肘关节恐怖三联征中桡骨小头HotchkissⅢ型骨折的处理策略选择：内固定或置换?

目的 探讨保留桡骨小头内固定和桡骨小头假体置换治疗肘关节恐怖三联征中桡骨小头Hotchkiss Ⅲ型骨折的临床疗效,并为该类骨折的处理策略选择提供科学依据。方法 对在我院行手术治疗的23例伴桡骨小头HotchkissⅢ型骨折的恐怖三联征患者的临床资料行回顾性分析,对患者就桡骨小头的处理方式进行分组,其中10例行保留桡骨小头的切开复位内固定者为内固定组,13例行桡骨小头切除后行桡骨小头假体置换者为置换组。对所有患者行至少1年,结合手术相关指标、肘关节功能评分、成本-效益分析、患者满意度及生活质量等综合分析两种方案处理恐怖三联征中桡骨小头Hotchkiss Ⅲ型骨折的医疗、经济效益并作比较评价。结果 手术时间内固定组长于置换组（P<0.05）,切口长度、术后当天疼痛评分两组无统计学差异（P>0.05）,术后1年复查,患者Mayo肘关节功能评分示,置换组总分优于内固定组（P<0.05）,其中其肘关节疼痛、功能范围恢复均优于内固定组（P<0.05）,但两组稳定性、日常活动完成情况评分对比数据无统计学差异（P>0.05）,两组患者治疗质量-效益分析显示,内固定组治疗费用低于置换组（P<0.05）,治疗效益、患者满意度均高于置换组（P<0.05）,术后1年生活质量对比两组数据差异无统计学意义（P>0.05）。结论 两种方法均能有效治疗TTE中该类复杂骨折,从而恢复肘关节日常功能,改善生活质量。桡骨小头置换术创伤较小,功能改善较优,但内固定术治疗效益及患者满意度更高。     

Longitudinal Model of Periprosthetic Joint Infection in the Rat

The majority of periprosthetic joint infections occur shortly after primary joint replacement (<3 months) and require the removal of all implant components for the treatment period (~4 months). A clinically relevant animal model of periprosthetic infection should, therefore, establish an infection with implant components in place. Here, we describe a joint replacement model in the rat with ultrahigh molecular weight polyethylene (UHMWPE) and titanium components inoculated at the time of surgery by methicillin-sensitive Staphylococcus aureus (S. aureus), which is one of the main causative microorganisms of periprosthetic joint infections. We monitored the animals for 4 weeks by measuring gait, weight-bearing symmetry, von Frey testing, and micro-CT as our primary endpoint analyses. We also assessed the infection ex vivo using colony counts on the implant surfaces and histology of the surrounding tissues. The results confirmed the presence of a local infection for 4 weeks with osteolysis, loosening of the implants, and clinical infection indicators such as redness, swelling, and increased temperature. The utility of specific gait analysis parameters, especially temporal symmetry, hindlimb duty factor imbalance, and phase dispersion was identified in this model for assessing the longitudinal progression of the infection, and these metrics correlated with weight-bearing asymmetry. We propose to use this model to study the efficacy of using different local delivery regimens of antimicrobials on addressing periprosthetic joint infections. Statement of clinical significance: We have established a preclinical joint surgery model, in which postoperative recovery can be monitored over a multi-week course by assessing gait, weight-bearing, and allodynia. This model can be used to study the efficacy of different combinations of implant materials and medication regimens. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1101-1112, 2020     

Similitude of cement-bone micromechanics in cemented rat and human knee replacement

A preclinical rat knee replacement model was recently developed to explore the biological and mechanobiological changes of trabecular resorption for cement-bone interdigitated regions. The goal here was to evaluate the relevance of this model compared with human knee replacement with regards to functional micromechanics. Eight nonsurvival, cemented knee replacement surgeries were performed, the interdigitated gap morphology was quantified, and interface micromotion between cement and bone was measured for 1 to 5 bodyweight loading. Computational fluid dynamics modeling of unit cell geometries with small gaps between trabeculae and cement was used to estimate fluid flow. Gap width (3.6 μm) was substantially smaller compared with cement-bone gaps reported in human knee replacement (11.8 μm). Micromotion at the cement-bone border was also decreased for the rat knee replacement (0.48 μm), compared with human (1.97 μm), for 1 bodyweight loading. However, the micromotion-to-gap width ratio (0.19 and 0.22 for, rat and human), and estimated fluid shear stress (6.47 and 7.13 Pa, for rat and human) were similar. Replicating the fluid dynamic characteristics of cement-bone interdigitated regions in human knee replacements using preclinical models may be important to recapitulate trabecular resorption mechanisms due to proposed supraphysiologic fluid shear stress. Statement of clinical significance: local cement-bone micromotion due to joint loading may contribute to the process of clinical loosening in total joint replacements. This work shows that while micromotion and gap morphology are diminished for the rat knee model compared to human, the motion-to-gap ratio, and corresponding fluid shear stress are of similar magnitudes     

Cemented Proximal Femoral Replacement for the Management of Non-Neoplastic Conditions: A Versatile Implant but Not Without Its Risks

BackgroundThe demand for revision arthroplasty continues to grow. Proximal femoral bone loss poses a significant challenge to surgeons and proximal femoral replacements (PFRs) are one option to address this problem. The aim of our study is to assess the reoperation, complication, and mortality rates following PFR for treatment of non-neoplastic conditions.MethodsA retrospective observational study was conducted of a consecutive group of patients treated with a PFR for non-neoplastic conditions between 2010 and 2018. Mortality was confirmed using the Irish national death events publication service.ResultsOver the 8-year study period, 79 PFRs in 78 patients were performed. Mean age of patients was 78.3 years (standard deviation 11.9), of which 37.2% were male. Periprosthetic fracture was the most common indication for PFR (63.3%). The 30-day mortality rate was 7.6% (6 patients), of which bone cement implantation syndrome occurred in 4 patients. One-year mortality was 12.7%. Complications occurred in 22.8%.ConclusionA cemented PFR is a versatile prosthesis in the armamentarium of a revision arthroplasty surgeon that allows immediate full weight-bearing. However, it may appropriately be considered a last resort procedure that poses specific risks that must be explained to patients and family. We present the short-term outcomes on one of the largest series of PFR to date.     

Recurrence of left atrial myxoma mimicking a mitral annuloplasty ring thrombosis

Cardiac myxomas (CM) is by far the most common type of primary cardiac neoplasm that commonly arise within the left atria and is composed of primitive connective tissue cells and stroma. Despite the benign nature, the CMs are often surgically removed because they can lead to severe complications. Large, thin, and hypermobile forms are unusual. The frequency of recurrence is about 22% for complex forms and 12% for other familial forms and 1% to 3% for sporadic myxomas, which seldom recur after surgery. Although transesophageal echocardiography shows usually accurate imaging capabilities to detect the myxoma, further imaging methods including computed tomography, cardiovascular magnetic resonance imaging, and ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography may be useful to diagnosis for it. Surgery is the mainstay of treatment     

Unsuccessful surgical treatment of thoracic aortic thrombosis in a patient with essential thrombocythemia

Essential thrombocythemia (ET) is a rare condition with an incidence of several persons per million in Japan, while the incidence of thrombosis ranges from 11% to 25%. We present a woman in her 70 seconds with ET who developed small intestinal necrosis and thrombosis in the proximal descending aorta. The patient underwent partial small bowel resection and replacement of the descending aorta, followed by multiple reoperations for thrombotic and hemorrhagic complications. She eventually died of empyema and sepsis caused by Klebsiella oxytoca. In patients with ET and large vessel thrombosis, we have to carefully judge the indications for surgery.