What is the Kapanji procedure and how is it used in orthopedic surgery?

The Kapandji Procedure: Surgical Technique for Distal Radius Fractures and DRUJ Disorders

The Kapandji procedure refers to two distinct but related surgical techniques developed by Dr. Kapandji: intrafocal pinning for distal radius fractures and the Sauvé-Kapandji procedure for distal radioulnar joint (DRUJ) disorders.

Kapandji Intrafocal Pinning Technique for Distal Radius Fractures

This technique uses percutaneous pins inserted directly through the fracture site to achieve and maintain reduction of distal radius fractures 1.

Technical Execution

• Pin placement: Pins are inserted through small incisions directly into the fracture site, using the fracture line itself as the entry point 1.
• Pin trajectory: The pins are advanced through the fracture into the proximal fragment, acting as internal buttresses to prevent collapse 1.
• Number of pins: Typically 2-3 pins are used, with a third pin sometimes necessary for optimal stability 1.
• Direct visualization: The technique requires primary reduction with direct control of tendinous and nervous elements through the incisions 1.

Clinical Outcomes

• Success rate: 93% very good or good results in a series of 159 fractures 1.
• Fracture types treated: 129 extra-articular fractures, 27 intra-articular fractures, and 3 both-bone forearm fractures 1.

Critical Pitfall

• Anterior over-reduction: Progressive secondary displacement can occur, necessitating regular postoperative radiographic follow-up to detect and correct this complication early 1.

Sauvé-Kapandji Procedure for DRUJ Disorders

This procedure combines arthrodesis of the distal radioulnar joint with creation of a pseudarthrosis in the distal ulna, providing both stability and preserved forearm rotation 2, 3.

Surgical Technique

Technique I: For Chronic Instabilities and Dislocations

• Indication: Chronic instabilities secondary to sprains and DRUJ dislocations where the ulnar head sits correctly in the sigmoid notch 4.
• Fixation method: The ulnar head is blocked in place with two screws in mid-position of pronation-supination 4.
• Gap management: The space between ulnar bone ends must be filled with the pronator quadratus muscle to prevent bony reconstruction 4.

Technique II: For Post-Colles Fracture Deformities

• Indication: Limitations of pronation-supination after Colles fractures with radial shortening causing DRUJ incongruency and positive ulnar variance 4.
• Key modification: The ulnar head must be lifted up before blocking it in the sigmoid notch to correct the deformity 4.

Clinical Indications

• Rheumatoid arthritis affecting the DRUJ 2, 3.
• Post-traumatic arthritis following distal radial fractures 2, 3.
• DRUJ osteoarthritis and ulnar impaction syndrome 5.
• Chronic DRUJ instability and dislocations 4.
• Failed previous wrist surgery: Serves as a reliable salvage procedure when other treatments have failed 3.

Functional Outcomes

• Pain relief: Excellent patient satisfaction with resolution or significant reduction of pain 2, 3.
• Range of motion: Normal pronation-supination achieved in 3-6 weeks, averaging 82° pronation and 83° supination 3, 4.
• Wrist contact mechanics: Scaphoid contact area to radius increases significantly from 112.6 mm² to 127.5 mm² postoperatively, with improved contact area ratio of scaphoid to lunate from 1.01 to 1.20 5.
• Clinical scores: Mayo Wrist Score improves significantly from 60.3 preoperatively to 80.3 postoperatively 5.
• Success rate: Six of nine patients with post-traumatic arthritis achieved excellent results (painless wrist with preserved rotation) 3.

Advantages Over Alternative Procedures

The Sauvé-Kapandji procedure is superior to simple ulnar head resection (Darrach procedure) because it maintains DRUJ stability while preserving forearm rotation 4. The arthrodesis component eliminates painful DRUJ motion, while the proximal ulnar pseudarthrosis allows physiologic pronation-supination 2, 3.

Postoperative Expectations

• Residual symptoms: Slight pain may persist when holding loads in supination or resting the hand unsteadily 4.
• Functional recovery: Patients regain ability to unscrew caps and turn door knobs 4.
• Long-term durability: Results remain stable at 33-month average follow-up 3.

When to Consider This Procedure

Use the Sauvé-Kapandji procedure as a salvage operation when conservative management has failed and at least one previous wrist operation has not resolved pain and functional limitations 3. This is particularly appropriate for patients with intractable DRUJ disorders who have exhausted other treatment options 3.