Acromial and Scapular Spine Stress Fractures

Overview:

Stress fractures of the acromion and scapular spine are common complications after reverse total shoulder arthroplasty (RTSA), a type of shoulder replacement surgery. These fractures occur due to the increased stress on the shoulder bones after surgery.

What are Acromion and Scapular Spine Stress Fractures?

• Acromion:'The highest point of the shoulder blade.
• Scapular Spine:'A ridge on the back of the shoulder blade.

Causes of Stress Fractures:

• Falls:'Direct impacts can cause fractures.
• Surgery-Related Stress:'Changes in shoulder mechanics after RTSA increase stress on these bones.

Symptoms:

• Pain:'Sudden increase in pain over the acromion or scapular spine.
• Loss of Function:'Difficulty moving the shoulder.
• Slow Recovery:'Delayed progress during rehabilitation may indicate a fracture.

Diagnosing Stress Fractures:

• Initial Imaging:'X-rays to identify fractures.
• CT Scans:'For detailed images, especially if X-rays are inconclusive.

Types of Fractures:

• Levy Classification:'Based on the location of the fracture relative to the deltoid muscle.
• Crosby Classification: Based on the relation to the AC joint.

 

'	Levy Classification			Crosby Classification
Type I		Fracture involving portion of anterior and middle deltoid origin	Small avulsion of anterior acromion
Type II		Fracture involving entire middle and portion of posterior deltoid origin	Fracture just posterior to AC-joint
Type III		Fracture involving entire middle and posterior deltoid origin	Dislocated fractures of posterior acromion or scapular spine

   

Treatment Options:

1. Non-Surgical Management:
   • Suitable for less severe fractures (Type I and some Type II).
   • Rest and Immobilization:'Stopping physiotherapy and using a sling to support the shoulder.
   • Follow-Up:'Regular X-rays to monitor healing.
2. Surgical Management:
   • Required for more severe fractures (Type III and some Type II).
   • Open Reduction and Internal Fixation (ORIF):'Surgical techniques to realign and stabilise the bones using plates and screws.

Post-Operative Rehabilitation:

• Immobilisation:'Using a sling or brace for 6 to 8 weeks.
• Gradual Exercises:'Starting with gentle movements after immobilisation.

Possible Complications:

• Implant Failure:'Need for revision surgery if the hardware fails.
• Non-Union:'Fractures are not healing properly and require additional surgery.
• Malunion:'Bones healing in an incorrect position.

Lessons Learned:

• Accurate diagnosis and imaging are essential for effective management.
• Non-surgical treatment can work for some fractures, but surgery is often needed for more severe cases.
• Understanding shoulder mechanics helps guide treatment decisions.
• Post-operative rehabilitation and careful monitoring are crucial for successful outcomes.
• Further research is needed to establish the best treatment protocols.