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.

Geometric variations of acetabular component design and its effect on radiographic osseointegration.

The Reflection uncemented acetabular component (Smith & Nephew, Memphis, Tenn) for total hip arthroplasty is available in 2 geometric variants. The first has a completely hemispherical design; the second has a peripheral rim expansion designed to increase initial press fit and aid osseointegration. The clinical and radiologic outcomes of 527 consecutive primary total hip arthroplasties were reviewed to investigate the differences in component design. Of the components, 95.6% survived at 96 months with revision for aseptic loosening as the end point, with no significant difference between the 2 component designs. Eighty percent of hemispherical and 57% of peripherally expanded components were considered completely osseointegrated at final radiologic review. The midterm radiologic outcome of peripherally expanded acetabular components is inferior to that of a completely hemispherical design.

Computer navigation in the reduction and fixation of femoral shaft fractures: a randomized control study.

OBJECTIVES: We investigated the accuracy of reduction of intramedullary nailed femoral shaft fractures in human cadavers, comparing conventional and computer navigation techniques. METHODS: Twenty femoral shaft fractures were created in human cadavers, with segmental defects ranging from 9 to 53 mm in length (Winquist 3-4, AO 32C2). All fractures were fixed with antegrade 9 mm diameter femoral nails on a radiolucent operating table. Five fractures ("Fluoro" group) were fixed with conventional techniques and fifteen fractures ("Nav 1" and "Nav 2" groups) with computer navigation, using fluoroscopic images of the normal femur to correct for length and rotation. Postoperative CT scans compared femoral length and rotation with the normal leg. RESULTS: Mean leg length discrepancy in the computer navigation groups was smaller, namely, 3.6 mm for Nav 1 (95% CI: 1.072 to 6.128) and 4.2 mm for Nav 2 (95% CI: 0.63 to 7.75) vs. 9.8 mm for Fluoro (95% CI: 6.225 to 13.37) (p<0.023). Mean rotational discrepancies were 8.7° for Nav 1 (95% CI: 4.282 to 13.12) and 5.6° for Nav 2 (95% CI: -0.65 to 11.85) vs. 9.0° for Fluoro (95% CI: 2.752 to 15.25) (p=0.650). CONCLUSIONS: Computer navigation significantly improves the accuracy of femoral shaft fracture fixation with regard to leg length, but not rotational deformity.

A biomechanical comparison of two triple-screw methods for femoral neck fracture fixation in a synthetic bone model.

BACKGROUND: Fixation of femoral neck fractures is often accomplished by several screws inserted along the neck axis. Alignment and number of screws remain at the discretion of the surgeon. Two fracture repair methods were compared. METHODS: Sixteen large, left, adult, synthetic femurs, known as Third Generation Composite Femurs (Pacific Research Laboratories, Vashon, WA), were osteotomized with a transverse cut perpendicular to the neck axis. Fractures were reduced and repaired using method 1 (n = 8) or method 2 (n = 8) cannulated cancellous screw methods. Method 1 screws were inserted parallel in an upside-down triangle configuration and abutted against the cortical walls inferiorly, anteriorly, and posteriorly. Method 2 screws were placed adjacent to one another as often done clinically. Femoral shafts were positioned in a nonclinical vertical orientation to obtain conservative "lower bound" measurements. Specimens were tested for torsional and axial stiffness using subclinical loads followed by axial failure tests. RESULTS: Method 1 showed statistically higher values compared with method 2 for torsional stiffness (9.9 vs. 7.9 Nm/deg, method 1/method 2 ratio = 1.25, p = 0.018), axial stiffness (1469.0 vs. 1278.1 N/mm, method 1/method 2 ratio = 1.15, p = 0.023), and axial failure load (3493.5 vs. 2863.5 N, method 1/method 2 ratio = 1.22, p = 0.000). However, there were no statistical differences in axial failure displacement (10.9 vs. 16.9 mm, method 1/method 2 ratio = 0.64, p = 0.101) or axial failure energy (29.9 vs. 35.9 J, method 1/method 2 ratio = 0.83, p = 0.453). For both methods, femoral heads move distally while screw shafts cut through the spongy cancellous matrix of the femoral neck in knife-like fashion. CONCLUSIONS: Method 1 was more mechanically stable than method 2 in femoral neck fracture fixation as detected by three of five biomechanical measurements and equivalent to method 2 for two of five biomechanical measurements.

Biology versus mechanics in the treatment of distal radial fractures.

This manuscript aims to address the biologic and mechanical principles underlying the treatment of displaced distal radial fractures. A literature review was performed using Ovid Medline 1950-2007 and all evidence-based medicine reviews. A recent Cochrane review and a meta-analysis were reference searched. All randomized trials comparing internal and external fixation and all articles related to volar locked plates were searched for. Based on current literature, there is no evidence to support internal fixation with plates over minimally invasive fixation with external fixation. Recent results using volar locked plate fixation are promising, but comparative studies with either conventional plating or external fixation are lacking.