PMC8129905_01
Imaging of the left shoulder before
arthroplasty removal.
(a) Axial CT image of the left shoulder demonstrating erosion of the anterior
and central glenoid (solid yellow arrow) with heterogeneously
hypoattenuating material centered within the glenohumeral joint space,
suggestive of complex effusion (*) and multiple intra-articular fragments of
ossific debris (arrowheads) abutting the margins of the thickened joint
capsule. This appearance would be most suspicious for septic arthritis,
though neoplasm with necrosis could have a similar appearance. Apparent
linear and punctate calcification within the subacromial-subdeltoid bursa
(dashed white arrows) would be most compatible with displaced articular
debris and heterotopic soft tissue ossification, chondroid neoplasm not
excluded. Streak artifact from the arthroplasty humeral component limits
assessment of fine detail. (b) Anteroposterior radiograph of the left shoulder demonstrating erosive
changes and extensive demineralization of the left proximal humerus (solid
white arrow) with left shoulder arthroplasty hardware in place. Osseous
fragmentation and erosion at the acromioclavicular joint, with secondary
acromioclavicular joint separation (dashed white arrows), and ossific debris
in the subacromial-subdeltoid bursa and/or soft tissue heterotopic
ossification (arrowheads). There is additionally erosion and fragmentation
of the glenoid (yellow arrow).
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Ch1.F1
The mass measured  cm and contained internal calcifications (Fig. 1a). A radiograph of the left shoulder demonstrated erosive changes and extensive demineralization of the left proximal humerus with left shoulder arthroplasty hardware in place (Fig. 1b), erosion and separation of the acromioclavicular joint, ossific debris in the subacromial-subdeltoid bursa, and destruction of the glenoid.
Imaging of the left shoulder 18 months after
arthroplasty removal.
(a) Anteroposterior radiograph of the left shoulder demonstrating erosion of
the left proximal humerus at the site of explanted arthroplasty hardware
(arrowheads) with extensive osseous mottling, demineralization, patchy
sclerosis, and cortical thinning of the proximal humeral metadiaphysis
(white arrows). Osseous fragmentation and erosion at the acromioclavicular
joint, with secondary AC joint separation (dashed white arrow). These
findings are highly suspicious for septic arthritis with osteomyelitis. (b) Coronal T1-weighted magnetic resonance image of the shoulder with fat
saturation demonstrating peripheral gadolinium contrast enhancement
(arrowheads) surrounding a moderate glenohumeral joint effusion in the
location of the eroded humeral head (*) with extension to the
subacromial-subdeltoid bursa (dashed arrow) and in continuity with a large,
rim-enhancing proximal humeral metadiaphyseal intra-osseous abscess (white
arrows).
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Ch1.F2
A radiograph of the left shoulder revealed erosion of the left proximal humerus at the site of explanted arthroplasty hardware, along with other findings highly suspicious for osteomyelitis and septic arthritis of the proximal humerus and acromioclavicular joint (Fig. 2a). Magnetic resonance imaging (MRI) demonstrated a peripherally enhancing glenohumeral joint effusion and intra-humeral abscess (Fig. 2b).