Accuracy of cup placement in total hip arthroplasty by means of a mechanical positioning device: a comprehensive cadaveric 3d analysis of 16 specimens.

INTRODUCTION: We tested whether a mechanical device (such as Hipsecure) to pinpoint the anterior pelvic plane (APP) as a guide can improve acetabular cup placement. To assess accuracy we asked: (1) is the APP an effective guide to position acetabular cup placement within acceptable ° of divergence from the optimal 40° inclination and 15° anteversion; (2) could a mechanical device increase the number of acetabular cup placements within Lewinnek's safe zone (i.e. inclination 30° to 50°; anteversion 5° to 25°)? METHODS: 16 cadaveric specimens were used to assess the 3D surgical success of using a mechanical device APP to guide acetabular cup placement along the APP. We used the Hipsecure mechanical device to implant acetabular cups at 40° inclination and 15° anteversion. Subequently, all cadaveric specimens with implants were scanned with a CT and 3D models were created of the pelvis and acetabular cups to assess the outcome in terms of Lewinnek's safe zones. RESULTS: The mean inclination of the 16 implants was 40.6° (95% CI, 37.7-43.4) and the mean anteversion angle was 13.4° (95% CI, 10.7-16.1). All 16 cup placements were within Lewinnek's safe zone for inclination (between 30° and 50°) and all but 2 were within Lewinnek's safe zone for anteversion (between 5° and 25°). CONCLUSION: In cadaveric specimens, the use of a mechanical device and the APP as a guide for acetabular cup placement resulted in good positioning with respect to both of Lewinnek's safe zones.

Wound complications after total hip arthroplasty: a prospective, randomised controlled trial comparing staples with sutures.

OBJECTIVE: Does the use of staples or sutures for wound closure have a lower surgical site infection rate in patients receiving primary total hip arthroplasty (THA)? DESIGN: Prospective, randomised controlled multicentre trial. METHODS: 535 patients undergoing THA were included and randomised into 2 groups: 268 wounds were closed with staples, and 267 with sutures. Primary outcome was surgical site infection (SSI). Secondary outcomes were prosthetic joint infection (PJI), other wound complications (dehiscence, necrosis and prolonged drainage) and duration of admittance. Follow-up occurred at 2, 6, and 12 weeks, and at 1 year. RESULTS: There were no significant demographic differences between the 2 groups. SSI occurred more frequently when wounds were closed with staples (4% compared to 1% with sutures; OR 2.8; CI, 0.885-0.952; p = 0.057). SSI was treated with oral antibiotics. The staples group showed significantly more wound complications (17% compared to 5%; OR 3.943, CI 2.073-7.498; p = 0.000). Wound discharge was significantly prolonged in the staples group (n = 40, compared to n = 12 in the sutures group; OR 3.728; CI, 1.909-7.281; p = 0.000). There was no significant difference in PJI (p = 0.364). CONCLUSIONS: In this large RCT comparing staples with sutures after THA, the use of staples is associated with a nearly 3 times greater risk of SSI (OR 2.8; p = 0.057). Staples significantly prolong wound discharge. The use of sutures for wound closure after THA is advised. Trial registration: Staples Or Sutures trial (S.O.S. trial) http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3946 , NTR3946.

Detecting scaphoid fractures in wrist injury: a clinical decision rule.

INTRODUCTION: The aim of this study was to develop and validate an easy to use clinical decision rule, applicable in the ED that limits the number of unnecessary cast immobilizations and diagnostic follow-up in suspected scaphoid injury, without increasing the risk of missing fractures. METHODS: A prospective multicenter study was conducted that consisted of three components: (1) derivation of a clinical prediction model for detecting scaphoid fractures in adult patients following wrist trauma; (2) internal validation of the model; (3) design of a clinical decision rule. The predictors used were: sex, age, swelling of the anatomic snuffbox, tenderness in the anatomic snuffbox, scaphoid tubercle tenderness, painful ulnar deviation and painful axial thumb compression. The outcome measure was the presence of a scaphoid fracture, diagnosed on either initial radiographs or during re-evaluation after 1-2 weeks or on additional imaging (radiographs/MRI/CT). After multivariate logistic regression analysis and bootstrapping, the regression coefficient for each significant predictor was calculated. The effect of the rule was determined by calculating the number of missed scaphoid fractures and reduction of suspected fractures that required a cast. RESULTS: A consecutive series of 893 patients with acute wrist injury was included. Sixty-eight patients (7.6%) were diagnosed with a scaphoid fracture. The final prediction rule incorporated sex, swelling of the anatomic snuffbox, tenderness in the anatomic snuffbox, painful ulnar deviation and painful axial thumb compression. Internal validation of the prediction rule showed a sensitivity of 97% and a specificity of 20%. Using this rule, a 15% reduction in unnecessary immobilization and imaging could be achieved with a 50% decreased risk of missing a fracture compared with current clinical practice. CONCLUSIONS: This dataset provided a simple clinical decision rule for scaphoid fractures following acute wrist injury that limits unnecessary immobilization and imaging with a decreased risk of missing a fracture compared to current clinical practice. CLINICAL PREDICTION RULE: 1/(1 + EXP (-(0.649662618 × if man) + (0.51353467826 × if swelling anatomic snuffbox) + (-0.79038263985 × if painful palpation anatomic snuffbox) + (0.57681198857 × if painful ulnar deviation) + (0.66499549728 × if painful thumb compression)-1.685). TRIAL REGISTRATION: Trial register NTR 2544, www.trialregister.nl.

What Are the Applications and Limitations of Artificial Intelligence for Fracture Detection and Classification in Orthopaedic Trauma Imaging? A Systematic Review.

BACKGROUND: Artificial-intelligence algorithms derive rules and patterns from large amounts of data to calculate the probabilities of various outcomes using new sets of similar data. In medicine, artificial intelligence (AI) has been applied primarily to image-recognition diagnostic tasks and evaluating the probabilities of particular outcomes after treatment. However, the performance and limitations of AI in the automated detection and classification of fractures has not been examined comprehensively. QUESTION/PURPOSES: In this systematic review, we asked (1) What is the proportion of correctly detected or classified fractures and the area under the receiving operating characteristic (AUC) curve of AI fracture detection and classification models? (2) What is the performance of AI in this setting compared with the performance of human examiners? METHODS: The PubMed, Embase, and Cochrane databases were systematically searched from the start of each respective database until September 6, 2018, using terms related to "fracture", "artificial intelligence", and "detection, prediction, or evaluation." Of 1221 identified studies, we retained 10 studies: eight studies involved fracture detection (ankle, hand, hip, spine, wrist, and ulna), one addressed fracture classification (diaphyseal femur), and one addressed both fracture detection and classification (proximal humerus). We registered the review before data collection (PROSPERO: CRD42018110167) and used the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). We reported the range of the accuracy and AUC for the performance of the predicted fracture detection and/or classification task. An AUC of 1.0 would indicate perfect prediction, whereas 0.5 would indicate a prediction is no better than a flip-of-a-coin. We conducted quality assessment using a seven-item checklist based on a modified methodologic index for nonrandomized studies instrument (MINORS). RESULTS: For fracture detection, the AUC in five studies reflected near perfect prediction (range, 0.95-1.0), and the accuracy in seven studies ranged from 83% to 98%. For fracture classification, the AUC was 0.94 in one study, and the accuracy in two studies ranged from 77% to 90%. In two studies AI outperformed human examiners for detecting and classifying hip and proximal humerus fractures, and one study showed equivalent performance for detecting wrist, hand and ankle fractures. CONCLUSIONS: Preliminary experience with fracture detection and classification using AI shows promising performance. AI may enhance processing and communicating probabilistic tasks in medicine, including orthopaedic surgery. At present, inadequate reference standard assignments to train and test AI is the biggest hurdle before integration into clinical workflow. The next step will be to apply AI to more challenging diagnostic and therapeutic scenarios when there is absence of certitude. Future studies should also seek to address legal regulation and better determine feasibility of implementation in clinical practice. LEVEL OF EVIDENCE: Level II, diagnostic study.

Online Studies on Variation in Orthopedic Surgery: Computed Tomography in MPEG4 Versus DICOM Format.

The purpose of this study was to compare the observer participation and satisfaction as well as interobserver reliability between two online platforms, Science of Variation Group (SOVG) and Traumaplatform Study Collaborative, for the evaluation of complex tibial plateau fractures using computed tomography in MPEG4 and DICOM format. A total of 143 observers started with the online evaluation of 15 complex tibial plateau fractures via either the SOVG or Traumaplatform Study Collaborative websites using MPEG4 videos or a DICOM viewer, respectively. Observers were asked to indicate the absence or presence of four tibial plateau fracture characteristics and to rate their satisfaction with the evaluation as provided by the respective online platforms. The observer participation rate was significantly higher in the SOVG (MPEG4 video) group compared to that in the Traumaplatform Study Collaborative (DICOM viewer) group (75 and 43%, respectively; P < 0.001). The median observer satisfaction with the online evaluation was seven (range, 0-10) using MPEG4 video compared to six (range, 1-9) using DICOM viewer (P = 0.11). The interobserver reliability for recognition of fracture characteristics in complex tibial plateau fractures was higher for the evaluation using MPEG4 video. In conclusion, observer participation and interobserver reliability for the characterization of tibial plateau fractures was greater with MPEG4 videos than with a standard DICOM viewer, while there was no difference in observer satisfaction. Future reliability studies should account for the method of delivering images.

6-week radiographs unsuitable for diagnosis of suspected scaphoid fractures.

INTRODUCTION: Six week follow-up radiographs are a common reference standard for the diagnosis of suspected scaphoid fractures. The main purpose of this study was to evaluate the interobserver reliability and diagnostic performance characteristics of 6-weeks radiographs for the detection of scaphoid fractures. In addition, two online techniques for evaluating radiographs were compared. MATERIALS AND METHODS: A total of 81 orthopedic surgeons affiliated with the Science of Variation Group assessed initial and 6-week scaphoid-specific radiographs of a consecutive series of 34 patients with suspected scaphoid fractures. They were randomized in two groups for evaluation, one used a standard website showing JPEG files and one a more sophisticated image viewer (DICOM). The goal was to identify the presence or absence of a (consolidated) scaphoid fracture. Interobserver reliability was calculated using the multirater kappa measure. Diagnostic performance characteristics were calculated according to standard formulas with CT and MRI upon presentation in the emergency department as reference standards. RESULTS: The interobserver agreement of 6-week radiographs for the diagnosis of scaphoid fractures was slight for both JPEG and DICOM (k = 0.15 and k = 0.14, respectively). The sensitivity (range 42-79 %) and negative predictive value (range 79-94 %) were significantly higher using a DICOM viewer compared to JPEG images. There were no differences in specificity (range 53-59 %), accuracy (range 53-58 %), and positive predictive value (range 14-26 %) between the groups. CONCLUSIONS: Due to low agreement between observers for the recognition of scaphoid fractures and poor diagnostic performance, 6-week radiographs are not adequate for evaluating suspected scaphoid fractures. The online evaluation of radiographs using a DICOM viewer seem to improve diagnostic performance characteristics compared to static JPEG images and future reliability and diagnostic studies should account for variation due to the method of delivering medical images. LEVEL OF EVIDENCE: Diagnostic level II.

Reliability of classification for post-traumatic ankle osteoarthritis.

PURPOSE: The purpose of this study was to identify the most reliable classification system for clinical outcome studies to categorize post-traumatic-fracture-osteoarthritis. METHODS: A total of 118 orthopaedic surgeons and residents-gathered in the Ankle Platform Study Collaborative Science of Variation Group-evaluated 128 anteroposterior and lateral radiographs of patients after a bi- or trimalleolar ankle fracture on a Web-based platform in order to rate post-traumatic osteoarthritis according to the classification systems coined by (1) van Dijk, (2) Kellgren, and (3) Takakura. Reliability was evaluated with the use of the Siegel and Castellan's multirater kappa measure. Differences between classification systems were compared using the two-sample Z-test. RESULTS: Interobserver agreement of surgeons who participated in the survey was fair for the van Dijk osteoarthritis scale (k = 0.24), and poor for the Takakura (k = 0.19) and the Kellgren systems (k = 0.18) according to the categorical rating of Landis and Koch. This difference in one categorical rating was found to be significant (p < 0.001, CI 0.046-0.053) with the high numbers of observers and cases available. CONCLUSIONS: This study documents fair interobserver agreement for the van Dijk osteoarthritis scale, and poor interobserver agreement for the Takakura and Kellgren osteoarthritis classification systems. Because of the low interobserver agreement for the van Dijk, Kellgren, and Takakura classification systems, those systems cannot be used for clinical decision-making. LEVEL OF EVIDENCE: Development of diagnostic criteria on basis of consecutive patients, Level II.

The effect of concentrated bone marrow aspirate in operative treatment of fifth metatarsal stress fractures; a double-blind randomized controlled trial.

BACKGROUND: Fifth metatarsal (MT-V) stress fractures often exhibit delayed union and are high-risk fractures for non-union. Surgical treatment, currently considered as the gold standard, does not give optimal results, with a mean time to fracture union of 12-18 weeks. In recent studies, the use of bone marrow cells has been introduced to accelerate healing of fractures with union problems. The aim of this randomized trial is to determine if operative treatment of MT-V stress fractures with use of concentrated blood and bone marrow aspirate (cB + cBMA) is more effective than surgery alone. We hypothesize that using cB + cBMA in the operative treatment of MT-V stress fractures will lead to an earlier fracture union. METHODS/DESIGN: A prospective, double-blind, randomized controlled trial (RCT) will be conducted in an academic medical center in the Netherlands. Ethics approval is received. 50 patients will be randomized to either operative treatment with cB + cBMA, harvested from the iliac crest, or operative treatment without cB + cBMA but with a sham-treatment of the iliac crest. The fracture fixation is the same in both groups, as is the post-operative care.. Follow up will be one year. The primary outcome measure is time to union in weeks on X-ray. Secondary outcome measures are time to resumption of work and sports, functional outcomes (SF-36, FAOS, FAAM), complication rate, composition of osteoprogenitors in cB + cBMA and cost-effectiveness. Furthermore, a bone biopsy is taken from every stress fracture and analysed histologically to determine the stage of the stress fracture. The difference in primary endpoint between the two groups is analysed using student's t-test or equivalent. DISCUSSION: This trial will likely provide level-I evidence on the effectiveness of cB + cBMA in the operative treatment of MT-V stress fractures. TRIAL REGISTRATION: Netherlands Trial Register (reg.nr NTR4377 ).

Computed tomography versus magnetic resonance imaging versus bone scintigraphy for clinically suspected scaphoid fractures in patients with negative plain radiographs.

BACKGROUND: In clinically suspected scaphoid fractures, early diagnosis reduces the risk of non-union and minimises loss in productivity resulting from unnecessary cast immobilisation. Since initial radiographs do not exclude the possibility of a fracture, additional imaging is needed. Computed tomography (CT), magnetic resonance imaging (MRI) and bone scintigraphy (BS) are widely used to establish a definitive diagnosis, but there is uncertainty about the most appropriate method. OBJECTIVES: The primary aim of this study is to identify the most suitable diagnostic imaging strategy for identifying clinically suspected fractures of the scaphoid bone in patients with normal radiographs. Therefore we looked at the diagnostic performance characteristics of the most used imaging modalities for this purpose: computed tomography, magnetic resonance imaging and bone scintigraphy. SEARCH METHODS: In July 2012, we searched the Cochrane Register of Diagnostic Test Accuracy Studies, MEDLINE, EMBASE, the Database of Abstracts of Reviews of Effects, the Cochrane Central Register of Controlled Trials, the NHS Economic Evaluation Database. In September 2012, we searched MEDION, ARIF, Current Controlled Trials, the World Health Organization (WHO) International Clinical Trials Registry Platform, conference proceedings and reference lists of all articles. SELECTION CRITERIA: We included all prospective or retrospective studies involving a consecutive series of patients of all ages that evaluated the accuracy of BS, CT or MRI, or any combination of these, for diagnosing suspected scaphoid fractures. We considered the use of one or two index tests or six-week follow-up radiographs as adequate reference standards. DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts and assessed full-text reports of potentially eligible studies. The same authors extracted data from full-text reports and assessed methodological quality using the QUADAS checklist. For each index test, estimates of sensitivity and specificity from each study were plotted in ROC space; and forest plots were constructed for visual examination of variation in test accuracy. We performed meta-analyses using the HSROC model to produce summary estimates of sensitivity and specificity. MAIN RESULTS: We included 11 studies that looked at diagnostic accuracy of one or two index tests: four studies (277 suspected fractures) looked at CT, five studies (221 suspected fractures) looked at MRI and six studies (543 suspected fractures) looked at BS. Four of the studies made direct comparisons: two studies compared CT and MRI, one study compared CT and BS, and one study compared MRI and BS. Overall, the studies were of moderate to good quality, but relevant clinical information during evaluation of CT, MRI or BS was mostly unclear or unavailable.As few studies made direct comparisons between tests with the same participants, our results are based on data from indirect comparisons, which means that these results are more susceptible to bias due to confounding. Nonetheless, the direct comparisons showed similar patterns of differences in sensitivity and specificity as for the pooled indirect comparisons.Summary sensitivity and specificity of CT were 0.72 (95% confidence interval (CI) 0.36 to 0.92) and 0.99 (95% CI 0.71 to 1.00); for MRI, these were 0.88 (95% CI 0.64 to 0.97) and 1.00 (95% CI 0.38 to 1.00); for BS, these were 0.99 (95% CI 0.69 to 1.00) and 0.86 (95% CI 0.73 to 0.94). Indirect comparisons suggest that diagnostic accuracy of BS was significantly higher than CT and MRI; and CT and MRI have comparable diagnostic accuracy. The low prevalence of a true fracture among suspected fractures (median = 20%) means the lower specificity for BS is problematic. For example, in a cohort of 1000 patients, 112 will be over-treated when BS is used for diagnosis. If CT is used, only 8 will receive unnecessary treatment. In terms of missed fractures, BS will miss 2 fractures and CT will miss 56 fractures. AUTHORS' CONCLUSIONS: Although quality of the included studies is moderate to good, findings are based on only 11 studies and the confidence intervals for the summary estimates are wide for all three tests. Well-designed direct comparison studies including CT, MRI and BS could give valuable additional information.Bone scintigraphy is statistically the best diagnostic modality to establish a definitive diagnosis in clinically suspected fractures when radiographs appear normal. However, physicians must keep in mind that BS is more invasive than the other modalities, with safety issues due to level of radiation exposure, as well as diagnostic delay of at least 72 hours. The number of overtreated patients is substantially lower with CT and MRI.Prior to performing comparative studies, there is a need to raise the initially detected prevalence of true fractures in order to reduce the effect of the relatively low specificity in daily practice. This can be achieved by improving clinical evaluation and initial radiographical assessment.

Surgical versus conservative treatment for high-risk stress fractures of the lower leg (anterior tibial cortex, navicular and fifth metatarsal base): a systematic review.

AIM: To compare surgical and conservative treatment for high-risk stress fractures of the anterior tibial cortex, navicular and proximal fifth metatarsal. METHODS: Systematic searches of CENTRAL, MEDLINE, EMBASE, CINAHL, SPORTDiscus and PEDro were performed to identify relevant prospective and retrospective studies. Two reviewers independently extracted data and assessed methodological quality. Main outcomes were return to sport and complication rate. RESULTS: 18 studies were included (2 anterior tibia (N=31), 8 navicular (N=200) and 8 fifth metatarsal (N=246)). For anterior tibial fracture, no studies on initial surgery were eligible. Conservative treatment resulted in high complication rates and few cases returned to sport. For navicular fracture, a weighted mean return to sport of 22 for conservative and 16 weeks for surgical treatment was found. Six weeks of non-weightbearing cast was mostly used as conservative treatment. Surgical procedures varied widely. For the fifth metatarsal fracture, weighted mean return to sport was 19 for conservative and 14 weeks for surgical treatment. Surgery consisted of intramedullary screw fixation or tension band wiring. For conservative methods, insufficient details were reported. Overall, there was a high risk of bias; sample sizes were small and GRADE level of evidence was low. CONCLUSIONS: Strong conclusions for surgical or conservative therapy for these high-risk stress fractures cannot be drawn; quality of evidence is low and subjected to a high risk of bias. However, there are unsatisfying outcomes of conservative therapy in the anterior tibia. The role of initial surgery is unknown. For the navicular, surgery provided an earlier return to sport; and when treated conservatively, weightbearing should be avoided. For the fifth metatarsal, surgery provided the best results. Treatment decision-making would greatly benefit from further prospective research. STUDY REGISTRATION NUMBER: PROSPERO database of systematic reviews: CRD42013004201.

Clinical diagnostic evaluation for scaphoid fractures: a systematic review and meta-analysis.

PURPOSE: To provide an overview of available clinical evaluation tests for scaphoid fractures and to compare their diagnostic accuracies. METHODS: PWe performed a systematic review of all studies assessing diagnostic characteristics of clinical evaluation in scaphoid fractures by searching MEDLINE, EMBASE, Cochrane, and CINAHL databases. Only studies on clinical testing prior to radiographic evaluation and with acceptable reference standard for occult fractures were included. Thirteen relevant articles were analyzed that described a total of 25 tests. Diagnostic characteristics of the tests were used to construct contingency tables. If possible, data were pooled and summary receiver operating characteristic curves were fitted. RESULTS: Anatomic snuff-box tenderness (ASB, 8 studies, 1,164 patients) and longitudinal thumb compression (LTC, 8 studies, 961 patients) had sufficient data for statistical analyses. Sensitivity for ASB ranged from 0.87 to 1.00; for LTC, 0.48 to 1.00. Specificity of ASB ranged from 0.03 to 0.98; for LTC, 0.22 to 0.97. Owing to considerable heterogeneity, pooled estimate points were not calculated. Other high-sensitivity tests were scaphoid tubercle tenderness, with sensitivity and specificity ranging from 0.82 to 1.00 and 0.17 to 0.57, respectively, and painful ulnar deviation, ranging from 0.67 to 1.00 and 0.17 to 0.60, respectively. Three studies showed that combining tests increased the specificity and post-test fracture probability while maintaining high sensitivity. Quality assessment showed high or unclear risk of bias and applicability concerns in reference standard and patient selection. Twelve study designs were prospective, and 1 was retrospective. CONCLUSIONS: Anatomical snuff box tenderness was the most sensitive clinical test. The low specificity of the clinical tests may result in a considerable number of overtreated patients. Combining tests improved the post-test fracture probability. This can be used to limit unnecessary immobilization, number of hospital visits, and use of imaging. The data presented herein may help to develop clinical prediction rules that could increase specificity without reducing sensitivity. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

Computed tomography for suspected scaphoid fractures: comparison of reformations in the plane of the wrist versus the long axis of the scaphoid.

BACKGROUND: Definitive diagnosis of occult scaphoid fractures remains difficult. We tested the null hypothesis that, for diagnosis of true fractures among suspected scaphoid fractures, computed tomography (CT) reformations along the long axis of the scaphoid have the same accuracy as reformations made relative to the anatomical planes of the wrist. METHODS: In a prospective trial, 34 patients with a suspected scaphoid fracture underwent CT scanning within 10 days after trauma. CT reformations along the long axis of the scaphoid (CT-scaphoid) and along planes relative to the wrist (CT-wrist) were made. We used radiographs obtained 6 weeks after injury as the reference standard for a true fracture. A blinded panel including two surgeons and one radiologist came to a consensus diagnosis for each reformation plane. RESULTS: The reference standard showed six fractures of the scaphoid (prevalence, 18 %). Using CT-wrist, a scaphoid fracture was diagnosed in five patients (15 %), with three false positive, four false negative and two true positive diagnoses. Using CT-scaphoid, a scaphoid fracture was diagnosed in five patients (15 %), with one false positive, two false negative and four true positive results. Sensitivity, specificity and accuracy were 33, 89 and 79 % for CT-wrist and 67, 96 and 91 % for CT-scaphoid, respectively. This resulted in positive predictive values of 36 % for CT-wrist and 76 % for CT-scaphoid. Negative predictive values were 87 % for CT-wrist and 94 % for CT-scaphoid. No significant differences were found with the number of patients available. CONCLUSIONS: For diagnosis of true fractures among suspected scaphoid fractures, the diagnostic performance characteristics of CT scans reformatted along the long axis of the scaphoid were better than CT scans in the planes of the wrist, but the differences were not significant.

[Variations in management of suspected scaphoid fractures]. / Variatie in beleid bij vermoeden op scafoïdfractuur.

OBJECTIVE: This study evaluated the daily clinical practice for management of patients with suspected scaphoid fractures in hospitals in the Netherlands and compared it with recommendations from the current literature. DESIGN: Questionnaire-based investigation. METHOD: Doctors working in emergency departments in hospitals in the Netherlands were asked to complete an 8-question survey including questions on diagnostic strategies, treatment type and the time between different steps in the management policy. RESULTS: Doctors from 90 of the 100 hospitals approached completed the questionnaire. A total of 71 of these 90 hospitals had an established protocol. In the other 19 it depended on the preference of the treating doctor. In 75 hospitals a follow-up outpatient clinic appointment was made for within 10 days. In 70 hospitals X-rays were repeated before additional imaging investigation. CT was the most frequently used additional investigation in 35 hospitals, followed by bone scintigraphy (12) and MRI (2). No additional investigation was carried out in 11 hospitals and when X-rays showed no abnormalities treatment was implemented on the basis of clinical evaluation. In 72 hospitals the wrist was immobilised with a lower-arm plaster cast including the thumb. Lower-arm plaster cast not including the thumb was used in 1 hospital. CONCLUSION: There is a great deal of variation in diagnosis and treatment of patients with a suspected scaphoid fracture within hospitals in the Netherlands. Furthermore, management policy in most hospitals is not in keeping with the most recent recommendations. Evidence-based guidelines are required in order to limit over-diagnosis and unnecessary immobilisation.

Diagnostic performance tests for suspected scaphoid fractures differ with conventional and latent class analysis.

BACKGROUND: Evaluation of the diagnostic performance characteristics of radiographic tests for diagnosing a true fracture among suspected scaphoid fractures is hindered by the lack of a consensus reference standard. Latent class analysis is a statistical method that takes advantage of unobserved, or latent, classes in the data that can be used to determine diagnostic performance characteristics when there is no consensus reference (gold) standard. PURPOSES: We therefore compared the diagnostic performance characteristics of MRI, CT, bone scintigraphy, and physical examination to identify true fractures among suspected scaphoid fractures. PATIENTS AND METHODS: We used data from two studies, one that prospectively studied 34 patients who had MRI and CT of the wrist, and a second that studied 78 patients who had MRI, bone scintigraphy, and structured physical examination. We compared the diagnostic performance characteristics calculated by latent class analysis with those calculated using formulas based on a reference standard. RESULTS: In the first cohort, the calculated sensitivity and specificity with latent class analysis were different than those with traditional reference standard-based calculations for the CT in the scaphoid planes (sensitivity, 0.78 versus 0.67; specificity, 1.0 versus 0.96) and the MRI (sensitivity, 0.80 versus 0.67; specificity, 0.93 versus 0.89). In the second cohort, the greatest differences were in the sensitivity of MRI (0.84 versus 0.75) and the sensitivities of physical examination maneuvers (range, 0.63-0.73 versus 1.0). CONCLUSIONS: The diagnostic performance characteristics calculated using latent class analysis may differ from those calculated according to formulas based on a reference standard. We believe latent class analysis merits further study as an option for assessing diagnostic performance characteristics for orthopaedic conditions when there is no consensus reference standard. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.