The tangential view described by Moneim to demonstrate scapholunate dissociation: an update

PURPOSE

Scapholunate dissociation is a common and significant injury to the wrist. Radiographs are important in the diagnosis of this injury and in the planning of treatment. The tangential radiograph view was described almost 40 years ago as a method for accurately measuring scapholunate gaps. The hand is positioned on a 20° foam rubber block and the thumb on the cassette, which positions the scaphoid and lunate articular surfaces parallel, without patient discomfort or effort. The goal of this study was to review this method with more recent data and in a larger group of patients.

METHODS

Radiographs of 31 patients who had scapholunate interosseous ligament tears and surgical repair over a 9 year period were retrospectively evaluated. Each of the four authors independently measured scapholunate gaps for posteroanterior and tangential views.

RESULTS

The tangential view gaps were significantly greater than the posteroanterior gaps overall. Similar results were found for borderline cases where the posteroanterior gap was less than 3 mm. Every tangential view gap measurement was greater than its respective posteroanterior gap with good inter-rater reliability.

CONCLUSION

The tangential view is a reliable radiographic method to identify scapholunate gaps. It should be obtained when there is clinical concern for scapholunate dissociation, especially in patients with borderline posteroanterior gaps.

A comparison of ferumoxytol with gadolinium as contrast agents for the diagnostic magnetic resonance imaging of osteomyelitis

BACKGROUND

Ferumoxytol, an FDA-approved superparamagnetic iron oxide nanoparticle (SPION) preparation used for the treatment of iron deficiency anemia, is also known to be taken up by macrophages in areas of infection or inflammation, where it produces negative contrast changes on T2-weighted MR images.

PURPOSE

We sought to compare Ferumoxytol-induced MRI contrast changes with those observed using standard-of-care Gadolinium in patients presenting with symptoms suggestive of osteomyelitis.

SUBJECTS

Out of eighteen enrolled patients, 15 had MR imaging with both ferumoxytol and gadolinium. Based on clinical and/or pathologic criteria, 7 patients were diagnosed with osteomyelitis, 5 patients had osteomyelitis ruled out, and in 3 patients a definitive diagnosis could not be made.

FIELD STRENGTH

1.5 Tesla.

SEQUENCES

Used included STIR, T1-weighted and T2-weighted spin echo.

ASSESSMENT

The mean contrast changes upon ferumoxytol and gadolinium administration were measured from lesion regions of interest and compared with control regions.

STATISTICAL TESTS

Student's t-test, propagation of errors. Data are reported as means ± S.E.

RESULTS

The mean contrast changes, ΔC, associated with a diagnosis of osteomyelitis were found to be ΔCFe = -2.7 ± 0.7 when Ferumoxytol and T2w imaging sequences were used and ΔCGd = +3.1 ± 1.1 (P < 0.001) when Gadolinium and a T1w imaging sequence was used. The MRI contrast changes for both agents correlated with systemic markers of inflammation, such as the erythrocyte sedimentation rate. In patients without osteomyelitis, no significant contrast changes were observed in T2-weighted, Ferumoxytol-contrasted MRI. The macrophages in osteomyelitic lesions were found to take up at least 16 times as much iron as benign bone marrow.

DATA CONCLUSION

We conclude that in terms of its MRI diagnostic accuracy for osteomyelitis Ferumoxytol-contrasted MRI is a promising approach for diagnosing osteomyelitis that merits further study.

Psychosocial and demographic factors influencing pain scores of patients with knee osteoarthritis

BACKGROUND

Pain levels in patients with osteoarthritis (OA) of the knee are commonly assessed by using a numeric scoring system, but results may be influenced by factors other than the patient's actual physical discomfort or disease severity, including psychosocial and demographic variables. We examined the possible relation between knee-pain scores and several psychosocial, sociodemographic, disease, and treatment variables in 355 patients with knee OA.

METHODS

The pain-evaluation instrument was a 0- to 10-point rating scale. Data obtained retrospectively from the patients' medical records were demographic characteristics, body mass index (BMI), concomitant disorders, illicit and prescription drug use, alcohol use, smoking, knee OA treatment, and severity of knee OA indicated by Kellgren-Lawrence (KL) radiographic grade. Univariate and multivariate analyses were performed to determine whether these variables correlated with reported pain scores.

RESULTS

On univariate analysis, higher pain scores were significantly associated with Native American or Hispanic ethnicity; a higher BMI; current prescription for an opioid, antidepressant, or gabapentinoid medication; depression; diabetes mellitus; fibromyalgia; illicit drug use; lack of health insurance; smoking; previous knee injection; and recommendation by the clinician that the patient undergo knee surgery. Neither the patient's sex nor the KL grade showed a correlation. On multivariate analysis, depression, current opioid prescription, and Native American or Hispanic ethnicity retained a significant association with higher pain scores.

CONCLUSIONS AND IMPLICATIONS

Our results in a large, ethnically diverse group of patients with knee OA suggest that psychosocial and sociodemographic factors may be important determinants of pain levels reported by patients with knee OA.

Postmortem X-ray Computed Tomography (CT) and Forensic Autopsy: A Review of the Utility, the Challenges and the Future implications

The utility of computed tomography (CT) for forensic autopsy is being defined. Small studies have indicated potential areas of use. Systematic studies are few. Evidence of the utility of CT as an autopsy substitute in fatal trauma cases has been inconsistent. Some studies show that there are injuries seen by CT that aren't detected by autopsy indicating that CT, at least, is likely useful as an autopsy adjunct. Research has been limited by small study populations, variation in postmortem interval, differences in protocols including CT slice thickness, who interpreted the scans (radiologists vs. pathologists), and how injuries were scored. Challenges exist to implement and use advanced imaging technology for the forensic autopsy. It is important to determine how to arrange these technologies into a coherent approach to postmortem diagnosis while not encumbering forensic pathologists. Forensic pathologists and radiologists require training in interpreting the unique aspects of postmortem CT scans. Some forensic pathologists might perceive imaging technology as a threat and express concern that it will make the autopsy obsolete.

If CT is found to supplant or supplement autopsy in valuable ways, more comprehensive diagnostic information can be provided. If CT can supplant the use of autopsy in certain situations and significantly decrease autopsy numbers it will allow offices to achieve an annual cost savings and divert these resources to other needs. If CT becomes widely available and can supplant autopsy, it could make up some of the gap between the numbers of forensic pathologists available and the numbers needed nationally.

Extensor hallucis capsularis: frequency and identification on MRI

BACKGROUND

The extensor hallucis capsularis (EHC) is the most common name given to the accessory tendon sporadically seen medial to the extensor hallucis longus (EHL). We performed cadaver dissections and MRI evaluation to determine the frequency of its occurrence, the pattern of its origin and insertion, and its potential suitability as tendon graft.

METHODS

The EHC was examined by dissection in 81 cadaver feet. Physical parameters pertaining to EHC size and location were recorded. MRI was performed on six cadaver legs to determine if the EHC can be identified radiographically. MRI images were evaluated independently by a foot and ankle specialist and a radiologist.

RESULTS

The EHC was present in 71 (88%) of the specimens. It originated from the EHL tendon or muscle in 93% and inserted into the first metatarsophalangeal joint capsule in 99% of cases. All EHC tendons were less than or equal to 4 mm in width; only 16% were more than 2 mm wide. Correct prediction of the presence or absence of EHC by MRI varied according to EHC width: two of two in tendons more than 2 mm, five of eight in tendons 1 to 2 mm, and zero of two in tendons 1 mm or less.

CONCLUSION

Up to 14% of the population may have an EHC tendon suitable for grafting in reconstructive surgeries, particularly surgeries related to hallux dysfunction. MRI may have a role in the preoperative identification of the EHC.