Imaging of the elbow: a review of imaging findings in acute and chronic traumatic disorders of the elbow

Computed tomography-based angle measurements of the sagittal capitulum and trochlea position in relation to the humeral shaft

The radiologic evaluation of the sagittal angulation of the distal humerus is commonly based on standard lateral radiographs. However, lateral radiographs do not allow to examine the lateral angulation of the capitulum and the trochlea, separately. Although this problem could be approached via computed tomography, there are no data available describing the difference between the angulation of the capitulum and trochlea. Therefore, we aimed to assess sagittal angles of the capitulum and trochlea in relation to the humeral shaft based on 400 CT-scans of the elbow in healthy adults. Angles were measured in sagittal planes at the capitulum center and three anatomically defined trochlea locations and were spanned between the axis of the joint component and the humerus shaft. Angles were tested for differences between measurement locations and correlation with patient characteristics (age, sex, trans-epicondylar distance). Angles increased from lateral to medial measurement locations (107.4 ± 9.6°, 167.4 ± 8.2°, 171.8 ± 7.3°, 179.1 ± 7.0°; p < 0.05). Largest angle differences were detected between the capitulum and trochlea with smallest angles measured at the capitulum. Patient characteristics did not correlate with angles (p > 0.05). Intra-rater-reliability was r = 0.79-0.86. As CT-imaging allows to distinguish between sagittal capitulum and trochlea locations, it might benefit the radiologic diagnostic of sagittal malalignments of the distal humerus at the capitulum and trochlea, separately.

Comparative dosimetry of radiography device, MSCT device and two CBCT devices in the elbow region

The aim of the study was to estimate and to compare effective doses in the elbow region resulting from four different x-ray imaging modalities. Absorbed organ doses were measured using 11 metal oxide field effect transistor (MOSFET) dosimeters that were placed in a custom-made anthropomorphic elbow RANDO phantom. Examinations were performed using Shimadzu FH-21 HR radiography device, Siemens Sensation Open 24-slice MSCT-device, NewTom 5G CBCT device, and Planmed Verity CBCT device, and the effective doses were calculated according to ICRP 103 recommendations. The effective dose for the conventional radiographic device was 1.5 µSv. The effective dose for the NewTom 5G CBCT ranged between 2.0 and 6.7 µSv, for the Planmed Verity CBCT device 2.6 µSv and for the Siemens Sensation MSCT device 37.4 µSv. Compared with conventional 2D radiography, this study demonstrated a 1.4-4.6 fold increase in effective dose for CBCT and 25-fold dose for standard MSCT protocols. When compared with 3D CBCT protocols, the study showed a 6-19 fold increase in effective dose using a standard MSCT protocol. CBCT devices offer a feasible low-dose alternative for elbow 3D imaging when compared to MSCT.

The Acutely Injured Elbow

The acutely injured elbow can present as a diagnostic challenge, encompassing a spectrum of conditions that involve the various osseous and soft tissue structures of this complex joint. Imaging plays a vital role in the management of these patients by providing an accurate interpretation of the underlying trauma sustained, which can have important implications on the preservation of joint function and stability. This article examines the mechanisms, patterns, classifications, and imaging findings of acute elbow injuries, providing key concepts for the radiologist in the interpretation of these injuries.

MDCT findings after elbow dislocation: a retrospective study of 140 patients

OBJECTIVE

To assess the number and anatomical location of fractures associated with elbow dislocation, to study the correlation between the direction of dislocation and the trauma energy, and to assess radiographs' diagnostic performance characteristics for fractures using MDCT as a reference standard.

MATERIALS AND METHODS

A retrospective study was performed at a level 1 trauma center, finding a total of 140 patients who had sustained an elbow dislocation and who had undergone a subsequent MDCT examination. The CT and radiographs of the patient were reviewed by two musculoskeletal radiologists. CT images were analyzed for the site and size of the fracture fragments. In addition, the primary direction of the dislocation, patients' age, and gender were recorded. Trauma energy was also assessed.

RESULTS

One hundred and thirty-four out of 140 patients (96%) had a fracture that was seen on the correlative CT examination. The most common anatomical fracture locations were the coronoid process of the ulna 84 out of 140 (60%), the radial head 75 out of 140 (54%), and the humeral capitellum 57 out of 140 (41%). Multiple fractures were seen in 71 out of 134 (53%) patients with fractures. The left elbow was more commonly dislocated than the right one. The overall sensitivity of the radiographs was 62% and the specificity 96%.

CONCLUSION

Small fractures and impaction fractures are almost invariably present in elbow dislocations, and half of the patients have more than one fracture. Radiographs have a sensitivity of only 62%. MDCT is an invaluable method for determining the extent of bony injury and revealing occult fractures.

Modern imaging of the hand, wrist, and forearm

A review of the current state of the relevant diagnostic imaging technologies and methods and their clinical application in imaging common conditions of the hand, wrist, and forearm is presented. Evolving and future imaging technologies are also considered.