Postoperative change and fracture healing tend to decrease over time. Fracture confirmation can also be identified with anatomic imaging (eg, radiographs, CT with metal artifact reduction techniques). Normal uncomplicated postoperative change tends to decrease over time and up to 2 years or longer after surgery [21,22], whereas aseptic loosening generally tends to progress. The specificity of bone scans increases in older prostheses once the postoperative remodeling has stabilized. The addition of SPECT/CT with the In-111 WBC and sulfur colloid scans increases contrast resolution and anatomic localization of radiopharmaceutical activity. Utilizing subtraction imaging on the SPECT/CT studies (subtracting the sulfur colloid from WBC images) can identify whether an area of concern on the bone scan is concordant with similar increased WBC and marrow activity (reactive marrow) or discordant (WBC activity with absent sulfur colloid activity), the latter consistent with an acute pyogenic process/osteomyelitis. 3-Phase Bone Scan with SPECT or SPECT/CT Shoulder The use of nuclear imaging for the evaluation of periprosthetic infection has been limited to the evaluation of hip and knee arthroplasties, but various clinical studies anecdotally suggest utilizing this modality in shoulder arthroplasties [30]. Imaging After Shoulder Arthroplasty Tc-99m 3-phase bone scan is a highly sensitive modality for the detection of acute osteomyelitis in the setting of normal radiographs but remains low in specificity as the imaging findings can overlap with other abnormalities such as mechanical loosening and osteolysis [30]. In addition, increased bone uptake can be seen at the site of arthroplasty, related to postoperative bone remodeling, for up to 1 year following surgery [30]. A bone scan is also limited in its ability to assess the periprosthetic soft tissues for the presence of an abscess.
Imaging After Shoulder Arthroplasty PCAs. Postoperative change and fracture healing tend to decrease over time. Fracture confirmation can also be identified with anatomic imaging (eg, radiographs, CT with metal artifact reduction techniques). Normal uncomplicated postoperative change tends to decrease over time and up to 2 years or longer after surgery [21,22], whereas aseptic loosening generally tends to progress. The specificity of bone scans increases in older prostheses once the postoperative remodeling has stabilized. The addition of SPECT/CT with the In-111 WBC and sulfur colloid scans increases contrast resolution and anatomic localization of radiopharmaceutical activity. Utilizing subtraction imaging on the SPECT/CT studies (subtracting the sulfur colloid from WBC images) can identify whether an area of concern on the bone scan is concordant with similar increased WBC and marrow activity (reactive marrow) or discordant (WBC activity with absent sulfur colloid activity), the latter consistent with an acute pyogenic process/osteomyelitis. 3-Phase Bone Scan with SPECT or SPECT/CT Shoulder The use of nuclear imaging for the evaluation of periprosthetic infection has been limited to the evaluation of hip and knee arthroplasties, but various clinical studies anecdotally suggest utilizing this modality in shoulder arthroplasties [30]. Imaging After Shoulder Arthroplasty Tc-99m 3-phase bone scan is a highly sensitive modality for the detection of acute osteomyelitis in the setting of normal radiographs but remains low in specificity as the imaging findings can overlap with other abnormalities such as mechanical loosening and osteolysis [30]. In addition, increased bone uptake can be seen at the site of arthroplasty, related to postoperative bone remodeling, for up to 1 year following surgery [30]. A bone scan is also limited in its ability to assess the periprosthetic soft tissues for the presence of an abscess.