Fractures of the distal radius are common injuries and their management depends on the alignment of the bone fragments. When the fragments are not displaced, the fracture may be treated nonoperatively. In cases where the bone fragments have moved out of their normal alignment, the fracture will usually require a manipulation of the fragments to restore the normal anatomy. Following manipulation, the application of surgical implants (such as wires, plates, and screws) or a molded plaster cast is needed to support the healing bone fragments, preventing them from falling back out of normal alignment. However, the effect of wire implants on the functional outcome compared to a cast remains unclear. The authors of a Cochrane review published in 2020 were unable to draw a conclusion on wrist function comparing K-wire fixation with plaster cast after manipulation, based on 11 randomized or quasi-randomized trials judged to be at high risk of bias. The recently published DRAFFT2 randomized trial conducted in the United Kingdom aimed at investigating wrist function in a large number of patients using validated patient-reported outcomes.
DRAFFT2 enrolled 504 patients 16 years and older with a dorsally displaced distal radius fracture that achieved adequate closed reduction after manipulation. Patients were randomized to receive surgical fixation and a cast or a molded cast only. Surgical fixation included the application of K-wires passing through the skin over the back of the wrist and directly into the bone. Details on the size and number of wires, insertion technique and configuration of the wires were at the discretion of the treating surgeons. In addition, both groups received standardized written physiotherapy advice. After removing four patients due to randomization errors, the trial included 500 patients (mean age 60), mostly female (83 percent). Wrist function was assessed using the Patient Rated Wrist Evaluation (PRWE) questionnaire. Score on PRWE ranges from zero to 100 points, with a higher score indicating more disability and with a six-point difference considered clinically important. The mean PRWE score before the intervention was 81.9 points in the surgical fixation group and 84.3 points in the molded cast group.
Twelve months after the intervention, 395 patients (78.3 percent) were assessed and were included in the analysis. Although both groups exhibited an improvement in PRWE scores compared with their scores at baseline, there was no significant difference between the patients treated with surgical fixation and a cast and those receiving a molded cast only (mean PRWE score 20.7 points vs. 21.2 points, p = 0.87). However, surgical fixation significantly decreased the risk of having a surgery due to a loss of fracture reduction within six weeks after the intervention, compared with a molded cast (surgery in 0.4% vs. 13%, p < 0.001). Health-related quality of life scores were similar in both groups, whereas complications were rare and included a complex regional pain syndrome (3% vs. 2%, p = 0.55) and deep venous thrombosis or pulmonary embolism (0.4% in both groups).
This trial did not find a significant difference in wrist function comparing K-wire implants with a molded cast for the support of the healing bones, but it indicated that K-wire implants may offer a benefit by reducing the need of a surgery secondary to a loss of fracture reduction. Our biggest problem with the study is the high loss to follow up (21.7 percent), the handling of missing data, and how the data were analyzed. While the authors call the analysis intention-to-treat (ITT), it’s not. You can’t even call it a modified ITT because they excluded patients who died, withdrew, or were lost to follow-up. This information can only be found by looking at data in the figures and tables, making this a cautionary tale of trusting the prose and table titles regarding the type of analysis that was done. All in all, while surgery for all (by way of K-wires) may reduce the need for more involved surgery for some later, the functional results appear to be equivalent between K-wires and molded casting.
For more information, see the topic Distal Radius Fractures in DynaMed®.
