Distal Radius Fractures: A Comprehensive Explanation From Anatomy To Surgery

Distal radius fractures account for 75% of forearm fractures and are particularly common in the clinic. In this article, we have compiled a list of anatomy, classification, treatment strategies, and surgical approaches to distal radius fractures for your reference.

Summarize

Fractures of the distal radius are part of wrist fractures. The “three-column theory” can better explain the pathological mechanism of wrist fractures, in which the radial column, consisting of the radial tuberosity and navicular fossa, is important for maintaining the stability of the wrist joint.

All distal radius fractures, with the exception of avulsion fractures of the dorsal margin of the radius, are in fact caused by overextension violence. The hand is positioned differently when acted upon by external forces, and the effects of the external forces are different.

1.Flexion violence can result in dorsally displaced intra- or extra-articular fractures in low-energy injuries such as falls.

2.Shear stress can result in partial displacement of the articular surfaces on the palmar side thus leading to instability.

3.In high-energy injuries, compression violence predominates and excessive axial loading leads to compression of the articular surface bone.

4.The primary mechanism of fracture dislocation is an avulsion injury where the avulsed bone mass is usually the bony attachment point of a ligament.

Radiologic anatomy of the distal radius

1.Anteroposterior films (radial height, ulnar deviation, ulnar varus)

2. Lateral films (palmar inclination)

Fernandez Classification

Type I Metaphyseal flexion fracture

Type II Articular and Shear Fracture

Type III Compression Fracture of Articular Surface

Type IV avulsion fracture of the radial wrist, dislocation

Type V Mixed Fractures (High Energy Avulsion Fractures)

Indications For Surgery

Most distal radius fractures are treated with braking after closed reduction, unfortunately many of these fractures will be displaced or the reduction will not be acceptable with a poor outcome.

Five destabilizing factors were identified by LaFontaine et al:

① Initial dorsal angulation > 20° (palmar tilt);

② Comminuted fracture of the dorsal epiphysis;

③ fracture in the joint;

④ Associated ulnar fracture;

⑤ Patient's age > 60 years.

There are no definitive standards or guidelines to guide treatment, and treatment plans are made taking into account a large number of factors, including initial injury characteristics, calibration after repositioning, patient age, bone quality, patient requirements, and desired outcomes.

For closed reduction of fractures with suspected stability, then close follow-up is recommended. It is important to note that if a series of x-rays after reduction suggest instability or displacement, then a change in treatment may be necessary. If the fracture is potentially unstable, then radiographs should be taken and evaluated until the fracture has healed and stabilized.

Conservative Treatment

Stable fractures can be successfully closed-displaced and treated with braking, initially with splinting and later with a tubular cast, with weekly radiographs up to 3 weeks.

If significant changes in radial length, palmar inclination, or ulnar deviation occur, surgical treatment should be considered.

In frail and low-demand patients, closed treatment is often appropriate, even when surgery is indicated.

Closed reset percutaneous needle fixation

Closed reduction followed by percutaneous pinning and fixation is useful in distal radius fractures with metaphyseal instability or simple intra-articular fractures.

The first step is anatomical repositioning, then stabilization is provided with gram pins. Usually the first pin is passed from the radial styloid to the radial metaphysis medial to the diaphysis.

A minimum of 2 pins are used to provide adequate stable repositioning in the orthogonal and lateral positions, and the lunate facet can be pinned if desired.

Intrafracture pinning (Kapanji technique) provides dorsal support. Postoperative immobilization in a splint is applied for 2 weeks to control rotation and minimize pin irritation, after which it can be replaced with a soft forearm cast.

Closed-replacement external fixation bracket fixation

External fixation braces are useful for initial or adjunctive treatment in specific distal radius fractures.

The external fixator neutralizes the axial stresses acting on the distal radius during contraction of the forearm muscle groups. Fixation may or may not be across the wrist, or additional fixation may be added.

Parallel traction does not fully restore palmar inclination, but a neutral position is acceptable. Postoperatively, the wrist is braced in a tubular cast in a rotated posterior position for 10 days until the pain and edema subside.

Plate fixation with incision and repositioning

1、Dorsal plate internal fixation of distal radius fracture

A straight incision is made along the Lister's node, with the distal end crossing the radial carpal joint line and ending 1 cm proximal to the base of the second metacarpal wrist joint. The proximal end extends along the radial stem for 3 to 4 cm, exposing the middle column through the base of the third extensor interval.

2、Palm plate internal fixation of distal radius fracture

A longitudinal incision is made along the radial carpal flexor tendon, with the bunion flexor tendon located on the deep surface of the radial carpal flexor tendon, which is retracted ulnarly to expose the anterior rotator ani muscle, and the anterior rotator ani muscle is severed at the beginning of the radial side and retracted ulnarly to expose the distal end of the radius.

Case ①

Case ②

Case ③

3. Traction plate fixation of distal radius fracture

- A 4-cm longitudinal incision is made dorsal to the third metacarpal stem, and the extensor tendon of the middle finger is contracted to expose the third metacarpal;

- A second 4-cm incision is made at least 4 cm dorsal to the comminuted radius;

- A third 2-cm dorsal incision is made at the Lister's node to expose the extensor hallucis longus tendon.

From the distal incision, the traction plate is inserted proximally along the plane between the extensor tendon (fourth dorsal compartment), the joint capsule and the periosteum. The extensor tendon can be moved if necessary.

4. Individualized fixation of comminuted fractures of the distal radius based on the TriMed system