Risk Factors for Distal Radius Fractures
Mechanisms of Injury
Signs and Symptoms
Prediction of Instability
Prediction of Function
Indications for Treatment
Author’s Preferred Treatment
Author’s Preferred Method of Treatment for Unstable Extra or Minimal Articular
Fractures of the Distal Ulna
Complex Regional Pain Syndrome (CRPS)
Controversies and Future Directions
Undisplaced or minimally displaced fractures are treated without manipulative reduction. I define minimal displacement as fractures without carpal malalignment, less than 10 degrees of dorsal tilt and less than 3 mm of ulnar variance. Undisplaced or minimally displaced fractures are treated in either a forearm cast or removable splint with radiologic review at 1 week. If the fracture is undisplaced, the risk of metaphyseal instability is calculated at less than 70%, and the position has not changed, the patient is reviewed at 3 weeks and if x-rays are satisfactory the wrist is mobilized.
For minimally displaced fractures, the risk of instability is calculated and if this is less than 70%, review is undertaken at 1 week. I recommend further radiologic review at 2 weeks and immobilization in a forearm cast for a total of 4 weeks from injury. In a low-demand patient who is not considered suitable for fracture fixation, immobilization is required only for pain relief. Radiologic review is only required at cast or splint removal to confirm union.
Displaced distal radius fractures are carefully assessed for risk of instability and articular malalignment. If there is articular displacement of more than 2 mm gap or step or if the risk of metaphyseal instability is greater than 70%, I recommend early operative reduction and stabilization. Calculation of the instability risk234 is easily performed online (www.trauma.co.uk/wristcalc).
If there is acceptable articular alignment and the risk of instability is less than 70%, manual manipulative reduction is performed under regional anesthesia. Agee’s technique is used if necessary to restore volar tilt (Fig. 32-13). If an acceptable reduction (Table 32-4) is obtained then the wrist is immobilized in the neutral position in a forearm back slab. If the reduction maneuvers fail then surgery is planned. Reduced fractures are reviewed at 1, 2, and 3 weeks with the back slab being completed or replaced with a full forearm cast at 1 week. Cast immobilization is maintained for 4 to 6 weeks depending on the evidence of radiologic healing and the patient’s symptoms.
In low-demand patients with unstable extra- or minimal articular distal radius fractures, I do not recommend manipulative or operative treatment. The main effect of malunion of the distal radius is to reduce the individual’s ability to undertake the activities of daily living which require strength in the hand and wrist. The frailer the patient, the less likely it is they will need such activities on a daily basis, which I believe explains the results of studies which show limited or no evidence of an advantage to frailer patients in restoration of normal anatomy by any means.16,92,250
I therefore do not undertake any intervention in this patient group including manipulation. The deformity should be accepted with appropriate patient counseling and a plaster cast applied until the patient is comfortable mobilizing the wrist.
In the fitter, less dependent patients, my treatment of choice is nonbridging external fixation where there is space for pins in the distal fragment and when it can be predicted that the fracture is reducible by closed means. Augmentation with this technique is not required. I believe that the radiologic and functional outcomes of nonbridging external fixation and volar locked plating are similar in most cases but when complications are encountered, those associated with nonbridging external fixation are minor (usually minor pin track infection), do not result in reoperation, and do not affect the final outcome. In contrast, the complications associated with volar locked plating are usually major, result in a higher reoperation rate, and may affect the final outcome.
The external fixator is retained for 5 to 6 weeks and the patient is encouraged to mobilize the wrist and hand during this period. Removal is achieved in the outpatient setting and does not require a further anesthetic. Physiotherapy is rarely required.
Where the fracture is likely to be irreducible closed, usually because of marked bayoneting of the volar cortex or because there has been a delay in diagnosis and there is a nascent malunion, then I recommend open reduction and locked volar plating, provided there is room for screws in the distal fragment. It is important to counsel the patient about the risk of complications such as tendon rupture, fracture collapse, and the need for plate removal. If possible I use the lift technique (Fig. 32-21) to ensure restoration of the volar tilt. It is essential to ensure correct placement of the plate proximal to the watershed and to ensure that screws do not penetrate the dorsal cortex. If there is a large metaphyseal defect with a risk of fracture collapse, I augment the fixation with a bone substitute. Postoperatively, the wrist is placed in a removable splint for 10 days to 2 weeks after which the patient is advised to mobilize within limits of their comfort.
Where there is no space for pins or screws in the distal fragment, I use bridging external fixation augmented with percutaneous pins, one running diagonally from the radial styloid and extending through the cortex of the proximal radius and one from dorsal to volar in the midline. The fixator and pins are retained for 5 to 6 weeks when both are removed. I usually bury the percutaneous pins below the skin to reduce the possibility of pin track infection, so local anesthetic is required for their removal.