History and Physical Examination
In a patient with a distal radius fracture (DRF), the history should be directed toward ascertaining the probable amount of energy involved. A fall from 20 ft (~6 m) can be associated with a larger and more complex constellation of injuries (ie, beyond the distal fracture seen on the radiograph) than would be seen with a fall from a standing position. A history of prior fractures should be sought. A history of fragility fractures helps predict the stability of any reduction. A history of multiple high-energy fractures in a younger patient helps predict the patient's ability to comply with directions.
The median nerve is always compressed by a fall on the palmar aspect of the hand that results in a DRF, and the chart note should specifically document the quality (not just the presence or absence) of median nerve function. This should be clearly documented at the initial visit and then at each visit for the first several weeks or months.
Most therapies for DRF have implications for the median nerve. A cast or splint without a reduction may result in median nerve compromise due to pressure. A reduction, whether closed or open, involves some level of anesthesia, temporarily compromising the ability to assess the median nerve. Careful documentation of median nerve function at the first assessment is critical for planning and assessing treatment, not to mention protecting the surgeon from subsequent claims. DRFs are overrepresented in orthopedic malpractice suits.
Classification
The goals of any classification system are as follows:
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To stratify the injuries
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To guide treatment
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To facilitate discussion
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To predict outcome
Each classification system has its merits and weaknesses with respect to each goal, and often, more than one classification system is needed. (See the report How to Classify Distal Radial Fractures.)
The classification systems used most frequently for DRFs are the Frykman, Melone, AO (Arbeitsgemeinschaft für Osteosynthesefragen [Association for the Study of Osteosynthesis]), and Fernandez systems. Their key characteristics are as follows:
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The Frykman classification highlights the injury to the distal radioulnar joint (DRUJ)
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The Melone classification, based on the paper by Scheck, [7] highlights the fragmentation of the articular surface, especially the dorsoulnar corner of the distal radius
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The AO classification emphasizes the location as extra-articular, partial articular, or completely articular
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The Fernandez classification is based on the mechanism of injury, deduced from the displacement of the bone and the location of the fracture lines
A classification system that approaches the topic from another angle categorizes fracture patterns according to the three-column concept of the wrist and proposes treatment accordingly. This approach was independently developed by Medoff in 1994 (personal communication) and by Rikli and Rigazzoni. [8] The three columns are as follows:
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Lateral column (the radial half of the radius, including the radial styloid and the scaphoid facet, though Medoff differentiates these two)
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Central column (the ulnar half of the radius, including the lunate facet)
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Medial column (the ulna, the triangular fibrocartilage [TFC], and the DRUJ)
Each column is considered separately as to its need for reduction and stabilization. It should be noted that this conceptual approach does not exclude any other approaches; rather, it is complementary to them.
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Posteroanterior radiograph demonstrating typical features of common distal radius fracture: loss of radial length, loss of radial tilt, and comminution at fracture line.
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Lateral radiograph demonstrating other common features (also see preceding image) of distal radial fracture: loss of normal volar tilt and documentation that comminution is primarily in dorsal metaphysis.
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Volar surface of radius.
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Dorsal surface of radius.
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Radial surface of radius.
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Ulnar surface of radius.
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Distal surface of radius.
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Posteroanterior radiograph of normal wrist.
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Lateral radiograph of normal wrist.
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Volar anatomic landmarks important for volar approach. Region marked "pronator fossa" is covered by pronator quadratus (PQ) . It extends distally to PQ line, marked in blue. Watershed line (WS) marks highest crest (most volarly projecting surface) of radius. Red X marks volar radial tuberosity, which lies just off PQ. It is usually not dissected and therefore usually not seen, but it is easily palpable clinically. VR = volar radial ridge.
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Percutaneous pinning with Clancey technique, posteroanterior view.
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Percutaneous pinning with Clancey technique, lateral view.
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Dorsal plate fixation using Synthes Pi plate, posteroanterior view.
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Dorsal plate fixation using Synthes Pi plate, lateral view.
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Three-column concept of wrist anatomy.
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Standard (bridging) external fixation using Orthofix RadioLucent external fixator.
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Nonbridging external fixation using Howmedica Mini-Hoffman external fixator.
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Volar fixed-angle plate using Orthofix Contours VPS plate, posteroanterior view. This is facet posteroanterior view, which is tilted at same angle as tilt of distal articular surface, thus allowing assessment of intra-articular vs extra-articular placement of screws. Note that distal screws engage both radial styloid fragment and dorsal ulnar fragment.
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Volar fixed-angle plate using Orthofix Contours VPS, lateral view. This is not facet lateral view, and distal articular surface is not seen tangentially. Consequently, some screws appear to be intra-articular; however, posteroanterior view demonstrates that they are not. Note also that distal screws do not past-point dorsal cortex but instead stop few millimeters short of dorsal cortex. Because of difficulty of evaluating screw length, even with fluoroscopy, screws should stop 2-4 mm short of dorsal cortex.
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Posteroanterior view of fragment-specific fixation. Hardware to radial side is radial pin plate. Pins hold fragment in place, and pin plate gives greater stabilization to pins. Hardware to ulnar side is dorsal pin plate (also see image below), which holds dorsal ulnar corner in place. Image courtesy of Rob Medoff, MD.
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Lateral view of fragment-specific fixation. Hardware on volar side (known as wireform) is supporting subchondral bone. Hardware in center of image is pin plate along radial border of radial styloid and serves to hold large radial styloid fragment in place. Small pin plate is situated along dorsal surface. Image courtesy of Rob Medoff, MD.
