Does the location of short-arm cast univalve effect pressure of the three-point mould?

The Pressure Is on: Dorsal Versus Volar Univalves for Long-arm Casts

BACKGROUND

Fiberglass casts are routinely used to treat fractures of the upper extremity. When posttraumatic edema is anticipated, the cast is often valved to hopefully prevent potential complications, especially compartment syndrome. Due to volar forearm compartments being most involved with upper extremity compartment syndrome, volar skin surface pressures (SSP) are paramount. Despite past literature showing that a univalved cast will retain a 3-point mold better than a bivalved cast, there is a paucity of information analyzing the effects of univalving on the volar SSP. We hypothesized that a volar univalve technique would have a greater decrease in the volar skin surface pressures compared to a dorsal univalve in long-arm casts.

METHODS

A 100-mL saline bag attached to an arterial line pressure transducer was placed between a long-arm cast and the skin along the volar forearm of a single adult volunteer. Fourteen casts were applied by a single certified orthopaedic technologist with 30 years of experience and assigned randomly to receive either a volar or dorsal univalve. We calculated the change in volar forearm SSP on each cast in 4 stages: isolated univalve, with a 3-mm cast spacer, with a 6-mm spacer, and with bivalve. Statistical analysis of the data was performed using a Mann-Whitney U test.

RESULTS

When comparing volar versus dorsal univalve, volar SSP significantly dropped by a mean of 32.00 versus 20.43 mm Hg ( P value=0.001) in stage I, 45.14 versus 38.00 mm Hg in stage II ( P value=0.026), and 56.53 versus 49 mm Hg in stage III ( P value=0.001). There was no significant difference between the 2 groups after a bivalve was performed at stage IV ( P value=0.318).

CONCLUSION

Our findings support that a volar univalve with a 6-mm spacer will provide the greatest reduction of skin surface pressure while theoretically maintaining the cast's structural integrity and biomechanical properties when compared to a bivalved cast.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Effect of childhood overweight on distal metaphyseal radius fractures treated by closed reduction

BACKGROUND

The medical community has recognized overweight as an epidemic negatively affecting a large proportion of the pediatric population, but few studies have been performed to investigate the relationship between overweight and failure of conservative treatment for distal radius fractures (DRFs). This study was performed to investigate the effect of overweight on the outcome of conservative treatment for DRFs in children.

METHODS

We performed a retrospective study of children with closed displaced distal metaphyseal radius fractures in our hospital from January 2015 to May 2020. Closed reduction was initially performed; if closed reduction failed, surgical treatment was performed. Patients were followed up regularly after treatment, and redisplacement was diagnosed on the basis of imaging findings. Potential risk factors for redisplacement were collected and analyzed.

RESULTS

In total, 142 children were included in this study. The final reduction procedure failed in 21 patients, all of whom finally underwent surgical treatment. The incidences of failed final reduction and fair reduction were significantly higher in the overweight/obesity group than in the normal-weight group (P = 0.046 and P = 0.041, respectively). During follow-up, 32 (26.4%) patients developed redisplacement after closed reduction and cast immobilization. The three risk factors associated with the incidence of redisplacement were overweight/obesity [odds ratio (OR), 2.149; 95% confidence interval (CI), 1.320-3.498], an associated ulnar fracture (OR, 2.127; 95% CI, 1.169-3.870), and a three-point index of ≥ 0.40 (OR, 3.272; 95% CI, 1.975-5.421).

CONCLUSIONS

Overweight increases the risk of reduction failure and decreases the reduction effect. Overweight children were two times more likely to develop redisplacement than normal-weight children in the present study. Thus, overweight children may benefit from stricter clinical follow-up and perhaps a lower threshold for surgical intervention.