Reliability of range-of-motion measurement in the elbow and forearm

The purpose of this study was to examine intratester, interester, and interdevice reliability of range of motion measurements of the elbow and forearm. Elbow flexion and extension and forearm pronation and supination were measured on 38 subjects with elbow, forearm, or wrist disease by 5 testers. Standardized test methods and a randomized order of testing were used to test groups of patients with universal standard goniometers, a computerized goniometer, and a mechanical rotation measuring device. Intratester reliability was high for all 3 measuring devices. Meaningful changes in intratester range of motion measurements taken with a universal goniometer occur with 95% confidence if they are greater than 6° for flexion, 7° for extension, 8° for pronation, and 8° for supination. Intertester reliability was high for flexion and extension measurements with the computerized goniometer and moderate for flexion and extension measurements with the universal goniometer. Meaningful change in interobserver range of motion measurements was expected if the change was greater than 4° for flexion and 6° for extension with the computerized goniometer compared with 10° and 10°, respectively, if the universal goniometer was used. Intertester reliability was high for pronation and supination with all 3 devices. Meaningful change in forearm rotation is characterized by a minimum of 10° for pronation and 11° for supination with the universal goniometer. Reliable measurements of elbow and forearm arm movement are obtainable regardless of the level of experience when standardized methods are used. Measurement error was least for repeated measurements taken by the same tester with the same instrument and most when different instruments were used.     

Pronation and supination after forearm fractures in children: Reliability of visual estimation and conventional goniometry measurement

Background

Forearm fractures are common amongst children and often result in limited rotational function. In daily practice, pronation and supination of the arm are often visually estimated or measured using a conventional goniometer. The aim of this study was to compare the reliability of these two methods in paediatric patients who had previously sustained a forearm fracture.

Methods

Intra- and interrater reliability of visual estimation and conventional goniometry were determined in 47 children who had previously sustained a forearm fracture.

Results

Intra- and interrater reliability of visual estimation and conventional goniometry was fair to excellent, with intraclass correlation coefficients (ICCs) ranging between 0.75 and 0.94. In addition, the overall goniometer data consistently showed lower smallest detectable differences (SDDs) compared to the visual estimation data, also indicating better reliability for the goniometer method.

Conclusions

A conventional goniometer is an easy, fast and reliable method to determine the pronation and supination in a child who had sustained a forearm fracture. If an uncooperative child hinders the measurement, visual estimation is a good second choice. Measurements are more reliable when repeated by the same professional.     

Reliability of 2 functional goniometric methods for measuring forearm pronation and supination active range of motion

STUDY DESIGN: Test-retest reliability study. OBJECTIVES: To determine intra- and intertester reliability of the hand-held pencil (HHP) and the plumbline goniometer (PLG) methods for measuring active forearm pronation and supination motions in individuals with and without injuries. BACKGROUND: The distal forearm method has been considered the gold standard for measuring forearm pronation and supination motion. The HHP and PLG, however, are 2 more functional methods for measuring forearm motions, though limited information on the psychometric properties of these tests is currently available. METHODS AND MEASURES: Intra- and intertester reliability of the HHP and PLG methods were determined in 40 subjects of convenience (20 injured and 20 noninjured). Two testers performed 3 repeated measurements for each motion and method on all subjects. Intraclass correlation coefficients (ICC3,1 for intratester reliability, ICC2,3 for intertester reliability) and standard error of measurements (SEMs) were determined. RESULTS: The ICCs for the measurements of pronation and supination using the HHP and PLG methods were high (range, 0.86-0.98) for individuals with and without injuries, with the reliability for the PLG method being equal or slightly greater than the HHP method for the majority of pronation and supination measurements. Intratester ICCs were higher (SEMs were conversely lower) than intertester ICCs for nearly all measurements. The ICC values were generally the same or higher for individuals with injuries compared to individuals without injuries. CONCLUSIONS: The HHP and PLG are highly reliable methods for measuring functional forearm pronation and supination. Because plumbline goniometers are not commercially available and the instrumentation for the HHP method is readily accessible, clinicians should consider the latter as their method of choice for measuring functional forearm pronation and supination.     

Goniometric versus computerized angle measurement in assessing hallux valgus

BACKGROUND: Digital workstations with high-resolution monitors are replacing standard radiographs for image evaluation and interpretation. Radiographic angles in the foot have been evaluated for interobserver and intraobserver reliability with plain films, but use of digital workstations has not been validated. Because the 1-2 intermetatarsal (IM) and hallux valgus (HV) angles help determine the most appropriate bunion procedure, the reliability of these measurements is important. METHODS: The HV and 1-2 IM angles were evaluated on preoperative radiographs of 25 patients who subsequently underwent bunion procedures. A standardized technique using a film marker and goniometer on plain film was compared with use of a mouse and computerized angle measurement software at a digital workstation. Three foot and ankle surgeons conducted these measurements at various intervals. Completion of three readings of each radiograph in each format by each observer totaled 1,800 measurements. RESULTS: Computerized measurement gave better overall reliability. For the HV angle, interobserver agreement (measurements within 2 degrees) improved from 66% with plain films to 81% with the digital workstation (p < 0.001). Intraobserver agreement increased from 72% to 80%. The 1-2 IM angle was similarly reliable with both methods for inter- and intraobserver agreement. CONCLUSIONS: This study validates the use of computer-assisted angle measurement on digital radiographs for assessment of HV and 1-2 IM angles. Computerized measurement may result in more reliable readings because it eliminates the error inherent with use of a goniometer and facilitates adjustment of radiographic lines on the computer to ensure correct alignment.     

Reproducibility of the radiographic metatarsophalangeal angle in hallux surgery

BACKGROUND: Five different methods have been described to define the longitudinal axis of the first metatarsal for radiographic measurements of the first metatarsophalangeal angle. None of these methods has been validated for both preoperative and postoperative assessment of patients undergoing hallux valgus surgery. Previous studies have demonstrated conflicting results regarding the measurement accuracy of these methods. METHODS: To evaluate the measurement accuracy of these five methods, we calculated the intraobserver and interobserver coefficients of repeatability for all five methods with use of twenty preoperative and twenty postoperative standardized plain dorsoplantar weight-bearing radiographs of patients undergoing chevron distal osteotomy. RESULTS: The preoperative assessment of the metatarsophalangeal angle revealed small differences among the five methods. The intraobserver coefficient of repeatability ranged from 2.10 degrees to 3.34 degrees, and the interobserver coefficient ranged from 2.17 degrees to 3.44 degrees. The postoperative assessment demonstrated substantial differences between methods in which the diaphysis of the first metatarsal is used as a reference (intraobserver coefficient, 5.06 degrees to 7.23 degrees; interobserver coefficient, 5.29 degrees to 8.19 degrees) and methods in which there is one reference point in the metatarsal head and one reference point in the base of the first metatarsal (intraobserver coefficient, 1.88 degrees to 2.67 degrees; interobserver coefficient, 1.86 degrees to 2.34 degrees). CONCLUSIONS: For the assessment of patients undergoing a distal metatarsal osteotomy, we cannot recommend methods in which the metatarsal shaft is used as a reference for the axis of the first metatarsal. Such methods had poor measurement accuracy, especially postoperatively. Methods with reference points distal and proximal to any possible osteotomy site had much better measurement reproducibility. We recommend the method described by Miller in 1974, in which a line is drawn from the center of the first metatarsal head through the center of the base of the first metatarsal, as it was the most precise method and was least biased by postoperative effects.     

Remote self-measurement of wrist range of motion performed on normal wrists by a minimally trained individual using the iPhone level application only demonstrated good reliability in measuring wrist flexion and extension

Study DesignThis is a reliability study using the intraclass correlation coefficient.PurposeThe purpose of this study was to determine whether an individual with minimal training could use the iPhone Level application to self-measure the range of motion of the forearm and wrist from a remote location.MethodsForty healthy participants (80 wrists) were measured twice by two examiners using a universal goniometer and the iPhone Level application. After measurement, each participant received a training session in the self-measurement method. They were then asked to perform remote self-measurements two to three days later and report their findings to the examiners using Skype or FaceTime.ResultsSPSS, version 26, was used to run intraclass correlation coefficients using a two-way random analysis at a 95% confidence interval with absolute agreement. Comparisons of single measurements were used to determine reliability. Good inter-rater reliability was found between wrist flexion and extension in all testing conditions. Measurement of active motion in supination, pronation, radial, and ulnar deviation demonstrated moderate reliability compared with the universal goniometer where the measurements were performed by the investigators. Self-measurement of the participant resulted in moderate reliability for supination and poor reliability in pronation, radial, and ulnar deviation.DiscussionSome participants found the procedures technologically and perceptually challenging. Anatomical variances, positional requirements, and substitution patterns complicated the process.ConclusionsThe iPhone Level application may be used to perform reliable self-measurements of wrist flexion and extension from a remote location. Further research exploring methods for remote selfmeasurement is indicated.     

Effects of forearm rotation on the clinical evaluation of ulnar variance

Neutral rotation radiographs of the wrist are recommended to standardize the measurement of ulnar variance because it is known that changes in forearm rotation result in changes of this measurement. The purpose of this study was to examine whether there are clinically measurable differences in ulnar variance between radiographs in various degrees of forearm rotation in human subjects. Forty-five wrist radiographs of 15 normal adults were obtained in 3 positions: maximum forearm pronation, neutral rotation, and maximum supination. The ulnar variance on each view was measured by 3 independent observers using a standard millimeter ruler. The average absolute difference in ulnar variance was 0.4 mm between pronation, 0.6 mm between pronation and supination, and 0.2 mm between neutral and supination. Although we found a statistically significant difference in ulnar variance between the pronated and neutral positions, this difference may not be clinically significant and may not justify concerns of forearm position during the radiographic evaluation of ulnar variance.     

A comparative analysis of 4 curvature measurement methods in early-onset scoliosis

STUDY DESIGN.: Observational study with 3 examiners. OBJECTIVE.: The aim of this study was to enhance the reproducibility and reliability of coronal curvature measurements in early-onset scoliosis. SUMMARY OF BACKGROUND DATA.: Previous reports show high variability of the Cobb method, especially on the measurement of the immature spine. METHODS.: A total of 115 whole-spine posteroanterior radiographs were collected to compare the reliability of the Cobb, lateral tangent, pedicle, and centroid methods in early-onset scoliosis. Radiographs were measured twice by each of the 3 examiners using the 4 measurement methods. Statistical analysis was performed to determine the inter- and intraobserver reliability. RESULTS.: In this study, total inter- and intraobserver inter- and intraclass correlation coefficients (ICCs) in 115 radiographs were excellent in all methods (ICCs >0.961). However, mean absolute differences (MADs) in the lateral tangent method were less than 3.78°, which was higher than other methods (MADs <2.95°). In analysis of different severity groups (<15°, 15°-30°, and >30°), total inter- and intraobserver ICCs gradually increased with increasing the severity of the deformity, whereas MADs of each severity group were similar despite their increased measurement scale. Particularly, interobserver ICCs and MADs of lateral tangent method were more than 0.474 and less than 3.76° with poor reliability, which showed high variability in the less deformed spine group (<15°). However, intraobserver ICCs and MADs of pedicle method were more than 0.853 and less than 2.61°, interobserver ICCs and MADs were more than 0.729 and less than 2.86° with excellent reliability, which showed constantly high reliability regardless of coronal curvature severity. CONCLUSION.: In this study, the pedicle method showed constantly higher ICCs and lower MAD values in the early-onset scoliosis regardless of severity. However, the other 3 methods showed lower ICCs and higher MAD values, which showed lowest reliability in the lateral tangent method. For improved treatment of early-onset scoliosis, we recommend the pedicle method for measuring curvature regardless of severity.     

Use of videographic examination for analysis of efficacy of botulinum toxin in the lower limbs in children with cerebral palsy

The objective of this study was to test the interobserver and intraobserver reproducibility of videographic gait analysis in paediatric cerebral palsy patients following botulinum toxin type-A injections. Standardized videos according to gait-specific functional criteria were assessed for 1 h. For intraobserver reproducibility, 13 of 17 items showed good/moderate correlation, one mediocre and three poor correlation. For interobserver reproducibility, 12 of 17 items showed excellent, good or moderate agreement, five items showed poor agreement. Overall, 9 of 17 items showed good intraobserver or interobserver reproducibility. Mean interobserver scores for sagittal plane items were slightly lower than mean intraobserver scores (kappa=0.509 and 0.536, respectively). In conclusion, video analysis of children with cerebral palsy based on functional criteria is useful.     

Reliability of popliteal angle measurement: a study in cerebral palsy patients and healthy controls

The popliteal angle is a widely used clinical measure for hamstring contracture in cerebral palsy (CP) patients and in healthy individuals. The reliability of popliteal angle measurement is being questioned. The aim of this study is to determine the reliability of popliteal angle measurement by means of visual and goniometric assessment. METHODS: Three different observers measured the popliteal angle in 15 CP patients and 15 healthy volunteers. In each subject, popliteal angles were visually estimated and measured with a blinded goniometer twice by all observers with approximately 1 hour between measurement sessions. RESULTS: All intraclass correlation coefficients (ICCs) were lower in the CP group compared with healthy controls. The ICC for intraobserver differences was higher than 0.75 for both groups. The ICC for interobserver reliability of visual estimates and goniometric measurements was low for both groups. Intermethod ICC was higher than 0.75 for both groups. CONCLUSIONS: Measurements in the CP group seemed to be less reliable than measurements in the control group. Intraobserver reliability is reasonable for both groups, but lower in CP patients than in controls. Interobserver reliability of both visual estimates and goniometrical measurements is poor. No significant differences in reliability have been found between visual estimation and goniometric measurement. Because of poor interobserver reliability of popliteal angle measurement, this should not be the only variable in clinical decision making in CP patients.     

How does torsional deformity of the radial shaft influence the rotation of the forearm? A biomechanical study

OBJECTIVE: The aim of this experimental study was to measure the exact influence of isolated torsional deformities at the middle third of the radial shaft on the rotation of the forearm. DESIGN: Biomechanical study in cadavers. SETTING: Trauma Surgery Research Laboratories at the Medical School of Hannover, Hannover, Germany. INTERVENTION: Fourteen intact and fresh cadaver specimens were fixed in a newly developed apparatus that allowed free pronation and supination. A ring fixator was applied to the radial shaft with K-wires that allowed us to stabilize torsional deformities in steps of 10 degrees. The middle of the radial shaft was osteotomized via a small soft tissue window, leaving the other soft tissues, including the interosseous membrane, intact. MAIN OUTCOME MEASUREMENT: Supination and pronation were measured using a goniometer in a standardized fashion. RESULTS: The mean (standard deviation) supination value before osteotomy of the radius was 71.6 degrees (15.2 degrees), and the mean (standard deviation) pronation value was 64.5 degrees (12.4 degrees). Radial osteotomy caused no significant difference in the range of motion before creation of torsional deformities. Supination torsional deformities >30 degrees showed a significant loss of pronation. In turn, pronation torsional deformities >30 degrees resulted in a significant loss of supination. The amount of mean rotational loss was approximately the same in the respective pronation and supination torsional deformities. CONCLUSION: An axial torsional deformity of the radius of >30 degrees causes a statistically significant loss of forearm rotation in fresh cadavers.     

Angular deformities and forearm function.

Angular deformities were created in cadaver forearms at proximal, middle, and distal third levels of the radius and ulna separately, and at middle and distal third levels of both bones, to determine the corresponding limitations of pronation and supination. The ranges of pronation and supination were recorded using a rotational motion measurement apparatus instrumented with a 360 degrees goniometer. These experimental results were compared to data obtained from clinical and radiographic examination of 105 patients with similar residual deformities following treatment of fractures by nonsurgical means, to evaluate the accuracy of the experimental model and to determine if loss of rotational motion could be predicted based on radiographic findings. With cadaver forearms, on the average, angulation of 10 degrees of the radius or ulna in coronal or sagittal planes limited pronation and supination by less than 24 degrees, whereas angulation of 10 degrees of both the radius and the ulna limited pronation and supination by less than 18%. Comparison of experimental results with clinical findings showed that, despite the errors involved in measuring forearm deformities in patients using biplanar radiographs, the experimental results predicted the clinical loss of pronation and supination to within 17% for the fractures of the radius, and within 8% accuracy for the fractures of the ulna.     

Inter- and intraobserver reliability assessment of the Cobb angle: manual versus digital measurement tools

The objective of this study is to determine the intraobserver and interobserver reliability of end vertebra definition and Cobb angle measurement using printed and digital radiographs of 48 patients with scoliosis. The Cobb angle and the end vertebra were assessed by six observers in 48 patients with scoliosis using printed and digital radiographs. Definition of end vertebra and measurement of the Cobb angle was repeated three times with a 3 week interval. Intraclass correlation coefficients (ICC) were used to determine the interobserver and intraobserver reliabilities. 95% prediction limits for the errors in measurements are provided. For the Cobb angle a mean ICC of 0.97 was determined for intra- and interobserver reliability measurement of the printed radiographs. For the electronic radiographs a mean ICC value of 0.93 was determined for interobserver reliability and a mean ICC value of 0.96 for intraobserver reliability. Intraobserver ICC for definition of end vertebrae was 0.8 for both methods. Interobserver ICC was 0.83 for the manual and 0.74 in the digital method. One pitfall in angle measurement implies the Cobb method itself which measures in two dimensions. Until we develop a proper tri-dimensional measuring system an error is introduced. For the Cobb angle measurement the definition of end vertebrae introduces the main source of error. Digital radiography does not improve the measurement accuracy.     

Reliability of the quadriceps angle measurement

The quadriceps angle (Q-angle) is used to determine patellofemoral alignment. Although this measurement has been used to evaluate and treat patellofemoral joint pathology, few studies have examined its reliability. This study evaluated the interobserver and intraobserver reliability of the Q-angle measurement. To investigate the interobserver reliability of the Q-angle, 25 individuals of varying levels of training served as observers and participants as each measured the other 24 participants. To investigate the intraobserver reliability of the Q-angle, 3 of the observers measured 13 of the participants an additional 2 times. Additionally, clinically derived Q-angle measurements were compared with radiographically derived measurements. The reliability analysis was performed using intraclass correlation coefficients. For interobserver measurements, the intraclass correlation coefficients ranged from 0.17-0.29 for the four variables evaluated (right and left, extension and flexion). For intraobserver measurements, the intraclass correlation coefficients ranged from 0.14-0.37. The average intraclass correlation coefficient between the clinically and radiographically derived measurements ranged from 0.13-0.32. This study demonstrates poor interobserver and intraobserver reliability of Q-angle measurement and poor correlation between clinically and radiographically derived Q-angles.     

The proximal ligamentous component of the triangular fibrocartilage complex

The proximal ligamentous component of the triangular fibrocartilage complex (TFCC) was studied anatomically using 15 fresh-frozen cadaver hand forearm specimens. Changes in the length of either side of this component were analysed during forearm rotation with the complete three-dimensional structure of the TFCC preserved. The proximal ligamentous component consists of three portions: dorsal, central and palmar. The dorsal and palmar portions connect the radius and ulna directly. These were recognized in all specimens whereas the central portion was not constant. The morphology of the proximal component was categorized into three types: fan-shaped, V-shaped, and funnel-shaped in five wrists each. Changes in ligament length during forearm rotation were measured using fine wires under slight tension that paralleled the ligaments from origin to insertion. The dorsal and palmar portions demonstrated three trends: the dorsal portion increased in length from supination to pronation whereas the palmar portion increased in length from pronation to supination; the length of the dorsal portion remained almost constant as the palmar portion increased in length from pronation to supination; the length of the palmar portion remained almost constant while the dorsal portion lengthened from supination to pronation. These variations appear to be related to which portion of the ligament was attached nearest to the centre of the ulnar fovea, where the rotational axis of the forearm passes. The portion attaching nearest to the fovea demonstrated a nearly isometric length pattern, whereas the portion which attached at a distance showed greater extensibility. These findings suggest that the proximal component of the TFCC corresponds to a true radioulnar ligament, and the isometric and eccentric fibres act mutually during forearm rotation.     

Interobserver reliability and intraobserver reproducibility of powers ratio for assessment of atlanto-occipital junction: comparison of plain radiography and computed tomography

Powers ratio, as assessed on plain radiographs or computed tomography (CT) images, appears to have clinical and prognostic value. To date, the validation of this assessment tool has been limited to a small number of observers at a single site. No study has examined the intraobserver reproducibility and interobserver reliability of the Powers ratio measurement on plain radiographs or CT images among a large cohort of spine surgeons. This type of validation is critical to allow for the broader use of the Powers ratio methodology in research studies and clinical applications. Plain radiographs and spiral CT images of the cervical spine of 32 patients were assessed, and the Powers ratio was determined by five spine surgeons. Each surgeon performed three readings, 7 months apart. In the first round of measurements, the observers used only the Powers’ method of instruction. The second and third measurement sets were obtained after an interactive teaching session on the methodology. The order of the images was altered for the second and third set of measurements. The coefficient of variation (Cv) was calculated to determine the intraobserver repeatability and interobserver reliability for each imaging technique. A Bland-Altman plot was then used to assess the agreement between the two imaging techniques. For interobserver reliability, the mean Cv of the Powers ratio was 9.09 and 4.31% for plain radiographs and CT, respectively. The Cv mean value for intraobserver reproducibility averaged 4.95% (range 1.39–9.08) when CT scans were used and 14.17% (range 7.54–34.30) when plain radiographs were used. For intraobserver reproducibility, the lowest and highest Cv mean value of five raters was 1.39 and 9.08% using CT scans and 7.54 and 34.3% using plain radiographs. The Bland-Altman plot, demonstrated that the two methods were in close agreement on the −0.8 and 0.89% interval for limits of agreement (bias ± 1.96σ). The intraobserver reproducibility and interobserver reliability of Powers ratio measurement was acceptable (<5%) with CT scans but not with plain radiographs. However, despite the statistically inferior reliability and repeatability, the Bland-Altman plot analysis showed that given the −0.8 and 0.89% limits of agreement, the two methods may be used interchangeably in clinical practice.     

终板法与椎弓根法对青少年特发性胸椎脊柱侧凸Cobb角测量的比较

目的:对青少年特发性胸椎脊柱侧凸Cobb角测量的终板法和椎弓根法进行对比研究,比较两种方法的可信度、可重复性及两种方法测量结果的差异。方法:选取我院2010年7月～2011年3月门诊就诊的55例特发性胸椎脊柱侧凸患者,由一名高年资医师预先确定测量主弯的上、下端椎后,3名脊柱外科医师分别使用终板法和椎弓根法对站立位X线片进行手工测量评估,记录冠状面侧凸Cobb角数值,同时根据Nash-Moe法评估测量主弯上、下端椎的旋转度。1周后,打乱患者顺序,再由该3名医师重复测量。对测量结果进行可信度和可重复性分析,检验一致性并对两种方法的测量结果根据端椎旋转度和Cobb角大小分组进行分析比较。结果:终板法和椎弓根法测量主胸弯Cobb角的可信度和可重复性均为好～极佳的水平。终板法测量的总体可信度和可重复性分别为0.969和0.900,椎弓根法测量的总体可信度和可重复性分别为0.972和0.880。根据下端椎旋转度将AIS患者分组后的结果显示:下端椎无旋转组(Nash-Moe 0度)中椎弓根法与终板法测量结果无明显差异(P>0.05),而下端椎旋转明显组(Nash-MoeⅠ度和Ⅱ度)中椎弓根法测量结果较终板法小,差异有统计学意义(P<0.05)。根据Cobb角是否大于25°进行分组后的统计分析表明,在两组中椎弓根法测量结果均显著小于终板法(P<0.05)。结论:对于青少年特发性胸椎脊柱侧凸而言,终板法和椎弓根法测量Cobb角的可信度和可重复性均较好,但对于下端椎旋转明显(Nash-MoeⅠ度以上)的患者,椎弓根法较终板法测量结果小,建议对此类患者采用终板法测量Cobb角。     

Roentgenographic measurement of angle between shaft and distal epiphyseal growth plate of radius

To assess the accuracy of the use of the growth plate to shaft angle (GP-S) in the fractured distal radius, two prospective studies were performed. The first intraobserver study was made by three different observers who measured the GP-S angles of anteroposterior and lateral views of 62 wrist radiographs on two different occasions. The results showed a 95% concordance for a 5 degrees tolerance on anteroposterior views and 7 degrees on lateral views. The second, an interobserver study with six different observers, showed the same results. The results favored the use of the distal radius GP-S angle. It is an easy and accurate measurement that can be useful for the assessment of distal forearm deformities in children.     

Intra- and interobserver variability in the measurements of abdominal aortic and common iliac artery diameter with computed tomography. The Troms? study.

OBJECTIVES: to assess intra- and interobserver variability in the measurement of aortic and common iliac artery diameter by means of computed tomography (CT). DESIGN: reproducibility study. MATERIAL AND METHODS: three radiologists performed measurements of aortic diameter at five different levels and of both common iliac arteries with CT. Fifty-nine subjects were examined, 29 with and 30 without abdominal aortic aneurysms (AAA) as assessed by ultrasound. RESULTS: intraobserver variability varied between radiologists, measurement plane (anterior-posterior vs transverse) and measurement level. The interobserver variability was markedly higher at the bifurcation than at the suprarenal level and higher than intraobserver variability for measurements at all levels. Both intraobserver and interobserver variability increased with increasing vessel diameter and were largest in patients with AAA. The absolute intraobserver difference of the maximal infrarenal aortic diameter was 2mm or less in 94% of intraobserver pairs. The corresponding interobserver difference was 82%. CONCLUSIONS: interobserver variability of CT measurements of aortic and common iliac artery diameter is not negligible and should be taken into account when making clinical decisions. When assessing change in aortic diameter, previous CT-scans should be reviewed simultaneously as a routine to exclude interobserver variability.     

Reliability and necessity of dynamic computerized tomography in diagnosis of atlantoaxial rotatory subluxation

Dynamic computerized tomography (DCT) has been accepted to be the standard diagnostic method of atlantoaxial rotatory subluxation (AARS) although its reliability and reproducibility has not been shown yet. The purpose of this study was to evaluate the intraobserver reproducibility and interobserver reliability of DCT. Standard DCT scans of 18 patients with acute torticollis and 12 normal subjects were examined two times in between a time interval of 1 month by three specialists and a last-year resident to define any existing AARS. The interobserver reliability kappa coefficient was -0.015 (poor) for the first examination and 0.327(fair) for the second one. The intraobserver reproducibility kappa coefficients were 0.135 (slight), -0.204 (poor), 1.00 (almost perfect), and 0.474 (moderate) respectively. It was found that DCT has a poor reliability and reproducibility in diagnosing AARS in patients with acute torticollis. Therefore, its routine use is not cost effective in patients with acute torticollis where the deformity usually resolves by a simple cervical mobilization.