Monteggia Fractures – Approach To Malunion

Modern Study Review (AI-Generated)

High-Yield Summary

Monteggia fractures involve a proximal ulna fracture with dislocation of the radial head and are critical to recognize early to prevent chronic instability and malunion. Malunited Monteggia fractures often present with pain, limited range of motion, and progressive radiocapitellar subluxation or dislocation, requiring careful clinical and radiographic evaluation. Reconstruction aims to restore ulnar alignment and radial head congruency to improve elbow function and prevent long-term complications such as arthritis and instability. The Bell Tawse procedure remains a cornerstone surgical technique for chronic radial head dislocation with ulnar malunion.

Key Diagnostic Findings

Anatomy

• Monteggia fracture: Fracture of the proximal third of the ulna with dislocation of the radial head at the elbow joint.
• Radiocapitellar joint: Articulation between the radial head and the capitellum of the humerus, critical for forearm rotation and elbow stability.
• Annular ligament: Stabilizes the radial head; often disrupted in Monteggia injuries.

Clinical Presentation

• Pain localized to the radiocapitellar or radioulnar joints.
• Restricted range of motion of the elbow and forearm, especially pronation and supination.
• Progressive valgus deformity or instability of the elbow.
• Subtle radial head subluxation may be missed initially; high suspicion is necessary.

Imaging

• X-rays: Essential to evaluate ulnar shaft alignment and radial head position on AP and lateral views.
• Look for plastic deformation or malunion of the ulna, which may cause persistent radial head dislocation.
• CT or MRI may be used in complex cases to assess joint congruency and soft tissue interposition.

Classification Systems

• Bado Classification: Most widely used for Monteggia fractures, categorizing based on direction of radial head dislocation and ulnar fracture pattern.
• No major updates to Bado classification, but emphasis on early recognition and treatment to prevent malunion.

Current Gold Standard Treatment

Non-operative Indications

• Acute Monteggia fractures with minimal displacement and stable radial head reduction.
• Pediatric patients with plastic deformation without significant displacement may be managed conservatively with close monitoring.

Operative Indications

• Malunion with progressive radiocapitellar subluxation or dislocation.
• Persistent pain and limited range of motion due to joint incongruity.
• Failure of non-operative management or late presentation with chronic radial head dislocation.

Operative Treatment

• Ulnar osteotomy: Corrects malunion and restores length and alignment to allow radial head reduction.
• Radial head reduction: Achieved after ulnar correction; stable reduction is critical.
• Bell Tawse Procedure:
• Reconstruction of the annular ligament using a strip of triceps fascia or palmaris longus graft.
• Approach via Boyd incision, removal of interposed soft tissue, and fixation of the ulna.
• Aggressive irrigation to reduce risk of radioulnar synostosis.
• Timing: Reconstruction ideally performed after skeletal maturity if radial head congruency cannot be restored earlier.

Modern Complications & Outcomes

Classic Clinical Notes

Monteggia Fractures – Approach to Malunion

Consider reconstruction if:

• Progressive radiocapitellar subluxation or dislocation, progressive valgus, limited range of elbow or forearm motion
• Pain at radiocapitellar or radioulnar articulations

Clinical pearls:

• Most kids present with pain and restricted range of motion
• Beware the subtle subluxation of the radial head – it might not be so obvious
• Carefully scrutinize the ulnar shaft – what is the deformity? Was it fractured or just plastically deformed?
• Look closely at the dislocated radial head – will it be congruent if you put it back? If not, you cannot do the reconstruction – wait until skeletally mature and excise it
• Decide how to correct the ulnar deformity

Bell Tawse Procedure:

• Position prone; Boyd approach
• Lateral capsular incision to get into the elbow
• Remove interposed soft tissue, including joint capsule, annular ligament
• Reduce the radial head
• If cannot reduce the radial head, then osteotomize the ulna at the pre-determined spot
• Then reduce the head; usually stable once reduced
• Dissect a 1×7 cm strip of fascia off the lateral portion of the triceps; preserve the distal attachment on the olecranon
• Pass the strip medial to the olecranon at a point opposite the origin of the annular ligament, then pass it around the neck of the radius, suturing it onto itself. Use a palmaris longus graft if triceps is unsuitable
• Fix the ulna
• Irrigate aggressively to try to prevent radioulnar synostosis

Last Updated on January 25, 2026 by orthonet