Occult scaphoid fractures: comparison of multidetector CT and MR imaging--initial experience

PURPOSE: To compare the diagnostic performance of multidetector computed tomography (CT) and magnetic resonance (MR) imaging in patients clinically suspected of having a scaphoid fracture and who had normal initial radiographs, with radiographs obtained 6 weeks after trauma as the reference standard. MATERIALS AND METHODS: The ethics committee approved the study, and all patients gave written informed consent. Twenty-nine patients (17 male, 12 female; age range, 17-62 years; mean age, 34 years +/- 13) underwent multidetector CT and MR imaging within 6 days after trauma. CT data were obtained with 0.5-mm collimation. For image review, 0.7-mm-thick multiplanar reformations were performed in transverse, coronal, and sagittal planes relative to the wrist. The 1.0-T MR examination consisted of coronal and transverse short inversion time inversion-recovery, coronal and transverse T1-weighted spin-echo, and coronal volume-rendered T2-weighted gradient-echo sequences. Two radiologists analyzed the CT and MR images. A binomial test was used to evaluate the significance of the differences between MR imaging and CT in detection of scaphoid fractures and cortical involvement (P < .05). RESULTS: The 6-week follow-up radiographs depicted a scaphoid fracture in 11 (38%) patients. Eight patients had a cortical fracture, while three patients had only a bandlike lucency within the trabecular portion of the scaphoid. MR imaging depicted all 11 fractures but only three [corrected] cortical fractures. Multidetector CT depicted all eight cortical fractures but failed to depict trabecular fractures. No false-positive fractures were seen on MR or CT images. Differences between MR imaging and CT were not significant for the detection of scaphoid fractures (P = .25) but were significant for cortical involvement (P = .03). CONCLUSION: Multidetector CT is highly accurate in depicting occult cortical scaphoid fractures but appears inferior to MR imaging in depicting solely trabecular injury. MR imaging is inferior to multidetector CT in depicting cortical involvement.     

Occult fractures of the waist of the scaphoid: early diagnosis by high-spatial-resolution sonography

OBJECTIVE: This study evaluated the diagnostic accuracy of high-spatial-resolution sonography in the diagnosis of occult fractures of the waist of the scaphoid. SUBJECTS AND METHODS: Sonography of the scaphoid bone with a 12-MHz transducer was performed in 54 patients with clinically suspected scaphoid fracture and normal findings on initial radiographs, including specific scaphoid images. Three levels of clinical suspicion were considered: high (20%), moderate (30%), and low (50%). Attention was paid to the continuity of the scaphoid cortex and to the surrounding soft tissues (i.e., hemarthrosis or hematoma). Data from early sonograms were then compared with the results of radiography repeated 10-14 days after the initial trauma. In cases of persistent suspicion despite normal findings on follow-up radiographs, the presence of fracture was evaluated on CT (four patients), MR imaging (one patient), or bone scanning (one patient). RESULTS: Follow-up examinations proved fracture of the scaphoid waist in five patients. In all patients, diagnosis of fracture was suspected on initial sonograms showing cortical disruption associated with soft-tissue abnormalities. There was one false-positive finding and no false-negative results. Using cortical disruption as a diagnostic criterion, we found the sensitivity, specificity, and accuracy of high-resolution sonography for the depiction of scaphoid fracture to be 100%, 98%, and 98%, respectively. Using soft-tissue abnormalities alone as a criterion, we found the sensitivity, specificity, and accuracy of high-resolution sonography to be 100%, 65%, and 68%, respectively. The overall prevalence of occult fracture was 9%, ranging from 3.7% for low suspicion to 27% for high suspicion of fracture. CONCLUSION: High-resolution sonography is a reliable and accurate method of evaluating occult fractures of the scaphoid waist. Cortical disruption is the diagnostic key. Soft-tissue abnormalities alone lack specificity.     

Early MRI in the management of clinical scaphoid fracture

The incidence of MRI detected scaphoid and other wrist fractures was determined in a clinical setting in patients with suspicion of scaphoid injury and negative initial radiographs. The influence on subsequent patient management was examined. Patients attending Accident and Emergency over a 25 month period with suspected scaphoid fracture and normal scaphoid series plain films were referred for wrist MRI. Scans comprising T(1) weighted spin echo and short tau inversion recovery (STIR) coronal sequences were performed in a dedicated extremity low field MRI scanner within 14 days of injury. Subsequent effects on patient management were ascertained by clinician completed questionnaire. 195 patients were scanned. There were 37 scaphoid fractures (19%), 28 distal radius fractures (14%), 9 fractures of other carpal bones (5%) and 119 studies with no fracture. The management of 180 patients (92%) was altered as a result of the MRI scan. Occult fractures are present in almost two fifths of patients with suspected scaphoid fracture and normal initial plain films. Half of these are scaphoid fractures. MRI allows an early definitive diagnosis to be made, changing patient management in over 90% of cases and should be regarded as the gold standard investigation in this population.     

Scaphoid fracture detection in a military population: a standardized approach for medical referral

OBJECTIVE: The objective was to test, refine, and implement an algorithm for early detection and referral of clinical scaphoid fractures by U.S. Army medical personnel. Our goal was to reduce complications resulting from delayed diagnosis and to improve outcomes affecting soldier health and unit readiness. METHODS: Data on scaphoid fractures treated in the orthopedic department at Tripler Army Medical Center were collected from January 1, 2001, through December 31, 2003. Demographic variables included gender, age, and military rank. RESULTS: The incidence of scaphoid fractures in our population was 43 cases per 100,000 personnel per year. An algorithm to guide nonorthopedic providers was developed after review of the medical literature. CONCLUSION: We present an algorithm-based approach to soldiers presenting with post-traumatic wrist pain. The algorithm was fashioned with the aim of reducing complications and poor outcomes associated with delayed diagnosis of scaphoid fractures, affecting soldier health and unit readiness. A prospective study of the algorithm is underway.     

Scaphoid fracture and nonunion: current status of radiological diagnostics

Scaphoid fractures, which involve approximately two-thirds of all wrist injuries, are often not detected during initial radiographic examination. By using high-resolution CT and dedicated MRI, it is possible to recognize scaphoid fractures soon at the first diagnostic approach and to assess fragment stability. CT imaging provides all the relevant information of the fracture extent and of the fracture healing in the follow-up. MRI is most sensitive in the detection of scaphoid fractures; however, fracture signs must be differentiated from those of a bone bruise. Both the initially overseen scaphoid fracture and the unsuccessful healing can lead to the natural history of scaphoid nonunion. In the injured scaphoid, CT imaging is essential for depicting the osseous morphology, whereas contrast-enhanced MRI is crucial for assessing the viability of the proximal fragment.     

Skaphoidfraktur und -pseudarthrose

Scaphoid fractures, which involve approximately two-thirds of all wrist injuries, are often not detected during initial radiographic examination. By using high-resolution CT and dedicated MRI, it is possible to recognize scaphoid fractures soon at the first diagnostic approach and to assess fragment stability. CT imaging provides all the relevant information of the fracture extent and of the fracture healing in the follow-up. MRI is most sensitive in the detection of scaphoid fractures; however, fracture signs must be differentiated from those of a bone bruise. Both the initially overseen scaphoid fracture and the unsuccessful healing can lead to the natural history of scaphoid nonunion. In the injured scaphoid, CT imaging is essential for depicting the osseous morphology, whereas contrast-enhanced MRI is crucial for assessing the viability of the proximal fragment.     

A comparison of bone scintigraphy and MRI in the early diagnosis of the occult scaphoid waist fracture

Objective. To determine the accuracy of MRI in the assessment of the radiographically occult scaphoid fracture. Design. This prospective study compared the sensitivity and specificity of MRI for detection of radiographically occult scaphoid fractures with bone scintigraphy (BS), the currently accepted imaging modality of choice. Consecutive patients with clinical signs of a scaphoid injury but no evidence of fracture on plain radiographs at presentation and after 7–10 days were evaluated by MRI and BS. All images were reported in masked fashion and the sensitivities and specificities of the imaging modalities determined. All patients with a scaphoid fracture demonstrated by MRI or BS were followed for at least a year after injury. Patients. Forty-three subjects (aged 12–74 years) had both MRI and BS carried out on average 19 days from the injury date. Results and conclusions. Six patients (14%) had scaphoid waist fractures. There were other bony injuries in a further six. In 40 patients there was agreement between the BS and MRI findings. In three cases there was discrepancy between the imaging modalities; in all three MRI was found to be the more sensitive and specific. MRI could become the investigation of choice for this injury.     

Multiplanar reconstruction computed tomography for diagnosis of scaphoid waist fracture union: a prospective cohort analysis of accuracy and precision

Objective

To examine reliability and validity concerning union of scaphoid fractures determined by multiplanar reconstruction computed tomography randomized at 6, 12, and 24 weeks after injury.

Materials and methods

We used Fleiss’ kappa to measure the opinions of three observers reviewing 44 sets of computed tomographic scans of 44 conservatively treated scaphoid waist fractures. We calculated kappa for the extent of consolidation (0–24 %, 25–49 %, 50–74 %, or 75–100 %) on the transverse, sagittal and coronal views. We also calculated kappa for no union, partial union, and union, and grouped the results for 6, 12, and 24 weeks after injury. As the reference standard for union, CT scans were performed at a minimum of 6 months after injury to determine validity.

Results

Overall inter-observer agreement was found to be moderate (κ?=?0.576). No union (κ?=?0.791), partial union (κ?=?0.502), and union (κ?=?0.683) showed substantial, moderate, and substantial agreement, respectively. The average sensitivity of multiplanar reconstruction CT for diagnosing union of scaphoid waist fractures was 73 %. The average specificity was 80 %.

Conclusions

Our results suggest that multiplanar reconstruction computed tomography is a reliable and accurate method for diagnosing union or nonunion of scaphoid fractures. However, inter-observer agreement was lower with respect to partial union.     

Diagnostic value of cone beam computed tomography (CBCT) in occult scaphoid and wrist fractures

ObjectiveEvaluate the diagnostic value of cone beam computed tomography (CBCT) for scaphoid and wrist fractures that are missed on standard radiographs.Materials and methodsBetween September 2014 and October 2015, we prospectively enrolled 49 patients with a clinically suspected scaphoid fracture following an acute injury but had normal radiographs. Each patients underwent radiographs, CBCT and (magnetic resonance imaging) MRI within 7 days of the initial injury event. Both exam were evaluated independently by two radiologists.ResultsFor scaphoid cortical fractures CBCT sensitivity is 100% (95% CI: 75%–100%), specificity 97% (95% CI: 83%–100%). CBCT diagnosed all 24 corticals wrist fractures, corresponding to a sensitivity of 100% (95% CI: 83%–100%), specificity of 95% (95% CI: 75%–100%). Kappa agreement rate between the two radiologists was K = 0.95 (95% CI: 0.85–1) for scaphoid fractures and K = 0.87 (95% CI: 0.73–1) for wrist fractures.ConclusionsCBCT is superior to radiographs for diagnosing occult cortical fractures. Because of its low radiation dose, we believe that CBCT can be used in current practice as a replacement or supplement to radiographs to detect these fractures and optimize the cost-effectiveness ratio by limiting the number of needless immobilizations.     

Panoramic versus conventional radiography of scaphoid fractures

OBJECTIVE: The objective of this study was to compare the diagnostic value of panoramic and conventional radiography in the detection of fractures of the carpal scaphoid bone. MATERIALS AND METHODS: Panoramic (orthopantomographic) and conventional radiographs of 90 patients with acute or chronic wrist trauma were reviewed retrospectively. Images were analyzed and reviewed independently by four observers: two radiologists and two traumatologists. The kappa statistic was used to calculate intraand interobserver agreement and the correlation between the two imaging techniques. RESULTS: Panoramic radiography of the wrist was superior to conventional radiography in ruling out scaphoid fractures (74%, 20/27) in patients with suspicious findings on conventional radiography; revealed more cases of scaphoid fractures (21.4%, 12/56); and revealed more cases of delayed union (n = 2), nonunion (n = 3), and union (n = 3). Agreement values were higher, with better inter- and intraobserver agreement, for the panoramic examinations than for the conventional radiographic examinations. CONCLUSION: The panoramic examination of the wrist is a useful technique for the diagnosis and follow-up of scaphoid fractures. Its use is recommended as a complement to conventional radiography in cases with inconclusive findings.     

Imaging and treatment of scaphoid fractures and their complications

The scaphoid is the most commonly fractured carpal bone, with frequent complications that are predisposed by its anatomical location, anatomical configuration (shape and length), and vascular supply. The most common mechanism of injury is a fall onto an outstretched hand. Imaging plays a significant role in the initial evaluation and treatment of scaphoid fractures and their complications. Radiography should be the first imaging modality in the initial evaluation and follow-up of scaphoid fractures. Computed tomography with its superb spatial resolution enables better visualization and characterization of the fracture line, and the amount of displacement and angulation of the fracture fragments. Using the metal reduction artifact with computed tomography allows good follow-up of scaphoid fractures despite surgical hardware. Magnetic resonance imaging without contrast is the imaging modality of choice for depiction of radiographically occult scaphoid fracture, bone contusion, and associated soft tissue injury; contrast-enhanced imaging aids assessment of scaphoid fracture nonunion, osteonecrosis, fracture healing after bone grafting, and revitalization of the necrotic bone after bone grafting. Proper identification and classification of scaphoid fracture and its complications is necessary for appropriate treatment. This article describes the normal anatomy, mechanism of injury, and classification of stable and unstable fractures, together with the imaging and treatment algorithm of scaphoid fractures and their complications with an emphasis on magnetic resonance imaging.     

Can follow-up radiography for acute scaphoid fracture still be considered a valid investigation?

AIM: To determine whether follow-up radiography is a valid diagnostic investigation in patients with suspected acute scaphoid fractures and normal initial radiographs. MATERIALS AND METHODS: Fifty sets of radiographs (initial and follow-up) were independently assessed by four expert observers for the presence or absence of a scaphoid fracture. Magnetic resonance imaging (MRI), performed in all cases, was used as the gold standard to determine the sensitivity, specificity, positive and negative predictive values of the observers' assessment of the follow-up radiograph. In addition, the reliability among observers of the follow-up radiograph was determined by reliability variance analysis. RESULTS: Of the 50 sets of radiographs, 35 patients had a scaphoid fracture and 15 were normal, as established from MRI report. For individual observer's assessment of the follow-up radiograph, sensitivities of 11, 9, 43 and 49%; specificities of 93, 93, 87 and 80%; positive predictive values of 80, 75, 88 and 85%; and negative predictive values of 31, 30, 39 and 40%. A reliability coefficient of more than 60% is needed for a diagnostic test to be considered reliable. Overall, the inter-observer reliability coefficient was 33%, with pair-wise inter-observer coefficients ranging from 18-53%. CONCLUSION: With poor sensitivity, poor negative predictive value and poor reliability, follow-up radiography cannot be considered a valid diagnostic examination for the detection of scaphoid fracture in patients with normal initial radiographs.     

Scaphoid fractures: evaluation with high-spatial-resolution US initial results.

PURPOSE: To evaluate the diagnostic accuracy of high-spatial-resolution ultrasonography (US) in the diagnosis of scaphoid fractures. MATERIALS AND METHODS: In 72 hours after acute wrist trauma, 15 consecutive patients were examined for possible scaphoid fractures clinically and with conventional radiographs, including scaphoid views. Thereafter, high-spatial-resolution US was performed by two experienced radiologists blinded to the results of the previously performed investigations. High-spatial-resolution US of the scaphoid bones was performed from the palmar, lateral, and dorsal directions in the longitudinal and transverse planes. US findings indicative of a scaphoid fracture were cortical discontinuity and/or periosteal elevation. Finally, magnetic resonance (MR) images (short inversion time inversion-recovery, T1- and T2*-weighted) (ie, the standard) of the affected wrist were obtained and evaluated for a possible scaphoid fracture by two radiologists in consensus. RESULTS: Nine of 15 patients had scaphoid fractures. Seven (78%) of nine patients had positive findings at high-spatial-resolution US and five (56%) had such findings at conventional radiography (ie, four occult scaphoid fractures), with an accuracy of 87% and 73%, respectively. Two (50%) of four radiographically occult scaphoid fractures were depicted with high-spatial-resolution US. Sonographic findings of scaphoid fractures were either cortical discontinuity (n = 4), periosteal elevation (n = 2), or a combination of these two findings (n = 1). CONCLUSION: High-spatial-resolution US is a reliable diagnostic tool for the evaluation of occult scaphoid fractures and should be considered an adequate alternative diagnostic tool prior to computed tomography or MR imaging.     

Reliability of bone scintigraphy for suspected scaphoid fractures

PURPOSE: To examine the observer variation for bone scintigraphy in the detection of occult scaphoid fractures in daily practice, using only the early bone scanning images. METHODS: One hundred bone scans of patients with a suspected scaphoid fracture but negative initial radiographs were prospectively included to calculate the inter- and intraobserver variation. Three nuclear medicine physicians independently evaluated all bone scans at 2 different points in time with a 3-month interval. The observers filled out a blinded scoring sheet for each patient. They scored if a scaphoid fracture was present or not. In addition, they scored the presence or absence of another fracture. The inter- and intraobserver variation was analyzed using the kappa statistic. RESULTS: The interobserver variation showed substantial agreement for a scaphoid fracture and almost perfect agreement for another fracture. The intraobserver variation showed almost perfect agreement for both a scaphoid fracture and another fracture. CONCLUSIONS: In the present study, early static images of bone scintigraphy for suspected scaphoid fractures showed very little inter- and intraobserver variation. In addition, expertise does not seem to have a negative influence on the results. This enhances the possibility of using bone scintigraphy in daily practice.     

Significance of a hot spot on the bone scan after carpal injury —evaluation by computed tomography

The use of bone scintigraphy in patients with negative radiographs after carpal injury is widely advocated. However, focally increased activity on the bone scan in the scaphoid or other carpal bones cannot always be radiologically confirmed as a fracture. To confirm scintigraphically suspected carpal fractures, computed tomography (CT) of the wrist was performed in patients with clinically suspected scaphoid fracture and initially negative radiographs. All patients underwent plain radiography, bone scintigraphy and CT. The combination of plain radiographs and CT, as judged by a panel of experienced observers, was used as the reference standard. In 18 patients, 21 out of 22 carpal hot spots on bone scintigraphy could be radiologically confirmed as a fracture. The diagnosis was missed by CT scan in three patients with proven fractures on plain radiographs. We conclude that, in patients with negative initial radiographs following carpal injury, a positive bone scan must be interpreted as a fracture. Correspondence to: M.M.C. Tiel-van Buul     

Helical CT of diaphragmatic rupture caused by blunt trauma

OBJECTIVE: The purpose of this study was to determine the diagnostic sensitivity and specificity of helical CT with sagittal and coronal reformatted images in detecting diaphragmatic rupture after blunt trauma. MATERIALS AND METHODS: Chest and abdominal helical CT scans obtained in 41 patients with suspected diaphragmatic injury after major blunt trauma were reviewed by three observers who were unaware of surgical findings. Coronal and sagittal reformatted images were reviewed for each patient as well. Findings consistent with diaphragmatic injury, such as waistlike constriction of abdominal viscera (i.e., the "collar sign"), intrathoracic herniation of abdominal contents, and diaphragmatic discontinuity were recorded. Sensitivity and specificity of helical CT were calculated on the basis of surgical findings and clinical follow-up. RESULTS: Helical CT was performed preoperatively in 23 patients with diaphragmatic rupture (left, n = 17; right, n = 5; bilateral, n = 1). An additional 18 patients underwent helical CT to further evaluate suspicious findings seen on chest radiography at admission and were found to have an intact diaphragm. Sensitivity for detecting left-sided diaphragmatic rupture was 78% and specificity was 100%. Sensitivity for the detection of right-sided diaphragmatic rupture was 50% and specificity was 100%. The most common CT finding of diaphragmatic rupture was the collar sign, identified in 15 patients (sensitivity, 63%; specificity, 100%). Diaphragmatic discontinuity was seen in four patients. CONCLUSION: Helical CT, especially with the aid of reformatted images, is useful in the diagnosis of acute diaphragmatic rupture after blunt trauma. Helical CT can be used to detect 78% of left-sided and 50% of right-sided injuries.     

16-MDCT in the detection of occult wrist fractures: a comparison with skeletal scintigraphy

OBJECTIVE: Our objective was to assess the potential use of MDCT in the detection of occult scaphoid fractures. Fifty-one patients with suspected radiographically occult scaphoid fractures at 10-14 days after trauma were investigated prospectively with skeletal scintigraphy and CT on the same day. Planar images of the wrist were taken 3 hr after IV injection of 400 MBq of (99m)Tc-methylene diphosphonate using a single-head gamma camera. CT was performed on a 16-MDCT machine using 0.75-mm detectors and reconstruction in 0.5-mm slices. Multiplanar reformatted images were then viewed in interactive cine mode. The examinations were reported independently, and discordant results were compared at follow-up. CT was positive for wrist fracture in 14 (27.4%) of 51 patients and skeletal scintigraphy in 23 (45.1%) of 51 patients. Even after retrospective review, there were seven discrepant cases (13.7%), all of which were positive for wrist fracture on scintigraphy but negative on CT. Four of these seven patients with discordant findings underwent further radiography at 6 weeks, which did not show fracture. CONCLUSION: Although CT was preferred by most patients and was quicker, scintigraphy appears to detect bony abnormality more frequently. However, there appears to be an interesting group of patients (7/51) with normal initial radiography findings but positive scintigraphy findings who would normally be considered to have a fracture but for whom CT results were negative. In some of these patients, the results of follow-up radiography at 6 weeks were also negative, suggesting that this group of patients warrants further study.     

Value of bone scintigraphy in patients with carpal trauma

OBJECTIVE: We planned this study to evaluate the role of bone scintigraphy in patients with suspected carpal fracture and normal or suspicious radiographs following carpal injury. METHODS: Three-phase bone scintigraphy using Tc-99m-MDP was performed on 32 patients with negative radiographs but clinically suspected fracture at two weeks after the trauma. Focally increased radiopharmaceutical uptake was interpreted as a fracture. The final diagnosis was established with clinical follow-up. RESULTS: Twelve (38%) patients had a normal scan excluding fracture. Twelve patients had a single fracture. Multifocal fracture was present in 8 (25%) patients. Eight patients showed scaphoid fractures; of these three showed single scaphoid fracture, and the other five patients revealed accompanying fractures. Distal radius fractures and carpal bone fractures other than scaphoid were both observed in 12 patients. These were eleven fractures of distal radius; three fractures of pisiform; two fractures of hamate; and single fractures of lunate, trapezium and triquetrum. In one patient there was fracture of a first metacarpal bone. CONCLUSION: In patients with suspected carpal bone fracture and normal or suspicious radiographs, bone scintigraphy can be used as a reliable method to confirm or exclude the presence of a scaphoid fracture and to detect clinically unsuspected fractures of distal radius and other carpal bones.     

Scaphoid and pronator fat stripes are unreliable soft tissue signs in the detection of radiographically occult fractures

AIM: To determine the clinical value of scaphoid and pronator fat stripes in identifying occult underlying scaphoid and distal radius fractures, respectively. MATERIALS AND METHODS: In our department, all patients with clinically suspected scaphoid fractures and normal scaphoid series of radiographs undergo magnetic resonance imaging (MRI) of the wrist. We selected 50 cases with unequivocal MRI evidence of scaphoid fracture, 50 cases with distal radius fracture and 50 cases with no MRI evidence of bony injury. All 150 initial plain radiographs were examined retrospectively in random order without knowledge of the MRI findings and the scaphoid and pronator fat stripes scrutinized. RESULTS: The scaphoid fat stripe was abnormal in only 25 cases (50%) with confirmed scaphoid fracture on MRI. The pronator fat stripe was abnormal in 13 cases (26%) with confirmed distal radius fracture. In the 50 cases with no MRI evidence of bony injury, the scaphoid fat stripe and pronator fat stripe were abnormal in 25 (50%) and 15 (30%) cases, respectively. The sensitivity and specificity for an abnormal scaphoid fat stripe was 50%. The sensitivity and specificity for an abnormal pronator fat stripe was 26 and 70%, respectively. CONCLUSION: Scaphoid and pronator fat stripes are poor predictors of the presence or absence of underlying occult fractures.     

CT of the wrist in suspected scaphoid fracture.

Bone scan and sagittal projection CT of the scaphoid was performed in 10 patients with clinically suspected scaphoid fractures. The primary and follow-up plain radiographs were negative or equivocal for fracture. CT examination demonstrated scaphoid fracture in 7 patients and normal findings in 3. It is concluded that CT of the scaphoid can replace bone scan to diagnose or rule out fracture in institutions where nuclear medicine facilities are not available.