Authors: (including presenting author): :
Tam JPH (1), Yung C (1), TW Lau (1), F Leung (1), Fang C (1)
Affiliation: :
Department of Orthopaedics & Traumatology, Queen Mary Hospital
Keyword 1: :
fragility fracture
Keyword 3: :
rehabiliation
Introduction: :
Fragility fractures in the elderly population is increasing due to the global aging population. In the Asian population, around 40% of those aged over 65 will have a fall every year. By 2050, it is predicted that six million hip fractures will occur each year of which the majority will happen in Asia. Rehabilitation in the early post-hip fracture surgery period plays a crucial role in restoring functional independence and quality of life. Currently, there are no validated bedside tools for patient to do rehabilitation exercise yet also provide objective feedback on their progress. A novel clinical assessment tool, Time-Up and Flex [TUF], was designed to assess rehabilitation progress and to encourage patients to perform unsupervised bedside rehab exercises, reducing the need for an allied health professional. TUF is a 3D printed modular system and consists of: base, pole with numerical markings and an adjustable horizontal limb according to the desired marking on the pole. It is sturdy, durable, inexpensive and can be easily sanitised after each use. The tool provides a visual reference to mark the point when hip flexion has reached 30 degrees. 30 degrees hip flexion is a desirable rehabilitation goal as biomechanical studies have shown that during gait cycle, the hip moves between 10 degree extension to 30 degree flexion. Since the primary aim in hip fracture rehabilitation is early weightbearing and restoring the ability to walk, this tool may help in assessment patient’s rehabilitation progress by testing the time taken to flex the operated hip to 30 degrees. Ideally, using a goniometer will be the most accurate method of measuring hip flexion to 30 degrees, however, given the post-operative state with pain and overlying wound dressing, it would be cumbersome to use a goniometer against the operated hip, hence the development of the TUF tool which utilises the trigonometry equation sin30 = ½, where the opposite side of sin30 is ½ the length of the hypotenuse length (leg length). Hence, the operator will simply measure the tibia length, the measured length in centimetres will be used as reference and the horizontal limb will be raised to that number, the TUF tool is then ready to be used for testing the subject.
Objectives: :
In order to determine whether TUF is able to appropriately evaluate rehabilitation in hip fracture patients, we aim to assess the psychometric properties: content validity, construct validity, responsiveness and reproducibility. If the device demonstrates similar or superior outcomes compared to standard rehabilitation methods, it will validate its effectiveness and its use in hip fracture rehabilitation.
Methodology: :
A single centre, double-blinded, prospective validation study. Subjects are recruited according to the inclusion criteria. Objective of this study is to validate TUF tool by assessing for correlation between the subject’s performance as measured by the tool and functional outcomes such as pain and mobility, assessing the tool’s responsiveness to change over time and reproducibility of the results when tested in a short period of time. Hypothesis is TUF time decreases over time and correlates with a decrease in pain, increase in functional scale and ambulation score. An assessor will use TUF to measure time taken to actively flex the operated hip to 30 degrees, as an average from 3 attempts, on post-operative days [POD] 1, 7 and 14. An independent assessor blinded to the subject’s TUF results will record subjective outcome (Numerical Patient Reported Pain Scale [NPRS]) and objective outcomes (Tinetti Scale [TS], Functional Ambulation Category [FAC]) on post-operative days [POD] 1, 7 and 14. These scales are validated and reliable in assessing elderly functional recovery post injury. NPRS is a numeric scale from 0-10 that reflects the intensity of pain during movement (0 being no pain, 10 being severe pain). TS measures balance and walking ability (0 being the worse and 28 being the best), the total score indicates the risk of future falls. FAC is a 0-5 rating scale (0 being unable to walk, 5 being an independent walker). Construct validity and inter-class correlation is assessed using Spearman’s correlation between TUF time and NPRS, TS and FAC. Responsiveness, a measure of effect size, is assessed using Cohen’s D and calculating the size of effect at different timestamps (POD1, 7 and 14). A subgroup of subjects were assessed on multiple occasions during the same day to test the tool’s reproducibility, Cronbach’s alpha is used to calculate reproducibility and assess internal consistency.
Result & Outcome: :
95 subjects (29M, 66F) who had hip fracture surgery (58 fixation, 37 arthroplasty) at the same centre were included. Mean time for TUF were 11.7s (seconds), 7.9s and 5.9s, NPRS were 7.2, 4.6, 2.9, TS were 9.8, 13.7, 17.9, FAC were 1.1, 1.9, 3.0 on POD1, 7 and 14 respectively. Spearman’s coefficient of correlation for TUF time against NPRS was 0.719 (p< 0.05), against TS was -0.597 (p< 0.05), against FAC -0.651 (p< 0.05). A decrease in TUF time correlates to a statistically significant decrease in NPRS, increase in TS and FAC. Cohen’s D was calculated between POD1 and POD14. Cohen’s D was 0.9, 1.1 and 1.0 for NPRS, TS and FAC respectively, demonstrating a high responsiveness between TUF and the outcome measures over this short post-operative period. A subgroup of subjects were assessed on multiple occasion during the same day to test for TUF tool’s ability to reproduce the same result over a small period of time. Cronbach’s alpha for this subgroup of subjects was 0.84, meaning there is a high amount of covariance and demonstrates the high internal consistency of TUF. TUF is a novel bedside clinical assessment tool which not only lets patients perform self-directed rehabilitation exercise, but also gives objective feedback which correlates to pain and functional recovery. This study has demonstrated TUF’s validity and has potential to be incorporated into geriatric hip fracture rehabilitation pathway.
