Systematic review of rotator cuff tears in workers

Occupational Medicine 2011;61:556–562
Advance Access publication on 19 October 2011 doi:10.1093/occmed/kqr068
Systematic review of rotator cuff tears in workers’
compensation patients
K. A. R. Kemp1, D. M. Sheps2, C. Luciak-Corea3, F. Styles-Tripp3, J. Buckingham4 and L. A. Beaupre2,5
1
Orthopaedic Research, Alberta Health Services—Capital Health Region, 1F1.52, 8440 – 112 Street, Edmonton, Alberta T6G 2B7,
Canada, 2Department of Surgery, University of Alberta, 1F1.52, 8440 – 112 Street, Edmonton, Alberta T6G 2B7, Canada,
3
Department of Rehabilitation Medicine, Covenant Health, Grey Nuns Hospital, 110 Youville Drive West, Room 1107, Edmonton,
Alberta T6L 5X8, Canada, 4John W. Scott Health Sciences Library, University of Alberta, 2K3.28 Walter C. MacKenzie Health
Sciences Centre, Edmonton, Alberta T6G 2R7, Canada, 5Department of Physical Therapy, University of Alberta, 3-71 Corbett Hall,
Edmonton, Alberta T6G 2G4, Canada.
...................................................................................................................................................................................
Background The burden imposed by workplace rotator cuff (RC) injuries has been reasonably defined. However,
literature associated with the demographic characteristics and ‘best practices’ to manage such injuries
among workers’ compensation (WC) patients is scant.
...................................................................................................................................................................................
Aims
To consolidate the existing literature on full-thickness RC tears among WC patients. Subject, shoulder
and injury characteristics were examined to determine if and how WC recipients may differ from their
non-compensable counterparts.
...................................................................................................................................................................................
Methods
A systematic search (databases, clinical practice guideline web resources, conference proceedings and
reference lists) revealed 450 abstracts. Two blinded reviewers independently assessed abstracts for
inclusion. Sixty abstracts were subsequently included in a blinded full manuscript review. Seventeen
of these manuscripts (3.8% of sample; 11 intervention and 6 determinant) were included in the
present review.
...................................................................................................................................................................................
Results
Previous studies demonstrate that operative interventions are appropriate for full-thickness RC tears
as substantial gains in range of motion, strength and quality of life were witnessed within the first postoperative year. Non-operative interventions, including workplace-based work hardening, physical
therapy and the use of an early referral system, were shown to improve outcomes. Conflicting results
exist with respect to determinants such as age and sex. Importantly, WC patients had consistently
poorer outcomes than non-WC patients.
...................................................................................................................................................................................
Conclusions Our results show that although WC patients experience substantial benefits from various treatments
for full-thickness RC tears, disparities exist between them and their non-WC counterparts. The lack of
WC-specific literature limited our results. Larger studies, particularly ones comparing WC patients
with their non-compensable counterparts, are crucial to allow for future evidence-based recommendations.
...................................................................................................................................................................................
Key words
Evidence-based practice; musculoskeletal; occupational rehabilitation; physiotherapy; quality of life;
rehabilitation; upper limb disorder.
...................................................................................................................................................................................
Introduction
Disorders of the rotator cuff (RC) include a broad spectrum of pathological conditions, including bursitis,
tendonitis, tendonosis, partial thickness tears and fullthickness tears [1]. Given the daily demands that are
placed upon the RC, it is not surprising that RC tears
are the most common source of shoulder pain, disability
and discomfort [2,3]. In fact, RC disease is the most common cause of shoulder pain seen by physicians. Based
upon magnetic resonance imaging, 4% of individuals
under 40 years of age may have an asymptomatic RC tear
(partial or full thickness). This figure climbs to .50%
among individuals .60 years old [4]. Although these
tears are classified as asymptomatic, previous literature
has shown that pain develops within 5 years in approximately half of these individuals [5]. As the current population is aging, increasingly active and perhaps less
willing to accept functional limitations, the incidence of
symptomatic RC disease is expected to grow in future
years.
The Author 2011. Published by Oxford University Press on behalf of the Society of Occupational Medicine.
All rights reserved. For Permissions, please email: [email protected]
Downloaded from http://occmed.oxfordjournals.org/ at University of Alberta on March 3, 2012
Correspondence to: K. A. R. Kemp, Ottawa Hospital – General Campus, Critical Care Wing, Room W1636, Box 502, 501 Smyth
Road, Ottawa, Ontario K1H 8L6, Canada. Tel: +1 613 737 8920; fax: +1 613 737 8837; e-mail: [email protected]
K. A. R. KEMP ET AL.: SYSTEMATIC REVIEW OF RC TEARS 557
(a) In WC patients with full-thickness RC tears, what
operative or non-operative interventions are effective
in restoring function, reducing pain and allowing
return to pre-injury work?
(b) Are WC RC patients different from non-WC patients
in terms of the following patient characteristics:
(i) demographics (e.g. age, gender, smoking status),
(ii) shoulder characteristics [e.g. pain, strength, range
of motion (ROM)],
(iii) general health status and
(iv) type of employment (e.g. demands, number of
hours worked)?
(c) Are WC RC patients different from non-WC patients
in terms of injury characteristics:
(i) mechanism of injury (e.g. traumatic, overuse, degenerative),
(ii) tear characteristics (e.g. size, location, muscle(s)
torn)?
Through the provision of such evidence, our goal was
to shed light on areas where research has found conclusive
results, as well as to highlight areas in need of further
research.
Methods
To identify potential articles, systematic searches of
MEDLINE, Cochrane Library, EMBASE, CINAHL,
SCOPUS, Sport Discus, PEDRO, BIOSIS Previews,
TRIP, Clinical Evidence, StatRef, OCLC Papers First
and Proceedings First, Dissertation Abstracts and Web
of Science databases were performed up to December
2008. A further search of ‘grey literature’, including
clinical practice guideline web resources, conference
proceedings and reference lists of key manuscripts, was
also performed. Medline, EMBASE and CINAHL were
searched using a combination of thesaurus terms and text
words (see Figure 1, available as Supplementary data at
Occupational Medicine Online), while a simple text word
search (rotator cuff and [Workers compensation OR
WCB]) was conducted on the other databases.
Only studies containing data that were collected from
1990 to present day were included in this review to
represent current medical and rehabilitative practices.
In order to ensure the inclusion of recent manuscripts
(those published following our initial literature search),
a final scan of the MEDLINE database was performed
immediately prior to this final report.
The target population was adult patients (aged $18
years) who were receiving WC benefits related to
full-thickness RC tears. As such, our review is limited
to countries/jurisdictions where formal WC programs
are available. Studies which included this target population as a subset (i.e. articles not exclusively containing
WC patients) were included if data pertaining to WC patients could be extracted. Our investigation, however, was
limited to literature concerning interventions and determinants associated with full-thickness RC tears only. Any
sources of literature encompassing the broad definition of
‘tendinopathy’ were not included, unless an explicit reference to ‘full-thickness RC tear’ was present. Interventions included both operative and non-operative (i.e.
physical therapy, medication, steroid injection) management. Outcomes included objective (ROM, strength and
return to work), patient reported (pain scales and healthrelated quality of life questionnaires) and economic
(length/cost of WC claim) measures. Our eligibility criteria spanned numerous study designs, including randomized trials, cohort, case–control, retrospective reviews,
comprehensive reviews and meta-analyses. Determinant
studies that described or compared characteristics of subjects and allowed comparison of patient-/work-related
characteristics between WC and non-WC subjects were
included.
For potentially eligible abstracts, two blinded reviewers independently assessed studies for inclusion/
exclusion according to standardized criteria regarding
patient populations, interventions, outcomes and study
design (Figure 2, available as Supplementary data at
Occupational Medicine Online). For the evaluation of determinant studies (i.e. non-interventional evaluations),
a comprehensive list of demographic and potentially
modifiable risk factors was developed (Figure 3, available
as Supplementary data at Occupational Medicine Online).
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As RC pathology ranks second only to back and neck
pain in frequency of occurrence in the workplace [6],
work productivity is substantially affected as indicated
by high claims rates and costs attributed to workplace
RC injuries [6–8]. RC injuries are also the second most
common reason for lost time from work in manual workers [4–6]. Although the scope of burden imposed by
workplace RC injuries has been reasonably defined,
literature associated with the demographic characteristics
and ‘best practices’ to manage such injuries among
workers’ compensation (WC) cases is scant at best. When
compared to non-WC patients, several studies have
demonstrated the lower recovery (i.e. physical measures,
quality of life), patient satisfaction and longer time periods to return to employment or full activities following
RC injury experienced by WC claimants [9–12]. Very
few studies, however, have expanded upon this in order
to investigate whether this differential recovery following
RC injury in WC patients can be explained by patient,
shoulder, injury or occupational characteristics.
Therefore, the main goal of this review was to consolidate
the existing literature on the management of RC injuries focusing on patients insured by WC. In addition, subject,
shoulder and injury characteristics were examined to determine if and how WC recipients with a RC tear may differ
from those non-compensation subjects with RC tears.
The specific research questions which we aimed to
address were
558 OCCUPATIONAL MEDICINE
Systematic searches of Databases, clinical practice guideline
web resources, conference proceedings, reference lists
450 abstracts retrieved
Blinded review of abstracts by two reviewers
390 abstracts excluded (pre-1990,
irrelevant, insufficient data)
82.4% agreement between reviewers
(k = 0.45; moderate agreement)
60 eligible abstracts
Full-text manuscripts retrieved
Blinded review of manuscripts by two reviewers
43 manuscripts excluded (did not
answer any of research questions)
71.7% agreement between reviewers
(k = 0.39; moderate agreement)
17 eligible manuscripts
(11 intervention, 6 determinant)
Data extraction into standardized forms
Fig 1. Flowchart of study selection and evaluation.
Results
Four hundred and fifty potentially eligible abstracts were
assessed, of which 390 abstracts were excluded as they did
not answer our predetermined research questions. The
reviewers were in agreement in 82% (n 5 369) of the
450 cases. The corresponding kappa statistic was k 5
0.45, indicating moderate agreement [14]. Following
full-text assessment, the reviewers excluded a further
43 manuscripts and the reviewers were in agreement in
72% (n 5 43) of the remaining 60 cases. The corresponding kappa statistic was k 5 0.39, indicating fair agreement
[14]. Therefore, a total of 17 manuscripts (11 intervention and 6 determinant) were included in the present
review.
The methodological details of intervention studies
(n 5 11), including author and year published, study
design, sample size, mean age, gender, number and proportion of WC patients, interventions, outcomes assessed
and follow-up periods are provided in Table 1 (available
as Supplementary data at Occupational Medicine Online).
The details of the determinant studies (n 5 7) are
provided in Table 2 (available as Supplementary data
at Occupational Medicine Online).
Of the 11 intervention studies retrieved, 8 focused on
surgical interventions [10,15–22]. Of these eight surgical
studies, seven examined outcomes relating to RC repair,
either alone or in combination with other procedures
(subacromial decompression, acromioplasty and biceps
repair), while the remaining study examined outcomes
associated with subacromial decompression performed
in isolation. Patient follow-up periods ranged from 12
months to 10 years. With respect to the study quality,
three were rated as ‘high quality’, five were rated as ‘good’
and the remaining three were rated ‘fair’. Due to the small
number of studies retrieved, we have chosen to present
comprehensive results, as opposed to ones stratified
according to study quality.
The complete list of results from intervention studies
is provided in Table 1. Generally, these previous studies
demonstrated that operative interventions are an appropriate treatment for dealing with full-thickness RC tears
as subjects had substantial gains in ROM, strength and
various measures of quality of life post-operatively. Gains
in ROM, strength and function were primarily witnessed
within the first post-operative year. Although one study
demonstrated that patient satisfaction and the patient’s
subjective disability rating may improve from 2 to 10 years
post-operatively, it should be noted that only one WC patient was included at the 10-year post-surgery mark [16].
Therefore, these results should be interpreted with caution. Among the remaining studies, which included follow-up beyond the 1-year post-operative mark, patients
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Based on these a priori criteria, each reviewer was asked
to determine if each abstract should be included or excluded for full manuscript review. Following the initial abstract evaluation, the corresponding full-text manuscript
was retrieved for each remaining abstract. The same two
reviewers independently assessed each full-text article
for eligibility using standardized criteria as described
above. In cases where consensus was not obtained, the
reviewers reviewed the article in question and a decision
with respect to inclusion was made.
Following study selection, the included articles were
divided among the two reviewers. Each reviewer independently assessed one half of the total articles. Data regarding study population, design, interventions and outcomes
were extracted and transcribed onto standardized data
collection sheets. Once each reviewer completed data
extraction for their respective articles, the reviewers exchanged articles and verified the other’s data extraction.
The internal validity of each intervention article was
assessed by the same two reviewers using a modified version of the Newcastle–Ottawa Scale [13]. Studies were
rated as ‘high quality’ if they met at least 80% of criteria,
‘good’ if they met 70–79% of criteria, ‘fair’ if they met
60–69% of criteria and ‘poor’ if they met ,60% of standard criteria. A flowchart of manuscript selection and
evaluation is provided in Figure 1.
K. A. R. KEMP ET AL.: SYSTEMATIC REVIEW OF RC TEARS 559
(n 5 4) [12,25–27], cortisone injection use (n 5 3)
[25,26,29], presence of co-morbid health conditions
(n 5 2) [27,29], surgical technique used (n 5 2)
[26,27], previous shoulder surgery (n 5 2) [12,29] and
sleep interruption [25]. Time off work was the only determinant assessing the impact of shoulder injury and
management on employment.[25].
From a demographic perspective, the most significant
findings were observed for age and sex. It was generally
found that age did not significantly impact patient outcomes, although one study found that WC patients were
significantly younger when compared to their non-compensable counterparts [26]. It was also found that patients under the age of 55 years were significantly more
likely to be displeased with surgical results and were less
likely to have additional surgery [12].
There also appeared to be sex-based differences among
patient outcomes. Women may experience more postoperative pain than their male counterparts [28]. In
addition, although women expressed slightly greater satisfaction with their RC treatments, they had a reduced
ability to perform certain shoulder tasks, including placing objects on a high shelf, tucking in a shirt, placing their
hand behind their head and tossing a ball underhand [12].
However, given that the sample in each of these studies
was only partially comprised of WC patients, these findings may not necessarily apply to the WC population.
Most importantly, studies reported that patients with
active WC claims do experience poorer outcomes, both
pre- and post-operatively. WC claimants consistently
experience greater pain, lower quality-of-life (as shown
via subjective questionnaires) and have poorer function
(by way of ROM or strength). Given that tear size and
muscle involvement (number of tendons torn) did not
appear to be associated with compensation status, this
suggests that other mechanisms may be at play.
Discussion
Overall, it was seen that both operative and non-operative
interventions are beneficial for WC recipients who have
a full-thickness RC tear. Although there were only a small
number of studies available, 70% of these studies were
considered to be of at least good quality. In all studies,
both WC and non-WC subjects made substantial gains
in both objective (ROM and strength) and subjective
(pain and health-related quality of life) symptoms in
the first year following treatment.
For operative interventions, these benefits appear to be
maintained over time. In light of the magnitude of RC
pathology in the working population, these results must
be viewed as encouraging. However, studies also consistently reported that outcomes for WC recipients were of
lower magnitude than their non-WC counterparts. WC
patients experienced slower objective gains, had longer
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did typically experience modest but non-significant gains
[10,15,17–20].
Only four studies directly compared WC patients to
those not receiving any form of compensation. Studies
that directly compared WC patients to those not receiving
any form of compensation reported that WC patients
experienced lower outcomes at each assessment period
[10,15,18,19]. Additionally, WC patients typically experienced less post-operative satisfaction, and a lower
proportion of WC patients returned to their similar preoperative work when compared to a non-WC population
[10,18,19]. In instances where these patients did return
to work/activities, it was often at a slower rate than
non-WC patients.
Two of the remaining studies examined non-operative
interventions associated with RC tears [23,24]. These
included the role of clinical versus workplace workhardening programs [23] and physical therapy [24]. Both
reported short-term results (within 1 year) of treatment.
It was shown that in instances of clinical versus workplacebased work-hardening programs, those involved in
workplace-based work hardening had better shoulder
function and return-to-work rates upon program completion. Additionally, physical therapy, by way of patient
education and manual therapy, was shown to be
beneficial, regardless of compensation status.
The final interventional study examined the use of an
early referral system in the surgical management of RC
tears. An important finding was that the use of an early
referral system, as opposed to a traditional ‘gatekeeper’
approach (i.e. where care and potential referral to an
orthopedic specialist is managed by the primary care
physician), resulted in significant cost reductions
($75 000 per patient; P , 0.05) [22].
In addition to a 10-fold decrease in direct and indirect
medical costs, patients in the ‘early referral’ group experienced significant decreases in time spent waiting for surgery (3.9 months in early referral versus 10.1 in
‘gatekeeper’ system) and time off work (6.6 versus 17.1
months).
The complete results of the six determinant studies are
provided in Table 2. These studies examined a wide variety of determinants associated with outcomes relating to
RC injury. The most frequently examined demographic
determinants included age, sex and compensation status,
which were examined in all six studies [12,25–29].
Other demographic determinants included smoking
status (n 5 3) [26,27,29] and hand dominance (n 5 2)
[25,29].
Determinants relating to shoulder status included RC
tear size (n 5 4) [25,26,28,29], pain severity [25], biceps
deformity [25], supraspinatus atrophy (in millimeters)
[25], presence of a drop-arm sign [25] and the number
of RC tendons involved [29]. With respect to general
health status/medical determinants, those examined included time-to-treatment (n 5 6) [12,25–29], injury type
560 OCCUPATIONAL MEDICINE
tients to their non-compensable counterparts is scarce
within the current literature. As such, evidence-based
‘best practices’ in the treatment and assessment of RC
outcomes among WC patients are lacking. In addition,
due to the heterogeneity of WC patients, results from
these studies may not apply to all WC patients with
full-thickness RC tears as there was generally little consideration for the varying nature of occupational demands.
A wide variety of measures were used to assess
outcomes including ‘objective measures’ (e.g. ROM,
strength), ‘patient-reported questionnaires’ (e.g. Constant score, American Shoulder and Elbow Score; Western Ontario Rotator Cuff) and ‘length of time to return to
work/activities’. These included items relating to activities of daily living, functional limitations, work-related
disability and post-operative function. In many cases,
these were simply generic items developed for a particular
study by the investigators. Furthermore, despite the magnitude of the problem in the working population, costrelated data were only reported in a single study. The
heterogeneity of outcomes, interventions, assessment
tools and assessment periods used in previous studies
make it very difficult for clinicians and decision makers
to make cross-comparisons among studies, much less
determine if the findings are meaningful to the subpopulation of WC patients.
The existing body of literature does not provide
clinicians with clear guidance in the treatment of fullthickness RC tears in WC patients. Because of the lack
of consensus in the literature and the extremely limited
body of well-conducted research, it is impossible to extract any variety of meta-analytic data related to the treatment of these injuries. As such, this review cannot provide
evidence-based recommendations and there remains considerable debate as to the most appropriate practices in
the management of these tears in the WC population.
Although limited, the results of the present investigation highlight the disparity in outcomes between WC
claimants and their non-WC counterparts. There is
evidence to suggest that the WC population with fullthickness RC tears start and finish below their nonWC counterparts, especially with respect to quality of life.
Preliminary data suggest that significant benefits may
come from an accelerated model of care, which expedites
the management of such cases. However, despite the cost
savings associated with accelerated care, outcomes of
treatment in the WC population remain below those of
the non-WC population. Thus, accelerated care in isolation does not provide a complete solution to the management question, despite considerable cost savings. Further
research examining compensation status, patient characteristics and the nature of employment as primary outcomes is necessary in order to clarify the mechanisms
responsible for the inferior outcomes. Despite the lack
of evidence in previous literature, outcome, medical cost
and quality of life data indicate that if managed in an
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periods for return to work/activities and perhaps most
importantly experienced greater post-operative dissatisfaction. The reasons for these differential outcomes
remain unclear as the current body of evidence is primarily comprised of retrospective, single surgeon, heterogeneous (WC and non-WC patients in same sample)
designs or studies lacking appropriate risk-adjustments.
Studies examining exclusively WC patients (100% of
sample) or studies that are large enough to do WC subject
sub-analyses are especially needed.
Indeed, there may be great variability among WC
recipients themselves. Traditionally, previous research
has simply categorized patients based upon their WC status alone. Such efforts combine construction workers
with repetitive above-head tasks with those who have
a shoulder injury, but work at a desk job. Given this
heterogeneity within the WC population itself, further
research is necessary to determine how job demands
may affect patients’ expectations and outcomes.
Perhaps, the most interesting findings were related to
the use of an early referral system in the surgical management of RC tears. The results of this study, particularly
the 10-fold decrease in medical costs and the 60% decrease in time spent waiting for surgery and time off work,
demonstrate that there is much improvement to be made
in this area. Further research advocating a proactive approach in the management of RC tears among WC claimants would not only benefit patients and their employers
but may also result in significant cost reductions among
health care systems. Such benefits may also have a greater
societal impact.
From our results, it was also shown that females and
younger patients particularly those under the age of 55
years may experience less promising outcomes and/or
more post-operative dissatisfaction. Although this may
be the product of a ‘survivor effect’, we feel that this is
primarily due to differences in the nature of the work demands placed upon younger patients and their older
counterparts. Further research is also necessary in order
to further clarify the potential reasons for this.
The results of the present study are limited by the lack
of literature regarding WC recipients. In many cases, WC
claimants are excluded from research studies.
Even in cases where WC recipients have been included
within research, stratified or risk-adjusted analyses were either not performed or WC responses could not be separated
from non-WC responses. The current evidence should also
be interpreted with caution as in many cases, these studies
did not include long-term results or were retrospective in
nature. Few studies looked at outcomes beyond the first
year of intervention and few measured the ability of the subject to return to work or unrestricted activities.
Although the majority of studies included in this review
were of sufficient quality, in most cases, WC patients were
represented by only a small subset of each study sample.
The present study highlights that comparisons of WC pa-
K. A. R. KEMP ET AL.: SYSTEMATIC REVIEW OF RC TEARS 561
appropriate fashion, WC patients are capable of returning
to productive employment. What remains unclear, however, are the associated best practices to be employed in
the management of such injuries, which would further
enhance the outcomes that may be associated with expedited care.
Key points
Funding
Workers Compensation Board of Alberta.
Acknowledgements
L.A.B. is a Population Health Investigator who receives salary
support from Alberta Innovates-Health Solutions (formerly
Alberta Heritage Foundation for Medical Research).
Conflicts of interest
None declared.
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