason for amputation was tumor, trauma, or ischemia in 97 limbs and infection in five. All patients were referred from other orthopaedic centers owing to difficulty with use or to be fitted with socket prostheses. If found ineligible for this implant procedure no other treatment was offered at our center. Osteomyelitis was diagnosed by medical chart review of clinical signs, tissue culture results, and plain radiographic findings. Proportion of daily prosthetic use when osteomyelitis was diagnosed was semiquantitatively graded as 1 to 3. Survivorship free from implant- associated osteomyelitis and extraction attributable to osteomyelitis respectively was calculated using the Kaplan-Meier estimator. Indication for extraction was infection not responsive to conservative treatment with or without minor débridement or loosening of implant.
Implant-associated osteomyelitis was diagnosed in 16 patients corresponding to a 10-year cumulative risk of 20% (95% CI 0.12-0.33). Ten implants were extracted owing to osteomyelitis, with a 10-year cumulative risk of 9% (95% CI 0.04-0.20). Prosthetic use was temporarily impaired in four of the six patients with infection who did not undergo implant extraction. With the numbers available, we did not identify any association between age, BMI, or diabetes with osteomyelitis; however, this study was underpowered on this endpoint.
The increased risk of infection with time calls for numerous measures. First, patients should be made aware of the long-term risks, and the surgical team should have a heightened suspicion in patients with method-specific presentation of possible infection. Second, several research questions have been raised. Will the surgical procedure, rehabilitation, and general care standardization since the start of the program result in lower infection rates? Will improved diagnostics and early treatment resolve infection and prevent subsequent extraction? Although not supported in this study, it is important to know if most infections arise as continuous bacterial invasion from the skin and implant interface and if so, how this can be prevented?
Level IV, therapeutic study.
使用骨整合钛植入物经皮固定股骨截肢假体已应用超过25年。与传统的接受腔假体相比，该方法在日常生活中具有显著优势，然而，与植入物相关的感染，尤其是骨髓炎，可能会危及长期疗效，但这种并发症的长期风险尚不清楚。
问题/目的：（1）量化骨髓炎风险；（2）描述骨髓炎的临床影响（包括植入物取出风险和功能损害）；（3）确定常见患者因素（年龄、性别、体重、糖尿病和植入物部件更换）是否与接受骨整合钛植入物治疗的经股骨截肢患者的骨髓炎有关。
我们回顾性分析了1990年至2010年在我们中心接受股骨植入物治疗的首批96例患者（102枚植入物；平均植入时间95个月）的骨髓炎情况。6例患者失访。97条肢体的截肢原因是肿瘤、创伤或缺血，5条肢体是感染。所有患者均因使用困难或因接受腔假体适配问题从其他骨科中心转诊而来。如果发现不符合该植入手术条件，我们中心不提供其他治疗。通过查阅病历中的临床体征、组织培养结果和X线平片检查结果来诊断骨髓炎。诊断骨髓炎时的日常假体使用比例半定量分为1至3级。分别使用Kaplan-Meier估计器计算无植入物相关骨髓炎和因骨髓炎导致植入物取出的生存率。取出植入物的指征是感染对保守治疗（有无轻微清创）或植入物松动无反应。
16例患者被诊断为植入物相关骨髓炎，10年累积风险为20%（95%CI 0.12 - 0.33）。10枚植入物因骨髓炎被取出，10年累积风险为9%（95%CI 0.04 - 0.20）。6例未取出植入物的感染患者中有4例的假体使用暂时受到影响。根据现有数据，我们未发现年龄、体重指数或糖尿病与骨髓炎之间存在任何关联；然而，本研究在该终点的检验效能不足。
随着时间推移感染风险增加需要采取多种措施。首先，应让患者了解长期风险，手术团队对有特定方法相关可能感染表现的患者应提高警惕。其次，提出了几个研究问题。自该项目启动以来，手术操作、康复和一般护理的标准化是否会降低感染率？改进的诊断和早期治疗能否解决感染并防止随后的植入物取出？尽管本研究未提供支持，但了解大多数感染是否源于皮肤和植入物界面的持续细菌入侵以及如果是这样如何预防是很重要的。
IV级，治疗性研究。
