What is the appropriate diagnosis and treatment for a fracture of the surgical neck of the humerus?

Surgical Neck of Humerus Fracture: Diagnosis and Treatment

Initial Diagnosis

Start with plain radiographs, but immediately obtain CT imaging to accurately characterize the fracture pattern, as CT is superior to radiographs for delineating complex proximal humerus fractures and changes management in up to 41% of cases. 1, 2

Imaging Algorithm

• Plain radiographs serve as the initial screening tool but have poor inter-observer agreement for grading humeral head fractures 1
• CT with 3D reconstruction is the gold standard for characterizing fracture patterns, assessing displacement, and evaluating humeral neck angulation—all critical factors affecting treatment decisions and functional outcomes 1, 3
• MRI without contrast may be useful for assessing rotator cuff integrity in patients who will not undergo surgical fixation, as rotator cuff tears occur in up to 40% of proximal humerus fractures 1, 3, 2
• Avoid MR arthrography in the acute setting, as hemarthrosis provides adequate joint distention for identifying pathology 1

Treatment Decision

For displaced surgical neck fractures, nonsurgical treatment with sling immobilization followed by early mobilization should be the default approach, as a landmark randomized trial showed no significant difference in outcomes between surgical and nonsurgical treatment over 2 years. 4

Nonsurgical Management (First-Line)

• Sling immobilization initially, followed by standardized rehabilitation 4
• Initiate early active motion immediately after reduction to prevent stiffness 3
• This approach avoids the 10 medical complications (cardiovascular, respiratory, gastrointestinal events) that occurred in the surgical group during postoperative hospitalization 4
• Oxford Shoulder Scores at 2 years were equivalent: 39.07 points (surgical) vs 38.32 points (nonsurgical), with no clinically meaningful difference 4

Surgical Indications (Select Cases Only)

Reserve surgery for specific patient populations and fracture patterns where nonsurgical treatment is likely to fail:

Patient-Specific Surgical Considerations

• Geriatric patients with pre-existing rotator cuff dysfunction: Reverse shoulder arthroplasty is preferred over hemiarthroplasty 3
• Younger, active patients with severely displaced fractures: Consider open reduction and internal fixation with locking plates 3
• Frail elderly patients with severely displaced fractures: Hemiarthroplasty may be appropriate 3

Surgical Technique Selection (When Surgery is Indicated)

• Locking compression plates demonstrate superior biomechanical stability compared to intramedullary nails, with less displacement in bending (p=0.002) and less angular rotation in torsion (p=0.04) 5
• Intramedullary nails show high early failure rates in torsion and may cause symptomatic mechanical impingement requiring hardware removal 6, 5
• Both techniques yield similar clinical outcomes at 2 years when surgery is performed, with no significant differences in pain scores (VAS 1.3 vs 0.9), ASES scores (90.2 vs 91.9), or UCLA scores (30.7 vs 31.8) 7

Critical Pitfalls to Avoid

• Do not rely solely on plain radiographs to judge fracture stability or guide treatment decisions, as they miss fracture complexity that CT reveals 2
• Screen for rotator cuff tears in all cases, as they are present in up to 40% of proximal humerus fractures and may necessitate modified rehabilitation protocols 3, 2
• Avoid routine surgery based on radiographic displacement alone, as the PROFHER trial definitively showed no benefit over nonsurgical treatment for most displaced fractures 4
• If surgery is performed and intramedullary nails are used, counsel patients about the high likelihood (8 of 10 patients) of requiring hardware removal for symptomatic impingement 6

Associated Injury Assessment

• Evaluate for rotator cuff tears using MRI in nonsurgically managed patients, as significant tears occur in up to 40% of cases 1, 3, 2
• Address rotator cuff tears during open reduction if surgical fixation becomes necessary 3
• Note that delayed rotator cuff repair by up to 4 months does not adversely affect outcomes, so immediate soft-tissue diagnosis is not mandatory 1