Abstract
Clinical teams are under increasing pressure to facilitate early hospital discharge for total hip replacement and total knee replacement patients following surgery. A wide variety of wearable devices are being marketed to assist with rehabilitation following surgery. A review of wearable devices was undertaken to assess the evidence supporting their efficacy in assisting rehabilitation following total hip replacement and total knee replacement. A search was conducted using the electronic databases including Medline, CINAHL, Cochrane, PsycARTICLES, and PubMed of studies from January 2000 to October 2017. Five studies met the eligibility criteria, and all used an accelerometer and a gyroscope for their technology. A review of the studies found very little evidence to support the efficacy of the technology, although they show that the use of the technology is feasible. Future work should establish which wearable technology is most valuable to patients, which ones improve patient outcomes, and the most economical model for deploying the technology.
Background
Total knee replacement (TKR) and total hip replacement (THR) are highly successful operations for controlling pain, restoring function, and enhancing quality of life for patients with hip and knee osteoarthritis.1–3 They are amongst the most common surgical procedures worldwide. 4 However, approaches to rehabilitation following surgery vary greatly and evidence is limited with regard to successful interventions. 5 The introduction of enhanced recovery after surgery protocols to improve post-surgical recovery has reduced hospital length of stay6,7 for THR and TKR patients, with recent studies indicating that same day discharge is feasible. 8 This decrease in time for inpatient rehabilitation post-surgery highlights the need for guidance for patients on rehabilitation once home, particularly as recent research has shown that physical activity does not increase following THR or TKR. 9 Innovative methodologies such as the use of Actigraph data 10 are now available to assess specific activity intensity post-surgery and so enable the evaluation of the use of wearable technologies as part of a suitable programme that empowers patients to complete physiotherapy at home. 2 Traditionally patient adherence to recommended home-based physiotherapy programmes is poor. For example, only 24% of patients with osteoarthritis were found to comply with their exercise programme. 11 A lack of time, 12 failure to remember how to do the exercises, 13 limited understanding of how the programme makes them better, 14 and a lack of feedback 15 are some of the barriers to patients being more compliant.
The economic burden from both direct and indirect associated costs of rehabilitation post THR and TKR in the National Health Service is also a major consideration. Commonly physiotherapy is not provided post discharge for THR and only occasionally provided for TKR, mostly within a group setting. 16 Therefore, proving cost neutrality or effectiveness against current practice may be difficult when introducing additional technology or cost to rehabilitation. This is the economic reality and so research needs to demonstrate improvement to clinical outcomes and provide a proven business case for adoption.
Recently, there has been a proliferation of devices designed to monitor activity, educate patients, and provide feedback following TKR and THR surgery. 2 Their aim is to develop the relationship between physiotherapist and patients, and increase exercise adherence.
In broad terms, patient monitoring can be categorised into five types of system:
The goal for all of these systems is to deliver better care at lower cost to patients and improve patient outcomes. 19 This review focuses on wearables tracking systems.
There are three types of platforms used by wearable devices, and indeed many devices use all three platforms:
20
Physiological sensing: These systems have sensors capable of detecting and quantifying force, motion, displacement, and vibration from internal biological functions;
21
Communication interface: This is in the shape of hardware or software to collect physiological and motion data; Data interpretation techniques: These extract clinically relevant information from physiological and motion data.
There is a wide variety of wearable devices currently being marketed, which are proposed to assist with rehabilitation following joint replacement. However, very little is known about how these technologies work, how they differ, and whether they are effective. The aim of this review is to provide an overview of wearable devices available for hip and knee replacement rehabilitation and assess the evidence on whether they do improve outcomes for patients.
Method
Literature search strategy
This review is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (www.prismastatement.org/PRISMAStatement). A computer-based search was completed in October 2017 using the mySearch Database (Bournemouth University). This included Cochrane Database of Systematic Reviews library, CINAHL Complete®, Science Citation Index, and Medline®.
Literature search strategy.
MM (MeSh term). “” used to find exact phrase. *used to find all word with a common stem. N5 to find all articles containing the keywords within five words.
Once the initial searches were completed, the results were manually filtered to remove duplicates. Three independent reviewers (SB, TWW, and TI) then screened journal titles and abstracts for relevance until only 40 papers remained (see Figure 1 for flow chart). SB and TW then assessed the full text of the papers, and five papers were found to meet the eligibility criteria. Any disagreements between reviewers were discussed with TI and resolved by consensus. Studies included were portable wearable technologies capable of providing feedback to the end user following hip or knee replacement surgery.
Prisma flow chart of results from the literature search48.
Data extraction process
Article summary.
Data quality
The Risk Of Bias In Non-randomized Studies – of Interventions (ROBINS-I) 22 tool was used to assess the risk of bias. The assessment includes seven domains including confounding, selection of participants into the study, classification of interventions, deviations from the intended interventions, missing data, measurement of outcomes, and selection of the reported result. The categories for risk of bias judgements for ROBINS-I are ‘low risk’, ‘moderate risk’, ‘serious risk’, and ‘critical risk’ of bias. 22
Results
Classification of technologies and physiotherapy applications
Chiang et al.
23
introduced a tracking device
A study by Jeldi et al.
25
measured upright time (UT) and sit-to-stand (STS) transition progression after THR. Using an accelerometer sensor
Kwasnicki et al.
26
aimed to investigate the feasibility of using an ear-worn motion sensor
A study by Lin and Kulić
27
used IMU sensors
Gonzalez-Franco et al.
24
used a sensor-enabled virtual reality gaming open-source platform using
No adverse effects were reported for any of the devices utilised in the studies reviewed; however, the quality of reporting in the papers was variable and this should be taken into account when reviewing the evidence. All five studies reviewed used an accelerometer and a gyroscope for their technology, with the aim to assess the feasibility of using a wearables sensor to monitor, evaluate, and educate patients’ recovery. Initial results demonstrate promise for use of these devices in clinical settings.
Risk of bias
Assessed using the ROBINS-I risk of bias tool, all reviewed studies were judged to be at serious risk as there were bias issues in more than one domain.
Discussion
Clinical assessments and the evidence of use
The main goal of wearable devices for rehabilitation is to capture movement and posture of patients for monitoring their motor activities during rehabilitation therapy. Clinical trials are crucial to assess the success of the new technologies, in particular when additional clinical results show improvement in patient condition. Post-operative monitoring with wearable technologies has already been examined clinically in patients undergoing spinal surgery, 34 stroke, and arm rehabilitation.35–37 Reported outcomes show excellent overall patient satisfaction. Hadjidj et al. 17 also outlined the innovation technologies currently used in enhanced recovery surgical programmes such as wireless and contact free sensors for monitoring functional recovery and improving post-surgical recovery using wearable sensors.
The search did not find any papers adopting randomised trials to assess the technology for rehabilitation post hip and knee replacement. As discussed the studies included in our review were small, feasibility studies, of varying quality, therefore they were not generalisable. Reviews on upper body wearable rehabilitation systems7,38 have found very little evidence as yet to support the use of the devices. This may be because of the length of time that is required for developing a new technology, or because predeveloped or early stage systems do not justify the time consuming and costly process of clinical trials. It is also important to acknowledge that the biggest challenge for TKR and THR wearable rehabilitation devices may be that the optimal rehabilitation pathway is yet to be defined, 39 therefore the question of what programmes rehabilitation wearables should help to facilitate and deliver remains unanswered.
It is worth noting that none of the studies examined or reported on the health economics of introducing the technology or on the longer term benefits to outcomes such as Patient Reported Outcome Measures using this technology. Even if evidence is collected that supports the clinical benefit of wearable devices, if there is not a sustainable business case for their use, they are unlikely to be widely adopted in health care systems.
Interestingly, devices used in the studies reviewed here have also been marketed to have the potential to measure heart rate variability in anorexic patients, 40 analyse cardiac health 41 by capturing the contextual and metabolic information of the user, monitor stroke patients’ physical activity, 42 and assess functional mobility in patients with neurological disorders. A study on the latter 43 uses the same sensor as that employed by Chiang et al., 23 and initial findings in a small randomised trial were positive.
In contrast to the focus of this paper which was to examine whether the devices reviewed can improve patient outcome reports post THR and TKR, it could be argued that the features of the motion tracking monitors such as the sensor location and placement are factors that should be included in the evaluation of the effectiveness of wearable devices. Evaluating whether these devices improve outcomes for patients is complex as the wearable monitoring platforms provide feedback information as well as coaching to the patients. The Gonzalez Franco et al. 24 paper is the only paper here that evaluates both the feedback and the coaching provided. It should be noted that the participants in the Gonzalez Franco paper were healthy, and not patients following hip or knee replacement, as stated in the search criteria. However, the wearable was designed to be used by patients following knee replacement so the authors felt that its inclusion was of value to the study.
New possibilities are rising with the use of smartphones and applications to estimate joint angles, 44 as well as the potential of exciting upcoming technologies such as nano-sensors and e-textiles. 45 It is important that further research is done to study their efficacy, and indeed study protocols are now being published for larger randomised controlled trials using wearable technologies for post TKR patients.46,47 The studies included in this review demonstrate that the technology is safe and feasible and that it shows promise. It is also popular with patients which is likely to drive research and development in this area. 24
Conclusion
Wearable technology is being promoted by companies as a way of improving rehabilitation following THR and TKR surgery. However, this review finds very little evidence to support its efficacy. The small numbers of studies do, however, show it is feasible, and like most new technology, including patient/technology interfaces, it will improve over time. Future work should establish which wearable technology is most valuable to patients, which ones improve clinical outcomes, and what are the best economical models for their deployment.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
Guarantor
TW
Contributorship
SB, TI and TW conceived the study. SB and TI developed the proposed literature search strategy. SB, TI and TW conducted a literature review, conducted the data analysis and wrote the manuscript. All authors reviewed and edited the manuscript and approved the final version of the manuscript.
Acknowledgements
None
