What is the treatment for humeral head flattening?

Treatment of Humeral Head Flattening

For humeral head flattening in the context of glenohumeral osteoarthritis, total shoulder arthroplasty (TSA) is the preferred definitive treatment over hemiarthroplasty, providing superior outcomes in pain relief, function, and quality of life. 1

Understanding the Clinical Context

Humeral head flattening typically occurs in two primary scenarios that require different treatment approaches:

1. Glenohumeral Osteoarthritis with Humeral Head Flattening

Surgical Management (Definitive Treatment):

• TSA is recommended over hemiarthroplasty based on Level II evidence showing superior outcomes in appropriately selected patients with glenohumeral osteoarthritis 1
• Both TSA and hemiarthroplasty provide significant improvements in pain, function, and quality-of-life scores, but TSA demonstrates better overall results 1
• Hemiarthroplasty may be considered when the glenoid is naturally concentric or can be reamed to concentricity 1

Non-Surgical Options (Limited Evidence):

• Injectable viscosupplementation is an option (Grade C recommendation) with Level IV evidence supporting three weekly injections of hyaluronate preparations 1
• Corticosteroid injections have insufficient evidence to recommend for or against use (Grade I, Level V evidence), though widely used in clinical practice 1
• Arthroscopic debridement has insufficient evidence to recommend for or against (Grade I, Level V evidence) 1

Critical Consideration for Younger Patients:

• Significant concern exists for shoulder arthroplasty in patients <50 years due to increased risk of prosthetic loosening and decreased survivorship 1
• For younger patients with severe humeral head flattening and joint incongruity, comprehensive arthroscopic management (CAM) shows 63.2% survivorship at 10 years, though severe humeral head flattening is a risk factor for failure (93.8% of failures had severe incongruity) 2

2. Osteonecrosis of the Humeral Head with Flattening

Stage-Based Treatment Algorithm:

Early-Stage Disease (Pre-Collapse):

• Core decompression is the surgical intervention of choice when conservative measures fail, with success rates of 94% for Stage I and 88% for Stage II disease 3
• Noninvasive therapy should be attempted first for early-stage disease, though supporting data remains limited 3
• MRI is essential for early detection and staging before radiographic changes appear 3

Advanced Disease (Post-Collapse):

• Arthroplasty is the definitive treatment for advanced disease with articular collapse 3
• Hemiarthroplasty is appropriate for late-stage osteonecrosis with articular collapse but preserved glenoid 3
• TSA is indicated for severe secondary osteoarthritis involving both humeral head and glenoid 3

Critical Prognostic Factors:

• Lesion size is the most critical prognostic factor: lesions involving <30% of humeral head have <5% progression to collapse, while lesions >30% have 46-83% risk of progression 3
• Core decompression should NOT be performed on Stage IV disease (success rates only 14%), as arthroplasty is indicated 3

Essential Diagnostic Workup

For Suspected Osteonecrosis:

• Begin with plain radiographs to exclude other causes, though they are less sensitive for early disease 3
• MRI is the gold standard for early detection and staging before radiographic changes appear 3
• CT imaging is essential for surgical planning when intervention is considered, showing precise location and extent of the necrotic lesion 3
• Screen for bilateral disease, as 70-80% of nontraumatic cases are bilateral 3

For Fracture-Related Flattening:

• CT is the preferred study for characterizing proximal humeral fractures and delineating fracture patterns 1
• Three-dimensional volume-rendered CT images better characterize fracture patterns and humeral neck angulation 1

Critical Pitfalls to Avoid

• Early detection is crucial in osteonecrosis, as delay in diagnosis leads to articular collapse and reduces treatment options 3
• Do not rely on radiographs alone for early osteonecrosis detection—MRI is necessary 3
• Evaluate the contralateral shoulder in osteonecrosis cases, as bilateral involvement occurs in 70-80% of nontraumatic cases 3
• Severe humeral head incongruity predicts poor outcomes with joint-preserving procedures in osteoarthritis 2
• Age <50 years requires careful consideration before proceeding with arthroplasty due to concerns about long-term prosthetic survival 1