Radiographic results after plaster cast fixation for 10 days versus 1 month in reduced distal radius fractures: a prospective randomised study

The contribution of lower-mineralized tissue to the healing of distal radius fractures assessed using HR-pQCT

High-resolution peripheral quantitative CT (HR-pQCT) enables quantitative assessment of distal radius fracture healing. In previous studies, lower-mineralized tissue formation was observed on HR-pQCT scans, starting early during healing, but the contribution of this tissue to the stiffness of distal radius fractures is unknown. Therefore, the aim of this study was to investigate the contribution of lower-mineralized tissue to the stiffness of fractured distal radii during the first twelve weeks of healing. We did so by combining the results from two series of micro-finite element (μFE-) models obtained using different density thresholds for bone segmentation. Forty-five postmenopausal women with a conservatively-treated distal radius fracture had HR-pQCT scans of their fractured radius at baseline (BL; 1-2 weeks post-fracture), 3-4 weeks, 6-8 weeks, and 12 weeks post-fracture. Compression stiffness (S) was computed using two series of μFE-models from the scans: one series (Msingle) included only higher-mineralized tissue (>320 mg HA/cm3), and one series (Mdual) differentiated between lower-mineralized tissue (200-320 mg HA/cm3) and higher-mineralized tissue. μFE-elements were assigned a Young's Modulus of 10 GPa (higher-mineralized tissue) or 5 GPa (lower-mineralized tissue), and an axial compression test to 1 % strain was simulated. The contribution of the lower-mineralized tissue to S was quantified as the ratio Sdual/Ssingle. Changes during healing were quantified using linear mixed effects models and expressed as estimated marginal means (EMMs) with 95 %-confidence intervals (95 %-CI). Median time to cast removal was 5.0 (IQR: 1.1) weeks. Sdual and Ssingle gradually increased during healing to a significantly higher value than BL at 12 weeks post-fracture (both p < 0.0001). In contrast, Sdual/Ssingle was significantly higher than BL at 3-4 weeks post-fracture (p = 0.0010), remained significantly higher at 6-8 weeks post-fracture (p < 0.0001), and then decreased to BL-values at the 12-week visit. EMMs ranged between 1.05 (95 %-CI: 1.04-1.06) and 1.08 (95 %-CI: 1.07-1.10). To conclude, combining stiffness results from two series of μFE-models obtained using single- and dual-threshold segmentation enables quantification of the contribution of lower-mineralized tissue to the stiffness of distal radius fractures during healing. This contribution is minor but changes significantly around the time of cast removal. Its course and timing during healing may be clinically relevant. Quantification of the contribution of lower-mineralized tissue to stiffness gives a more complete impression of strength recovery post-fracture than the evaluation of stiffness using a single series of μFE-models.

Cast-OFF Trial: One Versus 4 to 5 Weeks of Plaster Cast Immobilization for Nonreduced Distal Radius Fractures: A Randomized Clinical Feasibility Trial

BACKGROUND

Distal radius fracture is a common fracture of which the incidence appears to be increasing worldwide. This pilot study investigated whether 1 week of plaster cast is feasible for nonreduced (stable fractures including nondisplaced and displaced fractures) distal radius fractures.

METHODS

The study was a multicenter randomized clinical feasibility trial including patients from regional acute care providers. Patients with a nonreduced distal radius fracture were included in the study. Nonreduced fractures meant intra-articular or extra-articular fractures and including nondisplaced and minimal displaced fractures (dorsal angulation less than 5°-10°, maximum radial shortening of 2 mm, and maximum radial shift of 2 mm) not needing a reduction. Forty Patients were included and randomized. After 1 week of plaster cast, patients were randomized to 1 of the 2 treatment groups: plaster cast removed (intervention group) versus 4 to 5 weeks of plaster cast (control group).

RESULTS

The analysis shows no significant differences between the 2 groups in having less pain, better function after 6 weeks, and better overall patient satisfaction. No difference was shown in secondary displacement between the 2 groups (control 1 vs intervention 0).

CONCLUSION

One week of plaster cast treatment for nonreduced distal radius fracture is feasible, preferred by patients, with at least the same functional outcome and pain scores.

LEVEL OF EVIDENCE

According to the Oxford 2011 level of evidence, the level of evidence of this study is 2.

Comparison of two different ways to apply a circular plaster cast for distal radius fractures: biomechanical study

INTRODUCTION

Although conservative treatment with circular plaster cast is the most commonly used method in distal radius fractures, the best method to apply it remains unclear.

MATERIAL AND METHODS

Two frequently used configurations of circular plaster cast (with and without a splint) were selected to compare. Group C was applied only with circular bandages (three units) and group S with a splint (one unit) and over it, a circular bandage (two units). Both configurations had the same weight. Five prototypes of each group were built and mechanically tested. Three-point flexural tensile strength and maximum deflection were measured and compared.

RESULTS

The previously splinted prototypes (group S) obtained higher tensile strength with the same weight (p < 0.05).

DISCUSSION

No other study regarding strength and configuration of circular casts for distal radius fractures immobilization has been previously published, leading to a high variability in construction among orthopedic surgeons. Data confirms that applying a splint before circular bandage offers more mechanical resistance to the cast in flexion, with the same weight.

CONCLUSION

Applying a splint before circular bandage for plaster casts used for distal radius fractures make them more resistant to usual forces.

Clinical Outcome after Plaster Cast Fixation for 10 Days Versus 1 Month in Reduced Distal Radius Fractures: A Prospective Randomized Study

Introduction:

This study aimed to evaluate clinical results after plaster cast fixation for 10 days versus 1 month of moderately displaced and reduced distal radius fractures.

Material and Methods:

In a prospective randomized study, 109 patients with moderately displaced and conservatively treated distal radius fractures (age ≥50 years) were randomized 10 days after reduction to either removal of the plaster cast and immediate mobilization (active group) or to continued plaster cast fixation for another 3 weeks (control group). Grip strength, pincer strength, range of motion, and pain were assessed at 1, 4, and 12 months after reduction. Clinical outcome was evaluated using three functional assessment scores at 12 months.

Results:

Treatment failed in 3/54 (6%) patients in the active group. One of these patients had the plaster cast reinstituted because of feelings of instability. The fractures in the other two patients displaced severely after mobilization and were therefore treated surgically. For the remaining 51 patients in the active group, the range of wrist motion was slightly better at 1 month compared with the controls, but there were no differences in grip or pincer strength or pain at the 1-month follow-up. There were no differences between the active and control group in any outcome at 4 or 12 months, including functional assessment scores at 12 months.

Conclusion:

Treatment with mobilization 10 days after reduction of moderately displaced distal radius fractures resulted in a few treatment failures compared with none among controls. The only functional benefit for the remaining patients was a small and transient increase in range of motion at the 1-month follow-up. Plaster cast removal 10 days after reduction in moderately displaced distal radius fractures is therefore not recommended.