Does a knee joint position sense test make functional sense? Comparison to an obstacle clearance test following anterior cruciate ligament injury

ObjectivesTo evaluate knee joint position sense (JPS) among individuals with anterior cruciate ligament reconstruction (ACLR), cleared for return to sport, and investigate whether JPS errors are associated with outcomes of a functional obstacle clearance test (OC; downward vision occluded).DesignCross-sectional.SettingControlled laboratory.ParticipantsThirty-four individuals following ACLR, 23 non-athletic asymptomatic controls (CTRL), 18 athletes (ATH).Main outcome measuresabsolute error (AE) and variable error (VE) for weight-bearing knee JPS (target angles: 40°, 65°); minimal distances of the lower extremity from the obstacle (at any time and vertical clearance; two obstacle heights).ResultsLarger AE (P = 0.023) and VE (P = 0.010) were observed for CTRL compared with ACLR. CTRL also had larger OC distances for the trailing leg compared with ATH (P ≤ 0.046) and greater variability compared to both other groups (P ≤ 0.033). Moderate positive correlations (R_s ≥ 0.408, P ≤ 0.029) were observed between AE for the 40° angle and low-obstacle distances, for the injured ACLR leg.ConclusionsKnee JPS was worse in less-active individuals rather than following ACLR. Functional assessments like our OC test should complement isolated JPS tests, as they emphasize whole-body coordination and thus constitute more relevant estimations of proprioception.     

Postural control in karate practitioners: Does practice make perfect?

BackgroundKarate training likely leads to enhanced postural control, however, previous studies did not always include a healthy, physically active comparison group and the findings are inconsistent.Research questionWill the postural control of experienced karate practitioners be better than that of experienced swimmers, i.e., athletes with similar characteristics who do not practice under conditions that require upright postural control?MethodsIn this cross-sectional study, 20 experienced, male karate practitioners and 20 experienced, male swimmers, ages 20-50, performed four standing postural control tasks of increasing difficulty: (a) two-legged stance with eyes open; (b) one-legged stance with eyes open; (c) one-legged stance with eyes closed, and (d) a dual-task, one-legged stance with eyes closed and a verbal fluency challenge. The primary outcome measure was a functional, behavioral measure that reflects the loss of balance. Specifically, in tasks that included one-legged stance, every touch of the raised foot to the floor was counted. Center-of-gravity movements were measured using a wearable sensor.ResultsTask-related differences were seen in all of the postural control measures. In the OneLegEyesClosed task, the median number of touches was 0.00 in the karate group and 6.50 in the swimming group (p < 0.001). In the OneLegEyesClosedWords task, the median number of touches was 0.00 in the karate group and 5.00 in the swimming group (p < 0.001). Shannon entropy, a measure of the complexity of the sway of the center-of-gravity, was lower in the karate group (p = 0.002), compared to the swimmers.SignificanceKarate training is associated with a higher level of postural control, even when compared to a physically active age-matched comparison group. In addition to supporting the specificity of exercise training principle, these findings raise the intriguing possibility that karate may be useful as a form of pre-habilitation, potentially aiding in the prevention of age-associated declines in balance control.     

Physician-staffed HEMS dispatch in the Netherlands: Adequate deployment or minimal utilization?

INTRODUCTION: In the Netherlands, a physician-staffed helicopter emergency medical system (HEMS), called the Helicopter Mobile Medical Team (HMMT), provides prehospital care for severely injured patients in addition to ambulance services. This HMMT has proven to increase chances of survival and reduce morbidity. HMMT dispatch is performed following certain dispatch criteria. The goal of this study was to analyze actual dispatch rates and assess the protocol adherence of the emergency dispatchers in Rotterdam regarding HMMT dispatch. METHODS: All high priority ambulance runs between April 1 and July 1, 2003, were prospectively documented and cross-referenced to dispatch criteria. It was determined whether the emergency call warranted either immediate dispatch of the HMMT or a secondary dispatch after arrival of the first ambulance. When dispatch actually occurred, this was also documented. RESULTS: In The Studied Period A Total Of 5765 A1 Ambulance Runs During Daylight Were Documented. Of These, 1148 Runs Met Primary Dispatch Criteria And 38 Runs Met Secondary Dispatch Criteria. Actual Hmmt Dispatch Occured In 162/1186 (14%) Cases. CONCLUSIONS: HEMS dispatch rates and dispatch criteria adherence are low (14%). Better protocol adherence by emergency dispatchers could lead to a sevenfold increase of HMMT dispatches. The reasons for suboptimal protocol adherence remain unclear and persist, despite proven value of the HMMT in reducing patient mortality and morbidity.     

Does changing the configuration of a motor racing circuit make it safer?

Objectives: To assess the pattern of injuries presenting to a racing circuit medical centre in two three-year periods before and after two chicanes were built into the track.

Methods: Medical centre records were used to identify all patients assessed during the two time periods. Those referred to hospital were categorised by injury severity into three groups.

Results: The proportions of those attending the medical centre that were referred and admitted to hospital were the same in both periods (12–13% and 3% respectively). During the two study periods, the risk of a severe injury for a car driver decreased from 0.1% to 0.03% (p<0.05). For a motorcyclist, similar values were 0% and 0.2% (not significant).

Conclusions: Chicanes have improved the safety of the racing circuit for car drivers, reducing the risk of injury.

     

Does the Pulsatile Non-uniform Flow Matter in MR Flowmetry?

3D cine phase-contrast (4D flow) MRI is a sequence with great potential for non-invasive time-resolved 3D flowmetry at arbitrary vessel sections in various blood vessels. However, it is not widely known that the flowmetry with 4D flow MRI is vulnerable to pulsatile and non-uniform flow. Due to the limited spatial and temporal resolutions, averaging within the 3D voxel is occurring during the flowmetry. A simple solution is to avoid setting the measurement plane in the area where non-uniform flow is dominant, which is possible with an aid of streamline depictions generated by computational fluid dynamics (CFD) or 4D flow MRI data. Unlike 4D flow MRI, flowmetry in CFD simulation can use higher spatial and temporal resolution depending on computer performance; therefore, it is robust to fluctuating non-uniform flow. However, the performance of CFD simulations might be limited due to inlet conditions with low temporal resolution. Difficulty applying complex blood flow such as reflection flow from periphery may also limit accurate simulation. Caution should be taken when comparing the result of CFD simulation to that of 4D flow measurement.     

Does the C34T mutation in AMPD1 alter exercise capacity in the elderly?

Ageing does affect functional capacity through several changes at the peripheral muscle level that impair the muscles capacity to produce energy and generate force. The skeletal muscle-specific isoform of AMP deaminase (AMPD) plays an important regulatory role in muscle metabolism and in determining energy charge. Since nearly 20 % of the general Caucasian population is heterozygous (CT) for the most common C34T mutation of the gene (AMPD1) encoding for this enzyme, it would be worthwhile to study if such a condition further increases the effects of ageing. Twenty-one women (61 - 80 yrs) served as subjects, and depending on the results of previous genotyping, were assigned to a group with the C34T mutation (heterozygous; n=4; mean+/-SEM age: 71+/-1 yrs) or with no mutation (n=17; 68+/-1 yrs). Several indices of maximal (peak oxygen uptake [V.O (2 peak)], peak power output) and submaximal endurance performance (ventilatory threshold, mechanical efficiency) and functional tests (one-mile walk test and a specific test of lower-body functional performance [sit-stand test]) were compared between the two groups. No significant differences were found in exercise capacity between both groups, e. g. V.O (2 peak) of 19.1+/-1.0 vs. 20.1+/-1.9 ml . kg (-1) . min (-1), V.O (2) at the VT of 11.9+/-0.6 vs. 12.9+/-1.0 ml . kg (-1) . min (-1), or time to complete the one-mile walk test (951+/-18 s vs. 962+/-61 s) and sit-stand test (9.9+/-0.2 vs. 9.2+/-0.2) (no mutation vs. C34T mutation, respectively). Although more research is necessary, it seems that the C34T mutation of the AMPD1, at least in heterozygous individuals, does not affect functional capacity in the elderly.     

Does MRI help in the assessment of inflammatory breast disorders?

Objective

The aim of work is to evaluate the role of magnetic resonance imaging in the assessment of different entities of inflammatory breast disorders.

Materials and methods

Eighty-one non-lactating patients with mastitis had been evaluated by post contrast MR imaging; their ages ranged from 22 to 70 years (Average age: 41.6 years). MRI data analysis was performed regarding qualitative criteria and parametric color maps for image post processing. Diagnosis was made up regarding resolution in follow up sessions for simple mastitis and biopsy were done for cases with suspicious imaging findings.

Results

Mammary interstitial edema with no masses or abnormal enhancement was elicited in 28.4% (n = 23/81). T2-weighed and post contrast series were the sequences of choice to rely upon in evaluation. T2 had demonstrated lesions in 64.2% (n = 52/81) and contrast uptake was detected in 68% (n = 55/81). Quantitative analysis was overlapping.MR imaging had displayed sensitivity, specificity and accuracy of 87.5%, 72.3%, and 75.4% respectively in differentiating benign forms of mastitis from malignant ones.

Conclusion

In inflammatory breast disorders, MR imaging can precisely delineate disease extent and monitor response to therapy. Immediate distinction between infectious/non-infectious and malignant mastitis is difficult to be obtained.     

Does telesurgery fit in with the traditional Dutch legal framework?

This article will explore the content-related liability issues of Dutch medical law with respect to telesurgery. For now, telesurgery should be considered as a medical scientific research, as it is still a relatively new procedure which is not yet used on a daily and common basis. Ordinarily concepts of medical law, such as breach of contract, intramural liability, product liability and informed consent can be applied when adverse consequences occur in telesurgery. Since one of the key elements of telesurgery encompasses 'distance', international aspects are also discussed.     

Does immobilization of the shoulder in different positions affect gait?

BackgroundThe shoulder joint is immobilized in various positions after injury or reconstructive operative intervention. It is not clear how these immobilization positions in the shoulder joint affect gait.Research questionDoes the immobilized shoulder joint in different positions following shoulder surgery or injury affect gait?MethodsA total of 38 healthy individuals with a mean age of 25.94 years and BMI of 25.66 kg/m², underwent gait analysis in 4 different immobilized positions and normal gait. Gait parameters were evaluated using the GAITRite electronic walkway, and to determine symmetry, the bilateral spatiotemporal gait parameters were calculated using the Symmetry Index. Repeated-measures one way analysis of variance was used to compare the walking parameters in different positions.ResultsVelocity, step length and stride length were significantly decreased, and step width and single support time were increased in some immobilized positions (p < 0.05). Differences in asymmetry were determined in the gait parameters of the immobilized positions but not significantly. When the shoulder was immobilized in abduction, step width asymmetry tended to increase but it was not significant.SignificanceThis cross-sectional simulation study may be important in demonstrating the clinical changes of gait in injuries, pathologies, and postoperative rehabilitation that require the immobilization of the shoulder joint. It could be recommended that arm swing is included in gait rehabilitation, gait and balance training can be provided to patients after shoulder immobilization.     

Does the mechanical work in running change during the VO2 slow component?

PURPOSE: The origin of the slow component is not fully understood. The mechanical hypothesis is one of the potential factors, because an increase in external mechanical work with fatigue was previously reported for a constant velocity run. The purpose of this study was to determine whether a change in mechanical work could occur during the development of the VO2 slow component under the effect of fatigue. METHODS: Twelve regional-level competitive runners performed a square-wave transition, corresponding to 95% of the speed associated with peak VO2 obtained during an incremental test. The VO2 response was fit with a classical model including two exponential functions. A specific treadmill with three-dimensional force transducers was used to measure the ground reaction force. Kinetic work (W(kin)), potential work (W(pot)), external work (W(ext)), and an index of internal work (W(int)) per unit of distance were quantified continuously. RESULTS: During the slow component of VO2, a significant increase in W (P< 0.01), no change in W, and a significant decrease in W and W index (P< 0.05, P< 0.001, respectively) were observed. CONCLUSION: The present study showed that the slow component of VO2 did not result partly from a change in mechanical work under the effect of fatigue. Nevertheless, the decrease in stride frequency (P< 0.001) and contact time (P< 0.001) suggested an alternative mechanical explanation. The slow component during running may be due to the cost of generating force or to alterations in the storage and recoil of elastic energy, and not to the external mechanical work.     

Does computer-aided detection assist in the early detection of breast cancer?

PURPOSE: To evaluate whether breast cancers detected at screening are visible in previous mammograms, and to assess the performance of a computer-aided detection (CAD) system in detecting lesions in preoperative and previous mammograms. MATERIAL AND METHODS: Initial screening detected 67 women with 69 surgically verified breast cancers (Group A). An experienced screening radiologist retrospectively analyzed previous mammograms for visible lesions (Group B), noting in particular their size and morphology. Preoperative and previous mammograms were analyzed with CAD; a relatively inexperienced resident also analyzed previous mammograms. The performances of CAD and resident were then compared. RESULTS: Of the 69 lesions identified, 36 were visible in previous mammograms. Of these 36 "missed" lesions, 14 were under 10 mm in diameter and 29 were mass lesions. The sensitivity of CAD was 81% in Group A and 64% in Group B. Small mass lesions were harder for CAD to detect. The specificity of CAD was 3% in Group A and 9% in Group B. Together, CAD and the resident found more "missed" lesions than separately. CONCLUSION: Of the 69 breast cancers, 36 were visible in previous mammograms. CAD's sensitivity in detecting cancer lesions ranged from 64% to 81%, while specificity ranged from 9% to as low as 3%. CAD may be helpful if the radiologist is less subspecialized in mammography.     

Does intracranial venous thrombosis cause subdural hemorrhage in the pediatric population?

Unexplained SDH in infants and children is an accepted marker for AHT. It has been proposed that IVT may be the initiating event leading to the development of acute SDH, mimicking the appearance of traumatic SDH. Our study aims to investigate if nontraumatic IVT causes SDH in the pediatric population. We retrospectively identified 36 patients with IVT and reviewed neuroimaging studies for the concurrent presence of SDH. In our 36 patients with IVT, no associated SDH was observed. Even with extensive IVT, no SDH was present. Three false-positive diagnoses of IVT were identified in the setting of mastoiditis and traumatic SDH, demonstrating pitfalls in imaging. In conclusion, our findings do not support the previous AHT literature stating that IVT is associated with, or leads to, SDH in neonates, infants, or children.     

Interpreting urgent brain CT scans: Does review by a radiology trainee make a difference in accuracy?

An urgent brain CT scan is now commonly performed on patients presenting to hospital emergency departments for a wide variety of indications. At most institutions in Australia, such scans are reviewed immediately by an on-call radiologist, who is usually an accredited registrar. The value of the trainee radiologist in such a setting is unclear. In the present study, the rate of abnormal findings in a random sample of 100 brain CT scans performed on hospital patients is reviewed and the accuracy of detection of potentially urgent lesions is compared between three junior clinicians, an accredited radiology registrar and a junior radiographer, using the final radiological report as the standard of reference. At least one potentially urgent abnormality in 25% of the patients scanned was found. The RANZCR trainee recorded a significantly higher sensitivity compared to the other readers. It is concluded that an urgent brain CT is of greater value as a screening test if a contemporaneous radiological review is made available, and the implications this may have on current imaging practices are briefly considered.