Intraobserver Interobserver Intraclass Correlation Coefficient Research Articles

Validation and incorporation of digital entheses into a preliminary GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis

ObjectivesThe main objective was to generate a GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis and to test its reliability. To this end, we assessed the validity, feasibility and...

Reliability of Vertebral Pelvic Angles in Assessment of Spinal Alignment.

Reliability analysis. Vertebral pelvic angles (VPA) are gaining popularity given their ability to describe the shape of the spine. Understanding the reliability and minimal detectable change (MDC) is necessary to determine how these measurement tools should be used in the manual assessment of spine radiographs. Our aim is to assess intra- and interobserver intraclass correlation coefficients (ICC) and the MDC in the use of VPA for assessing alignment in adult spinal deformity (ASD). Three independent examiners blindly measured T1, T4, T9, L1, and L4PA twice in ASD patients with a 4-week window after the initial measurements. Patients who had undergone hip or shoulder arthroplasty, fused or transitional vertebrae, or whose hip joints were not visible on radiographs were excluded. Power analysis calculated a minimum sample size of 19. Both intra- and interobserver ICC and MDC, which denotes the smallest detectable change in a true value with 95% confidence, were calculated. Out of the 193 patients, 39 were ultimately included in the study, and 390 measurements were performed by 3 raters. Intraobserver ICC values ranged from .90 to .99. The interobserver ICC was .97, .97, .96, .95, and .92, and the MDC was 5.3°, 5.1°, 4.8°, 4.9°, and 4.1° for T1, T4, T9, L1, and L4PA, respectively. All VPAs showed excellent intra- and interobserver reliability, however, the MDC is relatively high compared to typical ranges for VPA values. Therefore, surgeons must be aware that substantial alignment changes may not be detected by a single VPA.

Artificial intelligence-based analyses of varus leg alignment and after high tibial osteotomy show high accuracy and reproducibility

PurposeThe aim of this study was to investigate the performance of an artificial intelligence (AI)-based software for fully automated analysis of leg alignment pre- and postoperatively after high tibial osteotomy (HTO) on long-leg radiographs (LLRs).MethodsLong-leg radiographs of 95 patients with varus malalignment that underwent medial open-wedge HTO were analyzed pre- and postoperatively. Three investigators and an AI software using deep learning algorithms (LAMA™, ImageBiopsy Lab, Vienna, Austria) evaluated the hip–knee–ankle angle (HKA), mechanical axis deviation (MAD), joint line convergence angle (JLCA), medial proximal tibial angle (MPTA), and mechanical lateral distal femoral angle (mLDFA). All measurements were performed twice and the performance of the AI software was compared with individual human readers using a Bayesian mixed model. In addition, the inter-observer intraclass correlation coefficient (ICC) for inter-observer reliability was evaluated by comparing measurements from manual readers. The intra-reader variability for manual measurements and the AI-based software was evaluated using the intra-observer ICC.ResultsInitial varus malalignment was corrected to slight valgus alignment after HTO. Measured by the AI algorithm and manually HKA (5.36° ± 3.03° and 5.47° ± 2.90° to − 0.70 ± 2.34 and − 0.54 ± 2.31), MAD (19.38 mm ± 11.39 mm and 20.17 mm ± 10.99 mm to − 2.68 ± 8.75 and − 2.10 ± 8.61) and MPTA (86.29° ± 2.42° and 86.08° ± 2.34° to 91.6 ± 3.0 and 91.81 ± 2.54) changed significantly from pre- to postoperative, while JLCA and mLDFA were not altered. The fully automated AI-based analyses showed no significant differences for all measurements compared with manual reads neither in native preoperative radiographs nor postoperatively after HTO. Mean absolute differences between the AI-based software and mean manual observer measurements were 0.5° or less for all measurements. Inter-observer ICCs for manual measurements were good to excellent for all measurements, except for JLCA, which showed moderate inter-observer ICCs. Intra-observer ICCs for manual measurements were excellent for all measurements, except for JLCA and for MPTA postoperatively. For the AI-aided analyses, repeated measurements showed entirely consistent results for all measurements with an intra-observer ICC of 1.0.ConclusionsThe AI-based software can provide fully automated analyses of native long-leg radiographs in patients with varus malalignment and after HTO with great accuracy and reproducibility and could support clinical workflows.Level of evidenceDiagnostic study, Level III.

Deep learning-based landmark recognition and angle measurement of full-leg plain radiographs can be adopted to assess lower extremity alignment.

Evaluating lower extremity alignment using full-leg plain radiographs is an essential step in diagnosis and treatment of patients with knee osteoarthritis. The study objective was to present a deep learning-based anatomical landmark recognition and angle measurement model, using full-leg radiographs, and validate its performance. A total of 11,212 full-leg plain radiographs were used to create the model. To train the data, 15 anatomical landmarks were marked by two orthopaedic surgeons. Mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and hip-knee-ankle angle (HKAA) were then measured. For inter-observer reliability, the inter-observer intraclass correlation coefficient (ICC) was evaluated by comparing measurements from the model, surgeons, and students, to ground truth measurements annotated by an orthopaedic specialist with 14years of experience. To evaluate test-retest reliability, all measurements were made twice by each measurer. Intra-observer ICCs were then derived. Performance evaluation metrics used in previous studies were also derived for direct comparison of the model's performance. Inter-observer ICCs for all angles of the model were 0.98 or higher (p < 0.001). Intra-observer ICCs for all angles were 1.00, which was higher than that of the orthopaedic specialist (0.97-1.00). Measurements made by the model showed no significant systemic variation. Except for JLCA, angles were precisely measured with absolute error averages under 0.52 degrees and proportion of outliers under 4.26%. The deep learning model is capable of evaluating lower extremity alignment with performance as accurate as an orthopaedic specialist with 14years of experience. III, retrospective cohort study.

Preoperative planning using computed tomography in tibial plateau levelling osteotomy: A comparison with conventional radiography.

BackgroundTibial plateau levelling osteotomy (TPLO) is currently one of the most common surgical procedures for the correction of the stifle joint with a ruptured cranial cruciate ligament. TPLO is based on the preoperative tibial plateau angle (TPA); therefore, it is essential to optimise the consistency and repeatability of TPA measurements.ObjectivesThis study aims to compare computed tomography (CT) with conventional radiography in the preoperative planning of TPLO.MethodsThis prospective study included six dogs (12 hindlimbs) and 13 canine cadaveric hindlimbs. In the six beagle dogs, TPAs were measured by three radiologists using digital radiographic and CT images to evaluate the intra‐ and inter‐observer agreement. To evaluate the intra‐observer agreement of the TPA before and after surgery, and the intended angle of the postoperative TPA according to the preoperative planning method, 13 cadaveric hindlimbs were evaluated thrice at random by a single radiologist.ResultsThe intra‐ and inter‐observer intraclass correlation coefficients (ICCs) of the CT method were higher than those of the radiographic method in normal beagle dogs. The intra‐observer ICC of the CT method before and after TPLO was generally higher than that of the radiographic method in the cadaver. However, no significant difference was noted in the evaluation of the intended postoperative TPA according to the preoperative planning method.ConclusionsThe intra‐ and inter‐observer ICCs allowed for easy identification of landmarks required to consistently determine the TPA in the preoperative planning of TPLO based on CT images.

Inter- and intraobserver agreement for CT measurement of mandibular and medial retropharyngeal lymph nodes is excellent in dogs with histologically confirmed oral melanoma.

Mandibular and medial retropharyngeal lymph nodes are routinely evaluated with CT when staging dogs with oral melanomas. While size alone is considered inadequate for detecting nodal metastasis, it is critical in evaluating treatment response, as clinical decisions are based on changes in size. It is common for different radiologists to measure the size of pre- and posttreatment lymph nodes in the same patient. The objective of this retrospective, observer agreement study was to evaluate the inter- and intraobserver agreement in measuring canine mandibular and medial retropharyngeal lymph nodes by a diverse population of veterinary radiologists and trainees. Fourteen dogs with documented oral melanoma and head CT studies identified from records of a single institution were included in this study. North American veterinary radiologists and trainees were recruited to measure the mandibular and medial retropharyngeal lymph nodes; in triplicate. Prior to performing the study measurements, participants completed a training tool demonstrating the lymph node measurements. Overall, interobserver intraclass correlation coefficient (ICC) was 0.961 (95% confidence interval [CI]: 0.946, 0.972) and intraobserver ICC was 0.977 (95% CI: 0.968, 0.983), indicating excellent agreement (ICC>0.9 considered excellent). Similar findings were noted following sub-analysis for most variables (experience, size, laterality, axis of measurement). These results suggest that follow-up measurement of the long and short axis of the mandibular lymph nodes and short axis of the medial retropharyngeal lymph nodes in the transverse plane, performed by different veterinary radiologists using the same method of measure, should have minimal impact on clinical decision making.

Radiographic union score for tibia (RUST) scoring system in adult diaphyseal femoral fractures treated with intramedullary nailing: an assessment of interobserver and intraobserver reliability.

The Radiographic Union Score for Tibia (RUST) scoring system has been validated in multiple studies assessing the healing of tibial fractures. Our objective was to assess the interobserver and intraobserver reliability for the RUST in diaphyseal femoral fractures treated with intramedullary (IM) nailing. A total of 60 sets of anteroposterior (AP) and lateral radiographs of diaphyseal femoral fractures treated by reamed IM nailing were randomly selected from a prospectively collected database. The 60 sets of radiographs were then scored by three reviewers using the RUST system. Interobserver reliability was measured at initial scoring. The 60 sets of radiographs were scored again by the three reviewers to calculate the intraobserver reliability. The RUST scores ranged from 4 to 12 with a mean score of 11.3 ± 1.3. The interobserver intraclass correlation coefficient (ICC) was 0.87 (95% CI, 0.81-0.92) and the intraobserver ICC was 0.91 (95% CI, 0.88-0.94), which indicated excellent agreement. This study demonstrated that the RUST system can be used reliably in the assessment of healing in diaphyseal femur fractures treated by reamed intramedullary nailing, with excellent interobserver and intraobserver reliability.

Three-dimensional assessment of patellofemoral anatomy: Reliability and reference ranges

BackgroundThree-dimensional (3D) imaging and analysis offer new possibilities in preoperative diagnostics and surgical planning. Simultaneous 3D analysis of the joint angles and the patellofemoral anatomy allow for a realistic assessment of bony pathologies in patients with patellofemoral complaints. This study aims to develop a standardized and validated assessment of the 3D patellofemoral morphology and to establish reference ranges. MethodsThirteen patellofemoral anatomic landmarks were defined on 3D bone models of the lower limbs based on computer tomography data and evaluated regarding inter- and intra-observer variability. Further, 60 3D models of the lower limbs of young subjects without any previous knee operation/injury were assessed and rescaled reference values for relevant patellofemoral indices were obtained. ResultsThe mean inter- and intra-observer deviation of all landmarks was below 2.3 mm. The interobserver intraclass correlation coefficient (ICC) was between 0.8 and 1.0 and the intra-observer ICC between 0.68 and 0.99 for all patellofemoral parameters. The calculated reference ranges are: Insall–Salvati index 1.0–1.4; patella tilt 6–18°; patella shift −4 to 3 mm; patella facet angle 118–131°; sulcus angle 141–156°; trochlear depth 3–6 mm; tibial-tuberosity to trochlear groove distance(TT-TG) 2D 14–21 mm; TT-TG 3D 11–18 mm; lateral trochlear inclination 13–23°; trochlear facet angle 43–65°. ConclusionThe demonstrated 3D analysis of the patellofemoral anatomy can be performed with high inter- and intra-observer correlation. Applying the obtained reference ranges and using existing 3D assessment tools for lower limb alignment, a preoperative 3D analysis and planning for complex knee procedures now is possible.

Healing pattern classification for thoracolumbar burst fractures after posterior short-segment fixation

BackgroundThoracolumbar burst fractures can be treated with posterior short-segment fixation. However, no classification can help to estimate whether the healed vertebral body will have sufficient stability after implant removal. We aimed to develop a Healing Pattern Classification (HPC) to evaluate the stability of the healed vertebra based on cavity size and location.MethodsFifty-two thoracolumbar burst fracture patients treated with posterior short-segmental fixation without fusion and followed up for an average of 3.2 years were retrospectively studied. The HPC was divided into 4 types: type I - no cavity; type II - a small cavity with or without the violation of one endplate; type III - a large cavity with or without the violation of one endplate; and type IV - a burst cavity with the violation of both endplates or the lateral cortical shell. The intraobserver and interobserver intraclass correlation coefficients (ICCs) of the HPC were assessed. The demographic characteristics and clinical outcomes of the cohort were compared between the stable group (types I and II) and the unstable group (types III and IV). Logistic regression was conducted to evaluate risk factors for unstable healing.ResultsThe intraobserver and interobserver ICCs of the HPC were 0.86 (95% CI = 0.74–0.90) and 0.77 (95% CI = 0.59–0.86), respectively. While the unstable healing group (types III and IV) accounted for 59.6% of the patients, most of these patients were asymptomatic. The preoperative Load Sharing Classification (LSC) comminution score may predict the occurrence of unstable healing (OR = 8.4, 95% CI = 2.4–29.7).ConclusionsA reliable classification for assessing the stability of a healed vertebra was developed. With type I and II healing, the vertebra is considered stable, and the implant can be removed. With type III healing, the vertebra may have healing potential, but the implant should not be removed unless type II healing is achieved. With type IV healing, the vertebra is considered extremely unstable, and instrumentation should be maintained. Assessing the LSC comminution score preoperatively may help to predict unstable healing after surgery.

The CUPAX questionnaire: Development and validation of a new scale for assessment of the functional level of elderly patients with a hip fracture

Background and aimHip fractures in elderly patients are very frequent and are associated with high morbidity and mortality. We do not have validated instruments in Spanish that can faithfully assess functional capacity prior to fracture. The aim of this study was to develop and validate the CUPAX questionnaire in elderly patients with a hip fracture. Materials and methodsProspective and observational validation study. We included 215 patients older than 65 years, who were admitted to our centre after suffering a hip fracture. They were evaluated using the CUPAX questionnaire, Barthel Index and Parker Score. The statistical study was performed to corroborate the validity and reliability of the questionnaire. ResultsThe median age of the patient population was 84.0 years (75.3% women). The majority were patients who had suffered an extracapsular fracture; they had walking capacity and suffered a fall in their place of residence. The statistical analysis on the validity and reliability of the questionnaire obtained the following results: Cronbach's alpha coefficient showed excellent internal consistency (value of 0.94). Factor analysis showed 3 underlying factors. The interobserver intraclass correlation coefficient (ICC) was 0.82 (95% CI: 0.75–0.87), and the intraobserver ICC was 0.96 (95% CI: 0.95–0.97). Correlation with other functional scales was assessed using the Spearman correlation coefficient, which was 0.83 with the Barthel Index and 0.81 with the Parker score. ConclusionsThese findings support the validity of the CUPAX questionnaire as a tool to measure the previous functional level in elderly patients affected by a hip fracture.

Anatomical sacral slope, a new pelvic parameter, is associated with lumbar lordosis and pelvic incidence in healthy Japanese women: A retrospective cross-sectional study.

Anatomical sacral slope (a-SS), a pelvic anatomical parameter that does not require the center of the femoral head, strongly correlates with pelvic incidence (PI) during three-dimensional measurements in normal subjects. Sagittal alignment of spinal and pelvic parameters is typically evaluated using two-dimensional radiographs; however, the relationship between a-SS and PI has not been evaluated using radiographs. This study aimed to evaluate the correlation between a-SS and other spinal and pelvic parameters using radiographs. We evaluated 144 healthy women. Using sagittal radiographs, we measured lumbar lordosis (LL), thoracic kyphosis, PI, SS, pelvic tilt, and a-SS, which were defined as the angle between the superior end plate of S1 and a line perpendicular to the anterior pelvic plane. Pearson coefficients were used to determine correlations, and intraobserver and interobserver intraclass correlation coefficients (ICCs) were used for validation. There was a strong correlation between PI and a-SS (r = 0.756). Moreover, correlations between a-SS and LL and between PI and LL were similar (r = 0.661 and r = 0.554, respectively). The intraobserver ICCs were 0.884 for a-SS and 0.840 for PI. The interobserver ICCs were 0.856 for a-SS and 0.653 for PI. a-SS was strongly correlated with PI. The correlation between a-SS and LL was equivalent to the correlation between PI and LL. Moreover, the ICC for a-SS was larger than that of PI. This study suggests that a-SS is a useful new pelvic anatomical parameter that can be used instead of PI.

Cuestionario CUPAX: desarrollo y validación de una nueva escala para la valoración del nivel funcional de pacientes mayores de 65 años con fractura de cadera

Background and aimHip fractures in elderly patients are very frequent and are associated with high morbidity and mortality. We do not have validated instruments in Spanish that can faithfully assess functional capacity prior to fracture. The aim of this study was to develop and validate the CUPAX questionnaire in elderly patients with a hip fracture. Materials and methodsProspective and observational validation study. We included 215 patients older than 65 years, who were admitted to our centre after suffering a hip fracture. They were evaluated using the CUPAX questionnaire, Barthel Index and Parker Score. The statistical study was performed to corroborate the validity and reliability of the questionnaire. ResultsThe median age of the patient population was 84.0 years (75.3% women). The majority were patients who had suffered an extracapsular fracture; they had walking capacity and suffered a fall in their place of residence. The statistical analysis on the validity and reliability of the questionnaire obtained the following results: Cronbach's alpha coefficient showed excellent internal consistency (value of .94). Factor analysis showed 3 underlying factors. The interobserver intraclass correlation coefficient (ICC) was .82 (95% CI:.75-.87), and the intraobserver ICC was .96 (95% CI:.95-.97). Correlation with other functional scales was assessed using the Spearman correlation coefficient, which was .83 with the Barthel Index and .81 with the Parker score. ConclusionsThese findings support the validity of the CUPAX questionnaire as a tool to measure the previous functional level in elderly patients affected by a hip fracture.

Digital Measurements With Hallux Valgus Before and After Modified Long Oblique Osteotomy

Radiographic measurements of the hallux valgus (HV) angle (HVA) and the first intermetatarsal angle (IMA1-2) are important for assessing the severity of HV. The purpose of the present study was to digitally investigate the intraobserver and interobserver reliability of various methods for measuring HVA and IMA1-2, as well as each axis composing them, such as axes of the first proximal phalanx (PP1), the first metatarsal (MT1), and the second metatarsal (MT2) in patients with a metatarsal shaft osteotomy-modified long oblique osteotomy. Three orthopedic surgeons measured the HVA, IMA1-2, and the angles between axes of PP1, MT1, and MT2, and the digitally-set reference line (α, β, and γ, respectively) using 6 different methods for 39 patients with a minimum of 1 year of follow-up after operative treatment. The intraobserver and interobserver intraclass correlation coefficients (ICC) and agreements were calculated. Significant differences were observed within the methods with regard to preoperative HVA, IMA1-2, α, and β, and postoperative IMA1-2 and β. Intraobserver and interobserver ICC were high or very high in most methods. For HVA and IMA1-2, the method connecting the center of the head through the center of the base showed the highest agreement. For α, β, and γ, this method showed the highest agreement, more than 80% intraobserver and interobserver agreement and a discrepancy of <2°. A digital method connecting the center of the head through the center of the base was regarded as the least variable for the HV evaluation and the assessment of the radiographic results in a metatarsal shaft osteotomy-modified long oblique osteotomy.

Feasibility and reproducibility of ShearWave(TM) elastography of fetal baboon organs.

The purpose of this study was to assess the feasibility and reproducibility of transabdominal ShearWave(TM) elastography of fetal organs in pregnant baboons. Fetal ultrasounds of all pregnant baboons in a single primate research center were performed prospectively during 9 months. The visualization of fetal targeted organs (liver, proximal and distal lungs, brain white matter and periventricular gray matter) was initially performed using 2D ultrasound, and then elastography mode was activated. For each organ, three measurements were carried out by two operators. Intra-observer and inter-observer intra-class correlation coefficients (ICC) were calculated. During the study period (03/2013-12/2013), 21 pregnant baboons (21 fetuses) were included. One to three ultrasound scans were performed for each fetus. The measurements were feasible by the two operators in all cases. The intra-observer and inter-observer ICC were 0.654, 95% CI (0.606 to 0.699) and 0.645, 95% CI (0.553 to 0.721) respectively. Transabdominal ShearWave(TM) Elastography of fetal organs can be achieved in pregnant baboons. The intra-observer and inter-observer reproducibility is correct but vary according to the targeted organs.

Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus

Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this study was to analyse the variation in mouth-opening measurements in patients treated for head and neck cancer, with and without trismus. Maximal mouth opening was measured in 120 patients in two sessions of three repeated measurements by one observer. To analyse the influence of interobserver variation on mouth-opening measurements a subgroup of 30 patients was measured by a second observer. The standard deviation of the six measurements per patient was used as the variation in measurements of maximal mouth opening. No significant difference was found in maximal mouth opening in patients with ( n = 33) or without ( n = 87) trismus. The interobserver intraclass correlation coefficient (ICC) was 0.98. Intraobserver ICC and intersession ICC reliabilities both were 0.99. The variation in the mean values of the three measurements was only slightly smaller than the variation of the single measurements. Variation in maximal mouth opening in patients with trismus does not differ from variation in maximal mouth opening in patients without trismus. Interobserver variation is limited.

Posterior Sloping Angle of the Capital Femoral Physis

The management of the contralateral hip after unilateral slipped capital femoral epiphysis (SCFE) is controversial. The aims of this study were to assess the interobserver and intraobserver reliability of the posterior sloping angle (PSA) as described by Barrios et al (J Pediatr Orthop. 2005;25:445-449) and whether it can be used as a predictor of need for prophylactic pinning of the contralateral hip. The PSA was measured by 4 different surgeons on 2 separated occasions in 47 unaffected contralateral hips after unilateral SCFE. The interobserver intraclass correlation coefficient (ICC) was 0.83 (excellent) for the first set of measurements and 0.74 (fair to good) for the second set of measurements. Measurement of the intraobserver ICC revealed an excellent agreement (ICC > 0.75) in 3 of the 4 surgeons and fair to good agreement in 1 of the surgeons (ICC between 0.4 and 0.74). Comparison of the PSA measurements of the first author (M.Z.) with a control group of 20 hips revealed that the PSA was significantly higher (P < 0.05) in the group of patients that eventually had a contralateral slip when compared with the PSA of patients in the study group who did not slip and with normal hips in the control group. Patients with contralateral SCFE that did not slip had a significantly higher PSA (P < 0.05) when compared with normal individuals. A PSA of 14.5 degrees or more is recommended for prophylactic pinning of the contralateral hip. The number needed to treat (NNT) at this cut off to avoid 1 future slip was calculated to be 1.9.

Comparison between constrained and non-constrained Cobb techniques for the assessment of thoracic kyphosis and lumbar lordosis

Sagittal curvatures of the spine can be assessed using the constrained or non-constrained Cobb techniques. However, there is no study that specifically compares these two techniques. The objective of this study is to assess the reproducibility and clinical relevance of the non-constrained Cobb technique (non-constrained limit vertebrae) compared to the constrained Cobb technique (constrained limit vertebrae). Standing sagittal radiographs of the spine of ten adolescents with idiopathic scoliosis, ten adolescents with spondylolisthesis and ten normal adolescents were selected. Thoracic kyphosis (TK) and lumbar lordosis (LL) were measured twice by three observers using both constrained and non-constrained Cobb techniques. Pearson's correlation coefficients, as well as intra- and inter-observer intra-class correlation coefficients (ICC) were calculated. Inter-observer ICCs were similar for TK and LL with both techniques, ranging from 0.84 to 0.89. Intra-observer ICCs for both techniques were between 0.74 and 0.92 for TK, while they were between 0.87 and 0.97 for LL. The two techniques were highly correlated for the measurement of the TK (r = 0.96) and LL (r = 0.94). Computer-assisted assessment of the sagittal profile using the non-constrained Cobb technique provides excellent reproducibility. As opposed to the constrained Cobb technique, the non-constrained Cobb technique takes into account the variability in the level of transition between the TK and LL. However, adequate use of this technique requires accurate identification of the limit vertebrae in the thoracolumbar spine. Consequently, a computer-assisted technique is recommended when using the non-constrained Cobb technique.

Knee alignment does not predict incident osteoarthritis: The Framingham osteoarthritis study

To examine the relationship of knee malalignment to the occurrence of knee osteoarthritis (OA) among subjects without radiographic OA at baseline to determine whether malalignment is a risk factor for incident disease or simply a marker of increasing disease severity. We selected 110 incident tibiofemoral (TF) OA case knees (76 subjects) and 356 random control knees (178 subjects) from among participants in the Framingham Osteoarthritis Study. Case knees did not have OA at baseline (1992-1994 examination) but had developed OA (Kellgren/Lawrence grade>or=2) at followup (2002-2005 examination) (mean of 8.75 years between examinations). Control knees did not have OA at baseline. Standardized digital radiographs of the fully extended knee with weight-bearing were read using a standard protocol and eFilm viewing software. We measured the anatomic axis, the condylar angle, the tibial plateau angle, and the condylar tibial plateau angle. The interobserver intraclass correlation coefficient (ICC) ranged from 0.93 to 0.96 and the intraobserver ICC from 0.94 to 0.97. In a knee-specific analysis, we examined the relationship of each alignment measurement to the risk of TF OA using generalized estimating equations, adjusting for age, sex, and body mass index (BMI). We used the same approach to assess the association between each alignment measurement and the risk of medial TF OA. Subjects in the case population were older and had a higher BMI than the controls. The alignment values were normally distributed and were not different between the cases and the controls. After adjustment for age, sex and BMI, there was no significant increase in incident OA in the highest quartile compared with the lowest quartile category for any of the alignment measures (P for trend for anatomic axis and condylar tibial plateau angle was 0.83 and 0.80, respectively). Similar results were also observed for medial compartment OA. We found that baseline knee alignment is not associated with either incident radiographic TF OA or medial TF OA. These results suggest that malalignment is not a risk factor for OA, but rather is a marker of disease severity and/or its progression.

Quantification of cutaneous sclerosis with a skin elasticity meter in patients with generalized scleroderma

Background: The skin score, a subjective assessment of skin elasticity, is widely used in patients with systemic sclerosis. Although this scoring method is regarded as a validated and accepted tool, the interobserver and intraobserver reproducibility is relatively poor. Objective: Our purpose was to investigate whether the recently developed SEM 474 cutometer, which exerts a controlled vacuum force to the skin, can measure skin elasticity more objectively than the skin score. Methods: Skin elasticity was measured in 74 different body areas in patients with systemic sclerosis and compared with the skin score obtained from the same areas. Results: The cutometer produced quantitative and reproducible data. A large-diameter (8 mm) measuring probe was superior to a small probe. The interobserver intraclass correlation coefficient (ICC) was 0.92; the intraobserver ICC was 0.94. A linear correlation was found with the clinical skin score; the Spearman rank correlation test was 0.69. Conclusion: The correlation with the skin score was reasonable, despite the observation that regional differences in skin elasticity were detected by the cutometer but not by the human observer, who automatically compensates for these factors and integrates them into the skin score. The high interobserver and intraobserver ICC makes the cutometer more suitable for quantifying changes in skin thickness than the subjective skin score.