A study protocol for a randomized controlled trial evaluating vibration therapy as an intervention for postural training and fall prevention after distal radius fracture in elderly patients

Fractures of the distal radius are one of the most common osteoporotic fractures in elderly men and women [1‐3] and account for approximately 18% of all fractures in the elderly [4]. Currently, there is approximately a 3:1 female-to-male ratio [2]. These fractures are a particular health concern amongst the elderly, who are at risk of fragility fractures, and they are associated with long-term functional impairment, pain and a variety of complications. Current medical costs for distal radius fractures are estimated to exceed US$535 million each year and projected to rise as the incidence increases [5, 6].

The occurrence of distal radius fractures is well known to be a sentinel event, as these fractures are associated with a two to four times increased risk of subsequent hip fractures in elderly patients [7‐9]. This is an important concept, as it is well established that these patients have an increased risk of falling [8]. Fall prevention is therefore crucial to decrease further morbidity and mortality. Studies have shown a significantly increased degree of postural sway in patients with distal radius fractures, in both the anteroposterior and lateral directions, which is strongly characterized in older patients for recurrent falls, and is related to lower limb strength [10]. Another strong association with fragility fractures is sarcopenia, which is loss in muscle mass and strength, leading to postural instability and falls [11]. Recent evidence has shown that the prevalence of sarcopenia reaches up to 95% in male and 64% in female patients after an osteoporotic fracture [12]. The instability of these patients has also been validated with the use of objective measurements from computerized instruments [9].

Despite on-going studies on distal radius fractures, the latest Cochrane systematic review shows a lack of evidence on the effectiveness of current rehabilitation interventions [13]. The American Academy of Orthopaedic Surgeons (AAOS) position statement also recommends patients with fragility fractures to undergo evaluation of osteoporosis and treatment to prevent future fractures [9]. Notably, there are currently no recommendations on the role of balance training or physical conditioning. Consequently, the evaluation and treatment of fall risks have been largely overlooked [14]. Further research that targets rehabilitation and treats postural instability after distal radius fracture to reduce fall rates is therefore warranted.

Low-magnitude high-frequency vibration (LMHFV) is a biophysical intervention that provides non-invasive, systemic mechanical stimulation and was shown to improve muscle strength and balancing abilities in healthy, independent and active elderly women in our previous studies [15, 16]. The device has been proven to act as a form of physical exercise, as muscle activity is induced during vibration [16, 17]. Numerous other studies have reported whole-body vibration to have positive effects on blood circulation in the lower extremities and enhanced muscle performance in the elderly [18, 19]. The use of this device has not yet been established in patients with fractures, but has great potential as a rehabilitation tool. This is the first study to translate LMHFV to distal radius fracture patients, who are high-risk patients prone to falls. This tool would also potentially be more cost-effective.

We hypothesize that LMHFV will improve postural stability and decreases fall rates. As current rehabilitation interventions lack effectiveness, the objective of this study is to investigate the effect of LMHFV on postural stability and recurrent falls in elderly patients post distal radius fracture.

Previous studies have stressed the importance of reducing risk of falls after distal radius fractures in elderly patients due to postural instability [25‐27]. A prospective, longitudinal cohort study had shown overall functional status and deterioration of mobility for these patients, and future fracture risk increased significantly 1 year after fracture [27]. With the ageing population, prevention of imminent fracture risk, i.e. secondary fractures within 2 years, for patients with distal radius fractures is crucial to decrease mortality and healthcare costs [28].

Numerous studies have proven the effect of vibration therapy in preventing falls and fractures and in improving balancing ability in normal elderly [29, 30]. Our previous randomized controlled trial with 710 healthy, active and independent postmenopausal women over 60 years old had shown LMHFV to have significant improvements in reducing falls, reaction time and movement velocity and in providing maximum excursion of balancing ability assessment as well as quadriceps muscle strength [15]. Our case-control study also showed that at 1 year post intervention of LMHFV, the benefits were retained for the patients [16].

The use of the Biodex Balance System SD (BBS) provides an objective measurement of postural stability and balancing ability for our patients. Several studies have used the device, and it has been proven to be reliable and valid for clinical studies [22, 31‐36].

Enrolment in this trial began on November 2018, and completion is expected to take 24 months. The results from this trial would change clinical practice, as currently there are no validated interventions addressing the problem of postural stability for patients with distal radius fractures. We speculate that positive results would allow the incorporation of LMHFV into multidisciplinary rehabilitation programs to improve healthcare for our patients in the future.