Statistical and health economic analysis plan for a randomized controlled trial of surgical fixation with K-wires versus plaster casting in the treatment of dorsally displaced distal radius fractures: DRAFFT2

Radiological outcomes following surgical fixation with wires versus moulded cast for patients with a dorsally displaced fracture of the distal radius: a radiographic analysis from the DRAFFT2 trial

Aims

The primary aim of this study was to report the radiological outcomes of patients with a dorsally displaced distal radius fracture who were randomized to a moulded cast or surgical fixation with wires following manipulation and closed reduction of their fracture. The secondary aim was to correlate radiological outcomes with patient-reported outcome measures (PROMs) in the year following injury.

Methods

Participants were recruited as part of DRAFFT2, a UK multicentre clinical trial. Participants were aged 16 years or over with a dorsally displaced distal radius fracture, and were eligible for the trial if they needed a manipulation of their fracture, as recommended by their treating surgeon. Participants were randomly allocated on a 1:1 ratio to moulded cast or Kirschner wires after manipulation of the fracture in the operating theatre. Standard posteroanterior and lateral radiographs were performed in the radiology department of participating centres at the time of the patient's initial assessment in the emergency department and six weeks postoperatively. Intraoperative fluoroscopic images taken at the time of fracture reduction were also assessed.

Results

Patients treated with surgical fixation with wires had less dorsal angulation of the radius versus those treated in a moulded cast at six weeks after manipulation of the fracture; the mean difference of -4.13° was statistically significant (95% confidence interval 5.82 to -2.45). There was no evidence of a difference in radial shortening. However, there was no correlation between these radiological measurements and PROMs at any timepoint in the 12 months post-injury.

Conclusion

For patients with a dorsally displaced distal radius fracture treated with a closed manipulation, surgical fixation with wires leads to less dorsal angulation on radiographs at six weeks compared with patients treated in a moulded plaster cast alone. However, the difference in dorsal angulation was small and did not correlate with patient-reported pain and function.

Cost-utility analysis of surgical fixation with Kirschner wire versus casting after fracture of the distal radius

Aims

The aim of this study was to compare the cost-effectiveness of surgical fixation with Kirschner (K-)wire ersus moulded casting after manipulation of a fracture of the distal radius in an operating theatre setting.

Methods

An economic evaluation was conducted based on data collected from the Distal Radius Acute Fracture Fixation Trial 2 (DRAFFT2) multicentre randomized controlled trial in the UK. Resource use was collected at three, six, and 12 months post-randomization using trial case report forms and participant-completed questionnaires. Cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY) gained from an NHS and personal social services perspective. Sensitivity analyses were conducted to examine the robustness of cost-effectiveness estimates, and decision uncertainty was handled using confidence ellipses and cost-effectiveness acceptability curves.

Results

In the base case analysis, surgical fixation with K-wire was more expensive (£29.65 (95% confidence interval (CI) -94.85 to 154.15)) and generated lower QALYs (0.007 (95% CI -0.03 to 0.016)) than moulded casting, but this difference was not statistically significant. The probability of K-wire being cost-effective at a £20,000 per QALY cost-effectiveness threshold was 24%. The cost-effectiveness results remained robust in the sensitivity analyses.

Conclusion

The findings suggest that surgical fixation with K-wire is unlikely to be a cost-effective alternative to a moulded cast in adults, following manipulation of a fracture of the distal radius in a theatre setting. Cite this article: Bone Joint J 2022;104-B(11):1225–1233.

Moulded cast compared with K-wire fixation after manipulation of an acute dorsally displaced distal radius fracture: the DRAFFT 2 RCT

BACKGROUND

Patients with a displaced fracture of the distal radius are frequently offered surgical fixation. Manipulation of the fracture and moulded plaster casting is an alternative treatment that avoids metal implants, but evidence of its effectiveness is lacking.

OBJECTIVE

To compare functional outcomes, quality-of-life outcomes, complications and resource use among patients with a dorsally displaced fracture of the distal radius treated with manipulation and surgical fixation with Kirschner wires (K-wires) and those treated with manipulation and moulded cast.

DESIGN

Pragmatic, superiority, multicentre, randomised controlled trial with a health economic evaluation.

SETTING

A total of 36 orthopaedic trauma centres in the UK NHS.

PARTICIPANTS

Patients (aged ≥ 16 years) treated for an acute dorsally displaced fracture of the distal radius were potentially eligible. Patients were excluded if their injury had occurred > 2 weeks previously, if the fracture was open, if it extended > 3 cm from the radiocarpal joint or if it required open reduction, or if the participant was unable to complete questionnaires.

INTERVENTIONS

Participants were randomly assigned in theatre (1 : 1) to receive a moulded cast (i.e. the cast group) or surgical fixation with K-wires (i.e. the K-wire group) after fracture manipulation.

MAIN OUTCOME MEASURES

The primary outcome measure was the Patient-Rated Wrist Evaluation score at 12 months, analysed on an intention-to-treat basis. Health-related quality of life was recorded using the EuroQol-5 Dimensions, five-level version, and resource use was recorded from a health and personal social care perspective.

RESULTS

Between January 2017 and March 2019, 500 participants (mean age 60 years, 83% women) were randomly allocated to receive a moulded cast (n = 255) or surgical fixation with K-wire (n = 245) following a manipulation of their fracture. A total of 395 (80%) participants were included in the primary analysis at 12 months. There was no difference in the Patient-Rated Wrist Evaluation score at 1 year post randomisation [cast group: n = 200, mean score 21.2 (standard deviation 23.1); K-wire group: n = 195, mean score 20.7 (standard deviation 22.3); adjusted mean difference -0.34 (95% confidence interval -4.33 to 3.66); p = 0.87]. A total of 33 (13%) participants in the cast group required surgical fixation for loss of fracture position in the first 6 weeks, compared with one participant in the K-wire group (odds ratio 0.02, 95% confidence interval 0.001 to 0.10). The base-case cost-effectiveness analysis showed that manipulation and surgical fixation with K-wires had a higher mean cost than manipulation and a moulded cast, despite similar mean effectiveness. The use of K-wires is unlikely to be cost-effective, and sensitivity analyses found this result to be robust.

LIMITATIONS

Because the interventions were identifiable, neither patients nor clinicians could be blind to their treatment.

CONCLUSIONS

Surgical fixation with K-wires was not found to be superior to moulded casting following manipulation of a dorsally displaced fracture of the distal radius, as measured by Patient-Rated Wrist Evaluation score. However, one in eight participants treated in a moulded cast required surgery for loss of fracture reduction in the first 6 weeks. After a successful closed reduction, clinicians may consider a moulded cast as a safe and cost-effective alternative to surgical fixation with K-wires.

FUTURE WORK

Further research should focus on optimal techniques for immobilisation and manipulation of this type of fracture, including optimal analgesia, and for rehabilitation of the patient after immobilisation.

TRIAL REGISTRATION

This trial is registered as ISRCTN11980540 and UKCRN Portfolio 208830.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 11. See the NIHR Journals Library website for further project information.

Surgical fixation with K-wires versus casting in adults with fracture of distal radius: DRAFFT2 multicentre randomised clinical trial

OBJECTIVE

To assess wrist function, quality of life, and complications in adult patients with a dorsally displaced fracture of the distal radius, treated with either a moulded cast or surgical fixation with K-wires.

DESIGN

Multicentre randomised clinical superiority trial, SETTING: 36 hospitals in the UK National Health Service (NHS).

PARTICIPANTS

500 adults aged 16 or over with a dorsally displaced fracture of the distal radius, randomised after manipulation of their fracture (255 to moulded cast; 245 to surgical fixation).

INTERVENTIONS

Manipulation and moulded cast was compared with manipulation and surgical fixation with K-wires plus cast. Details of the application of the cast and the insertion of the K-wires were at the discretion of the treating surgeon, according to their normal clinical practice.

MAIN OUTCOME MEASURES

The primary outcome measure was the Patient Rated Wrist Evaluation (PRWE) score at 12 months (five questions about pain and 10 about function and disability; overall score out of 100 (best score=0 and worst score=100)). Secondary outcomes were PRWE score at three and six months, quality of life, and complications, including the need for surgery due to loss of fracture position in the first six weeks.

RESULTS

The mean age of participants was 60 years and 417 (83%) were women; 395 (79%) completed follow-up. No statistically significant difference in the PRWE score was seen at 12 months (cast group (n=200), mean 21.2 (SD 23.1); K-wire group (n=195), mean 20.7 (22.3); adjusted mean difference -0.34 (95% confidence interval -4.33 to 3.66), P=0.87). No difference was seen at earlier time points. In the cast group, 33 (13%) of participants needed surgical fixation for loss of fracture position in the first six weeks compared with one revision surgery in the K-wire group (odds ratio 0.02, 95% confidence interval 0.001 to 0.10).

CONCLUSIONS

Among patients with a dorsally displaced distal radius fracture that needed manipulation, surgical fixation with K-wires did not improve patients' wrist function at 12 months compared with a cast.

TRIAL REGISTRATION

ISRCTN registry ISRCTN11980540.