Residency · Residency · Orthopedic Surgery

Distal Radius Fractures: Evidence-Based Management

Epidemiology and Mechanism

Demographics

Distal radius fractures exhibit a bimodal distribution: they affect young patients through high-energy mechanisms and elderly patients through low-energy falls on osteoporotic bone. This is the most common upper extremity fracture, with a female-to-male ratio of approximately 3:1 in elderly populations. In patients over 50, a distal radius fracture should be considered a sentinel fragility fracture that triggers a comprehensive metabolic bone health workup.

Mechanism

The most common mechanism is a fall on an outstretched hand (FOOSH). More than 90% of cases produce dorsal angulation (the Colles pattern). The less common Smith pattern (volar angulation) results from a fall on a flexed wrist or a direct blow to the dorsum of the hand. High-energy mechanisms include motor vehicle accidents, sports injuries, and falls from height.

Anatomy

Distal Radius

The distal radial articular surface is divided into the scaphoid fossa (lateral) and the lunate fossa (medial). The sigmoid notch on the medial aspect articulates with the distal ulna to form the distal radioulnar joint (DRUJ). Normal radiographic parameters on the AP view include radial inclination of 22-23 degrees and radial height of 11-12 mm. On the lateral view, the articular surface demonstrates 11-12 degrees of volar tilt. Ulnar variance is neutral (0 mm) on average.

Distal Radioulnar Joint (DRUJ)

The sigmoid notch of the radius articulates with the ulnar head, stabilized primarily by the triangular fibrocartilage complex (TFCC). DRUJ stability must always be assessed after fracture fixation, as unrecognized instability leads to chronic pain and disability.

Carpal Relationships

The normal scapholunate angle ranges from 30 to 60 degrees. Distal radius fractures may be associated with carpal ligament injuries, particularly scapholunate ligament tears identified by widening greater than 3 mm on the PA view.

Classification Systems

Frykman Classification

The Frykman system is based on intra-articular involvement and the presence or absence of an ulnar styloid fracture. Types I-II are extra-articular, Types III-IV involve the radiocarpal joint, Types V-VI involve the DRUJ, and Types VII-VIII involve both joints. Odd numbers indicate no ulnar styloid fracture; even numbers have an associated ulnar styloid fracture. This system has limited clinical utility in modern practice.

AO/OTA Classification

The AO/OTA system categorizes fractures as Type A (extra-articular), Type B (partial articular), and Type C (complete articular). It is more widely used in research and guides treatment based on the degree of articular involvement.

Fernandez Classification

The Fernandez classification is based on mechanism: bending, shear, compression, avulsion, and combined injuries. It provides useful insight into fracture personality and helps guide the treatment approach.

Indications for Treatment

Acceptable Alignment (Nonoperative)

Parameters for acceptable alignment include radial shortening less than 3 mm, dorsal tilt less than 5 degrees (or at least neutral), radial inclination greater than 15 degrees, intra-articular step-off less than 2 mm, and a congruent and stable DRUJ. These parameters may be relaxed in low-demand elderly patients who are less likely to experience functional limitations from mild deformity.

Indications for Operative Fixation

Operative treatment is indicated for dorsal tilt greater than 10 degrees after reduction, radial shortening greater than 3 mm, intra-articular displacement greater than 2 mm, DRUJ instability, associated carpal ligament injuries requiring treatment, loss of reduction in cast (a common occurrence), open fractures, and bilateral fractures or polytrauma.

Nonoperative Management

Closed reduction is performed under hematoma block, Bier block, or conscious sedation. A sugar-tong splint is applied initially to accommodate swelling, then converted to a short-arm cast at 1-2 weeks. Radiographic follow-up at 1, 2, and 3 weeks monitors for loss of reduction. Total immobilization time is 5-6 weeks. Loss of reduction occurs in 30-60% of initially reduced fractures, making radiographic vigilance during the first three weeks essential.

Operative Techniques

Volar Locking Plate (VLP)

The volar locking plate is the current gold standard for operative fixation of distal radius fractures. The approach is a modified Henry (between the FCR tendon and radial artery). The pronator quadratus is elevated and reflected ulnarly to expose the volar distal radius. The plate is applied to the volar surface where it acts as a buttress preventing dorsal collapse. Fixed-angle locking screws support the subchondral bone as pegs. These distal screws should be placed within 2 mm of the subchondral surface but must not penetrate the joint. Intraoperative fluoroscopy including the dorsal tangential (skyline) view is essential to assess for screw prominence. Advantages include the low-profile hardware, soft-tissue-friendly approach, and ability to allow early mobilization. Complications include flexor tendon irritation (FPL being the most commonly affected), articular screw penetration, and a hardware removal rate of 5-15%.

Fragment-Specific Fixation

Fragment-specific fixation addresses individual key fragments (radial column, dorsal wall, volar rim, ulnar corner) using pin plates, small screws, and wires. This approach is particularly useful for complex articular fracture patterns not amenable to single-plate fixation, especially when critical fragments such as the volar ulnar corner (lunate facet fragment) escape standard VLP capture.

Dorsal Plating

Dorsal plates were historically popular but are associated with higher rates of extensor tendon complications. Low-profile dorsal plate designs reduce but do not eliminate tendon irritation. Dorsal plating is now less commonly used as primary fixation since volar locking plates have largely replaced it, though it remains useful for dorsally comminuted fractures not adequately addressed from the volar side.

External Fixation

External fixation in bridging or non-bridging configurations uses ligamentotaxis to maintain reduction. Bridging fixation spans from the radius shaft to the second metacarpal. Non-bridging configurations place pins in the distal fragment and shaft, allowing wrist motion. External fixation is now primarily used as temporizing fixation in polytrauma or for severely contaminated open fractures, having been largely replaced by VLP for definitive treatment.

Percutaneous Pinning

Kapandji intrafocal pinning or cross-pinning with K-wires provides less rigid fixation than plating. It remains useful in certain settings including pediatric fractures, temporary stabilization, and resource-limited environments. Higher rates of loss of reduction compared to VLP limit its role in definitive adult fracture care.

Evidence: Surgery vs. Casting

DRAFFT2 Trial (2023)

This randomized controlled trial compared volar locking plate fixation to cast immobilization in adults over 16 years with dorsally displaced distal radius fractures. The primary outcome (Patient-Rated Wrist Evaluation at 12 months) showed no significant difference between groups. The VLP group demonstrated better early functional scores at 3-6 months but equivalent long-term outcomes. The implication is that casting is an acceptable treatment for many displaced distal radius fractures, even those with initial displacement.

CROSSFIRE Trial

This Australian RCT compared volar locking plate fixation to casting in patients over 60 years. It found no significant functional difference at 12 months, supporting nonoperative management in elderly patients who achieve adequate reduction.

Interpretation and Controversy

These trials challenge the reflexive operative fixation of all displaced distal radius fractures. However, specific subgroups may still benefit from surgery: young active patients with high functional demands, intra-articular fractures with significant displacement, and fractures that cannot be adequately reduced or maintained in a cast. Not all fractures enrolled in these trials were severely displaced, and generalizability to highly comminuted or significantly intra-articular fractures remains debated. Shared decision-making with patients is essential.

Special Populations

Elderly Patients

Osteoporotic bone increases the risk of loss of reduction in a cast, but functional demands may be lower, allowing tolerance of more deformity. Evidence increasingly supports nonoperative management with acceptable alignment in elderly patients. All patients with fragility fractures should be assessed for osteoporosis and have treatment initiated.

Young Active Patients

Higher functional demands mean less tolerance for malunion. Articular congruity is more important for long-term function in this population. Operative fixation is generally favored for displaced or unstable fractures. Fragment-specific fixation should be considered for complex articular patterns.

Volar Rim (Lunate Facet) Fractures

The volar lunate facet fragment is a critical structure that provides the volar buttress preventing carpal subluxation. Even small fragments can lead to volar carpal subluxation if not adequately fixed. Standard VLP may not capture very distal fragments, and specialized approaches including hook plates, fragment-specific fixation, or dedicated volar rim plates may be required.

Complications

Malunion

Malunion is the most common complication of nonoperative treatment, manifesting as residual dorsal angulation, radial shortening, and loss of radial inclination. This leads to altered wrist mechanics, decreased grip strength, and DRUJ dysfunction. Symptomatic malunion with significant deformity may be treated with corrective osteotomy.

Median Nerve Dysfunction

Acute carpal tunnel syndrome occurs in 5-10% of distal radius fractures and may require urgent carpal tunnel release at the time of fracture fixation. Progressive numbness in the median nerve distribution should be monitored closely in the postoperative period.

Tendon Complications

Extensor pollicis longus rupture occurs in 1-3% of cases and can develop even after nondisplaced fractures. The rupture typically occurs at Lister's tubercle, a watershed zone for tendon blood supply. Treatment is EIP-to-EPL tendon transfer. Flexor tendon irritation or rupture (FPL most commonly) can occur with volar locking plates, particularly when the distal plate edge is prominent or screws penetrate the dorsal cortex.

Complex Regional Pain Syndrome (CRPS)

CRPS develops in 1-10% of distal radius fractures and presents with burning pain, swelling, stiffness, and vasomotor changes out of proportion to the injury. Early recognition and aggressive hand therapy are key to management. Prolonged immobilization should be avoided.

DRUJ Instability

DRUJ stability must be assessed after fracture fixation. Ulnar styloid base fractures are associated with DRUJ instability. If the DRUJ remains unstable after adequate radius fixation, TFCC repair or ulnar styloid fixation should be considered.

<image>A lateral view diagram of the distal radius showing normal radiographic parameters. Illustrate volar tilt (11-12 degrees) measured as the angle between the distal radial articular surface and a line perpendicular to the radial shaft axis. Show a Colles fracture (dorsal tilt) and a Smith fracture (volar displacement) compared to the normal anatomy. Label the volar and dorsal cortices, articular surface, and measurement angles.</image>

<image>An intraoperative illustration of volar locking plate fixation of a distal radius fracture through the modified Henry approach. Show the volar surface of the distal radius with pronator quadratus reflected ulnarly, the plate applied to the volar surface with fixed-angle locking screws supporting subchondral bone. Include a cross-sectional inset showing how the locking screw threads engage the threaded plate hole creating a fixed-angle construct. Label the FCR tendon, radial artery, pronator quadratus, and plate position relative to the watershed line.</image>

<image>An anteroposterior radiograph diagram of the distal radius showing normal radiographic parameters: radial inclination (22 degrees angle from radial styloid to ulnar corner of lunate fossa relative to a line perpendicular to the shaft), radial height (11 mm distance from tip of radial styloid to ulnar articular surface), and ulnar variance (relationship of distal ulnar articular surface to distal radial articular surface). Label each measurement with reference lines and values.</image>

Clinical Pearls

Distal radius fractures in patients over 50 should trigger a bone health assessment because this is often a fragility fracture signaling underlying osteoporosis. Loss of reduction in cast occurs in up to 60% of cases, making close radiographic follow-up during the first three weeks essential. The DRAFFT2 and CROSSFIRE trials demonstrate that many displaced distal radius fractures in adults and elderly patients achieve equivalent outcomes with casting, cautioning against reflexive surgical fixation. The volar rim (lunate facet) fragment is a critical structure, and even small fragments can lead to volar carpal subluxation if not addressed. The intraoperative dorsal tangential (skyline) fluoroscopic view is essential to detect screw penetration of the dorsal cortex or articular surface. EPL rupture can occur even after nondisplaced fractures, and patients should be counseled to report sudden loss of thumb extension. DRUJ stability must always be tested after fixation because an unstable DRUJ changes the management algorithm. Plate placement distal to the watershed line increases the risk of flexor tendon irritation, so the plate should be kept proximal to this landmark.

References

• Costa ML, et al. (DRAFFT2 Investigators). Surgery vs cast for displaced fractures of the distal radius in adults. JAMA. 2023;329(16):1351-1360.
• Lawson A, et al. (CROSSFIRE Trial). Volar locking plate versus cast immobilization for distal radius fractures. JAMA. 2023;329(18):1563-1572.
• Meinberg EG, et al. AO/OTA fracture and dislocation classification compendium — 2018. J Orthop Trauma. 2018;32 Suppl 1.
• Soong M, et al. Volar locking plate implant prominence and flexor tendon rupture. J Bone Joint Surg Am. 2011;93(4):328-335.
• Orbay JL, Fernandez DL. Volar fixation for dorsally displaced fractures of the distal radius. J Hand Surg Am. 2002;27(2):205-215.

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