What are the next steps in managing a 2.5 cm area of increased bony lucency in the greater tuberosity of the left humeral head?

Management of 2.5 cm Bony Lucency in Greater Tuberosity of Left Humeral Head

The next step is to obtain an MRI without IV contrast to definitively characterize this lesion, as it is the most sensitive and specific imaging modality for distinguishing between osteonecrosis, cystic degeneration, tumor, and other pathologies that present as lucent lesions in the humeral head. 1

Diagnostic Algorithm

Initial Imaging Interpretation

• A 2.5 cm lucent lesion in the greater tuberosity requires advanced imaging beyond plain radiographs, as radiography alone cannot adequately characterize the nature of the lesion 1
• The differential diagnosis includes osteonecrosis (avascular necrosis), subchondral cyst, bone tumor (benign or malignant), infection, or post-traumatic changes 1

Recommended Next Imaging Study

MRI without IV contrast is the gold standard for evaluating lucent humeral head lesions:

• MRI demonstrates sensitivity and specificity approaching 100% for diagnosing osteonecrosis, which is a critical consideration given the location in the greater tuberosity 1
• MRI characterizes the lesion's location, volume, and presence of associated bone marrow edema or joint effusion 1
• For humeral head osteonecrosis specifically, the necrotic angle can be measured on mid-coronal plane—lesions with necrotic angle <90° do not collapse over 24 months, while larger angles predict progression 1
• MRI effectively differentiates osteonecrosis from transient bone marrow edema syndrome, subchondral insufficiency fracture, and tumors 1

Alternative Imaging Considerations

CT without IV contrast may be appropriate if MRI is contraindicated:

• CT is less sensitive than MRI for early osteonecrosis detection but superior for evaluating osseous details and cortical integrity 1
• CT is particularly useful if there is concern for fracture or if surgical planning requires precise bony anatomy delineation 1
• However, CT should not be the first-line study when MRI is available 1

Clinical Context Assessment

Risk Factor Evaluation

• Document history of corticosteroid use, alcohol consumption, HIV, chemotherapy, radiation therapy, trauma, or blood dyscrasias—all are risk factors for osteonecrosis 1
• Osteonecrosis commonly affects adults in their third to fifth decades and is often bilateral in nontraumatic cases (70-80% for femoral head; similar patterns occur in humeral head) 1
• Multifocal osteonecrosis occurs in 15% of patients with shoulder involvement when other sites are affected 1

Symptom Correlation

• Assess for shoulder pain, limited range of motion, and functional impairment 1
• Determine if symptoms are acute (suggesting trauma or fracture) versus chronic (suggesting osteonecrosis or degenerative process) 1

Differential Diagnosis Considerations

Osteonecrosis (Most Critical to Rule Out)

• The 2.5 cm size is significant—necrotic volume predicts articular collapse risk 1
• Early diagnosis is essential to allow for possible surgical prevention of collapse and avoid eventual joint replacement 1
• MRI will show characteristic findings: rim of high signal on T2 surrounding area of decreased signal, with the "double-line sign" being pathognomonic 1

Cystic Lesions

• Humeral head cystic defects are commonly encountered during rotator cuff pathology and may be idiopathic, related to rotator cuff disease, or secondary to previous anchor placement 2
• These reduce biological healing capacity and may require bone grafting if rotator cuff repair is planned 2

Tumor (Rare but Must Exclude)

• Epiphyseal tumors are uncommon but include clear cell chondrosarcoma in older adults or chondroblastoma in adolescents 1
• Infarct-associated sarcomas are extremely rare (<80 cases in literature) but must be considered 1

Fracture-Related

• Greater tuberosity fractures can be subtle on initial radiographs and may present as lucent areas 3, 4, 5
• Isolated greater tuberosity fractures often mimic rotator cuff tears clinically 4
• Displaced fractures (>3-5 mm) require surgical treatment to prevent impingement and restore rotator cuff biomechanics 3

Management Pathway After MRI

If Osteonecrosis is Confirmed

• Stage the disease using appropriate classification system (Ficat-Arlet, ARCO, or Steinberg) 1
• Measure necrotic angle on mid-coronal MRI plane—angle <90° suggests lower collapse risk 1
• Consider core decompression with or without bone marrow cell injection for early-stage disease without collapse 1
• Advanced disease with collapse may require resurfacing hemiarthroplasty or total shoulder arthroplasty 1

If Cystic Lesion is Confirmed

• Evaluate for associated rotator cuff pathology, as these often coexist 2
• If rotator cuff repair is indicated, consider arthroscopic allograft compaction technique to address the cystic defect and improve fixation strength 2

If Fracture is Identified

• Assess displacement: >3-5 mm superior displacement requires surgical fixation in active patients 3
• CT may be added for surgical planning to characterize fracture morphology and guide fixation technique 1
• Surgical options include suture anchors, transosseous sutures, tension bands, or plate/screw constructs 3

Critical Pitfalls to Avoid

• Do not assume the lesion is benign without advanced imaging—a 2.5 cm lucency requires definitive characterization 1
• Do not obtain CT first unless MRI is contraindicated—MRI is superior for soft tissue and early osteonecrosis detection 1
• Do not delay imaging if osteonecrosis is suspected—early intervention can prevent articular collapse and preserve the joint 1
• Do not overlook bilateral or multifocal disease—if osteonecrosis is confirmed, image the contralateral shoulder and consider screening other common sites (hips, knees) 1
• Ensure adequate radiographic views were obtained initially—axillary or scapular-Y views are essential to avoid missing displaced greater tuberosity fractures that appear reduced on AP views alone 1, 5