What is the treatment for pseudoarthritis?

Treatment of Pseudoarthrosis

The treatment of pseudoarthrosis primarily involves surgical intervention with a combination of excision of the pseudoarthrosis site, appropriate fixation methods, and bone grafting to achieve union and restore function. 1

Understanding Pseudoarthrosis

Pseudoarthrosis (false joint) refers to the failure of bone healing after a fracture or attempted fusion, resulting in persistent mobility at the fracture site. It can occur in various bones but is commonly seen in:

• Congenital pseudoarthrosis of the tibia (CPT) in children
• Spine following failed fusion attempts
• Scaphoid and other carpal bones
• Long bones after fracture treatment

Treatment Approach Based on Location

Congenital Pseudoarthrosis of the Tibia (CPT)

The CPAM-LRC consensus guidelines recommend the following approach 1:

1. Timing of surgery: Operative management is recommended when patients are over 2 years old

2. Surgical technique:

   • Complete excision of the pseudoarthrosis site
   • External fixation combined with intramedullary fixation
   • Sufficient autogenous bone grafting
   • Consideration of vascularized fibular graft as an alternative to corticocancellous autograft

3. Fixation methods:

   • Intramedullary rod (IMR)
   • Ilizarov method
   • Combined IMR with Ilizarov
   • Telescopic rod (TR)
   • Titanium elastic nails (TENs)
   • Fassier-Duval rod (FDR)

4. Emerging technique: Cross-union technique (tibiofibular fusion) shows promising results with 100% union rate and lowest refracture rate (22.5%), though long-term data is limited 1

Spinal Pseudoarthrosis

For spinal pseudoarthrosis following failed fusion 1:

1. Surgical approach:

   • Second attempt at fusion is typically required
   • May need a different approach from the index surgery
   • Additional instrumentation and bone graft material

2. Special considerations:

   • In ankylosing spondylitis with severe kyphosis and pseudoarthrosis, surgical stabilization may be required 1
   • Elective spinal osteotomy is generally not recommended for most patients with ankylosing spondylitis and severe kyphosis due to high risks (4% perioperative mortality and 5% permanent neurologic sequelae) 1

Scaphoid Pseudoarthrosis

Treatment options include 2:

1. Bone grafting: Trapezoidal bone grafting as outlined by Fernandez

2. Internal fixation with one of three methods:

   • Kirschner (K) wires (practical technique with advantages of cost and ease of insertion)
   • AO cannulated screw
   • Herbert screw

3. Key surgical principles:

   • Complete resection of fibrous tissue and sclerotic bone
   • Adequate bone grafting
   • Stable internal fixation

4. Alternative for advanced cases: Pyrocarbon implant (APSI) to replace the proximal part of the scaphoid in cases where curative treatment is no longer possible 3

Factors Affecting Treatment Success

Several factors influence the success of pseudoarthrosis treatment:

1. Biological factors:

   • Local biology (presence of myofibroblasts and fibromatous reaction) 4
   • Vascular supply to the area
   • Metabolic factors

2. Mechanical factors:

   • Stability of fixation
   • Quality of bone
   • Alignment and reduction

3. Patient factors:

   • Age
   • Comorbidities (especially neurofibromatosis in CPT)
   • Smoking status
   • Nutritional status

Treatment Algorithm

1. Diagnosis confirmation:

   • Clinical assessment for pain and instability
   • Radiographic evaluation (flexion-extension views)
   • CT scan for detailed assessment of bone healing

2. Treatment selection based on location and severity:

   • For CPT: Combined techniques including excision, fixation, and bone grafting
   • For spinal pseudoarthrosis: Revision fusion with appropriate instrumentation
   • For scaphoid: Bone grafting with internal fixation

3. Adjunctive treatments:

   • Bone stimulation techniques
   • Consideration of biological agents (though evidence for recombinant bone morphogenic protein is inconclusive) 1

Important Considerations and Pitfalls

• Complete excision of all fibrous tissue and sclerotic bone at the pseudoarthrosis site is essential for successful union 2
• The choice of fixation method should be based on the specific anatomical location and patient factors
• Long-term follow-up is necessary as refractures can occur, particularly in CPT
• In CPT, the primary goal should be a functional, pain-free limb with proper alignment and length, not just radiographic union 1

By following these evidence-based approaches, the majority of pseudoarthrosis cases can be successfully treated, though the time to union may be prolonged and multiple procedures are sometimes necessary.