Tibial component fixation with a peri-apatite coating: evaluation by radiostereometric analysis in a canine total knee arthroplasty model

Cementless fixation for the tibial component in total knee arthroplasty (TKA) remains problematic. Peri-Apatite (PA), a solution-deposited hydroxyapatite, is under investigation as an option for improving the fixation of cementless tibial components. In this study, radiostereometric analysis was used to document implant migration in 48 dogs that underwent TKA with cementless, PA-coated, or cemented tibial components. Migration at 12 weeks was similar in the 2 groups. At 12 months, there was greater migration in the PA-coated group, but the difference between the 2 groups was below the threshold considered clinically significant. In this canine TKA model, cementless fixation with PA performed less well than did cemented fixation, but not to a degree that would make a clinical difference in the short term.     

Outcomes of total hip and knee arthroplasty after cardiac transplantation

The outcomes of 18 primary or revision total hip (THA) and knee arthroplasties (TKA) in 9 patients with cardiac transplants were reviewed. Primary total joint arthroplasties were performed for osteonecrosis (5 hips) or osteoarthritis (5 hips, 4 knees). There were no infections in any of these patients. Final Harris Hip Scores were 71.8 for patients with osteonecrosis and 88.6 for osteoarthritis. Eight of 10 hips were pain-free at final follow-up. Two of the 10 primary THAs required late revision at 7 and 10 years after the index arthroplasty. One patient (2 hips and 1 knee) had chronic bilateral lower extremity pain. Total knee arthroplasty range of motion averaged from 7.5° to 118°. Average final Knee Society function score was 79, and objective score was 88. One of 4 patients with primary TKA required a manipulation under anesthesia. No reoperations were required in this group. Overall, patients with heart transplantations on immunosuppression had generally good pain relief after THA and TKA. There were no infections in this small cohort; however, there were many complications.     

Revision after total knee arthroplasty and unicompartmental knee arthroplasty in the medicare population

This study compares the relative risk of revision and associated risk factors after total or unicompartmental knee arthroplasty (TKA or UKA) in the Medicare population. A total of 61 767 TKA and 2848 UKA patients were identified. Reviewed data included type of treatment, gender, age, race, Charlson Index for comorbidity, length of stay, Medicare buy-in for socioeconomic status, region, and year. Unicompartmental knee arthroplasty patients were at increased risk for revision at 2 and 5 years. Those patients undergoing UKA were significantly more likely to require revision in the first 5 years as compared with those undergoing TKA. Risk factors contributing to TKA revision included younger male patients with higher comorbidities and lower socioeconomic status. About UKA, lower revision rates tend to favor those surgeons with higher volume.     

Access to arthroplasty in South Florida

Our objective was to compare the availability of hip and knee arthroplasty to an adult insured by Medicaid and by private insurance. All orthopedic surgeons' offices in a South Florida county were contacted by telephone and presented with a hypothetical patient that needed either a hip or a knee arthroplasty for end stage arthritis. Two scenarios were presented. The hypothetical patient was presented as either having private insurance or Medicaid. 14.3% of all offices contacted offered an appointment to patients with Medicaid coverage for hip and knee arthroplasty, respectively. All offices offered an appointment to patients with private insurance. The mean time until appointment was longer for patients with Medicaid when compared with private insurance. Adults insured with Medicaid currently have limited access to total joint arthroplasty within the studied community.     

SF-12量表评价全髋关节置换术患者生存质量

[目的]评估SF - 12量表用于评价全髋关节置换术后患者生存质量的适用性.[方法]Harris髋关节功能评分量表(Harris hip score,HHS)、SF - 12生存质量量表(MOS 12 -item Short Form Health Survey,SF - 12)评估接受全髋关节置换术治疗的患者283例381髋,采用内部一致性信度(Cronbach's alpha系数)评估SF - 12量表的信度;采用集合效度、区分效度和结构效度评估SF - 12量表的效度;Pearson相关分析评估HHS与生理总分、心理总分关联度;单因素方差分析评估生理及心理总分分级的组间差异性.[结果] SF-12量表总的Cronbach's alpha系数为0.879,各维度Cronbach's alpha系数均＞0.8;集合效度及区分效度定标实验均为100％;结构效度因子分析产生两个公因子生理及心理总分,累积解释72.229％的总方差,8个维度因子负荷与理论假设基本符合;HHS与生理总分、心理总分均为强相关(r1=0.745,r2=0.703,P＜0.01);组间差异F1=85.282,F2=61.377,P＜0.01.[结论]SF-12量表具有良好的信度和效度,适用于评价全髋关节置换术后患者的生存质量,评估效果良好.     

全膝关节置换术后隐性失血危险因素的分析

目的探讨全膝关节置换术后的隐性失血量,并分析影响隐性失血的相关因素。方法收集48例行初次单侧全膝关节置换术的患者,其中女42例,男6例;年龄29～79岁,平均年龄65岁。通过Gross方程,根据患者身高、体重和手术前后的红细胞压积(Hct)计算患者的总失血量,减去显性失血量后得隐性失血量。分析年龄、性别、诊断、身高、体重、BMI、术中出血量、术后引流量、术者以及止血带时间、手术时间与隐性失血的相关性。结果术中出血量为(541±271)mL(200～1700mL),术后引流量为(479±249)mL(50～1010mL),显性出血量为(1020±327)mL(440～2 220 mL),总失血量为(1 963±734)mL(92～3 926 mL),隐性失血量为(942±692)mL(-502～2 716 mL)。因此,隐性失血占总失血的48.0%。隐性失血与身高、体重都有明显正相关,但与BMI没有明显相关性,另外,隐性失血还与术后引流量呈明显负相关。结论全膝关节置换术后隐性失血量约占总失血量的一半,应引起我们足够的重视,并且术后引流量少时更不能忽视隐性失血的存在。     

颗粒骨打压植骨结合多孔非骨水泥臼杯在AAOSⅢ型髋臼大面积骨缺损翻修中的应用

背景：颗粒骨打压植骨是修复髋臼骨缺损的重要方法,对大面积髋臼骨缺损采用打压植骨结合非骨水泥臼杯重建仍然存在争议。目的：探讨同种异体颗粒骨打压植骨结合多孔非骨水泥臼杯髋臼重建术修复AAOSⅢ型髋臼大面积骨缺损的方法及近期疗效。方法：随访2005年6月至2010年4月收治的28例（28髋）AA0SⅢ型髋臼大面积骨缺损患者。男18例,女10例,年龄34-74岁,平均53．8岁。髋关节置换术后感染醐翻修9例,骨溶解及髋臼假体松动翻修19例。本组AAOSⅢ型髋臼骨缺损面积大,术中见髋臼骨缺损超过髋臼关节面的50％。全部采用同种异体颗粒骨打压植骨结合多孔非骨水泥臼杯髋臼重建术。术后定期随访,观察臼杯有无松动、植入骨与宿主骨整合情况,髋关节功能评分采用Harris评分。结果：28例均获得随访,术后随访时间为13-70个月,平均43个月。Harris评分由术前32-48分,平均41分,提高至末次随访时86-95分,平均90分。28例髋臼假体均固定牢固无松动征象,植入骨逐渐与宿主骨整合,无感染及坐骨神经损伤。结论：在获得臼杯初始稳定固定的情况下,大面积颗粒骨打压植骨（臼杯与宿主骨接触面积〈50％）结合多孔非骨水泥臼杯髋臼重建术修复AAOSⅢ型髋臼大面积骨缺损近期疗效较好,远期疗效尚待进一步随访。     

Quantifying subtle but persistent peri-spine inflammation in vivo to submicron cobalt–chromium alloy particles

Purpose

We evaluated the consequences of cobalt–chromium alloy (CoCr) wear debris challenge in the peri-spine region to determine the inflammation and toxicity associated with submicron particulates of CoCr-alloy and nickel on the peri-spine.

Methods

The lumbar epidural spaces of (n = 50) New Zealand white rabbits were challenged with: 2.5 mg CoCr, 5.0 mg CoCr, 10.0 mg CoCr, a positive control (20.0 mg of nickel) and a negative control (ISOVUE-M-300). The CoCr-alloy and Ni particles had a mean diameter of 0.2 and 0.6 μm, respectively. Five rabbits per dose group were studied at 12 and 24 weeks. Local and distant tissues were analyzed histologically and quantitatively analyzed immunohistochemically (TNF-α and IL-6).

Results

Histologically, wear particles were observed in all animals. There was no evidence of toxicity or local irritation noted during macroscopic observations in any CoCr-dosed animals. However, Ni-treated control animals experienced bilateral hind leg paralysis and were euthanized at Day 2. Histopathology of the Ni particle-treated group revealed severe neuropathy. Quantitative immunohistochemistry demonstrated a CoCr-alloy dose-dependent increase in cytokines (IL-6, TNF-α, p < 0.05) at 12 and 24 weeks.

Conclusions

Subtle peri-spine inflammation associated with CoCr-alloy implant particles was dose dependent and persistent. Neuropathy can be induced by highly reactive Ni particles. This suggests peri-spine challenge with CoCr-alloy implant debris (e.g., TDA) is consistent with past reports using titanium alloy particles, i.e., mild persistent inflammation.     

全髋关节表面置换术治疗股骨头坏死的Meta分析

目的通过综合分析已发表文献,探讨全髋关节表面置换术治疗股骨头坏死的效果及安全性。方法通过系统检索从1990年1月到2011年12月全髋关节表面置换术治疗股骨头坏死的相关文献,按照排除标准筛选后,提取需要的数据,通过循证医学Meta分析方法,加权汇总分析。结果共检出192篇相关文献检出,经过三个阶段的筛选,共有10篇被纳入分析,共有317例患者,376例髋关节,男性患者191例,女性126例,平均加权年龄为41.98岁（16～77岁）,加权平均随访时间36.69个月（6～140个月）。术后的髋关节Harris评分（92分）较术前（44分）的差异有统计学意义（t=18.07,P〈0.01）。主要并发症包括假体无菌性松动（1.06%）、异位骨化（0.80%）、疼痛（0.80%）和股骨颈骨折（0.27%）,最终翻修率为0.80%。结论全髋关节表面置换术治疗股骨头坏死是安全有效的,但需要注意其并发症。     

小切口辅助手法松解治疗TKA术后关节僵硬

目的探讨髌外侧小切口辅助麻醉下手法松解治疗初次全膝关节置换术后早期膝关节僵硬的临床疗效。方法对10例初次全膝关节置换术后早期（6周内）发生膝关节僵硬的患者行髌外侧小切口辅助麻醉下手法松解。其中男性3例,女性7例;术前膝关节平均活动度为（74.4±9.44）°（60°～85°）,平均年龄（72.8±7.18）岁（59～81岁）。排除因感染、假体松动、假体位置不良等明确原因导致术后关节僵硬的患者。术中给予蛛网膜下腔麻醉,反复、柔和、持续地对膝关节进行手法松解,结合髌外侧小切口,使其达到最大的活动度。采用KSS评分对膝关节术前及术后功能进行评价。结果平均随访（2.6±1.04）年（1～4年）,术中能达到的平均活动度为（112.5±9.20）°（100°～125°）,末次随访时平均活动度为（105±6.97）°（95°～115°）。KSS评分从术前平均69分提高到末次随访时平均82分。术前术后KSS评分差异有统计学意义（t=14.40,P〈0.01）。结论髌外侧小切口辅助麻醉下手法松解是治疗初次全膝关节置换术后早期发生膝关节僵硬安全、有效的治疗手段,通过早期治疗,能显著改善膝关节功能。