Imaging of shoulder arthroplasties and their complications: a pictorial review

Abstract

Currently, an increasing number of patients benefit from shoulder prosthesis implantation. Radiologists are therefore more often confronted with imaging examinations involving shoulder arthroplasty, whether during a dedicated examination or incidentally. Standard radiography is the first-line imaging modality in the follow-up of these implants, before the possible use of cross-sectional imaging modalities (computed tomography and magnetic resonance imaging), ultrasound, or nuclear medicine examinations. Shoulder arthroplasties are divided into three categories: reverse shoulder arthroplasty, total shoulder arthroplasty, and partial shoulder joint replacement (including humeral hemiarthroplasty and humeral head resurfacing arthroplasty). Each of these prostheses can present complications, either shared by all types of arthroplasty or specific to each. Infection, periprosthetic fractures, humeral component loosening, heterotopic ossification, implant failure, and nerve injury can affect all types of prostheses. Instability, scapular notching, and acromial fractures can be identified after reverse shoulder arthroplasty implantation. Glenoid component loosening and rotator cuff tear are specific complications of total shoulder arthroplasty. Progressive wear of the native glenoid is the only specific complication observed in partial shoulder joint replacement. Knowledge of different types of shoulder prostheses and their complications’ radiological signs is crucial for the radiologist to initiate prompt and adequate management.

Periprosthetic Fractures in Reverse Total Shoulder Arthroplasty: Current Concepts and Advances in Management

“…CT offers the further advantage of identifying nondisplaced acromial and scapular spine fractures, facilitating prompt treatment that may prevent subsequent fracture displacement [13]. For these reasons, it is recommended that patients with postoperative pain over the acromion or scapula without radiographic signs of fracture undergo CT imaging [24,25]. Single photon emission computed tomography (SPECT) has been cited as a useful adjunct for identifying acromial stress reactions in the post-RSA patient with clinical symptoms who lack radiographic evidence of fracture [13].…”

Ultrasound of the symptomatic shoulder arthroplasty: Spectrum and prevalence of periarticular soft tissue pathology

“…It is also important to be aware that certain postoperative complications are likely to be sonographically occult. Periprosthetic fractures, humeral component loosening and osteolysis are better recognized on radiographs and cross‐sectional imaging techniques 3 …”

“…An increasing number of shoulder arthroplasties being performed in the general population has led to an associated increased number of requests for radiological evaluation in the postoperative setting. This has brought a corresponding interest in the normal appearances of various shoulder arthroplasty systems and also the imaging features of complications 1–4 . Despite improvements in metal artifact reduction protocols in both computed tomography and magnetic resonance imaging (MRI), improving evaluation for potential complications involving the periarticular soft tissues and rotator cuff, these modalities can remain limited by the presence of artifact, which may partially or completely obscure the periprosthetic soft tissues.…”

Evaluation of the Painful Total Shoulder Arthroplasty

“…18 Advanced implant loosening will demonstrate lucencies around the implant on plain radiographs (Figure 2), but CT scans, bone scans, or positron emission tomography-CT scans may be necessary for more subtle cases. 4 Gregory et al 19 developed a CT protocol to evaluate glenoid loosening, which positions the patient in the lateral decubitus position with maximum shoulder forward flexion, which aligns the glenoid orientation with the axis of the CT scanner and almost eliminates metal artifact. With this technique, they were able to identify radiolucent lines in 54 of 55 CT scans.…”

“…4 Radionuclide imaging modalities such as Technetium-99m hydroxydiphosphonate (HDP) bone scintigraphy, gallium citrate scintigraphy, and 18F-fluorodeoxyglucose-positron emission tomography are all sensitive but not specific for an infection. 4…”