Clinical utility of tomosynthesis in suspected scaphoid fracture. A pilot study

Background  

Radiography alone will not detect all scaphoid fractures. There is a reported prevalence between 9 and 33% of occult scaphoid fractures. The evidence-based literature suggests that magnetic resonance imaging (MRI) is the most suitable secondary imaging modality due to the ability to evaluate the bone marrow directly and to also identify other injuries. However, there is no consensus on the choice of follow-up imaging strategy—computed tomography, MRI, or bone scan—across different institutions. Tomosynthesis is a new digital tomographic method creating multiple thin tomographic sections. The purpose of this study was to evaluate the clinical utility of tomosynthesis in suspected occult fracture.     

The management of scaphold fractures.

Appropriate management of scaphoid fractures is important because of the risk of long-term complications such as delayed or non-union, pain and disability. Up to 25% of scaphoid fractures are not visible on the initial radiographs. Consequently, all clinically suspected scaphoid fractures are treated as fractures with cast immobilisation until cause of the symptoms is clarified. The diagnosis often utilises a number of second line investigations that are generally performed 10-14 days after the injury. Bone scintigraphy is currently the most commonly used of these as it rarely misses a fracture. However, it does not visualise anatomical structure and therefore alternative diagnoses are difficult. Magnetic resonance imaging (MRI) is at least as sensitive and more specific than bone scanning and has the advantages of being able to identify other lesions and not expose the patient to any radiation. Furthermore, the scan may be performed as early as 2.8 days following an injury rather than 10 days later in the case of a bone scan. Although the cost of MRI is higher than other imaging modalities, it may be cost-effective in the overall management of patients with occult scaphoid fractures since it may prevent unnecessary cast immobilisation in active people. The most appropriate method of cast immobilisation is presently unclear but evidence exists for improved clinical outcomes in those that have both the thumb and elbow immobilised for the first six weeks.     

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.     

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.     

The role of MR imaging in scaphoid disorders

The scaphoid bone of the wrist is one of the most commonly fractured bones in the body. Due to its importance in the biomechanics and functionality of the wrist, it is important to depict and characterize the type of injury. Plain radiographs and scintigraphy may fail to disclose the type and severity of the injury. In patients with normal initial plain radiographs, MR imaging can discriminate occult fractures from bone bruises and may also demonstrate ligamentous disruption. MR imaging can also discriminate the proximal pole viability versus avascular necrosis secondary to previous fracture, which is important for treatment planning. Treatment of non-united fractures with vascularized grafts can be evaluated with contrast-enhanced MR imaging. Idiopathic osteonecrosis or Preiser’s disease was originally described after trauma. The non-traumatic disorders of the scaphoid include post-traumatic osteoarthritis, inflammatory bone marrow edema in patients with rheumatoid arthritis, and osteomyelitis. MR imaging is helpful in all the above disorders to demonstrate early bone marrow edema, cartilage degeneration and associated subchondral marrow changes. The most commonly found tumors in the scaphoid are usually benign and include enchondroma, osteoblastoma and osteoid osteoma. MR imaging is not mandatory for the initial diagnosis, which should be based on plain X-ray findings.     

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.     

Magnetic resonance imaging versus bone scintigraphy in suspected scaphoid fracture

Magnetic resonance imaging (MRI) has become increasingly useful in the evaluation of musculoskeletal problems, including those of the wrist. In patients with a wrist injury, MRI is used mainly to assess vascularity of scaphoid non-union. However, the use of MRI in patients in the acute phase following carpal injury is not common. Three-phase bone scintigraphy is routinely performed from at least 72 h after injury in patients with suspected scaphoid fracture and negative initial radiographs. We evaluated MRI in this patient group. The bone scan was used as the reference method. Nineteen patients were included. Bone scintigraphy was performed in all 19 patients, but MRI could be obtained in only 16 (in three patients, MRI was stopped owing to claustrophobia). In five patients, MRI confirmed a scintigraphically suspected scaphoid fracture. In one patient, a perilunar luxation, without a fracture, was seen on MRI, while bone scintigraphy showed a hot spot in the region of the lunate bone, suspected for fracture. This was confirmed by surgery. In two patients, a hot spot in the scaphoid region was suspected for scaphoid fracture, and immobilization and employed for a period of 12 weeks. MRI was negative in both cases; in one of them a scaphoid fracture was retrospectively proven on the initial X-ray series. In another two patients, a hot spot in the region of MCP I was found with a negative MRI. In both, the therapy was adjusted. In the remaining six patients, both modalities were negative. We conclude that in the diagnostic management of patients with suspected scaphoid fracture and negative initial radiographs, the use of MRI may be promising, but is not superior to three-phase bone scintigraphy.     

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.     

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     

Value of polydirectional tomography in the assessment of the postoperative spine after anterior decompression and vertebral body autografting

With the growing number of orthopedic reconstructive spinal procedures, the use of bone grafting has steadily increased in the past decade. An understanding of the biology of bone grafting is essential for both the clinician and radiologist. Despite the advent of computed tomography and magnetic resonance imaging, conventional polydirectional tomography remains an important tool in the evaluation of vertebral body autografts. Trispiral or hypocycloidal tomography plays a valuable role in the assessment of bone graft fusion and possible complications, especially in the presence of metallic fixation devices. We present our imaging experience derived from 375 patients with cervical, thoracic, or lumbar anterior spinal fusion. True graft complications occurred in 27 patients (7%) and consisted of fracture (4%), malpositioning (3%), and infection (<1%).     

Bildgebung bei Hüftgelenkendoprothesen

The hip joint is the largest joint in the human body and consequently, its evaluation by diagnostic imaging is highly important. This includes imaging of hip joint arthroplasty, which is used to avoid joint immobility following a wide spectrum of diseases, such as end-stage degenerative disease, avascular necrosis of the femoral head or post-traumatic fractures. Conventional radiography is still the standard imaging modality for the evaluation of hip arthroplasty both directly following surgery and for periodical follow-up. In the majority of cases conventional radiography enables adequate assessment of early and late complications that can arise following hip arthroplasty, such as loosening, prosthetic or periprosthetic fracture, luxation, infection and soft tissue calcification. If the diagnosis cannot be established by means of radiography, advanced imaging methods such as computed tomography (CT) and magnetic resonance imaging (MRI), with or without injection of contrast media, may provide additional information. This is particularly true for the depiction of inflammatory processes. Regardless of the imaging modality used patients’ clinical symptoms must also be taken into account in order to establish the correct diagnosis.     

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.     

Magnetic resonance imaging of the wrist: Bone and cartilage injury

Magnetic resonance imaging (MRI) is particularly useful for imaging the wrist due to its superior soft tissue contrast and ability to detect subtle bone marrow changes and occult fractures. A high field (1.5T or greater) strength, dedicated wrist coil, and high in‐plane and through‐plane resolution must be utilized to successfully visualize the relatively thin cartilage of the wrist. MRI can be used to detect occult carpal bone fractures, identify complications following scaphoid fractures, and assess for avascular necrosis in the setting in Kienböck's and Preiser's disease. MRI is useful to identify secondary soft tissue and chondral pathology in impaction/impingement syndromes. The use of an intermediate‐echo time fast spin echo sequence allows for accurate assessment of articular cartilage, allowing evaluation of chondral wear in the setting of primary osteoarthritis and posttraumatic degenerative arthrosis. MRI is the most sensitive imaging modality for the detection of early inflammatory arthropathies and can detect synovitis, bone marrow edema, and early erosions in the setting of negative radiographs. J. Magn. Reson. Imaging 2013;37:1005–1019. © 2012 Wiley Periodicals, Inc.     

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.     

Post traumatic facial nerve palsy without temporal bone fracture

Facial nerve injury following head trauma is a frequent event with or without temporal bone fractures. Computed tomography is the imaging modality of choice for assessing the possible bone disruption of the facial nerve canal. Magnetic resonance is helpful in presence of a facial nerve paralysis, unexplained by computed tomography findings. We present a case of delayed post-traumatic facial nerve palsy without radiological evidence of temporal bone fractures, in which magnetic resonance was crucial for diagnosing the nerve impairment. Radiological findings in accordance both with electrodiagnostic tests and clinical presentation suggested the successful conservative management.     

Survey of the initial management and imaging protocols for occult scaphoid fractures in UK hospitals

Objective

The aim of this research was to survey how occult fractures of the scaphoid bone are both imaged and managed initially.

Materials and methods

A total of 832 questionnaires were sent via e-mail to active associate members of the British Orthopaedic Association. Included was a series of questions regarding the timing of initial and subsequent orthopaedic review of this group of patients and the use of serial radiographs and second-line imaging techniques.

Results

Nearly half of the UK’s acute NHS trusts were represented (45%). The response rate was 16% (130 out of 832). Only 16% of respondents were aware of a local imaging protocol for the investigation of suspected fractures of the scaphoid. Ninety-four percent of respondents performed a second radiograph at first fracture clinic review. Fifty-eight percent used magnetic resonance imaging (MRI) as a second-line investigation; with computed tomography scan and radionuclide isotope bone scan being performed by 26% and 16% respondents, respectively.

Conclusions

The survey revealed a wide variation in the management of occult fractures of the scaphoid. MRI has been shown to be both sensitive and specific in diagnosing occult carpal bone fractures. There is a need to standardise the management of these injuries to ensure early diagnosis and limit unnecessary wrist immobilisation.     

Dorsal lunate tilt (DISI configuration): sign of scaphoid fracture displacement

Excessive dorsiflexion (dorsal tilting) of the lunate on a lateral wrist radiograph can be an important sign of carpal injury. Lunate dorsiflexion is a well-recognized sign of an intercarpal ligamentous injury pattern known as dorsal intercalated segment instability (DISI). It is less well recognized that excessive dorsal tilting of the lunate (DISI configuration) can also be produced by displacement of a scaphoid waist fracture. Since the management and prognosis of displaced scaphoid fractures may be quite different from those for nondisplaced fractures, radiologists can make an important contribution by recognizing dorsal tilting of the lunate and appreciating that it may be an important, indirect sign of scaphoid fracture displacement, which may not be directly visualized with standard wrist radiography. In this setting, computed tomography or complex motion tomography may be helpful for further evaluation of the scaphoid fracture.     

The efficacy of plain films vs MRI in the detection of scaphoid fractures

An investigation was carried out to determine whether or not professionals perceived plain film radiography to be the ‘gold-standard’ in the detection of scaphoid fractures. Literature highlighted that plain film radiography was an unreliable method for detecting such fractures and that magnetic resonance imaging (MRI) should now be regarded as the new ‘gold-standard’.Using a quantitative method, a total of 100 postal questionnaires were sent out to radiologists in 20 different imaging departments throughout the United Kingdom (UK) asking them their opinion on this controversial subject. In addition, the investigation looked into the use of MRI within each department in trying to determine whether or not it was surpassing plain film radiography as an established practice for detecting scaphoid fractures.Of the 100 questionnaires that were sent out, a total of 45 were returned from a total of 13 different departments.The results of this investigation conclude that plain film radiography is still used as a primary imaging modality to detect scaphoid fractures in all departments. There was much support for the use of plain film radiography with the modality being praised time and time again for its ease, 24-h availability, low cost and reproducibility.MRI was acknowledged as being superior in its capability to detect scaphoid fractures in comparison to plain films; its current use, however, is limited owing to high costs, lack of availability and long waiting lists. It would appear from this study that MRI is regarded as a useful modality in cases whereby plain film radiography fails to detect the presence or absence of a fracture in clinically positive patients, with great future potential.     

Modified carpal box technique in the diagnosis of suspected scaphoid fractures

PURPOSE: To establish and test the clinical efficacy of a new diagnostic algorithm with the extensive utilization of modified carpal box radiography (mX-CB) in the detection of scaphoid fractures. MATERIAL AND METHODS: Initial and early follow-up radiographic evaluation of 146 suspected scaphoid fractures were carried out by mX-CB. Patients with unconfirmed diagnosis were referred to CT. Patients were followed for 1 year after injury. Sensitivity, specificity and interobserver agreement of reading mX-CB images were determined statistically. RESULTS: No non-union or avascular necrosis was seen at 1 year after the injury. 90% of the fractures were diagnosed by mX-CB, only 6.8% of the patients needed referral to CT. Sensitivity of mX-CB at initial presentation was 81.6%. Interobserver agreement was very high among evaluators of mX-CB images. CONCLUSION: Extensive utilization of mX-CB as primary and early follow-up investigation resulted in high initial diagnostic accuracy and low referral rate to a more expensive diagnostic modality.