Aim

The purpose of this study was to investigate the effects of plaster/splint immobilisation of the knee/ankle on driving performance in healthy individuals.

The purpose of this study was to investigate the effects of right leg restriction at the knee, ankle or both, on a driver’s braking times. Previous studies have not investigated the effects of knee restriction on braking performance. A total of 23 healthy drivers performed a series of emergency braking tests in a driving simulator in either an above-knee plaster cast, a below-knee cast, or in a knee brace with an increasing range of restriction. The study showed that total braking reaction time was significantly longer when wearing an above-knee plaster cast, a below-knee plaster cast or a knee brace fixed at 0°, compared with braking normally (p < 0.001). Increases in the time taken to move the foot from the accelerator to the brake accounted for some of the increase in the total braking reaction time. Unexpectedly, thinking time also increased with the level of restriction (p < 0.001). The increase in braking time with an above-knee plaster cast in this study would increase the stopping distance at 30 miles per hour by almost 3 m.

These results suggest that all patients wearing any lower-limb plaster cast or knee brace are significantly impaired in their ability to perform an emergency stop. We suggest changes to the legislation to prevent patients from driving with lower-limb plaster casts or knee braces.

Methods: To participate in this study with a follow-up of 2 years the children with osteogenesis imperfecta (OI) had at least a restricted level of ambulation according to the criteria of Bleck and no history of prior bisphospho-nate use. Primary outcome measurements were BMD (L1-L4 and calcaneus), functional outcome (Bleck, Pediatric Disability Inventory (PEDI) and muscle strength) and quality of life (self-perception profile for children by Harter (CBSK)). Additional outcomes were sitting height, vertebral height (mean L1-L4) and fracture rate. Thirty-four children were included. Half of the children were treated with Olpadronate (dimethyl-APD, 10mg/m2/day), the others received placebo tablets. All children were supplied with calcium (500mg/m2/day) and vitamin D (400 I.U./day).

Results: Thirty-two children completed the two-year follow-up period of the study, 15 of them in the Olpadro-nate and 17 in the placebo group. The mean ages were 10.4 (SD 2.8) and 10.6 (SD 4.0) years, respectively, in both groups. In the complete study group, spinal BMD increased significantly during the two years of follow-up (p< 0.005), but the level of BMD accretion per year in the Olpadronate group was higher than in the placebo group (p< 0.0155). Increase of BMD at the os calcis was also seen in both groups (p< 0.05) with a borderline sig-nificant difference between the groups in favour of the Olpadronate group (p=0.085). Sitting height, vertebral height and muscle strength increased in both groups without a significant difference between the groups. No differences in changes in functional outcome (Bleck, PEDI) or self-perception (CBSK, Harter) were observed. Fracture rate and the percentage of children with 3 or more fractures during the 2 years follow-up were lower in the Olpadronate group compared to the placebo group. No side effects of the medication were noted during this study.

Conclusion: In this first double-blind randomized placebo-controlled study on the effects of bisphosphonates in children with OI, Olpadronate proved to be effective as demonstrated by a greater annual increase in BMD, independent from the effects of increase of age and calcium and vitamin D supplementation. Fracture risk seemed to decrease, however, given the interindividual variation in fracture rate within both groups, care must be taken in the wording of conclusions. The relationship between an increase in BMD and items such as functional outcome and quality of life remains unclear.