The management of distal radius fractures involves recognition of multiple factors, which influence the ultimate outcomes for the restoration of a functional and pain-free wrist. Although the radiographic classification of distal radius fractures may determine the optimal method for fracture reduction and stabilization, a global assessment of the patient and the upper extremity injury should be completed. Recently, the development of fixed angled plating systems has influenced the treatment of distal radius fractures; however, it is imperative to maintain an awareness of the use of various methods for distal radius fracture stabilization because individual patient considerations should continue to guide treatment.

To individualize the treatment of distal radius fractures, the surgeon must consider the anatomy of the injury. Radiographic assessment of the fracture can be supplemented with additional imaging modalities, such as a computed tomography (CT) scan. The fracture anatomy (extra-articular or intra-articular, involving the radiocarpal or distal radioulnar joints, the extent of volar or dorsal fracture comminution, and whether there is associated carpal subluxation) dictates the form of fixation to be considered. In determining treatment, also consider concomitant carpal or soft-tissue injuries about the wrist or other associated extremity injuries as well as associated acute conditions (e.g., compartment syndrome, neurovascular compromise, open or contaminated injury, or fractures or dislocations of the hand, forearm, elbow, and humerus), which may necessitate a different type of fracture fixation than that of an isolated distal radius fracture. Finally, consider the patient’s physiologic age, occupational and activity demands and expectations, and hand dominance when determining a treatment strategy.

Displaced distal radius fractures with unacceptable alignment may be treated initially with closed reduction techniques. If a satisfactory reduction can be obtained, but not maintained by closed manipulation and splinting, then some form of fracture fixation is warranted and the use of an external fixator with or without supplemental Kirschner wire (K-wire) fixation may be considered. Supplemental methods of fracture reduction and stabilization may be of benefit in certain fracture patterns. Such methods include the use of percutaneous or open pins or screws (1,2,3,4,5), bone graft or bone graft substitutes (6,7), and internal fixation with concurrent external fixator application.

If a satisfactory reduction cannot be obtained by closed methods, external fixation alone is unlikely to be sufficient for definitive fracture stabilization. Consequently, the use of external fixation may be inadequate on its own for certain unstable fracture patterns. Placement of external fixator pins at a site of active infection or gross contamination may be contraindicated. Although temporary stabilization of an unstable distal radius fracture may be necessary for open injuries, the external fixator may require revision to a method of internal fixation when performing definitive soft-tissue reconstruction. Relative contraindications to the use of an external fixator may include patients with psychiatric conditions for which the presence of the fixator may be distressful.

External fixators consist of pins or wires inserted into bone and stabilized by a connecting frame or rods. Several types of fixators are available, ranging from simple uniplanar devices to multiplanar
and modular fixators. Bridging and nonbridging fixation has been described, referring to whether the fixator spans the wrist joint. Nonbridging fixators do not cross the radiocarpal joint and thus allow for radiocarpal motion, whereas bridging fixators cross the radiocarpal joint and often enhance the stability of the construct, particularly for those cases of extensive fracture comminution or osteoporotic bone (8,9,10,11,12,13,14).

Understanding the biomechanics of external fixation is imperative when considering patient selection and the type and design of fixator construct. Rigidity of the external fixator will influence the biology of fracture healing (15,16,17). More rigid constructs facilitate primary bone healing via creeping substitution; however, less rigid constructs permits greater motion at the fracture site and results in bone healing through secondary intention and callus formation. Bone healing rates may differ between groups because primary healing occurs more slowly than secondary healing (17). Less rigid constructs permit increased forces at the bone–pin interface and can lead to a higher risk of pin loosening or pin-tract infection.

The rigidity or strength of the fixator construct is influenced by several factors. Variables include: (a) size, material, location, and number of pins; (b) dimensionality of the construct (uniplanar, multi-planar, or circular); (c) frame location with regard to bone and plane of fracture displacement; and (d) use of supplemental fixation such as K-wires or bone graft.

Pin size (core diameter) affects fixations strength. Larger diameter pins are more rigid, although they carry the risk of an increased stress-riser at their insertion site. Most pins are made of either stainless steel or titanium alloy; stainless steel has superior strength and stiffness when compared with titanium. Pins are most vulnerable to failure at the near cortex–pin interface. Additionally, the shank (unthreaded) portion of the pin is the least resistant to fatigue failure, especially at the shank–thread junction. Thus, pins used with longer threads, conical (tapered) thread designs, and with partial threads reduce the risk of failure. One of the disadvantages of conical pin designs is that, ideally, the pin should not be pulled back because this will reduce fixation strength. Pin placement relative to the site of fracture influences the strength of the fixator construct. Increased fixator rigidity will result from pin configurations that (a) place pins close to the fracture, (b) increase space between pins, and (c) increase the number and diameter of pins (15,18,19).

The nature and dimensions of the external fixator influence frame rigidity. Multiplanar and circular external fixators are generally stronger than uniplanar models (18,20). Additionally, fixator strength is optimized when at least one bar lies in the same plane as the fracture load (18). Stacking bars and placing bars closer to the bone have been shown to improve the biomechanical strength of fixation (21,22). In general, external fixator rods and frames are made of stainless steel, carbon-fiber, or plastic-type materials. As the diameter of the rod is increased, the rigidity of the construct improves.

External fixation distraction across the wrist results in ligamentotaxis and facilitates indirect fracture reduction. Uniplanar distraction can restore length and improve fracture alignment, but may fail to restore or maintain volar tilt of the distal radius articular surface (23). Multiplanar ligamentotaxis (palmar displacement of the carpus combined with longitudinal distraction) has been demonstrated to assist in restoring the volar tilt (24). Take care not to place excessive distraction across the wrist because this may result in prolonged finger and wrist stiffness, decreased strength, poorer functional outcomes, and an increased incidence of complex regional pain syndrome (25). Clinically, the appropriate amount of distraction can be assessed by passively flexing the fingers, noting the increased resistance to motion with overdistraction. Radiographically, excessive distraction can be appreciated by comparing the radiocarpal joint distraction with that of the midcarpal joint and by assessing the appearance of the joint spaces in general (26).

A global patient assessment is imperative; the mechanism of injury and the potential for associated injuries, the patient’s medical and surgical histories, and the patient’s current medications, drug allergies, and social history should all be considered in the preoperative planning stage. Consider concomitant ipsilateral extremity injuries for incision planning, wound care, and perioperative monitoring for compartment syndrome and neurovascular compromise. Contralateral upper extremity injuries, lower extremity injuries, or both may influence the selection of a specific fracture fixation method, owing to the injured upper extremity’s need for activity in the postinjury healing period.

Physical examination of the upper extremity should include an assessment for open wounds, the status of compartmental swelling, and a thorough neurovascular and musculotendinous examination.
Documentation of this assessment is crucial, particularly for care of patients in the multitrauma setting. Radiographs are the mainstay of fracture assessment and should include routine posteroanterior, lateral, and oblique views (27). A 20-degree inclined lateral view may be helpful in assessing the articular alignment of the distal radius (28). Radiographs of the hand and elbow may be indicated, based on the clinical examination findings. Occasionally, a CT scan of the wrist may be useful in defining articular fractures and for preoperative planning (29,30

Stay updated, free articles. Join our Telegram channel

Join