Postoperative Bildgebung der Schulter

Abstract

Correct interpretation of imaging findings in the postoperative shoulder is impaired by surgical distortion of normal anatomy and possible artifacts. Advanced postoperative imaging of the shoulder in addition to the selection of the best suited modality necessitates familiarity with the surgical procedure that has been performed and its consecutive morphological changes. This article reviews the most common arthroscopic and open techniques used for treatment of shoulder instability, lesions of the superior labral-bicipital complex, primary impingement, and rotator cuff tears, their typical postoperative imaging findings, as well as the diagnostic performance of cross sectional imaging techniques in the detection of recurrent lesions and complications.

Multimodality imaging of the postoperative shoulder

“…Suture anchors made of titanium, as applied in Bankart repair or rotator cuff repair, usually produce only minor artifacts, that do not substantially affect depiction of adjacent anatomic structure on MR imaging [10]. Since the use of multiple 180°refocusing pulses compensates for susceptibility effects, turbo spin echo (TSE) sequences, particularly if obtained with long echo trains, are less prone to postoperative artifacts than spin echo (SE) or gradient echo (GRE) sequences.…”

“…The quality of MR images of the shoulder obtained after surgery can be significantly impaired by susceptibility artifacts due to metallic hardware (screws, staples) and metal shavings from the use of surgical instruments [7][8][9][10][11]. Suture anchors made of titanium, as applied in Bankart repair or rotator cuff repair, usually produce only minor artifacts, that do not substantially affect depiction of adjacent anatomic structure on MR imaging [10].…”

“…Spectral fat saturation is often insufficient in the presence of metallic materials, because distortion of the magnetic field can lead to a mismatch between the resonance frequency of fat and the frequency of the saturation pulse. The short tau inversion recovery (STIR) technique as a relaxation-dependent method is relatively resistant to magnetic field imhomogeneity and thus, STIR TSE sequences might at times be more practical to produce fat-suppressed MR images in the postoperative shoulder [8][9][10][11].…”

“…The use of cross-sectional imaging on the other hand mostly obviates the need for additional radiographs in special projections [10].…”

“…Various findings that indicate pathology in non-operated patients are less significant or even within the range of normal after specific surgical procedures or might be negligible in the absence of symptoms and functional deficits. Furthermore, the efficacy of MR imaging, MR arthrography, CT arthrography, and ultrasound for the detection of recurrent lesions and specific complications in patients, who have undergone surgery for shoulder instability, impingement, or rotator cuff tears, has yet to be confirmed [1][2][3][4][5][6][7][8][9][10]. At present, the choice of the most suited imaging technique and the interpretation of imaging findings in a specific postoperative setting are therefore in many aspects not only based on reproducible results of scientific studies but also on personal experience [7,8,10].…”