The Performance of Diagnostic Tests for Identifying Periprosthetic Joint Infection After Failed Partial Knee Arthroplasty

BackgroundIndications for unicompartmental knee arthroplasty (UKA) and patello-femoral arthroplasty are expanding. Despite the lower published infection rates for UKA and patello-femoral arthroplasty than total knee arthroplasty, periprosthetic joint infection (PJI) remains a devastating complication and diagnostic thresholds for commonly utilized tests have not been investigated recently. Thus, this study evaluated if diagnostic thresholds for PJI in patients who had a failed partial knee arthroplasty (PKA) align more closely with previously reported thresholds specific to UKA or the 2018 International Consensus Meeting on Musculoskeletal Infection.MethodsWe identified 109 knees in 100 patients that underwent PKA with eventual conversion to total knee arthroplasty within a single healthcare system from 2000 to 2021. Synovial fluid nucleated cell count and synovial polymorphonuclear percentage in addition to preoperative serum erythrocyte sedimentation rate, serum C-reactive protein, and serum white blood cell count were compared with Student’s t-tests between septic and aseptic cases. Receiver operating characteristic curves and Youden’s index were used to assess diagnostic performance and the optimal cutoff point of each test.ResultsSynovial nucleated cell count, synovial polymorphonuclear percentage, and serum C-reactive protein demonstrated excellent discrimination for diagnosing PJI with an area under the curve of 0.97 and lower cutoff values than the previously determined UKA specific criteria. Serum erythrocyte sedimentation rateESR demonstrated good ability with an area under the curve of 0.89.ConclusionSerum and synovial fluid diagnostic thresholds for PJI in PKAs align more closely with the thresholds established by the 2018 International Consensus Meeting as compared to previously proposed thresholds specific to UKA.Level of EvidenceLevel III, retrospective comparative study.     

Extended Oral Antibiotic Prophylaxis After Aseptic Revision Total Hip Arthroplasty: Does It Decrease Infection Risk?

BackgroundExtended oral antibiotic prophylaxis (EOA) has been shown to reduce infection after high-risk primary total hip arthroplasties (THAs) and reimplantations. However, data are limited regarding EOA after aseptic revision THAs. This study evaluated the impact of EOA on infection-related outcomes after aseptic revision THAs.MethodsWe retrospectively identified 1,107 aseptic revision THAs performed between 2014 and 2019. Patients who received EOA >24 hours perioperatively (n = 370) were compared to those who did not (n = 737) using an inverse probability of treatment weighting model. Their mean age was 65 years (range, 19-98 years), mean body mass index was 30 kg/m² (range, 16-72), and 54% were women. Outcomes included cumulative probabilities of any infection, periprosthetic joint infection (PJI), and re-revision or reoperation for infection. Mean follow-up was 4 years (range, 2-8 years).ResultsThe cumulative probability of any infection after aseptic revision THA was 2.3% at 90 days, 2.7% at 1 year, and 3.5% at 5 years. The cumulative probability of PJI was 1.7% at 90 days, 2.1% at 1 year, and 2.8% at 5 years. There was a trend toward an increased risk of any infection (hazards ratio [HR] = 2.6; P = .058), PJI (HR = 2.6; P = .085), and re-revision (HR = 6.5; P = .077) or reoperation (HR = 2.3; P = .095) for infection in patients who did not have EOA at the final clinical follow-up.ConclusionsEOA after aseptic revision THA was not associated with a statistically significant decreased risk of any infection, PJI, or re-revision or reoperation for infection at all time points.Level of EvidenceLevel III.     

The National Trend in Arthroplasty Surgery Location and the Economic Impact on Surgeons,Hospitals and ASCs

BackgroundWe sought to understand the magnitude of the shift in care settings (hospital inpatient, hospital outpatient, or ambulatory surgery center) for primary total joint arthroplasty (TJA) and its economic impact on surgeons and hospitals.MethodsWe measured the shift in care settings for primary TJAs using national 100% sample Medicare fee-for-service (FFS) claims data from January 2017 through March 2021. We also measured the percent of case being discharged the same day over time. We calculated the national average hospital payment rate by setting and the weighted average hospital payment rates based on the mix of inpatient and outpatient cases over time. We compared average facility and physician payment rate changes over time across common types of surgeries.ResultsBy the first quarter of 2021, 29% of Medicare FFS primary TJAs were performed hospital inpatient (down from 100% in 2017), 64% were performed hospital outpatient, and about 7% in an ambulatory surgery center. The percent of hospital-based primary TJAs that were discharged the same day increased from less than 2% in the first quarter of 2018 to over 18% in the first quarter of 2021. Medicare increased its payment rates for both inpatient and outpatient TJAs, which offset the impact of TJAs shifting from being performed inpatient to outpatient. The average Medicare payment rates for TJAs declined by more than they did for most other major procedures.ConclusionThere was a significant shift in care setting from hospital inpatient to hospital outpatient for Medicare primary TJAs. This shift led to lower average TJA payment rates to hospitals; however, the impact was attenuated due to the increasing Medicare reimbursement rates in each setting, particularly for outpatient cases.     

The Efficacy and Safety of Periarticular Injection in Total Joint Arthroplasty: A Direct Meta-Analysis

BackgroundPeriarticular injection (PAI) is administered intraoperatively to help reduce postoperative pain and opioid consumption after primary total joint arthroplasty (TJA). The purpose of this study was to evaluate the efficacy and safety of PAI in primary TJA to support the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Medicine.MethodsThe MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched for studies published prior to March 2020 on PAI in TJA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of PAI.ResultsThree thousand six hundred and ninety nine publications were critically appraised to provide 60 studies regarded as the best available evidence for an analysis. The meta-analysis showed that intraoperative PAI reduces postoperative pain and opioid consumption. Adding ketorolac or a corticosteroid to a long-acting local anesthetic (eg, ropivacaine or bupivacaine) provides an additional benefit. There is no difference between liposomal bupivacaine and other nonliposomal long-acting local anesthetics. Morphine does not provide any additive benefit in postoperative pain and opioid consumption and may increase postoperative nausea and vomiting. There is insufficient evidence to draw conclusions on the use of epinephrine and clonidine.ConclusionStrong evidence supports the use of a PAI with a long-acting local anesthetic to reduce postoperative pain and opioid consumption. Adding a corticosteroid and/or ketorolac to a long-acting local anesthetic further reduces postoperative pain and may reduce opioid consumption. Morphine has no additive effect and there is insufficient evidence on epinephrine and clonidine.     

Survivorship and Outcomes of Femoral Neck Preserving Stems in Primary Total Hip Arthroplasty

BackgroundShort-stem femoral implants (SSFIs) promote the preservation of bone in the femoral neck, reduce soft tissue disruption, and facilitate minimally invasive surgical techniques. The purpose of this study was to report the revision rate, complication rate, patient satisfaction, patient-reported outcomes, and radiographic outcomes of patients who underwent total hip arthroplasty (THA) with the Alteon Neck Preserving Femoral Stem (ANPS).MethodsA prospectively maintained database was reviewed which analyzed 92 THAs between the years 2016 and 2018. Patient-reported outcomes, patient satisfaction, complication rates, and radiographic outcomes were assessed at 2-5 years postoperatively.ResultsThe final cohort consisted of 63 hips. Five patients (7.9%) underwent revision surgery and 2 (3.2%) had other complications not requiring revision. Survivorship when considering only the femoral component was 93.7% at an average of 41.4 months of follow-up. The average postoperative Oxford Hip Score (41.5 ± 8.3) and Harris Hip Score (77.9 ± 16.6) demonstrated significant improvement among our nonrevised patients, respectively (P < .001). Radiographs demonstrated spot welding in 56% of arthroplasties most commonly in Gruen Zones 2, 3, and 13 and that femur radiolucencies were visualized in 58% predominantly along the distal aspect of the stem. Radiographic femoral component subsidence was present in 9.7% of patients.ConclusionThe ANPS may be less reliable than previously reported. Our cohort’s revision rate was unacceptably high with 6.3% requiring revision surgery for femoral component loosening in less than 5 years. Surgeons should consider the challenges and prohibitive failure rate associated with SSFIs before routine usage in THA.     

Same-Day Discharge Total Hip and Knee Arthroplasty: Trends,Complications, and Readmission Rates

BackgroundAlthough total hip arthroplasty (THA) and total knee arthroplasty (TKA) are transitioning to surgery centers, there remain limited data on trends, comorbidities, and complications in patients discharged the same day of surgery. In addition, many studies are limited to the Medicare population, excluding a large proportion of outpatient surgery patients.MethodsPrimary, elective THA/TKA cases between 2010 and 2017 were retrospectively identified using the PearlDiver All-Payer Database and separated based on surgery as well as same-day discharge (SDD) or non-SDD. Data were collected on demographics, rates, comorbidities, and complications. Multivariable logistic regression determined adjusted odds ratios (ORs) for 90-day complications requiring readmission for each group.ResultsIn total, 1,789,601 (68.8% TKA, 31.2% THA) patients were identified where 2.9% of TKAs and 2.2% of THAs were SDD. Annual SDD rates are increasing, with a 15.8% mean annual change for SDD-THA and 11.1% for SDD-TKA (P < .001). SDD patients were younger with fewer comorbidities (P < .001). Regression analysis showed an overall slightly higher OR of complications requiring readmission for SDD-TKA vs non-SDD-TKA (OR 1.14, 95% confidence interval [CI] 1.07-1.21, P < .001). There was no significant difference for SDD-THA vs non-SDD-THA (OR 1.03, 95% CI 0.94-1.13, P = .49). In univariate analysis, SDD-THA vs SDD-TKA had more mechanical complications (P < .001), but less pulmonary embolisms (P < .001). Regression analysis showed a slightly higher risk of complications for SDD-THA vs SDD-TKA (OR 1.19, 95% CI 0.99-1.44, P = .05).ConclusionThe prevalence of SDD is rising. SDD-THA is increasing more rapidly than SDD-TKA. SDD patients are generally younger with fewer comorbidities. SDD-TKA has slightly higher odds of complications requiring readmission than non-SDD-TKA. SDD-THA and SDD-TKA have different complication profiles.     

High resolution T21 mapping in assessment of knee articular cartilage on 3T MRI

ObjectiveTo evaluate the spectrum of T21 values in healthy cartilage of young asymptomatic adults on high resolution 3T MRI.MethodsA total of 50 asymptomatic adult volunteers with age ranging from 18 to 35 years were enrolled for the study with the purpose of assessing T21 values in healthy cartilage without any degenerative changes. The articular cartilage was assessed on two sections, one each through the medial and lateral compartments. The cartilage was segmented into 8 regions through the tibio-femoral and patella-femoral joints. Further post processing was done using multiple ROI placement to delineate ROI areas for calculation of full thickness and zonal (superficial and deep) T21 values. Thus, a total of 1200 ROI areas (50 volunteers, 8 segments, and 3 areas for each segment) were assessed.ResultsThe results revealed a superior bulk T21 value of 29.2 ± 3.6 ms from the posterior medial femoral cartilage and 26.1 ± 3.1 ms from the patellar region. Intermediate values were obtained from posterior lateral femoral cartilage, central femoral cartilage, and trochlea. The tibial plateau cartilage had the lowest values – 19.6 ± 2.6 ms for the medial tibial plateau and 20.6 ± 2.8 ms for lateral tibial plateau. The study demonstrated substantial regional physiological variation existing in the T21 values across various regions of the knee joint, which could be attributed to varying amounts of shearing forces across the joint. No significant differences were noted in bulk T21 values between the two genders, with only the trochlear segment revealing significantly increased values in males (p = 0.007). All the cartilage segments revealed significantly increased T21 values in the superficial zone as compared to the deep zone.ConclusionThere is a significant regional difference in the bulk T21 values of articular cartilage in a normal physiological state across various joint segments. A zonal gradient with increasing values from the deep to the superficial zone also exists. These findings can prove invaluable in assessing changes in T21 values occurring in diseased/degenerative cartilage.     

膝关节周围截骨术治疗膝外翻性骨关节炎研究进展北大核心CSCD

目的对近年膝关节周围截骨术治疗膝外翻性骨关节炎的手术方式研究进展进行综述。方法查阅近年国内外膝外翻性骨关节炎截骨手术治疗相关文献,对膝关节周围截骨术不同手术方式的优缺点、疗效进行总结。结果对于有症状且年轻、活动度大的膝外翻性骨关节炎患者,膝关节周围截骨术是一种安全、可靠的治疗选择。目前,临床应用的主要手术方式有股骨远端内侧闭合楔形截骨术、股骨远端外侧张开楔形截骨术、胫骨近端内侧闭合楔形截骨术、胫骨近端外侧张开楔形截骨术。不同截骨手术方式的适应证和优缺点不同,选择正确的截骨手术方式对取得良好的临床疗效至关重要。结论膝关节周围截骨术治疗膝外翻性骨关节炎有多种手术方式,为获得良好预后、提高生存率、减少并发症发生,需要根据不同情况制定最合理的手术策略。     

基于免疫级联反应的蚕蛹浆比色法在关节假体周围感染精准诊断中的实验研究北大核心CSCD

目的探讨蚕蛹浆(silkworm larvae plasma,SLP)比色法在关节假体周围感染(periprosthetic joint infection,PJI)精准诊断中的应用价值。方法取90只健康雄性新西兰大白兔,采用Swanson假体行膝关节置换手术;然后根据致病菌不同随机分为3组:A组(金黄色葡萄球菌组)、B组(表皮葡萄球菌组)及C组(大肠埃希菌组),每组30只。术后第3天膝关节腔内注射1 mL不同浓度致病菌制备PJI模型。分别于接种菌液前及接种后7、14、21 d取样进行检测,参照2018年PJI费城国际共识诊断标准首先判定并计算3组实验动物的造模成功率,并采用SLP比色法计算其在PJI精准诊断中的敏感性、特异性、阳性预测值、阴性预测值和诊断效率。结果接种菌液21 d时,A、B、C组分别有26、18、23只实验动物诊断为感染,造模成功率分别为86.7%、60.0%、76.7%,3组间比较差异无统计学意义(χ^(2)=5.724,P=0.073)。PJI比色法结果显示,A组在7 d时出现1只假阳性动物(特异性75.0%),随时间推移(14、21 d)SLP的特异性升至100.0%;14、21 d,另出现了1只假阴性动物(敏感性由100.0%降至96.2%)。B组在7 d时出现1只假阳性动物(特异性91.7%),随着时间推移特异性回升至100.0%;在14、21 d时分别出现1只和4只假阴性动物(敏感性分别为94.4%及83.3%)。C组在7 d时有2只假阳性动物(特异性71.4%),随后回升至100.0%。A、C组在21 d时诊断效率极高(96.7%和100.0%);即使面对B组低毒力的表皮葡萄球菌,21 d时SLP的诊断效率也可保持在90.0%;总体诊断效率很好(95.6%)。结论 SLP比色法诊断PJI具有较高的敏感性、特异性以及诊断效率,是一种极具潜能的PJI诊断方法。     

双钢板技术及肱二头肌长头腱固定治疗肱骨近端Neer 3~4部分骨折

目的：探讨采用双钢板技术同时进行肱二头肌长头腱固定治疗肱骨近端Neer 3~4部分骨折的临床疗效。方法：2018年5月至2020年12月采用双钢板技术及肱二头肌长头腱固定治疗肱骨近端Neer 3~4部分骨折患者38例,其中男23例,女15例;年龄41~89（67.00±9.76）岁;Neer 3部分骨折23例,Neer 4部分骨折15例;伤后至手术时间5~12（8.00±2.86） d。术后第3天采用单维度疼痛数字评分法（numeric rating scale,NRS）评估疼痛程度;比较术后2 d及1年时肱骨头高度、肱骨颈干角变化情况;术后1年采用Neer评分评定术后肩关节恢复情况。结果：38例患者均获得随访,时间12~19（14.00±1.59）个月。术后3 d时NRS评分（1.95±0.73）分。骨折愈合时间2.2~3.2（2.60±0.27）个月。术后2 d与1年时肱骨头高度、肱骨颈干角比较,差异无统计学意义（P>0.05）。4例Neer 4部分骨折出现肱骨大结节吸收、肱骨头出现部分囊性变,但肩关节活动功能良好。术后1年Neer评分（89.50±5.19）分,其中优20例,良16例,中2例。结论：采用双钢板技术及肱二头肌长头腱固定治疗肱骨近端Neer 3~4部分骨折,治疗效果良好,术后疼痛较轻,手术无须特殊器械。