Total knee arthroplasty among working-age patients
Hylkema, Tjerk
DOI:
10.33612/diss.136229323
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Publication date: 2020
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Hylkema, T. (2020). Total knee arthroplasty among working-age patients. University of Groningen. https://doi.org/10.33612/diss.136229323
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7
The overall aim of this thesis was to expand our knowledge of working-age patients receiving TKA. This was achieved by providing more insight into preoperative characteristics, examining the recovery process with special attention to return to work and work functioning, and exploring sedentary and physical activity behaviors. The present chapter discusses these topics and presents methodological considerations. Recommendations for clinical practice and research are provided.
Working-age patients receiving TKA
Chapter 2 describes the preoperative characteristics of working-age TKA
patients. It was found that a majority of them were overweight or obese (83.8%), and dealing with two or more comorbidities (72.4%). Compared to elderly patients, working-age TKA patients scored better on physical functioning and vitality, were more physically active, and reported better mental health. In Chapter 3 we observed that most working-age TKA patients had positive postoperative outcomes. In the first three months after surgery they reported fewer physical and mental impairments, activity limitations, and participation restrictions in social roles. These findings are in line with previous studies which concluded that good preoperative performance is associated with positive outcomes, and that TKA is an effective procedure to reduce physical impairments and activity limitations [1-4].
Regarding work outcomes, we found that 24% of the patients fully returned to work within the first three months of surgery, 27% by six months, and 20% by 12 months. In particular patients with more knee-specific pain and worse physical functioning preoperatively, appeared to return to work after three months. Among patients returning to work later, recovery of general and knee-specific pain, stiffness, and physical functioning was hampered postoperatively (Chapter 4). Among patients who returned to work, improvements in work functioning and working all contractual hours started at six months and continued until 12 months postoperatively (Chapter
3). In the United States we found substantial work productivity losses at six
months postoperatively (33 hours on a monthly basis), which decreased over time but still existed at 24 months (21 hours on a monthly basis). High pain catastrophizers scored at least twice as high on productivity losses (Chapter 5).
Based on these findings it can be concluded that: 1. characteristics of working-age patients receiving TKA are important and should be taken into account to predict the recovery process and, most importantly, their work outcome; 2. the length of recovery often takes longer than three months for working-age TKA patients, including time to return to work, 3. beyond time to return to work, other work outcomes like work functioning and productivity loss should also be taken into account to assess the effect on work participation.
First, taking patients’ characteristics into account is important to establish good postoperative recovery and work outcome. Previous studies show that non-manual work and high patient motivation to return to work are associated with substantial earlier return to work after TKA [5,6]. Our findings add to the existing literature that especially patients with more knee-specific pain and worse physical functioning, and those dealing with pain catastrophizing and/or musculoskeletal comorbidities, are at risk for delayed return to work or high productivity losses. It might therefore be useful to identify and treat these patients during preoperative counseling, tailoring to the patients’ needs, to prevent potentially worse postoperative work outcomes. In such a tailored approach, working-age patients reporting for example pain catastrophizing could already be treated preoperatively with education, physiotherapy or cognitive behavioral therapy to prevent postoperative work productivity losses [7]. Subsequently, a tailored approach to the specific needs of working-age patients should preferably be continued during postoperative rehabilitation. Rehabilitation programs might look beyond knee-related recovery, where also comorbidities and effects of other aspects (expectations, work demands) should be considered.
Second, regarding length of recovery and time to return to work, the Dutch Orthopedic Association (NOV) recommends in its guideline to strive for return to work within the first three months of TKA [8] . Our findings show that the majority of working-age patients did not return to work that soon. Hence the current recommendation does not seem entirely realistic for working-age patients. Moreover, particularly for patients returning to work later than three months postoperatively rehabilitation seems important, as they experienced poor recovery of general and knee-specific pain and
stiffness, and worse physical functioning (Chapter 4). In the Netherlands, physiotherapy is generally done in the first 2-3 months after surgery [9], which might be too short for those patients dealing with poor recovery and delayed return to work. Similarly, previous qualitative studies among working-age TKA patients highlighted that rehabilitation mainly focused on the needs of elderly patients and that return to work was not specifically considered [10,11]. Rehabilitation should therefore be preferably not only occur in the first three months after surgery but also thereafter, tailoring it to working-age patients’ needs.
Third, the results in this thesis showed that we should also pay attention to work functioning and productivity when patients return to work. Patients’ improvement in work functioning (Chapter 3) was in line with previous studies showing that TKA patients experienced fewer work limitations one year postoperatively compared to the preoperative state [5,12]. Those authors additionally showed that patients reported ongoing problems with kneeling, crouching, clambering, operating vehicles at work, and concentrating. Experiencing unsuccessful work functioning might ultimately lead to productivity losses. In the United States productivity losses of 33 hours per month have been found, with the ensuing high indirect costs. These findings cannot be compared to Dutch work functioning levels, as instruments and populations were different. This does however illustrate that insight into these types of work outcomes are important from the perspective of the individual, as well as from the healthcare, and from a socioeconomic point of view. These findings evidence the need for future studies that will assess work productivity outcomes of Dutch TKA patients after they return to work as well as practical, work-related aspects.
Sedentary and physical activity behavior
The objectively measured physical activity levels after TKA (Chapter 6) showed that working-age TKA patients were highly sedentary during the week (60%), and about 25% of the time was spent in prolonged sedentary bouts of at least 30 minutes. This notwithstanding, 70% of the patients met the physical activity guideline of at least 150 minutes of moderate-to-vigorous physical
activity per week. Findings were in line with a general population, derived from pooled objective data of four European populations [13].
Although working-age TKA patients showed similar sedentary and physical activity behavior compared to a general population, high levels of sedentary time and physical inactivity remain worrisome. Being more physically active is an important determinant to promote healthy ageing. A rapid accumulation of epidemiological studies show that time spent in sedentariness is associated with premature mortality, certain cancers and type 2 diabetes. This association is often independent of higher levels of physical activity [14-16]. Prolonged sedentary time or uninterrupted sedentary bouts are detrimentally associated with several cardiometabolic health outcomes [17,18]. This suggests that working-age TKA patients are at risk of adverse health outcomes in the long term. TKA patients can benefit even more from physical activity, as there are indications that it increases bone density, improves prosthetic fixation, and reduces the risks of prosthetic loosening [19,20]. In addition, many TKA patients are overweight or obese (Chapter 2), which leads to considerably worse outcomes after TKA [21,22]. For these patients, physical activity, preferably combined with a diet, can be beneficial to lose excessive weight. In order to support physical activity, the workplace might be a good place to start, as approximately one-third to half of our daily sitting happens at work [23,24]. Chapter 6 shows that TKA patients with non-physical jobs continued their prolonged occupational sedentary bouts during leisure time. This implies that patients are generally sedentary the entire day. Workplace health promotion should therefore be directed at reducing sedentary time among TKA patients with non-physical jobs. For intervention development, every decrease in sedentary time leading to physical activity of any intensity counts already as beneficial [17,18].
Methodological considerations
In this section we address and discuss methodological issues concerning the study sample, study design, data quality and confounding factors.
Study samples
For this thesis we used primarily data of two prospective cohorts: the Dutch Work participation in Patients with Osteoarthritis (WIPO) cohort (Chapters
2, 3, 4), and the STudy outcomes in Arthritis Research (STARs) cohort (Chapter 5) in the United States. The WIPO cohort had high initial response
rates and high retention rates during follow-up (65% responded at two-years’ follow-up). Attrition bias was limited, as assessment of dropouts showed that responders and non-responders did not differ on preoperative characteristics
(Chapter 3). In the STARs cohort responses even increased by every
follow-up and there were no severe dropouts over time. In STARs, patients were included from different US states, increasing the generalizability of the results. Patients included in the WIPO cohort were derived from four hospitals in the northern Netherlands, including general, large teaching and tertiary hospitals. Results were therefore derived from a heterogeneous group of TKA patients and this prevented selection bias on disease severity. There may have been selection bias on preoperative working status, as all patients in the WIPO cohort needed to work preoperatively. Patients that were not working before surgery, but were able to return to work after TKA, were not included.
Quality of the data
Most of the studies (Chapters 2-5) used self-reported data, and in Chapter
6 objective measurements were used. Self-reported data were obtained
from reliable and valid questionnaires. The likelihood of information bias, i.e. systematic error in the obtained information, was limited by use of repeated measures on self-reported data and because of high retention rates. In several studies data was compared to the general population, but normative data of the general population was derived from several countries, which may limit valid comparison of the two populations. We used objective measures for sedentary and physical activity behavior. Triaxial actigraph accelerometers were used in Chapter 6, which are known to be accurate devices for measuring physical activity [25]. Accelerometers prevent recall bias from self-reported measurements of physical activity [26,27]. Social desirability bias is prevented by using objective measures, as people are
known to overestimate their physical activity behavior. However, results of sedentary and physical activity are calculated by algorithms, where, for example, we used the widely used cut-off point of <100 cpm. These cut-off points do vary in the literature, and a universally accepted cut-off point is not yet available [28].
Not all confounding factors could be been taken into account in our studies. We did adjust for main confounders such as age, gender, and comorbidity in all our models. And yet from other studies we know now that factors like preoperative sick leave, patient expectations, and environmental support play an important role in return to work [29-34]. We did not address these potential confounding factors, as data on these determinants was not collected.
Job type was assessed in our WIPO cohort (Chapters 2 and 4) by asking if participants performed a physically or mentally demanding job, or a combination of both. Many patients responded that their job was a mix of both physical and mental demands – for example, a clerical worker does not perform a mixed job but primarily a mentally demanding job. This may have led to misclassification. Using the ISCO-08 classification [35] for job titles therefore seems more reliable, as conducted in Chapter 5.
Recommendations for practice and research
Research in this thesis adds unique and important information to literature on working-age patients receiving TKA. This section gives recommendations for practice and research. We advise using a tailored approach in the pre- and post-surgical phase for working-age TKA patients, to improve their postoperative work participation. Preoperatively, orthopedic surgeons and occupational physicians might screen for patients with more knee-specific pain or worse physical functioning, dealing with pain catastrophizing, or coping with other comorbidities to prevent delayed return to work or high productivity losses after returning to work. Tailored screening on these characteristics during preoperative counselling might prevent poor postoperative work outcomes. We recommend continuing this customization
during the recovery period. To achieve this, we might learn from a promising study that evaluated Goal Attainment Scaling (GAS), where patient-specific targets are formulated preoperatively together with physical therapists and are subsequently endeavored during rehabilitation [32]. A treat-to-target strategy is currently being examined in the Physiotherapeutic Treat-to-target Intervention after Orthopedic Surgery (PaTIO) study, where rehabilitation focuses on reaching personal milestones before working on the next milestone [36]. Both strategies might be useful toward development of tailored rehabilitation for working-age patients, where we recommend not only fitting these strategies for knee-related problems but also taking patients’ comorbidities into account.
In addition to tailored rehabilitation we would recommend providing rehabilitation not only in the short term (until 3 months), but also in the longer-term (up to 12 months postoperatively). Rehabilitation in the long term does not necessarily need to be face-to-face with healthcare professionals, it can also be done by using e-health via tablets or web-based. Some studies have shown that home-based rehabilitation driven by a tablet app and mobility monitoring is feasible for TKA and total hip arthroplasty patients [37,38]. Future research should focus on implementation as well as general and cost effectiveness using e-health as a supplement or even a substitute for formal physiotherapy among working-age TKA patients. E-health can also be used for healthcare professionals to provide better guidance during the recovery process. Two studies reported that currently there is insufficient guidance by healthcare professionals [10,11], while contact with them can enhance confidence and offers reassurance, which helps facilitate the recovery process [39]. The Dutch Orthopedic Association has acknowledged the lack of collaboration between healthcare professionals, especially between orthopedic surgeons and occupational physicians, and aims to study it in the coming years.
We could learn from other patient groups, where two randomized controlled trials evaluated provision of better guidance by all healthcare professionals using e-health [40,41]. In those studies, all stakeholders in the treatment process provided guidance to patients by e-health applications, from the moment the surgery was planned until full postoperative resumption
of normal and work activities. This intervention led to significant earlier return to work rates [40,41]. Hence e-health can be promising to support tailored rehabilitation programs in the short- and long-term after surgery, as well as to provide adequate guidance by all healthcare professionals to foster return to work. Future studies might evaluate such interventions among working-age TKA patients.
We recommend the support of physical activity to promote a healthier working-age TKA population. Stimulation of physical activity might already start at the workplace, where patients with non-physical jobs are considerably sedentary the entire day. This puts them at an unnecessary risk for adverse health outcomes in the long term. Introducing sit-stand desks might stimulate physical activity behavior at the workplace, as might lunch walks or placing the coffee or printing machine at the other side of the hall [17,42]. For clinical practice, support of physical activity might also take place via e-health applications, but this should be explored in future studies.
Research in this thesis presented novel and valuable information on the first two-year follow-up period after TKA among working-age patients. There has been a lack of knowledge on this growing patient population. Individuals included in this thesis were on average 55 years old and thus need to continue working longer than two years following TKA. Due to higher retirement ages in the Netherlands these patients need to work even longer, and this should be facilitated by the knee prothesis. We therefore recommend future studies to include longer follow-up periods. Future research should further examine what the longer-term effects of TKA are on work functioning as well as on work productivity among Dutch patients. It is important to examine how work functioning and work productivity develop after two years to sustain work participation until retirement age.
Conclusion
We found that working-age patients had positive outcomes after TKA with respect to physical impairments and activity limitations, but their recovery of participation in the workforce was suboptimal. A majority of
the patients returned late to work, by six or twelve months postoperatively. Those returning to work late were having more pain and worse physical functioning preoperatively, and had worse recovery of pain, stiffness and physical functioning postoperatively. It was also found that TKA patients reported substantial work productivity losses, and patients dealing with pain catastrophizing reported even higher productivity losses. One year after surgery working-age patients were highly sedentary, which puts them at risk for adverse health outcomes. We recommend a tailored approach for working-age TKA patients starting at preoperative counselling already and continuing during rehabilitation, in order to enhance recovery and facilitate return to work. New technological developments like e-health can be helpful for general and cost effectiveness.
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