Does the brake response time of the right leg change after left total knee arthroplasty? A prospective study

Patients undergoing total knee arthroplasty often ask when they can safely resume car driving. There is little evidence available on which physicians can rely when advising patients on this issue. In a prospective study we assessed the brake response time of 24 patients admitted to the clinic for left total knee arthroplasty preoperatively and then 10 days after surgery. On each measurement day the patients performed two tasks, a simple and a complex brake response time task in a car simulator. Ten days after left TKA the brake response time for the simple task had decreased by 3.6% (p=0.24), the reaction time by 3.1% (p=0.34) and the movement time by 6.6% (p=0.07). However, the performance improvement was not statistically significant. Task complexity increased brake response time at both time points. A 5.8% increase was significant (p=0.01) at 10 days after surgery. Based on our results, we suggest that patients who have undergone left total knee arthroplasty may resume car driving 10 days after surgery as long as they drive a car with automatic transmission.     

Does arthroplasty type influence knee joint proprioception? A longitudinal prospective study comparing total and unicompartmental arthroplasty

Proprioception was assessed after knee replacement to compare total (TKA) to unicompartmental (UKA) knee arthroplasty. Thirty-four patients were recruited; seventeen patients underwent TKA and seventeen patients underwent UKA. The patient's age was similar in both groups. Two measures of proprioception, joint position sense (JPS) and postural sway (PS) were measured. Function was assessed using the Oxford Knee Score (OKS). Measurements were taken pre-operatively and 6 months post-operatively on both the operated and contralateral leg. Pre-operatively, no differences in JPS or PS were found between groups or between limbs in either group. Post-operatively, both groups had significant improvement of JPS in the operated limb only (20% increase). The improvement in JPS was similar in both groups. PS also improved significantly in both groups although the improvement of PS in the UKA group was twice that for the TKA group. The OKS improved by a similar amount in both groups. Both UKA and TKA result in a significant improvement in proprioception. Dynamic aspects of proprioception improve more after UKA than TKA, which may explain, in part, why UKA patients have superior functional outcome to that of TKA patients.     

How to quantify knee function after total knee arthroplasty?

Total knee arthroplasty (TKA) is being undertaken in a younger population than before and as a result the functional demands on the knee are likely to be increasing. As a consequence, it is important to define quantitative functional knee tests that can monitor any increase.A valuable functional knee test has to be able to distinguish small differences (selectivity) and has to be independent of pain (content validity). In this study, patient-based questionnaires (WOMAC and Knee Society score) and performance-based tests (sit-to-stand movement, maximal isometric contraction and timed-up-and-go) were used to assess which of these tests are selective and valid to measure knee function. Tests were considered to be selective if they could discriminate between knee patients and healthy control subjects, and to have functional content validity if they were relatively independent of pain. Twenty-eight patients were measured 16 months after surgery and compared to a healthy control group of 31 subjects.The sit-to-stand movement and timed-up-and-go test were both selective and functionally content valid. The timed-up-and-go test can be used for a quick initial assessment of global function and the sit-to-stand movement as a more biomechanical instrument identifying how the knee function of the patient is affected.     

Does standing limb alignment after total knee arthroplasty predict dynamic alignment and knee loading during gait?

Background

A principle of TKA is to achieve a neutral standing coronal alignment of the limb (HKA angle) to reduce risks of implant loosening, reduce polyethylene wear, and optimize patellar tracking. Several long-term studies have questioned this because the relationship between alignment and implant survivorship is weaker than previously reported. We hypothesize that standing HKA poorly predicts implant failure because it does not predict dynamic HKA, dynamic adduction moment, and loading of the knee during gait. Therefore, the aim of our study is to assess the relationship between the standing and the dynamic (gait activity) HKAs.

Does activity in research correlate with visibility?

BACKGROUND: A previous survey has highlighted the fact that most individuals in chemical pathology identifiable from specialist society membership failed to publish material in Medline cited journals during a five year period. It could be considered that published research that is not cited in other work is not useful unless it has achieved visibility, as demonstrated by citation in another research publication. AIMS: To determine whether the frequency of research publication is associated with research visibility. METHODS: A random selection from the previous survey was investigated to determine whether the frequency of research publication is associated with research visibility. RESULTS: There was a logarithmic relation between the frequency of publication and visibility, with an increasing probability of citation as publication frequency increases. CONCLUSIONS: If academic activity is to survive then individuals must stay active in research; this requires a continuing commitment to a tradition of support for individuals at all stages of their careers engaging in research.     

Does cruciate-retaining total knee arthroplasty enhance knee flexion in Western and East Asian patient populations? A meta-analysis

IntroductionThis study analyzed the published data to examine if CR TKAs can enhance the flexion and functional outcomes of the knee in the Western and East Asian populations using a meta-analysis approach.Materials and methodsA systematic review of literature published through Medline and EMBASE was conducted. The inclusion criteria were: primary TKA, follow up duration greater than one year, a fixed bearing CR prosthesis, and data for maximum pre- and post-operative flexion along with standard deviations or errors. We estimated the weighted mean differences between pre- and post-operative flexion, extension and knee scores (KSS and HSS) via a random effect model.ResultsSeventeen articles were selected and reviewed among 1229 studies that included 1090 knees of the Western and 516 knees of the East Asian. No significant difference was noted in maximal knee flexion pre- and post-operatively, when all the studies were pooled together (? 0.17°, p = 0.93, post-operative < pre-operative). The mean difference in flexion was ? 1.87° (p = 0.2) and 2.03° (p = 0.17), respectively in the both populations. However, the extension angle was significantly improved by ? 5.49° and ? 13.05° (p < 0.05), respectively. KSS scores were significantly improved by 46.39 and 51.63, and HSS scores by 36.65 and 30.67 (p < 0.05), respectively in the both populations.ConclusionThe meta-analysis indicated that contemporary CR TKAs have not been shown to enhance post-operative flexion capability in the Western and East Asian. The extension angles of the knee and the knee scores were significantly improved in both populations.     

Short term patient outcomes after total knee arthroplasty: Does the implant matter?

BackgroundNewer implants for total knee arthroplasty (TKA) often gain market share at higher cost with little patient-reported and long-term clinical data. We compared outcomes after TKA using two different implants: DePuy PFC Sigma and Attune.MethodsUsing a prospective data repository from an academic tertiary medical center, we analyzed 2116 TKAs (1603 Sigma and 513 Attune) from April 2011 through July 2016. Outcomes included length of surgery, length of stay, facility discharge, 90-day reoperation, range of motion (ROM) change, and patient-reported physical function (PCS).ResultsThere was no difference in length of surgery (Attune ? 2.87 min, P = 0.143). Implant type was not associated with extended LOS (> 3 days) (OR 0.80, P = 0.439). There was no difference in facility discharge (OR 0.65, P = 0.103). Unadjusted 90-day reoperations were 0.3% for Sigma and 1.0% for Attune cohorts (P = 0.158). Sigma implants were associated with more ROM improvement in unadjusted analyses (+ 2.1 degree improvement P = 0.031). Fifty nine percent of the Sigma cohort and 49% of the Attune cohort achieved the minimal clinically important (MCID) change for PCS improvement, although there was no adjusted difference in achieving MCID (Attune OR 0.84, P = 0.435). There was no adjusted difference in absolute PCS improvement (Attune + 0.12 score, P = 0.864).ConclusionsOur data show no difference in physical function and most outcomes between Sigma and Attune. Attune implants had shorter absolute LOS, but there were no differences in extended LOS.     

Does new instrumentation improve radiologic alignment of the Oxford® medial unicompartmental knee arthroplasty?

Background

A new instrument system has been introduced to improve the accuracy and reproducibility of implant positioning in Oxford® unicompartmental knee arthroplasty (UKA). This study aimed to determine if the new instrumentation could improve postoperative implant positioning and limb alignment, and reduce the occurrence of outliers in Oxford® UKA.

Does infrapatellar fat pad resection in total knee arthroplasty impair clinical outcome? A systematic review

IntroductionThe infrapatellar fat pad (IPFP) is often removed during total knee arthroplasty (TKA). No evidence based guidelines on changes in clinical outcome have yet been described. The aim of this review is to investigate whether regular removal of the IPFP during TKA should be performed.Material and methodsSeven databases were systematically searched. Clinical studies, in which TKA with IPFP resection was compared with IPFP preservation, were included. Risk of bias was assessed using the Cochrane collaboration tool. Studies reporting anterior knee pain, patellar tendon length, range of motion, patellar vascularisation or functional outcome were included.ResultsThe indication for TKA varied in the different studies: osteoarthritis (OA), rheumatic arthritis (RA) and multiple indications (OA, RA and osteonecrosis).After IPFP resection: 1. For OA, no differences in function, range of motion, and anterior knee pain were found. 2. In the RA study, there was a trend towards more discomfort and a decrease in function. 3. In OA and RA patients a decrease in patellar tendon length was observed. 4. One study reported no decrease in patellar vascularisation.DiscussionLimitations of this review are the high risk of bias scores of the included studies, the varying outcome measures, follow up, number and type of participants.Randomised clinical trials are required to support or refute the results, contributing to a possible future evidence based guideline on IPFP resection during TKA.     

Does temporary clamping of drains following knee arthroplasty reduce blood loss? A randomised controlled trial

In a randomised, blinded study 76 patients undergoing primary total knee arthroplasty were assigned to either immediate drain opening (n=45) or drains opened at 2 h (n=31). No significant differences were found between the groups for the volume of drained blood, transfusion requirements, knee motion or wound status. The authors conclude that the practice of clamping drains has no benefit in routine knee arthroplasty. However, when faced with immediate brisk blood loss, the results suggest that drains can be clamped without any excess morbidity.     

Does elastic tissue intrafraction motion with density changes forbid motion-compensated radiotherapy?

Intrafraction organ motion disturbs the otherwise highly conformal dose distributions planned for conformal radiotherapy and intensity-modulated radiotherapy. If the organ motions are rigid-body translations and preserve voxel density, techniques to make the beam follow the target by synchronous breathing can be arranged. Several potential difficulties disturb this oversimple statement and one of these is addressed in this paper. The effects of general elastic motion without preserving density are investigated. The effects are complex. Dose-space voxels disconnect from the planned irradiation bixel; voxels in a set aligned with a particular bixel cease to be so aligned even with a different bixel on elastic motion. Furthermore the density changes to conserve mass and this further perturbs the dose distribution. These effects are demonstrated here via simple examples but it may be impossible to make 'beam-breathing' strategies to compensate for them. Consequently understanding (and possibly ignoring) these second-order effects may be all that is possible.     

Does pre-operative anxiety and/or depression affect patient outcome after primary knee replacement arthroplasty?

Background

Chronic pain is associated with psychological distress, most commonly manifested as anxiety and/or depression.

Factors associated with non-home discharge after total knee arthroplasty: Potential for cost savings?

IntroductionIncreasing demand for total knee arthroplasties (TKA) has been targeted by legislation to minimize costs and maximize outcomes. Home discharges reduce costs, and it is important to determine patient variables associated with this discharge disposition. We explored non-modifiable and modifiable factors associated with non-home discharges to determine what patient specific factors require attention.MethodsThis retrospective study included 171,903 National Surgical Quality Improvement Program (NSQIP) patients between 2011 and 2016. Patient specific variables and discharge destinations included home, short-term nursing facilities (SNF), not home, and rehabilitation. Chi-squared analyses and analyses of variance (ANOVA) were conducted for categorical and continuous data, respectively. Multinomial regression model was utilized to assess associations between discharge destination and patient specific variables.ResultsEvery year increase above the mean age (66 years) was associated with a nine percent (p < .001) and six percent (p < .001) increased odds for discharge to SNF or rehabilitation, respectively, compared to home discharges. Every 10% increase in BMI from the mean was associated with a 10% increase in discharge to both SNF and rehabilitation (p < .001 for both).ConclusionWith increasing demands for TKAs and expenditures to Medicare, evaluating factors that impact patient discharge can help optimize costs and outcomes of TKA procedures. Arthroplasty surgeons can benefit by recognizing these correlations and exploring reductions to non-home discharges through pre-operative patient optimization. Future studies should evaluate the economic cost potential associated with optimizing routine home discharge in TKA patients.Level of Evidence: IV.     

Does cerebral activity change in middle-aged adults in a visual discrimination task?

The purpose of this study was to assess changes in cerebral activity in middle-aged adults (MA: 50 years) compared to young adults (YA: 20 years). Subjects had to compare the duration or the intensity of a visual stimulus with a previously memorized standard. Evoked potentials were recorded, and a dipole model (obtained from PET data on young adults) was applied for fitting late-latency components. MA performance was poorer than YA performance. Task-specific ERP late components were found (P3 in intensity, CNV in duration), but P3 had a lower amplitude and CNV was less frontal in MAs compared to YAs. The activity of the dipoles that generate late components - cuneus in the intensity task, right frontal in the duration task, and anterior cingulate in both tasks-was less ample or less peaked in MAs than in YAs. This study characterizes neurobiological effects of aging that may already be visible during midlife.     

Does patchouli oil change blood platelet monoamine oxidase-A activity of adult mammals?

Patchouli oil, an essential aroma oil extracted from patchouli leaf during short-term exposure with five and ten drops either inhibited (at 1 or 2 h) or stimulated (at 4 h) the platelet MAO-A activity depending on the dosages of the aroma oil mainly due to inhibition or stimulation of its K _m. The long-term 15 consecutive days exposure (with two or five drops) of patchouli oil, on the other hand, maximally stimulated the platelet MAO-A activity with five drops patchouli oil for 1 h exposure, but further continuation of its exposure with same doses (two or five drops) for 30 consecutive days significantly stimulated (with two drops) and inhibited (with five drops) the platelet MAO-A activity due to stimulation and inhibition respectively of its corresponding both K _m and V _max. These results thus suggest that this aroma oil exposure may modulate the blood platelet serotonergic regulation depending on the dose, duration, and conditions of exposure.     

Does adding corticosteroids to periarticular injection affect the postoperative acute phase response after total knee arthroplasty?

BackgroundPeriarticular injection (PAI) can reduce pain and improve early outcomes following total knee arthroplasty (TKA). Although corticosteroid PAI has been reported to be safe and effective, investigations on the postoperative acute phase response (APR) are scarce.MethodsThis retrospective cohort study with propensity score matching investigated two groups of patients after TKA: the steroid group (n = 50) received an intraoperative corticosteroid PAI (methylprednisolone 40 mg); the non-steroid group (n = 50) did not receive the corticosteroid. To evaluate the APR, C-reactive protein (CRP) levels and erythrocyte sedimentation rates (ESR) were determined preoperatively and on postoperative day (POD) 2, 4, 6, 14, and 28. A visual analogue scale (VAS) was used to measure pain on the night of surgery and on POD 1, 2, 4, and 6. Maximal flexion at discharge (POD 7), morphine equivalent dose (MED), and complications were also evaluated.ResultsThe steroid group showed significantly lower CRP levels on POD 2 (P < .05) and POD 4 (P < .05) but a higher CRP level on POD 6 (P < .05). However, ESR levels did not differ between the two groups in all measurements. Peak values in CRP and ESR in the steroid group (POD 4 and 6) appeared two days later compared with the non-steroid group (POD 2 and 4). The VAS pain score was significantly lower in the steroid group on POD 2 (P < .05). Maximal flexion on discharge, MED and complication rate were similar in the two groups.ConclusionsAdding a corticosteroid to the PAI following TKA attenuated the APR, and also provided significant pain relief.     

Does surgical volume affect outcome after primary and revision knee arthroplasty? A systematic review of the literature

BackgroundIn 2009 there were 72,980 primary and 4565 revision knee arthroplasties performed in England and Wales [1]. Given the large number of procedures done annually any factors that may influence outcome and benefit the patient must be considered seriously.ObjectivesTo find out whether a relationship exists between hospital and surgical volume and patient outcomes for primary and revision knee arthroplasty. A systematic review of the literature was performed to evaluate the current evidence using the PRISMA criteria [2].Data sourcesA computerised literature search was performed on the electronic databases PubMed, Medline, Embase and CINAHL between 1973 and 2011.Study eligibility criteriaAll abstracts, in the English language, pertaining to either surgical or hospital volume and outcome after primary and revision knee arthroplasty between 1973 and 2011 were considered. Outcomes of interest included morbidity, mortality, clinical and economic outcomes.ConclusionsBoth the orthopaedic and surgical specialties literature demonstrates a clear and consistent relationship between both surgeon and hospital volume with outcome, higher volume being associated with improved patient outcomes. In view of the literature consideration should be given to whether all orthopaedic operations should be carried out by all surgeons in all hospitals.     

Does overstuffing of the patellofemoral joint in total knee arthroplasty have a significant effect on postoperative outcomes?

Background

There is ongoing debate in the literature as to whether or not patellofemoral joint overstuffing has a clinically significant effect on postoperative outcomes following total knee arthroplasty (TKA). This study investigates the effect of patellofemoral joint overstuffing on patient-reported outcomes using novel methods of radiographic measurement.