Background: MR arthrography in the abduction and external rotation (ABER) position has been shown to increase the diagnostic rate of anterior labroligamentous complex tears. However, the diagnostic and discriminative value of MR arthrography in ABER position in the different categories of the anteroinferior labroligamentous lesions has not been fully revealed. Aim: To compare MR arthrography in the ABER position with the conventional MR arthrography regarding the detection rate and discrimination accuracy of several anteroinferior labroligamentous lesions with arthroscopy as the gold standard technique. Patients and Methods: We examined a total of 38 Patients with shoulder disorders and compared results of both conventional MR arthrography and MR arthrography in ABER position retrospectively. An anteroinferior labroligamentous lesion was supposed to exist when the anteroinferior labrum was absent, fraying, detached, displaced from the glenoid rim, or as the contrast material was seen within the labrum, or when the inferior glenohumeral ligament was avulsed or ruptured at the humeral or labral attachment. All patients underwent shoulder arthroscopy after MR examination. Results: MR arthrography in ABER position has significantly higher accuracy and diagnostic sensitivity than that of conventional MR arthrography for the detection of different subtypes of the anteroinferior labroligamentous lesions (p<0.05). Conclusion: According to our results, we suggest that ABER position imaging should be added when conventional MR arthrography is questionable or unremarkable in suspected anteroinferior labroligamentous complex injury.

Background: Shoulder arthrography is an accurate method that can help in diagnosing several diseases. When shoulder arthrography is done combined with magnetic resonance imaging (MRI), a more comprehensive assessment of the cartilaginous structures of the glenohumeral joint is performed. Objective: This study aims to compare the anterior with the posterior ultrasound-guided arthrography injection approaches in achieving optimal needle placement, ensuring the accuracy of shoulder arthrography injections. Subjects and Methods: A total of 38 individuals (suffering from shoulder dislocation) were enrolled, in the study. The efficacy of the technique was evaluated relative to the success or failure of contrast medium administration into the glenohumeral joint, and the number of attempts required to achieve that success. Results: The success rate among the anterior approach group was 84.2% versus 89.5% in the posterior approach group. The mean number of trials for the anterior and posterior approaches showed no statistically significant difference while the mean injected volume with the anterior approach was significantly lower than that of the posterior approach group (P-Value: 0.006). Conclusion:The posterior approach has a slight advantage over the anterior approach regarding the injected volume of the contrast medium. However, there were better results yet non-statistically significant regarding the anterior and posterior approaches accuracy, pain tolerance, and the number of trials.

Component position and overall limb alignment following Total Knee Arthroplasty (TKA) have been shown to influence device survivorships and clinical outcomes. However, these parameters are often assessed through 2D radiographs after surgery, which can be prone to inaccuracy. The purpose of this paper is to develop a new method for 3D CT based overall limb alignment and component position measurements. The technique utilizes a new mathematical model to calculate prosthesis alignment from the coordinates of anatomical landmarks used in RATKA. The hypothesis is that the proposed technique demonstrated good accuracy, as well as low intra and inter-observer variability.Two groups of patients (n=120 per group) underwent RATKA and conventional TKA at 4 imaging locations between October 2016 and August 2018, where they were recruited and consented for this prospective, non-randomized, multicenter study. CTs were collected 6 weeks post-operatively and analyzed using RATKA landmarks and the proposed technique. Measurements of 30 randomly selected cases were compared to the surgeons’ operative plan and component target positions for accuracy analysis. Two surgeons performed the same measurements separately for inter-observer variability analysis. One of the two surgeons repeated the measurements 30 days later to assess intra-observer variability.Average measurement error of overall limb alignment, femoral and tibial component positions were less than 1 degree. Bland Altman plots analysis showed great reproducibility between observers. Correlation analysis showed low variability within observer, with slopes between 0.8 to 1.0 and R-squared &gt; 0.8.The proposed method demonstrated great accuracy to plan and low intra and inter-observer variability. This can be a great tool for RATKA studies where component accuracy is assessed using post-operative CTs.

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