Distal Radius Fractures: Surgical Approaches, Indications, and Risks

What are the surgical approaches to the distal radius?

Surgical approaches to the distal radius primarily involve accessing the bone from its volar (anterior), dorsal (posterior), or less commonly, lateral aspects, each chosen based on the specific fracture pattern, required fixation, and anatomical considerations to optimize reduction and minimize complications.

Understanding the Distal Radius and Surgical Necessity

The distal radius, the larger of the two forearm bones, forms the wrist joint with the carpal bones. Fractures of the distal radius are among the most common orthopedic injuries, often resulting from falls onto an outstretched hand. While many can be managed non-surgically, complex, unstable, or significantly displaced fractures often necessitate surgical intervention to restore anatomical alignment, stability, and function. The choice of surgical approach is critical, guiding the surgeon's access to the fracture site and influencing the type of fixation used.

Key Anatomical Considerations

Successful surgical intervention relies on a deep understanding of the distal radius's intricate anatomy. The bone's volar surface is relatively flat and provides an ideal platform for plate fixation, while the dorsal surface is convex and covered by extensor tendons. Crucial neurovascular structures, including the median nerve, radial artery, superficial radial nerve, and various tendons, lie in close proximity, demanding meticulous dissection and protection during any approach.

Volar Approach (Henry's Approach)

The volar approach is the most frequently utilized surgical pathway for distal radius fractures, especially with the advent of low-profile, anatomically contoured volar locking plates.

• Description: An incision is made on the volar aspect of the forearm, typically along the radial side of the flexor carpi radialis (FCR) tendon. The FCR tendon is retracted ulnarly, and the radial artery is retracted radially. The pronator quadratus muscle is then carefully elevated or incised from its radial insertion to expose the distal radius.
• Advantages:
  • Direct Visualization: Provides excellent exposure of the volar articular surface and metaphysis, where most distal radius fragments displace.
  • Plate Application: Ideal for the application of volar locking plates, which provide strong, stable fixation by supporting the articular surface and resisting collapse.
  • Reduced Tendon Irritation: Less risk of extensor tendon irritation or rupture compared to dorsal plating.
  • Safety: Generally considered safer with respect to major neurovascular structures if proper dissection planes are maintained.
• Indications: Most unstable or displaced distal radius fractures, particularly those with volar comminution or displacement, and those requiring buttress plating for volar stability.
• Risks: Potential for injury to the radial artery, median nerve (especially in carpal tunnel release concomitance), or flexor tendons.

Dorsal Approach (Thompson's Approach)

The dorsal approach provides access to the posterior aspect of the distal radius and is less commonly used for primary fixation due to higher rates of tendon irritation and rupture with older plate designs.

• Description: An incision is made on the dorsal aspect of the forearm, typically centered over Lister's tubercle. The extensor retinaculum is carefully incised or elevated, and the extensor tendons (e.g., extensor pollicis longus, extensor digitorum communis) are retracted to expose the dorsal radius. Specific internervous planes can be utilized to minimize muscle damage.
• Advantages:
  • Direct Visualization: Excellent exposure of the dorsal articular surface and metaphysis.
  • Corrective Osteotomies: Useful for dorsal corrective osteotomies in malunited fractures.
• Indications: Fractures with significant dorsal comminution, dorsal articular displacement, or for certain types of external fixation pin placement. It is also used in conjunction with volar approaches for complex fracture patterns (e.g., "four-corner" fractures).
• Risks: Higher risk of extensor tendon irritation, adhesion, or rupture from hardware prominence. Injury to the superficial radial nerve is also a concern.

Lateral Approach (Kapandji's Approach / Radial Approach)

The lateral approach is less common as a primary exposure for plate fixation but is valuable for specific fracture patterns or in conjunction with other techniques.

• Description: An incision is made along the radial aspect of the distal forearm, often between the first and second dorsal compartments (abductor pollicis longus/extensor pollicis brevis and extensor carpi radialis longus/brevis).
• Advantages:
  • Specific Access: Provides good access to the radial styloid and the radial column of the distal radius.
  • Minimizes Major Neurovascular Risk: Avoids the primary neurovascular bundles on the volar and dorsal aspects.
• Indications: Radial styloid fractures, certain types of shearing fractures, or for specific external fixator pin placement. Can also be used to facilitate percutaneous pinning or fragment-specific fixation.
• Risks: Potential for injury to the superficial radial nerve or to the tendons of the first dorsal compartment.

Ulnar Approach

The ulnar approach is rarely used as the primary access for distal radius fractures but may be employed for specific issues related to the distal radioulnar joint (DRUJ) or ulnar styloid.

• Description: An incision is made along the ulnar aspect of the distal forearm, typically between the extensor carpi ulnaris (ECU) tendon and the flexor carpi ulnaris (FCU) tendon.
• Advantages:
  • DRUJ Access: Excellent exposure of the distal ulna and DRUJ.
• Indications: Ulnar styloid non-unions requiring fixation, DRUJ instability requiring stabilization, or repair of the triangular fibrocartilage complex (TFCC).
• Risks: Injury to the dorsal cutaneous branch of the ulnar nerve, ulnar artery, or ulnar nerve.

Minimally Invasive and Arthroscopic Approaches

Advancements in surgical techniques have led to the increased use of minimally invasive and arthroscopic methods.

• Description: These techniques involve smaller incisions or portals and the use of fluoroscopy (X-ray guidance) and/or an arthroscope (a small camera) to visualize the fracture and assist with reduction and fixation.
• Advantages:
  • Reduced Soft Tissue Disruption: Smaller incisions lead to less muscle and tissue damage.
  • Improved Recovery: Potentially faster recovery and reduced post-operative pain.
  • Direct Articular Visualization (Arthroscopy): Allows for precise assessment and reduction of articular step-offs and gaps, and management of associated soft tissue injuries (e.g., TFCC tears).
• Indications: Select intra-articular fractures, particularly those with small articular fragments or associated ligamentous injuries. Often used in conjunction with percutaneous pinning or small plate fixation.
• Risks: Requires specialized equipment and expertise. Potential for fluid extravasation with arthroscopy, as well as general surgical risks.

Factors Influencing Approach Selection

The decision regarding the most appropriate surgical approach is multifaceted and individualized:

• Fracture Morphology: The specific pattern of the fracture, including displacement, comminution (fragmentation), and involvement of the articular surface (intra-articular vs. extra-articular).
• Type of Fixation: The chosen hardware (e.g., volar plate, dorsal plate, external fixator, pins) dictates the required exposure.
• Associated Injuries: Concomitant carpal injuries, ligamentous tears (e.g., TFCC), or nerve compression may influence the approach or necessitate additional procedures.
• Surgeon's Experience and Preference: Surgeons often have a preferred approach based on their training and experience for certain fracture types.
• Patient Factors: Bone quality, age, activity level, and medical comorbidities are also considered.

Conclusion

The surgical management of distal radius fractures is a complex process requiring a thorough understanding of anatomy, biomechanics, and surgical principles. The choice of surgical approach – volar, dorsal, lateral, ulnar, or minimally invasive – is a critical determinant of surgical success, directly impacting the ability to achieve anatomical reduction and stable fixation while minimizing complications. Ultimately, the goal is to restore optimal wrist function and facilitate a safe and effective return to activity for the patient.