Does Immobilization Post Injection Reduce Contrast Extravasation in MR Arthrography of the Shoulder?

BACKGROUND: Contrast leakage after arthrography is common. We sought to investigate if immobilization could prevent it. PURPOSE: The purpose of this study was to determine the effects on contrast extravasation and image quality produced by strict immobilization of the shoulder between arthrography puncture and subsequent MR imaging. MATERIAL AND METHODS: Fifty patients underwent shoulder MR arthrography using a standard shoulder puncture in the anteroinferior quadrant. Ten milliliters of contrast mixture of saline, iodinated contrast, and gadolinium contrast was injected by a senior musculoskeletal (MSK) radiologist using a 21G needle. Half of the patients were immediately immobilized using a shoulder sling, and the other half were allowed to move their shoulder and arm freely during the time before MR imaging. MR arthrography was performed with a 3 T system using standard T1 and PD weighted sequences. The MR images were reviewed independently by 2 MSK radiologists and graded for extravasation using a five-point scale (1: none, 2: less than 2 cm, 3: 2-5 cm, 4: 5-10 cm, 5: more than 10 cm) and for image quality using a 5 point scale (1: poor, 5: good). The Pearson correlation was calculated to assess the correlation between leakage and image quality. RESULTS: There was no significant difference in amount of leakage between both groups, and global image quality was found equal in both groups. A negative correlation was found between leakage and quality assessment. CONCLUSION: This study shows that it cannot be avoided by strict shoulder immobilization and that it negatively affects image quality and interpretation.

Patient Age Is Inversely Associated with Injury Counts Caused by Motor Vehicle Crashes.

Associations between age and fracture incidence, total number of fractures, and total number of injuries per occupant occurring in motor vehicle crashes were evaluated. An observational study of the Crash Injury Research and Engineering Network was conducted. Multivariable logistic regression and negative binomial models were used to relate age (2064, 65+ years) to fracture incidence, total number of fractures per occupant, and total number of injuries, adjusting for sex and change in vehicle velocity (deltav). Over 90% of occupants had at least one fracture for a total of 5,846 fracture injuries. The older age group experienced a 15% increase in the incidence of total injuries sustained compared to the younger group (Incident Rate Ratio = 1.15, 95% Confidence Interval = 1.081.23, p 0.0001). Older patients should be considered for polytrauma evaluation even with a lower energy motor vehicle crash. (Journal of Surgical Orthopaedic Advances 29(1):3639, 2020).

Impact of Fluoroscopically Guided Bone Biopsy on Antibiotic Management of Osteomyelitis in the Lower Extremity.

This study evaluated the impact of fluoroscopically guided percutaneous bone biopsy on altering antibiotic regimens in lower extremity osteomyelitis. Eighty-eight patients who received fluoroscopically guided bone biopsies were identified. There was bacterial growth in 28% of bone biopsies overall. The rate of positive culture was decreased in patients started on empiric antibiotics before biopsy (23%) compare with patients without empiric antibiotics (44%). Antibiotic regimens were changed in 24% of patients overall in response to culture data. The majority of positive biopsy cultures (76%) but minority of negative biopsy cultures (3%) resulted in a change to antibiotic regimens. The impact of percutaneous bone biopsy on antibiotic management of adult patients with osteomyelitis diagnosed by magnetic resonance imaging is modest and is decreased in patients previously started on antibiotics. Despite its modest impact, bone biopsy results can provide useful information in antibiotic management, especially when positive (Journal of Surgical Orthopaedic Advances 27(4):277-280, 2018).

Criteria for level 1 and level 2 trauma codes: Are pelvic ring injuries undertriaged?

AIM: To determine the association of unstable pelvic ring injuries with trauma code status. METHODS: A retrospective review of all pelvic ring injuries at a single academic center from July 2010 to June 2013 was performed. The trauma registry was used to identify level 1 and level 2 trauma codes for each injury. The computed tomography scans in all patients were classified as stable or unstable using the Abbreviated Injury Scale. Pelvic injury classifications in level 1 and level 2 groups were compared. Patient disposition at discharge in level 1 and level 2 groups were also compared. RESULTS: There were 108 level 1 and 130 level 2 blunt trauma admissions. In the level 1 group, 67% of pelvic injuries were classified as stable fracture patterns and 33% were classified as unstable. In the level 2 group, 62% of pelvic injuries were classified as stable fracture patterns and 38% were classified as unstable. level 1 trauma code was not associated with odds of having an unstable fracture pattern (OR = 0.83, 95%CI: 0.48-1.41, P = 0.485). In the level 1 group with unstable pelvic injuries, 33% were discharged to home, 36% to a rehabilitation facility, and 32% died. In the level 2 group with unstable pelvic injuries, 65% were discharged to home, 31% to a rehabilitation facility, and 4% died. For those with unstable pelvic fractures (n = 85), assignment of a level 2 trauma code was associated with reduced odds of death (OR = 0.07, 95%CI: 0.01-0.35, P = 0.001) as compared to being discharged to home. CONCLUSION: Trauma code level assignment is not correlated with severity of pelvic injury. Because an unstable pelvis can lead to hemodynamic instability, these injuries may be undertriaged.

Spectrum of Fat-containing Soft-Tissue Masses at MR Imaging: The Common, the Uncommon, the Characteristic, and the Sometimes Confusing.

Fat-containing tumors are the most common soft-tissue tumors encountered clinically. The vast majority of fat-containing soft-tissue masses are benign. Lipomas are the most common benign fat-containing masses and demonstrate a characteristic appearance at magnetic resonance (MR) imaging. Less common benign soft-tissue masses include lipoblastoma, angiolipoma, spindle cell lipoma/pleomorphic lipoma, myolipoma, chondroid lipoma, lipomatosis of nerve, lipomatosis, hibernoma, and fat necrosis. Well-differentiated liposarcomas (WDLPSs)/atypical lipomatous tumors (ALTs) are locally aggressive soft-tissue masses that do not metastasize. Biologically more aggressive liposarcomas include myxoid, pleomorphic, and dedifferentiated liposarcomas. At MR imaging, lipomas typically resemble subcutaneous fat but may contain a few thin septa. The presence of thick, irregular, enhancing septa and nonfatty soft-tissue mass components suggests liposarcoma rather than lipoma. However, benign lipomatous lesions and WDLPS/ALT often have overlapping MR imaging findings. Distinguishing WDLPS/ALT from a benign lipomatous lesion or from fat necrosis at imaging can be challenging and often requires histologic evaluation. We present the spectrum of fat-containing masses, using the World Health Organization classification of adipocytic tumors, with an emphasis on commonly encountered lesions, characteristic MR imaging findings associated with specific tumors, and overlapping MR imaging findings of certain tumors that may require histologic sampling. We also briefly discuss the role of molecular markers in proper characterization and classification of fat-containing soft-tissue masses. (©)RSNA, 2016.

Spinopelvic dissociation: multidetector computed tomographic evaluation of fracture patterns and associated injuries at a single level 1 trauma center.

The objective of the present study is to evaluate multidetector computed tomographic (MDCT) fracture patterns and associated injuries in patients with spinopelvic dissociation (SPD). Our institutional trauma registry database was reviewed from Jan. 1, 2006, to Sept. 30, 2012, specifically evaluating patients with sacral fractures. MDCT scans of patients with sacral fractures were reviewed to determine the presence of SPD. SPD cases were characterized into the following fracture patterns: U-shaped, Y-shaped, T-shaped, H-shaped, and burst. The following MDCT features were recorded: level of the horizontal fracture, location of vertical fracture, kyphosis between major fracture fragments, displacement of fracture fragment, narrowing of central spinal canal, narrowing of neural foramina, and extension into sacroiliac joints. Quantitative evaluation of the sacral fractures was performed in accordance with the consensus statement by the Spine Trauma Study Group. Medical records were reviewed to determine associated pelvic and non-pelvic fractures, bladder and bowel injuries, nerve injuries, and type of surgical intervention. Twenty-one patients had SPD, of whom 13 were men and eight were women. Mean age was 41.8 years (range 18.8 to 87.7). Five fractures (24 %) were U-shaped, six (29 %) H-shaped, four (19 %) Y-shaped, and six (29 %) burst. Nine patients (43 %) had central canal narrowing, and 19 (90 %) had neural foramina narrowing. Eleven patients (52 %) had kyphotic angulation between major fracture fragments, and seven patients (33 %) had either anterior (24 %) or posterior (10 %) displacement of the proximal fracture fragment. Fourteen patients (67 %) had associated pelvic fractures, and 20 (95 %) had associated non-pelvic fractures. Two patients (10 %) had associated urethral injuries, and one (5 %) had an associated colon injury. Seven patients (33 %) had associated nerve injuries. Six patients (29 %) had surgical fixation while 15 (71 %) were managed non-operatively. On trauma MDCT examinations, patients with SPD have characteristic fracture patterns. It is important to differentiate SPD from other pelvic ring injuries due to high rate of associated injuries. Although all SPD injuries are unstable and need fixation, the decision for operative management in an individual patient depends on the systemic injury pattern, specific fracture pattern, and the ability to attain stable screw fixation.

Misclassification of Pelvic Ring Injuries in the National Trauma Data Bank.

BACKGROUND: The American College of Surgeons has advocated for all trauma centers to participate in the National Trauma Data Bank (NTDB); however, no previous study has evaluated the accuracy of coding included in this data bank. The purpose of this study was to determine whether pelvic ring injuries are coded accurately in the NTDB and, if not, how they were misclassified. METHODS: A retrospective review of all pelvic ring injuries based on Abbreviated Injury Scale (AIS) codes was performed at a single level I academic trauma center from July 2010 to June 2013. Thin-section computed tomography (CT) scans in all patients were reviewed and classified using AIS codes: posterior arch intact, incomplete posterior arch, or complete posterior arch. The surgeon was blinded to the AIS code from the registry. These CT-based classifications were then compared with the pelvic ring injury codes designated in the trauma registry for each patient to evaluate agreement. RESULTS: Two hundred thirty-five patients with a mean age of 42 years had pelvic ring injuries in our registry. The agreement between trauma registry codes and CT reclassification was 24% in the intact group, 43% in the incomplete group, and 59% in the complete group. Using only the trauma registry codes, injuries were underclassified in 48% of the incomplete group and 76% of the intact group. CONCLUSIONS: Many pelvic ring injuries are miscoded and misclassified in the NTDB. The etiology of this misclassification is unclear, but any research data mined from these databases should be regarded cautiously.

High-resolution 3-T MRI of the fingers: review of anatomy and common tendon and ligament injuries.

OBJECTIVE. With high-resolution 3-T MRI, the complex anatomy of the fingers can be imaged in exquisite detail to provide an accurate diagnosis of clinically important ligament and tendon injuries. CONCLUSION. We present our 3-T MRI protocol using a dedicated hand-and-wrist coil and review normal MRI anatomy of the fingers. We emphasize a systematic approach to the interpretation of finger MRI examinations and illustrate this approach with examples of tendon and ligament abnormalities.

Verrucous carcinoma of the foot and enhancement assessment by MRI.

Verrucous carcinoma (VC), also known as epithelioma cuniculatum, of the foot is an uncommon low-grade squamous cell carcinoma with slow, progressive local invasion with minimal dysplasia and low potential for metastasis. We report on a case of VC and the enhancement pattern associated with it on magnetic resonance (MR) imaging. MR imaging revealed a plantar ulcer with an interesting pattern of enhancement at the base of the mass. The interface between the mass and the normal stroma exhibited a fine-filamentous pattern of enhancement, analogous to teased cotton wool, with impressive correlation to the histological appearance of our specimen. It is our opinion that VC could be included in the differential of a plantar ulcer associated with a mass that exhibits this enhancement pattern.