Dedicated emergency department ultrasound rotation improves residents' ultrasound knowledge and interpretation skills

Background

Graduates of Emergency Medicine (EM) residency training programs are expected to be proficient in ultrasound. However, best practices for teaching residents ultrasonography has yet to be determined.

Study Objectives

To determine if a dedicated Emergency Department (ED) ultrasound rotation objectively improves residents’ EM ultrasound knowledge, interpretation accuracy, and clinical decision-making based on ultrasound findings.

Methods

EM residents completing a required ED-based ultrasound rotation were prospectively studied. Before the start of the rotation, each resident completed a 20-question pre-test. At the end of the rotation, residents completed a 20-question post-test. Both tests covered physics, trauma (focused assessment with sonography for trauma), first-trimester pregnancy, aorta, biliary, echocardiography, and vascular sonography, using a multiple-choice format. In both tests, ultrasound images were included in 11 of the 20 questions. The questions were divided into three categories: knowledge-based (8 questions), interpretation (9 questions), and clinical decision-making (3 questions), for both tests. Scores on pre-tests and post-tests were compared using a Wilcoxon signed-rank test.

Results

During the 2-year study period, 21 residents completed the rotation. The median pre-test score was 16 (interquartile range [IQR] 14.5–17), compared to a median post-test score of 19 (IQR 18–20), p < 0.001.

Conclusions

A dedicated ED ultrasound rotation improves residents’ EM ultrasound knowledge and interpretation accuracy based on ultrasound findings, as measured by improvement on ultrasound test scores.     

Should extramedullary fixations for hip fractures be removed after bone union?

Background

Osteosynthesis implants, which remain in the patient after fracture union to save additional surgery, may affect the strain distribution within the bone. A reduction of strain within the bone is known to result in localized bone loss (“stress shielding”) and increased fracture risk. The purpose of this study was to examine whether extramedullary fixations for femoral neck fractures have to be removed after fracture union to prevent reductions in cortex strains.

Methods

In a biomechanical experiment, six pairs of human cadaver femora (mean age 56 years, range 48 to 64) were supplied with five strain gauges per bone. The bones were equally supplied with a compression hip screw or a femoral neck plate. Before surgery, after surgery and after removal of the implants, axial compression tests were conducted to measure surface strains during loading.

Findings

The compression hip screw reduced the amount of strain at the superior neck by 88% (P = 0.015) and at the lesser trochanter by 51% (P = 0.038). The femoral neck plate reduced the amount of strain at the superior neck by 89% (P = 0.001), and increased the amount of strain at the inferior neck by 58% (P = 0.02) and at the lesser trochanter by 63% (P = 0.005). After implant removal, there was no significant difference in strain compared to pre-fracture levels, except for the compression hip screw with 21% less strain (P = 0.047) at the superior neck.

Interpretation

Removal of osteosynthesis implants after bone union reverts bone strains to pre-fracture levels, and might prevent further bone loss induced by stress shielding.     

Comparison of GlideScope(®) versus Macintosh laryngoscope for the removal of a hypopharyngeal foreign body: A randomized cross-over cadaver study

Objective

This study aimed to evaluate whether GlideScope^® is an effective and acceptable method for the removal of a hypopharyngeal foreign body.

Methods

This was a prospective study conducted in 28 first year emergency residents with little prior airway management experience. Participants extracted hypopharyngeal foreign bodies using a Macintosh laryngoscope and GlideScope^® with Magill and Sponge forceps. The primary endpoints were extraction time and success rate with each device. Participant preferences were also assessed.

Results

The cumulative success rate in relation to time to extraction was significantly higher with the Macintosh laryngoscope than with the GlideScope^® (p < 0.001) regardless of the extraction device. Significantly fewer attempts were required for the first successful extraction with the Macintosh laryngoscope versus GlideScope^® with Magill forceps (p = <0.001) and Sponge forceps (p = <0.001). The time for successful foreign body extraction using GlideScope^® was significantly lower when using Magill (median 46 s, IQR 28–75 s) forceps than Sponge forceps (median 79 s, IQR 41–88 s).

Conclusions

In this cadaver model, the Macintosh laryngoscope appeared to be more efficient and preferred than GlideScope^® for extracting hypopharyngeal airway foreign bodies that are associated with fatal asphyxiation.     

A two-year experience of an integrated simulation residency curriculum

Background

Human Patient Simulation (HPS) is increasingly used in medical education, but its role in Emergency Medicine (EM) residency education is uncertain.

Study Objectives

The objective of this study was to evaluate the perceived effectiveness of HPS when fully integrated into an EM residency didactic curriculum.

Methods

The study design was a cross-sectional survey performed in 2006, 2 years after the implementation of an integrated simulation curriculum. Fifty-four residents (postgraduate year [PGY] 1–4) of a 4-year EM residency were surveyed with demographic and curricular questions on the perceived value of simulation relative to other teaching formats. Survey items were rated on a bipolar linear numeric scale of 1 (strongly disagree) to 9 (strongly agree), with 5 being neutral. Data were analyzed using Student t-tests.

Results

Forty residents responded to the survey (74% response rate). The perceived effectiveness of HPS was higher for junior residents than senior residents (8.0 vs. 6.2, respectively, p < 0.001). There were no differences in perceived effectiveness of lectures (7.8 vs. 7.9, respectively, p = 0.1), morbidity and mortality conference (8.5 vs. 8.7, respectively, p = 0.3), and trauma conference (8.4 vs. 8.8, respectively, p = 0.2) between junior and senior residents. Scores for perceptions of improvement in residency training (knowledge acquisition and clinical decision-making) after the integration of HPS into the curriculum were positive for all residents.

Conclusion

Residents’ perceptions of HPS integration into an EM residency curriculum are positive for both improving knowledge acquisition and learning clinical decision-making. HPS was rated as more effective during junior years than senior years, while the perceived efficacy of more traditional educational modalities remained constant throughout residency training.     

The development and assessment of an evaluation tool for pediatric resident competence in leading simulated pediatric resuscitations

Introduction

It is critical that competency in pediatric resuscitation is achieved and assessed during residency or post graduate medical training. The purpose of this study was to create and evaluate a tool to measure all elements of pediatric resuscitation team leadership competence.

Methods

An initial set of items, derived from a literature review and a brainstorming session, were refined to a 26 item assessment tool through the use of Delphi methodology. The tool was tested using videos of standardized resuscitations. A psychometric assessment of the evidence for instrument validity and reliability was undertaken.

Results

The performance of 30 residents on two videotaped scenarios was assessed by 4 pediatricians using the tool, with 12 items assessing ‘leadership and communication skills’ (LCS) and 14 items assessing ‘knowledge and clinical skills’ (KCS). The instrument showed evidence of reliability; the Cronbach's alpha and generalizability co-efficients for the overall instrument were α = 0.818 and Ep² = 0.76, for LCS were α = 0.827 and Ep² = 0.844, and for KCS were α = 0.673 and Ep² = 0.482. While validity was initially established through literature review and brainstorming by the panel of experts, it was further built through the high strength of correlation between global scores and scores for overall performance (r = 0.733), LCS (r = 0.718) and KCS (r = 0.662) as well as the factor analysis which accounted for 40.2% of the variance.

Conclusion

The results of the study demonstrate that the instrument is a valid and reliable tool to evaluate pediatric resuscitation team leader competence.     

Comparison of ultrasound and X-ray in determining the position of umbilical venous catheters

Objective

Thoraco-abdominal X-ray (TAX) is the most frequent used method to determine the route and tip position (TP) of umbilical venous catheters (UVCs). The aim of this study was to compare ability of TAX and ultrasonography (US) to determine UVC route and TP.

Patients and methods

All neonates requiring UVC or admitted to our Paediatric and Neonatal Intensive Care with UVC were included in this prospective study. Catheter position was controlled by TAX and interpreted by the physician in charge of the patient. US examinations were performed by a paediatric radiologist blinded to TAX result. The UVC route (central or not central) and TP determined by each method were compared to the “actual UVC route and TP”, as determined by senior paediatric radiologist and neonatologist referents joint interpretation of TAX and US results.

Results

Sixty-one UVCs were assessed in 60 neonates of mean gestational age of 34.7 ± 4.2 weeks. To determine catheter route, sensitivity and specificity were respectively 96.4% and 93.9% for US and 92.8% and 78.8% for TAX. To determine catheter tip position, sensitivity and specificity were respectively 93.3% and 95.6% for US and 66.7% and 63.0% for TAX (p < 0.001). Failure of TAX to define UVC tip position increased with birth weight (p < 0.005).

Conclusion

TAX and US are reliable in determining UVC route (central or not) but US examination is superior to TAX in determining UVC TP.     

Comfort and midfoot mobility rather than orthosis hardness or contouring influence their immediate effects on lower limb function in patients with anterior knee pain

Background

Despite evidence for use of foot orthoses in the treatment of anterior knee pain, there is a paucity of research into their mechanisms of action. This study (i) determined the immediate lower limb kinematics and muscle activity adaptations, and (ii) evaluated the effect of individual's comfort and foot mobility.

Methods

Forty individuals diagnosed with anterior knee pain were measured for lower limb kinematics and electromyographic activity (via surface electrodes) while they jogged in three prefabricated contoured orthoses (hard, medium and soft) and a soft-flat orthosis. Subjects ranked orthoses in order of comfort.

Findings

Soft orthoses were more comfortable. No immediate adaptations in kinematics and electromyographic activity were observed when orthoses were added to shoes. There were few effects of perceived comfort and foot mobility, one being a significant interaction in frontal plane hip motion (Pillai's V = 0.089, P = 0.031) with the least comfortable orthosis producing the greatest relative adduction in those with mobile feet (0.54° (standard deviation 0.87)). Other main effects were a significant increase in vastus lateralis activity when wearing the least comfortable orthosis (6.94%, P = 0.007) and a delay in offset of medial gastrocnemius in individuals with less mobile feet (1.51%, P = 0.045).

Interpretation

It is becoming apparent that it is important to use more comfortable foot orthoses in a condition like anterior knee pain, where there is an associated increased hip adduction and vastus lateralis activity with least comfortable orthoses. Future research is needed to determine adaptations after ongoing wearing of orthoses.     

Gender and fatigue have influence on knee joint control strategies during landing

Background

Gender and fatigue are thought to affect the anterior cruciate ligament injury risk. In spite of much effort, the influence of these factors on knee joint biomechanics is still under discussion. The purpose of this study was to investigate kinematics, kinetics, and active muscle control strategies of the knee joint across gender in fatigue conditions during a landing task.

Methods

Thirteen females and thirteen males performed two-legged landings before and after a closed kinetic chain exercise protocol. Knee joint kinematics and vertical ground reaction forces were assessed as well as electromyography of the quadriceps, hamstring, and gastrocnemius muscles.

Findings

Females landed with increased knee flexion velocities (P < 0.001) and knee joint abduction angles (P < 0.01). Compared to males, females also showed different muscle activation patterns such as a delayed activation of the lateral hamstring (P < 0.05) and the m. vastus lateralis (P < 0.05) during the preparatory phase of the landing. Fatigue led to a reduced pre-activation of the medial and lateral hamstrings (P < 0.05 and P < 0.001) and the gastrocnemius muscle (P < 0.05) both in males and females.

Interpretation

The gender differences in knee flexion velocity, abduction angle, and muscle activation suggest that females and males possess different neuromuscular strategies to control the knee joint during dynamic landing movements. These differences as well as decreased hamstring and gastrocnemius muscle activity, due to fatigue, provide evidence for different knee joint control in females as well as in fatigued conditions.     

Biomechanical evaluation of two intramedullary nailing techniques with different locking options in a three-part fracture proximal humerus model

Background

Osteosynthesis of unstable proximal humerus fractures still remains challenging. The aim of this study was to investigate two intramedullary nailing techniques with different locking options in a three-part fracture model and prove whether two new fixation concepts, introducing additional locking screw-in-screws inserted through the head of the proximal screws, and a calcar screw, provide better stability.

Methods

A biomechanical testing model for three-part proximal humerus fractures including cyclic axial loading with increasing peak load and simultaneous pulling forces at the rotator cuff was used to test 12 pairs of human cadaver humeri, assigned to four groups and instrumented with either Targon PH (T1) or MultiLoc PHN in 3 different configurations (standard M1; two additional screw-in-screw M2; one additional calcar screw and two screw-in-screw M3).

Findings

Initial range of motion in internal–external rotation and mediolateral translation was smallest in M3 (1.82°; 0.11 mm), biggest in T1 (3.63°; 0.51 mm) and significantly different between these two groups (p = 0.02 and p = 0.04, respectively). M3 showed minimum head migration along the nail and varus tilting after 5000 cycles (0.31 mm; 0.20°) and 10000 cycles (1.59 mm; 0.34°). M2 and M3 performed better than M1 and T1 regarding varus collapse. The highest number of cycles to failure was observed for M3 (20733) and the lowest for T1 (10083) with significant difference between these two groups (p = 0.04).

Interpretation

The configuration with two screw-in-screw and a calcar screw was superior in most aspects. The screw-in-screws were found to contribute against varus collapse. Both new fixation concepts could provide better stability in proximal humerus fractures.     

The contribution of quasi-joint stiffness of the ankle joint to gait in patients with hemiparesis

Background

The role of ankle joint stiffness during gait in patients with hemiparesis has not been clarified. The purpose of this study was to determine the contribution of quasi-joint stiffness of the ankle joint to spatiotemporal and kinetic parameters regarding gait in patients with hemiparesis due to brain tumor or stroke and healthy individuals.

Methods

Spatiotemporal and kinetic parameters regarding gait in twelve patients with hemiparesis due to brain tumor or stroke and nine healthy individuals were measured with a 3-dimensional motion analysis system. Quasi-joint stiffness was calculated from the slope of the linear regression of the moment–angle curve of the ankle joint during the second rocker.

Findings

There was no significant difference in quasi-joint stiffness among both sides of patients and the right side of controls. Quasi-joint stiffness on the paretic side of patients with hemiparesis positively correlated with maximal ankle power (r = 0.73, P < 0.01) and gait speed (r = 0.66, P < 0.05). In contrast, quasi-joint stiffness in controls negatively correlated with maximal ankle power (r = − 0.73, P < 0.05) and gait speed (r = − 0.76, P < 0.05).

Interpretation

Our findings suggested that ankle power during gait might be generated by increasing quasi-joint stiffness in patients with hemiparesis. In contrast, healthy individuals might decrease quasi-joint stiffness to avoid deceleration of forward tilt of the tibia. Our findings might be useful for selecting treatment for increased ankle stiffness due to contracture and spasticity in patients with hemiparesis.     

Effects of repeated ankle stretching on calf muscle-tendon and ankle biomechanical properties in stroke survivors

Background

The objective of this study was to investigate changes in active and passive biomechanical properties of the calf muscle–tendon unit induced by controlled ankle stretching in stroke survivors.

Methods

Ten stroke survivors with ankle spasticity/contracture and ten healthy control subjects received intervention of 60-min ankle stretching. Joint biomechanical properties including resistance torque, stiffness and index of hysteresis were evaluated pre- and post-intervention. Achilles tendon length was measured using ultrasonography. The force output of the triceps surae muscles was characterized via the torque–angle relationship, by stimulating the calf muscles at a controlled intensity across different ankle positions.

Findings

Compared to healthy controls, the ankle position corresponding to the peak torque of the stroke survivors was shifted towards plantar flexion (P < 0.001). Stroke survivors showed significantly higher resistance torques and joint stiffness (P < 0.05), and these higher resistances were reduced significantly after the stretching intervention, especially in dorsiflexion (P = 0.013). Stretching significantly improved the force output of the impaired calf muscles in stroke survivors under matched stimulations (P < 0.05). Ankle range of motion was also increased by stretching (P < 0.001).

Interpretation

At the joint level, repeated stretching loosened the ankle joint with increased passive joint range of motion and decreased joint stiffness. At the muscle–tendon level, repeated stretching improved calf muscle force output, which might be associated with decreased muscle fascicle stiffness, increased fascicle length and shortening of the Achilles tendon. The study provided evidence of improvement in muscle tendon properties through stretching intervention.     

Are the kinematics of the knee joint altered during the loading response phase of gait in individuals with concurrent knee osteoarthritis and complaints of joint instability? A dynamic stereo X-ray study

Background

Joint instability has been suggested as a risk factor for knee osteoarthritis and a cause of significant functional decline in those with symptomatic disease. However, the relationship between altered knee joint mechanics and self-reports of instability in individuals with knee osteoarthritis remains unclear.

Methods

Fourteen subjects with knee osteoarthritis and complaints of joint instability and 12 control volunteers with no history of knee disease were recruited for this study. Dynamic stereo X-ray technology was used to assess the three-dimensional kinematics of the knee joint during the loading response phase of gait.

Findings

Individuals with concurrent knee osteoarthritis and joint instability demonstrated significantly reduced flexion and internal/external rotation knee motion excursions during the loading response phase of gait (P < 0.01), while the total abduction/adduction range of motion was increased (P < 0.05). In addition, the coronal and transverse plane alignment of the knee joint at initial contact was significantly different (P < 0.05) for individuals with concurrent knee osteoarthritis and joint instability. However, the anteroposterior and mediolateral tibiofemoral joint positions at initial contact and the corresponding total joint translations were similar between groups during the loading phase of gait.

Interpretations

The rotational patterns of tibiofemoral joint motion and joint alignments reported for individuals with concurrent knee osteoarthritis and joint instability are consistent with those previously established for individuals with knee osteoarthritis. Furthermore, the findings of similar translatory tibiofemoral motion between groups suggest that self-reports of episodic joint instability in individuals with knee osteoarthritis may not necessarily be associated with adaptive alterations in joint arthrokinematics.     

The Simulation Team Assessment Tool (STAT): development, reliability and validation

Introduction

Simulation sessions prepare medical professionals for pediatric emergencies. No validated tools exist to evaluate overall team performance. Our objective was to develop and evaluate the inter-rater reliability and validity of a team performance assessment tool during simulated pediatric resuscitations.

Methods

We developed the Simulation Team Assessment Tool (STAT) which evaluated 4 domains: basic assessment skills, airway/breathing, circulation, and human factors. Scoring of each element was behaviorally anchored from 0 to 2 points. Two teams of resuscitation experts and two teams of pediatric residents performed the same simulated pediatric resuscitation. Each team was scored by six raters using the STAT. Intraclass correlation coefficients (ICC) were calculated to assess inter-rater reliability. Overall performance and domain scores between expert and resident teams were compared using repeated measures of analysis of variance to assess construct validity.

Results

ICCs for overall performance were 0.81. Domain ICCs were: basic skills 0.73, airway/breathing skills 0.30, circulation skills 0.76, human factors 0.68. Expert versus resident average scores were: overall performance 84% vs. 66% (p = 0.02), basic skills 73% vs. 55% (p < 0.01); airway 80% vs. 75% (p = 0.25), circulation 90% vs. 69% (p = 0.02), human factors 89% vs. 66% (p = 0.02).

Conclusions

The STAT's overall performance, basic skills, circulation, and human factors domains had good to excellent inter-rater reliability, discriminating well between expert and resident teams. Similar performance in the airway/breathing domain among all teams magnified the impact of a small number of rater disagreements on the ICC. Additional study is needed to better assess the airway/breathing domain.     

Influence of cementing the pin on resistance to fracture in hip resurfacing

Background

Since the introduction of modern hip resurfacing systems, there has been a controversy regarding the fixation of the centering pin in the femoral component. It has been suggested that cementing the pin may increase strength of the femoral neck. This in-vitro analysis investigated the influence of a cemented, femoral pin on resistance to fracture in the resurfaced hip.

Methods

Five pairs of cadaveric, fresh-frozen femora underwent hip resurfacing (ASR™) using a high viscosity cementing technique. In one side of each pair only the inner surface of the implant was cemented, in the other side, cement was additionally hand-pressurized down the pinhole prior to implantation of the femoral component. Specimen were then mounted on a material testing machine and cyclic loading with increasing load steps was applied until fracture of the femoral neck.

Findings

Fracture load was increased (P = 0.013) in the cemented pin group (Median = 4200 N) when compared with the cementless pin group (Median = 2800 N). The number of cycles to failure in the group with the cemented pin (Median = 8072) was likewise higher (P = 0.01) when compared to the group, in which the pin was not cemented (Median = 5906).

Interpretation

Cementing the pin may provide additional fixation in hips with low bone mineral density or osteonecrotic lesions, as resistance to fracture could be improved in the presented in-vitro scenario. Although this was shown for a specific hip resurfacing system, this effect might be extrapolated to other, similar implant designs.     

Effect of lower limb dominance on knee joint kinematics after anterior cruciate ligament reconstruction

Background

Normal ambulatory kinematics of the knee joint is often not fully restored after anterior cruciate ligament reconstruction, which may increase the risk for cartilage degeneration and premature osteoarthritis in the involved knees. Lower limb dominance may have impacts on knee joint kinematics after anterior cruciate ligament reconstruction, which may lead to a different prevalence of cartilage degeneration. This study aimed to evaluate the knee joint kinematics among patients with reconstruction on the dominant and non-dominant side.

Methods

Forty-one subjects with unilateral anterior cruciate ligament reconstruction (19 dominant, 22 non-dominant) were recruited after being discharged from rehabilitation programs. Twenty healthy subjects were recruited as the control group. Six degrees-of-freedom tibiofemoral motion during level walking was determined using a redundant point cluster-based marker set. Tibiofemoral joint motion and its bilateral differences were compared within each group and between groups.

Findings

The non-dominant reconstructed knees had less extension compared to their contralateral knees at heel strike and during middle stance phase (P = 0.02); whereas, the dominant reconstructed knees exhibited significantly reduced varus rotation (− 2.1° on mean, P = 0.027) and internal tibial rotation (P = 0.034) compared to their contralateral knees during both stance and swing phases.

Interpretation

The results show that different kinematics has been developed between the involved dominant and non-dominant knees after anterior cruciate ligament reconstruction, especially the secondary rotations. The differences are consistent with the unequal prevalence of cartilage degeneration in the knee joint. The findings demonstrated that the lower limb dominance had a significant effect on post-surgery knee kinematics.     

Indian and United States paramedic students: comparison of examination performance for the American Heart Association Advanced Cardiovascular Life Support (ACLS) training

Background

The American Heart Association (AHA) Advanced Cardiovascular Life Support (ACLS) course is taught worldwide. The ACLS course is designed for consistency, regardless of location; to our knowledge, no previous study has compared the cognitive performance of international ACLS students to those in the United States (US).

Study Objectives

As international health educational initiatives continue to expand, an assessment of their efficacy is essential. This study assesses the AHA ACLS curriculum in an international setting by comparing performance of a cohort of US and Indian paramedic students.

Methods

First-year paramedic students at the Emergency Management and Research Institute, Hyderabad, India, and a cohort of first-year paramedic students from the United States comprised the study population. All study participants had successfully completed the standard 2-day ACLS course, taught in English. Each student was given a 40-question standardized AHA multiple-choice examination. Examination performance was calculated and compared for statistical significance.

Results

There were 117 Indian paramedic students and 43 US paramedic students enrolled in the study. The average score was 86% (± 11%) for the Indian students and 87% (± 6%) for the US students. The difference between the average examination scores was not statistically significant in an independent means t-test (p = 0.508) and a Wilcoxon test (p = 0.242).

Conclusion

Indian paramedic students demonstrated excellent ACLS cognitive comprehension and performed at a level equivalent to their US counterparts on an AHA ACLS written examination. Based on the study results, the AHA ACLS course proved effective in an international setting despite being taught in a non-native language.     

The use of pleural fluid procalcitonin and C-reactive protein in the diagnosis of parapneumonic pleural effusions: a systemic review and meta-analysis

Background

We aimed to perform a systematic review and meta-analysis of the diagnostic performance of pleural fluid procalcitonin (PCT) or C-reactive protein (CRP) in differentiating parapneumonic effusion in patients with pleural effusion.

Methods

We searched the EMBASE, MEDLINE, and Cochrane database in December 2011. Original studies that reported the diagnostic performance of PCT alone or compared with that of other biomarkers for differentiating the characteristics of pleural effusion were included.

Results

We found 6 qualifying studies including 780 patients with suspected parapneumonic effusion and 306 confirmed cases of parapneumonic effusion. Six studies examined the diagnostic performance of pleural fluid PCT, 3 also tested for serum PCT, and another 3 tested for serum CRP. The bivariate pooled sensitivity and specificity were as follows 0.67 (95% confidence interval [CI], 0.54-0.78) and 0.70 (95% CI, 0.63-0.76), respectively, for pleural fluid PCT; 0.65 (95% CI, 0.55-0.74) and 0.68 (95% CI, 0.62-0.74), respectively, for serum PCT; and 0.54 (95% CI, 0.47-0.61) and 0.77 (95% CI, 0.72-0.81), respectively, for serum CRP. There was evidence of significant heterogeneity (I² = 55.0%) for pleural fluid or serum PCT but not for CRP (I² = 0.0%).

Conclusion

The existing literature suggests that both pleural fluid and serum PCT tests have low sensitivity and specificity for differentiating parapneumonic effusion from other etiologies of pleural effusion. Compared with PCT, serum CRP has higher specificity and a higher positive likelihood ratio, and thus, it has a higher rule-in value than PCT.     

Gluteal muscle activation during running in females with and without patellofemoral pain syndrome

Background

Hip and knee joint motion in the transverse and frontal plane during running may increase patellofemoral joint stress and contribute to the etiology of patellofemoral joint pain. We evaluated the association between these kinematics and the magnitude and timing of gluteus medius and maximus activity during running in females with patellofemoral pain. We also compared the magnitude and timing of gluteal muscle activity during running between females with and without patellofemoral pain.

Methods

Twenty females with patellofemoral pain and twenty females without knee pain participated in this study. Three-dimensional running kinematics, gluteus medius and gluteus maximus onset time, activation duration, mean activation level, and peak activation level were recorded simultaneously. Gluteal muscle timing and activation level were compared between groups using independent t-tests. The association of gluteal muscle activation parameters running kinematics in females with patellofemoral pain was quantified using Pearson correlation coefficients.

Findings

Females with patellofemoral pain demonstrated delayed (P = 0.028, effect size = 0.76) and shorter (P = 0.01, effect size = 0.88) gluteus medius activation than females without knee pain during running. The magnitude and timing of gluteus maximus activation was not different between groups. Greater hip adduction and internal rotation excursion was correlated with later gluteus medius and gluteus maximus onset, respectively.

Interpretation

Neuromuscular control differences of the gluteal muscles appear to exist among females with patellofemoral pain during running. Interventions to facilitate earlier activation of these muscles may be warranted among females with patellofemoral pain who demonstrate altered running kinematics.     

A comparison of anterior cruciate ligament graft tunnel orientation: anatomic vs. transtibial

Background

Recent Anterior Cruciate Ligament reconstruction techniques have emphasized reproducing the insertion sites of the native Anterior Cruciate Ligament. Anatomic techniques have shown improvements in biomechanical testing, but their superior results have not been shown clinically. The hypothesis of this study is that more oblique tunnels utilized in anatomic reconstructions cause asymmetric loading across the graft.

Methods

Seven cadaver knees were tested in a knee simulator that performed a gait cycle and an anterior–posterior laxity test. Each knee underwent both reconstructions in random order utilizing the same Anterior Cruciate Ligament bone patellar tendon bone graft. Before reconstruction, the graft was split longitudinally and miniature force probes were inserted in the medial and lateral portions.

Findings

During anterior–posterior laxity testing, the transtibial medial bundle averaged 74.8 N compared to 87 N for the anatomic. The lateral bundles averaged 146.2 and 158 N respectively. Both reconstructions exhibited a similar ratio of force distribution between the bundles and there was no statistical difference. The average anterior–posterior motion for the intact knees was 10.8 mm compared to 17.0 mm after the Anterior Cruciate Ligament was sectioned. Anatomic reconstructions had an average of 14.0 mm of laxity compared to 14.9 mm for transtibial reconstructions (P < 0.038).

Interpretation

Greater obliquity did not lead to an increase in asymmetry of graft loading. The failure of anatomic reconstructions to show clinical improvement over transtibial reconstructions is not due to oblique tunnels causing asymmetric graft loading.