Follow-Up CT Imaging After Arthroscopic Shoulder Instability Repair
CT is not routinely indicated for follow-up after uncomplicated arthroscopic shoulder instability repair; standard radiographs (AP, Grashey, scapular Y, and axillary views) are the appropriate imaging modality for routine surveillance. 1
Primary Imaging Recommendation
Plain radiographs are the first-line and primary imaging modality for postoperative follow-up after arthroscopic shoulder stabilization, typically obtained at 3-6 weeks postoperatively and then at intervals determined by clinical need 1
CT examinations are not typically ordered for asymptomatic patients after shoulder surgery and should be reserved for specific clinical indications 1, 2
When CT Should Be Considered
CT imaging becomes appropriate only in specific symptomatic scenarios:
Suspected Complications Requiring CT
Occult fractures not visible on radiographs when clinical suspicion remains high despite negative plain films 1
Characterization of known fractures to assess displacement, extent, comminution, and surgical planning needs 1
Hardware-related concerns when radiographs are inconclusive, particularly using metal reduction protocols 1
Glenoid bone loss assessment when revision surgery is being considered, as CT is considered the gold standard for quantifying bone deficiency 3
CT Technical Specifications
Metal artifact reduction protocols should be employed using higher voltage (140 kVp), higher exposure (200-400 mAs), and reduced pitch with slice overlap (<1) 1
Multidetector CT with reconstructed images provides optimal evaluation when metallic hardware is present 1
Alternative Imaging Modalities
For Soft Tissue Assessment
MRI or MR arthrography (rated 9/9) are superior to CT for evaluating labral integrity, capsular structures, and rotator cuff pathology in patients with recurrent instability symptoms 1
Ultrasound (rated 9/9) can assess rotator cuff integrity and is operator-dependent but avoids radiation exposure 1
For Infection Concerns
- Three-phase bone scan with SPECT/CT or labeled WBC imaging with marrow scan are appropriate when infection cannot be excluded clinically, as CT alone has limited utility for infection diagnosis 1
Critical Pitfalls to Avoid
Do not order routine CT scans in asymptomatic patients as this adds unnecessary radiation exposure and cost without clinical benefit 1, 2
CT has limited value for soft tissue evaluation compared to MRI, particularly for assessing labral repair integrity or rotator cuff pathology 1
CT arthrography is rated only 5/9 (may be appropriate) for shoulder instability evaluation and should only be used when MRI or ultrasound cannot be performed 1
Risk Factors That May Warrant Enhanced Surveillance
While these factors increase recurrence risk and may influence surgical decision-making, they do not automatically mandate CT imaging unless symptoms develop:
- Glenoid bone loss >10-15% is associated with higher failure rates 3, 4
- Off-track Hill-Sachs lesions significantly increase recurrence risk 5, 4
- Age <28 years and participation in contact/overhead sports increase failure risk 5, 6, 4
- Shoulder hyperlaxity (inferior or anterior) correlates with higher recurrence rates 5
Summary Algorithm
For asymptomatic patients: Plain radiographs only at scheduled intervals 1, 2
For symptomatic patients: Begin with plain radiographs; advance to CT only if fracture characterization, hardware assessment, or bone loss quantification is needed for surgical planning 1
For soft tissue concerns: MRI or ultrasound, not CT 1
For infection concerns: Nuclear medicine studies, not CT alone 1