Polyethylene in knee arthroplasty: A review

Polyethylene (PE) has been used extensively in knee arthroplasty since the mid 20th century. Progress in material manufacturing and processing has led to newer polyethylenes over last few decades with different material properties. It has been established that PE wear in knee arthroplasty causes particle induced osteolysis which is the main reason for late failure and requires revision surgery. Although there are various causes of wear, the properties of PE have long been a matter of investigation as a contributory factor. The advent of newer highly cross linked PE has been shown to improve wear rates in hip arthroplasty but the benefits have not been shown to be of the same degree in knee arthroplasty. The laboratory and clinical studies so far are limited and slightly conflicting in their conclusions. The risks of using highly cross linked PE in knee arthroplasty include tibial post fracture, disruption of locking mechanism, liner fracture which can lead to increased wear and osteolysis. The current evidence suggests that highly cross linked polyethylenes should be used with caution and only considered in younger active patients. The results of a recently completed randomized trial to compare the conventional with high molecular weight PE in knee arthroplasty are awaited.     

Direct oral anticoagulants (DOACs) and neck of femur fractures: Standardising the perioperative management and time to surgery

Demographic projections for hip fragility fractures indicate a rising annual incidence by virtue of a multimorbid, ageing population with more noncommunicable diseases (NCDs). NCDs are characterised by slow progression and long duration ranging from ischaemic cardiovascular disease, cerebrovascular disease, diabetes, chronic obstructive pulmonary disease to various cancers. Management of this disease burden often involves commencing patients on oral anticoagulants to reduce the risk of thromboembolic events. The use of direct oral anticoagulants (DOACs) in clinical practice has increased due to their rapid onset of action, short half-life and predictable anticoagulant effects, without the need for routine monitoring. Safe and timely surgical intervention relies on reversal of anticoagulants. However, the lack of specific evidence-based guidelines for the perioperative management of patients on DOACs with hip fractures has proved challenging; in particular, the accessibility of DOAC-specific assays, justification of the cost-benefit ratio of targeted reversal agents and indications for neuraxial anaesthesia. This has led to potentially avoidable delays in surgical intervention. Following a literature review of the pharmacokinetic and pharmacodynamics of commonly used DOACs in our region including the role of surrogate markers, we propose a systematic, evidence-based guideline to the perioperative management of hip fractures DOACs. We believe this standardised protocol can be easily replicated between hospitals. We recommend that if patients are deemed suitable for a general anaesthesia, with satisfactory renal function, optimal surgical time should be 24 h following the last ingested dose of DOAC.     

Longer Operative Time Results in a Higher Rate of Subsequent Periprosthetic Joint Infection in Patients Undergoing Primary Joint Arthroplasty

Background

Whether prolonged operative time is an independent risk factor for subsequent surgical site infection (SSI) and periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant and underexplored issue. The aim of this study is to investigate the association between operative time and the risk of subsequent SSI and PJI in patients undergoing primary TJA.

Outcomes After Aortic Valve Replacement for Asymptomatic Severe Aortic Regurgitation and Normal Ejection Fraction

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Intra-articular Hymovis injection for managing hip OA in active sportsmen. A 24-month observational retrospective clinical investigation

BackgroundHip Osteoarthitis (OA) risk is sport-specific and depends on frequency, intensity, and type of mechanic stress the hip is subjected to. This retrospective observational study aims to investigate the safety and performance of Hymovis (HYADD-4) injection, a hexadecyl (C-16) HA-derivative, when used to manage symptomatic hip OA in active middle-aged sportsmen over a 24-month observation period.MethodsThe retrospective analysis included clinical records of active sportsmen, aged between 40 and 65 years, and suffering from symptomatic Kellgren-Lawrence grade II to III hip OA, treated with two (24 mg/3 ml) Hymovis injections, two weeks apart, every 3–4 months, for two years. When available, data on MRI examination were included in the analysis as well as Heidelberg Sports Activity Score (HAS) and Copenhagen Hip and Groin Outcome Score (HAGOS) questionnaires.ResultsThirty patients (56.4 ± 7.3 years) were included in the study, sixteen cyclists and 14 tennis players. For all patients, HAS and most HAGOS scores improved significantly (p < 0.05) at the first control visit (4 months) and further improved over time. For all other scores an important clinical benefit was experienced by more than 50% of participants. No adverse events were recorded.ConclusionTreatment of hip OA in active sportsmen with Hymovis seems a safe and effective approach for the management of OA symptoms, by potentially protecting cartilage and subchondral bone from further damage.     

不同手术方法治疗复杂胫骨平台骨折临床疗效观察

目的探讨不同手术方法治疗复杂胫骨平台骨折临床疗效。方法选择2016年1月—2018年12月84例复杂胫骨平台骨折患者,随机分组。单侧锁定钢板内固定组选择单侧锁定钢板内固定手术,双侧切口双侧解剖钢板内固定组选择双侧切口双侧解剖钢板内固定。分析手术操作时间、手术失血、平均住院天数以及复杂胫骨平台骨折愈合时间;治疗前后患者视觉模拟评分和Rasmussen膝关节功能评分;膝关节僵硬发生率。结果双侧切口双侧解剖钢板内固定组视觉模拟评分和Rasmussen膝关节功能评分、手术操作时间、手术失血、平均住院天数以及复杂胫骨平台骨折愈合时间、膝关节僵硬发生率和单侧锁定钢板内固定组比较有优势,P<0.05。结论复杂胫骨平台骨折患者实施双侧切口双侧解剖钢板内固定可获得较好效果。     

The effects of increased forward trunk lean during stair ascent on hip adduction and internal rotation in asymptomatic females

BackgroundIncreased hip adduction and internal rotation can lead to excessive patellofemoral joint stress and contribute to patellofemoral pain development. The gluteus maximus acts as a hip extensor, abductor, and external rotator. Improving hip extensor use by increasing one’s forward trunk lean in the sagittal plane may improve frontal and transverse plane hip kinematics during stair ascent.Research questionDoes increasing forward trunk lean during stair ascent affect peak hip adduction and internal rotation?MethodsTwenty asymptomatic females performed five stair ascent trials (96 steps/min) on an instrumented stair using their self-selected and forward trunk lean postures. Three-dimensional kinematics (200 Hz) and kinetics (2000 Hz) were recorded during the stance phase of stair ascent. Biomechanical dependent variables were calculated during the stance phase of stair ascent and included peak forward trunk lean, hip flexion, hip adduction, hip internal rotation angles, and the average hip extensor moment.ResultsDuring the forward trunk lean condition, decreases were observed for peak hip adduction (MD = 2.8˚; 95% CI = 1.9, 3.8; p < 0.001) and peak hip internal rotation (MD = 1.1˚; 95% CI = 0.1, 2.2; p = 0.04). In contrast, increases were observed during the forward trunk lean condition for the peak forward trunk lean angle (MD = −34.7˚; 95% CI = −39.1, −30.3; p < 0.001), average hip extensor moment (MD = −0.5 N·m/kg; 95% CI = −0.5, −0.4; p < 0.001), and stance time duration (MD = −0.02 s; 95% CI = −0.04, 0.00; p = 0.017).SignificanceIncreasing forward trunk lean and hip extensor use during stair ascent decreased peak hip adduction and internal rotation in asymptomatic females. Future studies should examine the effects of increasing forward trunk lean on hip kinematics, self-reported pain, and function in individuals with patellofemoral pain.     

Effect of contralateral cane use on hip moment impulse in the frontal plane during the stance phase

BackgroundRecent reports have shown that the daily cumulative moment in the frontal plane (i.e., product of hip moment impulse in the frontal plane during the stance phase and mean steps per day) is a risk factor for hip osteoarthritis. This study aimed to clarify the effect of contralateral cane use on hip moment impulse in the frontal plane of the stance limb.MethodsThis study included 15 healthy subjects who walked under four experimental conditions: (1) without a cane and (2–4) contralateral cane use with 10%, 15%, and 20% body weight support (BWS), respectively. To maintain the same walking speed in all conditions, the cadence was set to 80 steps/min, and the step length was fixed. The hip moment impulses in the frontal plane (i.e., area under the hip ab-adduction moment waveform) and peak hip adduction moments in all conditions were calculated.ResultsContralateral cane use significantly decreased the hip moment impulse in the frontal plane and peak hip adduction moment compared to non-cane use. Moreover, the hip moment impulse in the frontal plane and peak hip adduction moment decreased significantly with increased cane BWS. There were no significant differences in walking speed, cadence, and step length between the four conditions.ConclusionContralateral cane use decreases the hip moment impulse in the frontal plane and peak hip adduction moment in the stance limb. These findings may help clarify how to delay the progression of hip osteoarthritis.