What is the appropriate management of an 80‑year‑old patient with a humeral shaft non‑union, and under what circumstances should a reverse total shoulder arthroplasty be considered?

Management of Humeral Shaft Non-Union in an 80-Year-Old Patient

For an 80-year-old patient with humeral shaft non-union, the gold standard treatment is open reduction with compression plating and autologous bone grafting, achieving >90% union rates; reverse total shoulder arthroplasty should be reserved specifically for proximal humeral non-unions with rotator cuff deficiency or as salvage after failed osteosynthesis, not for humeral shaft non-unions.

Primary Management Approach for Humeral Shaft Non-Union

Standard Surgical Treatment

The established treatment for humeral shaft non-union consists of 1, 2:

• Open reduction and internal fixation with compression plating plus autogenous bone graft - this remains the gold standard with >90% union rates and good functional outcomes
• Technical requirements for successful fixation 2:
  • Resect atrophic non-union sites and drill sclerotic areas to expose bleeding bone
  • Use broad compression plates with at least 6-8 points of cortical fixation above and below the non-union (unsuccessful fixations average only 2.7-3.0 cortices per side)
  • Apply compression via interfragmentary lag screws, plate prestressing, or dynamic compression devices
  • Add autogenous cancellous iliac bone grafts

Alternative Techniques

For patients where donor site morbidity is a concern 3, 4:

• Compression intramedullary nailing may be considered if the non-union shows biological activity (not atrophic), using newer-generation nails with compression capability and multiple locking screws for rotational stability
• Proximal tibia cancellous autograft with fibular strut allograft provides an alternative graft source with less morbidity than iliac crest harvest
• Avoid bone grafting only if the non-union is clearly biologically active with good vascularity

When to Consider Reverse Total Shoulder Arthroplasty

Appropriate Indications

Reverse shoulder arthroplasty is indicated for 5:

1. Proximal humeral fracture non-unions (not shaft non-unions) in geriatric patients with:

   • Pre-existing rotator cuff deficiency
   • Failed primary osteosynthesis or hemiarthroplasty
   • Non-viable humeral head
   • Proximal fragment insufficient to support reconstruction

2. Specific advantages in elderly patients 6, 7:

   • Compensates for deficient rotator cuff by using deltoid as primary stabilizer
   • Medial and distal center of rotation reduces glenoid loosening risk
   • Can achieve significant pain reduction and functional improvement

Evidence for Proximal Humeral Non-Union

A prospective multicenter study of 35 patients (mean age 69 years) with proximal humeral non-unions treated with reverse total shoulder arthroplasty showed 7:

• Significant decrease in pain (p < 0.001)
• Significant improvement in flexion, abduction, external rotation, and Constant score (p < 0.001)
• Mean follow-up 51 months
• However, high complication rate: 9 complications in 7 patients (20%), including 6 dislocations, 1 glenoid loosening, 1 nerve palsy, 1 infection

Critical Distinction: Location Matters

This is crucial: The evidence supports reverse shoulder arthroplasty for proximal humeral non-unions, not humeral shaft non-unions. For shaft non-unions, the humeral head and glenoid are typically intact, making arthroplasty unnecessary and inappropriate 1.

Age-Specific Considerations for 80-Year-Old Patients

Safety Profile

Recent evidence demonstrates reverse shoulder arthroplasty is safe even in patients ≥90 years old 8:

• Average operative time 85 minutes
• Low blood loss (average 163cc)
• 23% achieved same-day discharge
• All patients returned to preoperative living arrangements
• Significant functional improvements maintained

Patient Selection Factors 5

For an 80-year-old patient, consider:

• Functional status and independence level - ambulatory patients with reasonable life expectancy benefit most
• Medical comorbidities - ASA score ≥3 is common but manageable with appropriate perioperative care
• Bone quality - osteopenic bone may favor locked compression plates or dual plating for shaft non-unions 1
• Living situation - prepare patient/family for likely need for rehabilitation facility stay (46% in one series)

Algorithmic Decision-Making

For Humeral Shaft Non-Union (Your Case):

1. Confirm diagnosis: No progressive healing on radiographs 6-8 weeks apart 1

2. Classify non-union type:

   • Atrophic (most common, 73% in one series 2) → requires resection, compression, and bone graft
   • Hypertrophic → may heal with compression alone
   • Infected → requires staged treatment with infection eradication first

3. Primary treatment: Compression plating + bone graft

4. Reserve arthroplasty only if non-union extends into proximal humerus with humeral head involvement

For Proximal Humeral Non-Union:

1. Assess rotator cuff status and bone quality
2. If cuff intact and good bone: Attempt locked plate reconstruction with bone graft
3. If cuff deficient OR failed prior fixation: Consider reverse shoulder arthroplasty 5

Common Pitfalls to Avoid

• Inadequate fixation: Ensure minimum 6-8 cortices of fixation on each side of non-union 2
• Omitting bone graft in atrophic non-unions: Only 55% of failed platings included bone grafting 2
• Using reverse shoulder arthroplasty for shaft non-unions: This is not indicated and removes the option for future shoulder arthroplasty if needed
• Underestimating dislocation risk: 17% dislocation rate in proximal humeral non-union series 7 - counsel patients appropriately

Postoperative Expectations

For successful compression plating of shaft non-union 2:

• Average healing time: 5.6 months
• Union rate: 92%

For reverse shoulder arthroplasty in proximal non-union 7:

• Significant functional improvement expected
• Higher complication rate (20%) must be accepted
• Dislocation most common complication requiring vigilant precautions