Article Text
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Abstract
Objective To investigate the effectiveness, risk of recurrence and return to activity (RTA) of surgery combined with exercise-based interventions (EBI) versus EBI alone after traumatic anterior shoulder dislocation (ASD).
Design Systematic review and meta-analysis.
Data sources Systematic literature search (MEDLINE, Web of Science, Scopus, Google Scholar).
Eligibility Studies focused on EBI or EBI as a part of postoperative care for adults with an ASD, written in English, and published after 1990. We excluded diagnostic, assessment-based studies on individuals experiencing recurrent shoulder dislocations, concomitant shoulder injury, animal or cadaveric studies. Primary outcomes were dislocation RTA. Secondary outcomes were self-reported outcome measures, strength and range of motion. Random-effects meta-analysis was used to estimate the effect of EBI (SMD; Hedges’ g, RR). The Grading of Recommendations Assessment, Development and Evaluation approach was used to assess the certainty of evidence.
Results Sixty studies were included (n=3598); seven were meta-analysed (n=345). The mean age of participants in the included studies was 26.71±9.19 and 56% of those included were male. Of the 60 studies included in the systematic review, 29 were fair quality (48.3%), 15 studies were good quality (25%) and 16 studies were poor quality (26.7%), (k=0.66). Individuals who underwent EBI alone were 2.03 times more likely to experience recurrent instability than individuals who underwent EBI in conjunction with surgery (RR 2.03, 95% CI 1.03 to 3.97). Individuals who underwent EBI with surgery appeared 1.81 times more likely to RTA than those who underwent EBI alone, although results were not statistically significant (RR 1.81, 95% CI 0.96 to 3.43).
Conclusions Surgery combined with EBI is more effective in reducing the risk of recurrence and possibly increasing RTA than EBI alone after traumatic ASD.
- meta-analysis
- shoulder
- sporting injuries
- sports medicine
- rehabilitation
Data availability statement
No data are available as the data extracted for this systematic review and meta-analysis is available in the published literature.
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WHAT IS ALREADY KNOWN ON THIS TOPIC
Primary traumatic anterior shoulder dislocation (ASD) is associated with complications and risk of recurrent instability.
Rehabilitation for ASD has primarily focused on postsurgical care.
The effectiveness of different types of exercise-based interventions (EBI) for ASD in comparison to surgical management plus EBI is unclear.
WHAT THIS STUDY ADDS
Surgery combined with EBI is more effective in reducing the risk of recurrence and possibly increasing return to activity when compared with EBI alone.
Stand-alone EBIs without shoulder surgery are effective in improving shoulder internal rotation strength and improving passive range of motion postinjury, with multimodal EBI demonstrating greater functional improvements.
The findings of this review are predominantly based on young male individuals who sustained a primary traumatic ASD in both athletic and non-athletic settings.
More research is needed to improve the quality of evidence informing EBI recommendations for ASD.
HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY
The key findings from this systematic review and meta-analysis help inform research, practice and policy by demonstrating the combined effectiveness of surgery and exercise-based interventions (EBI) following primary traumatic anterior shoulder dislocation (ASD).
Introduction
Dislocation of the glenohumeral joint refers to the complete loss of contact between the articulating surfaces of the glenoid and humeral head. This diagnosis is usually confirmed by radiography.1 The overall incidence of primary traumatic anterior shoulder dislocation (ASD) in the UK is between 11 and 51 per 100 000 person-years.2–4 The male incidence rate is 2.64 times higher than that of females, at 34.9 per 100 000 person-years.4 Nearly 47.1% of ASD episodes occur between the ages of 20 and 29 years.4 The frequency of instability, therefore, is inversely proportional to the age of an individual with a higher incidence in younger individuals.5 Sixteen per cent of older individuals (ie, over 60 years) sustained an ASD from simple falls6; while ASD in younger individuals (less than 30 years) occurs predominantly in athletic settings.6 ASD can be associated with secondary injuries such as avulsion of glenohumeral ligaments, labral damage, rotator cuff pathologies, axillary nerve injury and bony damage such as the Hill Sachs lesion.7 8 Injury of concomitant structures may predispose an individual to recurrence of dislocation, chronic symptoms, reduced activity participation and decreased quality of life (QOL).9 ASD and recurrence can contribute to shoulder muscle dysfunction and reduced proprioception.10 Indeed, recurrence of ASD is a common complication, especially in young active males with rates as high as 64%.11
Typical principles of ASD rehabilitation include a focus on dynamic strength and control of the glenohumeral and scapulothoracic musculature, proprioceptive retraining and functional progression.12 The deltoid and rotator cuff muscles form a force couple that keep the humeral head centred in the glenoid cavity, while an anterior–posterior force couple is formed by subscapularis anteriorly and the infraspinatus posteriorly.13 Disruption of the deltoid-rotator cuff force couple can give rise to deltoid overactivity, resulting in increased superior translation of the humeral head.14
Exercise-based interventions (EBIs) are an integral component of post-ASD recovery either alone, or in combination with surgical interventions. ASD management requires a phasic, criteria-driven and graded exercise programme that restores strength, range of motion (ROM) and function of the glenohumeral joint.15 The current literature reflects a range of different EBI, as summarised in table 1. There is a need to better understand the effects of EBI (ie, EBI in conjunction with surgery and EBI in the absence of surgery, hereafter: ‘EBI alone’ and ‘multimodal EBI’16 that uses additional strategies other than a home-exercise programme such as neuromuscular exercise and ultrasound-guided elastic resistance training) on recurrence and functional outcomes.17 Neuromuscular exercise in this context includes strength, coordination, balance and proprioception under the guidance of an exercise-based professional; whereas the elastic resistance training uses a range of movements, while using ultrasound to optimise recruitment of appropriate musculature.9 While several studies have investigated EBI as a component of ASD management,9 18 19 to date no systematic review and meta-analysis has evaluated the effectiveness of EBI for ASD by comparing different types of EBI. This study aimed to review and synthesise the literature to compare the effectiveness of surgery in conjunction with EBI to EBI alone on recurrence, return to activity (RTA) and functional outcomes in adults who sustain an ASD in athletic and non-athletic settings.
A summary of the multicomponent rehabilitation protocols described in the included studies9 33 34 55 97
Methods
We carried out a systematic review and meta-analysis investigating EBI following ASD. The Preferred Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed for the conduct and reporting of this study.20 Further, the PRISMA-S extension21 was used to guide our search methodology. This review was prospectively registered with the International Prospective Register of Systematic Reviews (PROSPERO) (registration number CRD42021262494).
Literature search
We searched the following electronic databases: MEDLINE (PubMed), Web of Science (EBSCO), Scopus (EBSCO) and Google Scholar (Google) for suitable studies conducted from 1990 to May 2022, in English language only. This search was updated in March 2023. Controlled vocabulary (Medical Subject Headings (MeSH) in MEDLINE), for example, “anterior shoulder dislocat*” for “anterior shoulder dislocation”, and “exercise therap*” for “exercise therapy”, were used. The full search strategy can be accessed in online supplemental table S1. From the search, all identified citations were collated and uploaded into Mendeley Reference Manager V.1.19.4 (Elsevier Mendeleyd, London, UK).
Supplemental material
Inclusion and exclusion criteria
The ‘PICOS framework’ (ie, population, intervention, comparison, outcomes, study type) was used for the inclusion and exclusion of studies.
Population
Adults who sustained an ASD in an athletic or occupational setting.
Intervention
Any EBI (ie, EBI alone or EBI in conjunction with surgery) for treating ASD, including strength, neuromuscular control/proprioception, plyometrics and mobility training.
Comparison
Standard treatment defined as usual practice either after surgery or as a stand-alone.
Outcomes
Primary outcomes: recurrence, RTA (ie, sport, work or regular activities of daily living).
Secondary outcomes:
Self-reported measures:
American Shoulder and Elbow Surgeons Scale (ASES).
Constant-Murley Score (CMS).
The Disabilities of the Arm, Shoulder and Hand questionnaire (DASH).
Rowe score.
Visual Analogue Scale (VAS).
Western Ontario Shoulder Index (WOSI).
Shoulder muscle strength.
Shoulder ROM.
Study type
We included randomised controlled trials (RCTs), quasi-RCTs or observational studies that only evaluated the efficacy of an EBI either postoperatively, or as stand-alone non-surgical management for ASD. We excluded case reports, secondary research and conference papers. For our meta-analyses, only studies that included both a control and an experimental (ie, surgery+EBI or multimodal EBI) group were synthesised.
Exclusion criteria
Non-human or cadaveric studies.
Studies involving non-ASD shoulder injuries such as recurrent shoulder dislocation, multidirectional instability, shoulder impingement syndromes, acromioclavicular or sternoclavicular injuries, and posterior shoulder dislocation;
Passive interventions or non-EBI such as immobilisation, closed reduction and passive pain modulating physiotherapeutic modalities such as electrotherapy.
Studies that did not describe or report any rehabilitation following an ASD.
Studies that focused on postoperative complications.
Studies that focused only on assessment of traumatic ASD only.
Study selection
Two authors (VC and TL) independently screened the title and abstracts of the studies identified from the search, and then independently screened full-texts of relevant studies. Following this, a reference list search was performed by CD to identify any additional relevant studies. Initially, any disagreements were discussed with a fourth author (RMJdZ) at both abstract and full-text stages, until consensus was reached.
Risk of bias assessment
Two independent reviewers (RMJdZ and VC) assessed the risk of bias and methodological quality of eligible articles using the previously validated Downs and Black checklist.22 Twenty-seven items were rated as yes (=1) or no/unable to determine (=0), and one item (number 27 that assessed power calculation) was rated on a 3-point scale (yes=2, partial=1 and no=0).23 Scores range from 0 to 28 including the adjustment question 27 to a binary (yes/no) response (ie, sufficient power with sample size or not). The higher the score, the better the methodological quality and hence lower risk of bias. The quality of studies was categorised as follows: excellent (26–28), good (20–25), fair (15–19) and poor (14).24 Points were only awarded if a study clearly met the criteria. If there was disagreement between reviewers (RMJdZ and VC), a third assessor (TL) provided consensus.
Data extraction
Data were extracted by TL and CD using a standardised data extraction tool (JBI SUMARI, JBI Adelaide, SA, Australia) and Excel spreadsheets (Microsoft Excel V.2016, Microsoft, Redmond, Washington, USA). The extracted data included details of the population, study methods, interventions and outcomes relevant to the review objective. The authors of papers were contacted to request any missing or additional data, where required. If the authors did not respond within 2 weeks, they were contacted again to follow-up. If data were not obtained within 4 weeks the study, or the relevant section thereof, was not included in the review.
Statistical analyses
Means, SD and sample sizes were extracted for all continuous outcome measures; hedges’ g effect sizes and the respective 95% CIs were calculated, with the magnitude of effect defined using standardised conventions, with small, moderate and large effect sizes aligning with 0.20, 0.50 and 0.80.25 Data were analysed via a change score from premeasurement to postmeasurement using weighted mean differences and Hedges’ g effect sizes in the random effects model (Knapp-Hartung SEs using the Sidik-Jonkman model, as the best model accounting for normality and sparse data bias.26–28 For categorical data (recurrence and RTA), data were analysed using both standardised (risk ratio) and unstandardised models (log risk ratio). For alternative methods of data reporting, they were converted into a corresponding effect size (eg, SE of the mean was converted to SD using the following formula SE x the square root of the number of participants=SD). If data extraction of an included study was not possible, the study was excluded from quantitative analysis. If requested data were not provided, the outcome was excluded from quantitative analysis, but used to inform qualitative synthesis. If data could be obtained from figures or graphs, extrapolation of the mean and respective measure of variance was conducted using digitisation software (Get Data Graph Digitizer), and conversions applied to estimate the respective effect size and 95% CIs. Statistical heterogeneity was investigated for studies by calculating Cochrane’s Q, where significant heterogeneity was indicated by p≤0.10. The magnitude of statistically significant heterogeneity was determined using the I2 statistic, where values of 25%, 25%–75% and 75% represent low, moderate and high levels of heterogeneity, respectively.29 Where heterogeneity exceeded moderate (>50%), follow-up analyses were conducted to investigate the source of this heterogeneity, such as time since surgery, point of measurement (follow-up time). Specifically, a leave-one-out sensitivity analysis was conducted, where the overall effect from removing a single study was examined. All analyses were carried out in Stata V.17.0 MP (StataCorp).
For the primary outcomes (recurrence and RTA), the potential of non-reporting bias was evaluated by using the Outcome Reporting Bias in Trials (ORBIT) framework30 31 to investigate potential missing results. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to determine the certainty and strength of evidence carried out in accordance with set recommendations.25 For example, observational studies were assigned a ‘low’ certainty of recommendation prior to then either being upgraded or downgraded from this point, based on the quality of the evidence.32 Studies were upgraded for factors such as large effect sizes or dose–response relationships between the intervention (eg, surgical+EBI) and outcomes (ie, recurrence, RTA, self-report measures and functional outcomes). Studies were downgraded according to GRADE for non-reporting bias, indirect relationships with results (unexplained confounding) or inconsistencies between studies. From this process, qualitative ratings for the certainty of evidence and recommendations were listed as ‘high’, ‘moderate’, ‘low’ or ‘very low’, and were able to be interpreted according to the GRADE approach.32
Equity, diversity and inclusion statement
Our research team comprises female and male members, early-career and mid-career researchers, representation from diverse disciplines, and hailing from three countries. In our study, we specifically focused on individuals with traumatic ASD in both athletic and non-athletic contexts, ensuring representation of both males and females. It is important to note that the majority of studies conducted in this field are carried out in higher resource countries, often published by more developed nations. Unfortunately, there is a notable absence of publications from lower resourced countries, which highlights a disparity in research findings between settings with varying resource levels. We acknowledge that the findings derived from our study may have limited generalisability due to the specific to settings with fewer resources, presenting distinct challenges and requiring tailored approaches. There is a need for further investigations conducted in diverse settings to help bridge the existing knowledge gaps and promote equitable healthcare practices globally. Despite these constraints, our study provides valuable insights that can significantly contribute to future research, interventions and policy-making within the identified context.
Results
Across four databases, 3616 studies were identified, and 842 duplicates were removed. Figure 1 illustrates the identification of studies and each of the stages for the review process according to the PRISMA flow diagram.20 From a total of 2285 titles and abstracts screened, and 576 full-text articles assessed, 60 studies (n=3598) were included for qualitative synthesis and 7 (n=345) studies were included in the meta-analysis. The mean age of participants in the included studies was 26.71±9.19 and 56% of those included were male.
PRISMA flow diagram20 delineating the number of studies included and excluded through each stage of screening. *Indicates the four outlined databases at the top of this figure. **Indicates total number of records excluded at title/abstract stage. ASD, anterior shoulder dislocation; PRISMA, Preferred Items for Systematic Reviews and Meta-Analyses.
Study characteristics
The characteristics of the studies, participants and interventions are summarised in online supplemental table S2. Of the included studies, 46 focused on EBI combined with surgical intervention, and 14 focused on EBI alone. Data from nine studies were pooled for meta-analysis, with a total of 411 participants (n=228 EBI in conjunction with surgery; n=168 EBI alone). Some of the common components of EBI were: mobility exercises such as active ROM, active assisted ROM, capsular stretching exercises and strength training, including: resisted rotator cuff and scapular stabilisation exercises (60 studies). Other interventions were sports-specific training (seven studies), overhead training (three studies), aerobic conditioning (four studies), isokinetic exercises (one study), Bodyblade resisted vibration training (one study), hydrotherapy (one study), plyometric training (three studies) and neuromuscular training (three studies). The median length of follow-up across the studies was 0.9 years and ranged from 3 weeks to 7 years. The included studies used a range of both self-reported and objective measures to assess physical function. In 36 out of 60 studies, the number of male participants was higher than female participants. Overall, there were 2150 male participants and 463 female participants, across the 60 studies.
Supplemental material
Quality of studies
Of the 60 studies included in the systematic review, 29 were fair quality (48.3%), 15 studies were good quality (25%) and 16 studies were poor quality (26.7%). The risk of bias (internal validity—confounding bias) within the included studies was low or unclear as a majority of the studies were observational in design (34/60). The individual scoring of each included study can be found in online supplemental table S2. The ‘reporting’ of the included papers scored high, with the commonly unreported aspect being failure to report adverse events following the intervention, and the characteristics of the participants lost due to adverse events. While these studies may not have had participants who experienced adverse events, reporting this in the paper would still have been beneficial. External validity was generally high due to the inpatient, outpatient or home settings incorporated in the included studies. However, all studies restricted normal daily free-living activities until 4–6 months following ASD to enhance internal validity. The included studies took a varied approach to the data collection and analysis of their outcome measures, influencing internal validity. One study used a blinded interpretation framework to reduce the bias of interpretation,9 thereby increasing its internal validity. Three studies blinded the investigator measuring the outcomes,33–35 while many studies (33/60) did not. The level of agreement (kappa) for the methodological quality assessment was 0.90 (weighted kappa: 0.66).
The GRADE certainty of evidence was low for recurrence and RTA (see online supplemental table S3).
Supplemental material
Meta-analysis
For each of the primary and secondary outcome measures, the results of the meta-analysis are presented below.
Non-recurrence
The meta-analysis for non-recurrence was based on pooled data from four studies with a total of 216 participants. Of the total, 94 underwent EBI alone while the remaining 122 underwent EBI in conjunction with arthroscopic surgery. There was substantial heterogeneity in the true outcomes of recurrence (I2=51.17%). Non-recurrence was significantly better following EBI in conjunction with surgery. Individuals who underwent EBI in conjunction with surgery were 2.03 times more likely to have treatment success (ie, not sustain a recurrent ASD) than individuals who underwent EBI alone (RR 2.03, 95% CI 1.03 to 3.97) (figure 2) (online supplemental figure 1).
Supplemental material
Forest plot from the meta-analysis showing head-to-head comparison between non-recurrence outcomes following EBI in conjunction with surgery and EBI alone. Event, successful treatment; yes, successful treatment with no episode of ASD recurrence; no, unsuccessful treatment marked by episode of ASD recurrence. ASD, anterior shoulder dislocation; EBI, exercise-based intervention.
Return to activity
The meta-analysis for RTA included three studies, with a total of 143 participants. Of the total, 39 participants underwent EBI alone and the remaining 104 underwent EBI in conjunction with surgery. There was low heterogeneity in the true outcomes of RTA (I2=12.68%). RTA was significantly better following EBI in conjunction with surgery. Individuals who underwent EBI in conjunction with surgery appeared 1.81 times more likely to RTA following ASD than individuals who underwent EBI alone, although results ranged from no improvement in RTA to over three times more likely with surgery (RR 1.81, 95% CI 0.96 to 3.43) (figure 3) (online supplemental figure 2).
Supplemental material
Forest plot from the meta-analysis showing head-to-head comparison between RTA outcomes following EBI in conjunction with surgery and EBI alone. EBI, exercise-based intervention; RTA, return to activity.
Self report measures
The meta-analysis included the following comparisons:
Rowe score
One study with a total of 65 participants. Of the total, 38 participants underwent EBI in conjunction with surgery and 27 underwent EBI alone (figure 4). The outcomes were in favour of EBI in conjunction with surgery when compared with EBI alone but were not statistically significant (Hedges’ g 0.33, 95% CI −0.16 to 0.82, p=0.19).
Forest plot from the meta-analysis showing comparison between self-report outcomes (ASES, CMS and Rowe Scores) following EBI in conjunction with surgery and EBI alone. ASES, American Shoulder and Elbow Surgeons Scale; CMS, Constant-Murley Score; EBI, exercise-based intervention.
Constant-Murley Score
One study with a total of 30 participants. Of the total, 15 participants underwent EBI in conjunction with surgery and 15 underwent EBI alone (figure 4) (online supplemental figure 3). The outcomes were in favour of EBI in conjunction with surgery when compared with EBI alone and were statistically significant (Hedges’ g 1.60, 95% CI 0.79 to 2.40, p<0.001).
Supplemental material
American Shoulder and Elbow Surgeons Scale
One study with a total of 45 participants. Of the total, 23 participants underwent EBI in conjunction with surgery while 22 underwent EBI alone (figure 4). The outcomes were in favour of EBI in conjunction with surgery when compared with EBI alone but were not statistically significant (standard mean difference (SMD) 0.21, 95% CI −0.37 to 0.78, p=0.48).
Overall, for these self-report measures the outcomes were in favour of EBI in conjunction with surgery when compared with EBI alone, but was not statistically significant (Hedge’s g 0.66, 95% CI −1.19 to 2.52, p=0.26). Heterogeneity was I2=82.07% (considerable heterogeneity) for this model (Sidik-Jonkman). The estimates and prediction intervals are shown in figure 4.
We conducted a subgroup analysis for the CMS per the function, pain, ROM, strength and overall composite score components. The scores for each component were compared between the EBI in conjunction with surgery group, and EBI alone group. Heterogeneity was I2=48.35% (considerable heterogeneity) for this model (Sidik-Jonkman). The CMS scores were not normally distributed as indicated by the skewness 1.81 for the mean change score for surgical and EBI and 0.97 for the mean change-score for EBI alone. The subgroup analysis demonstrated the following CMS component specific results:
Pain—outcomes in favour of EBI in conjunction with surgery when compared with EBI alone (Hedge’s g 0.95, 95% CI 0.21 to 1.69).
Function—outcomes in favour of EBI in conjunction with surgery when compared with EBI alone (Hedge’s g 1.43, 95% CI 0.65 to 2.22).
ROM—outcomes in favour of EBI in conjunction with surgery when compared with EBI alone (Hedge’s g 1.14, 95% CI 0.39 to 1.89).
Strength—outcomes in favour of EBI alone when compared with EBI in conjunction with surgery (Hedge’s g 2.32, 95% CI 1.41 to 3.24).
Total score—outcomes in favour of EBI in conjunction with surgery when compared with EBI alone (Hedge’s g 1.60, 95% CI 0.79 to 2.40).
Overall, for this one study, there were improved CMS scores for each subscale and total score for surgical and EBI, when compared with EBI alone (Hedge’s g 1.45, 95% CI 0.82 to 2.09, p<0.001). The estimates and prediction intervals are shown in figure 5 (online supplemental figure 4).
Supplemental material
Forest plot from the meta-analysis showing head-to-head comparison for CMS-specific outcomes following EBI in conjunction with surgery and EBI alone. CMS,Constant-Murley Score; EBI, exercise-based intervention.
Physical function measures: strength
The meta-analysis for strength outcomes was based on one study with a total of 45 participants.36 Of the 55 participants, 23 underwent EBI in conjunction with surgery and 22 underwent EBI alone. All participants followed the same rehabilitation protocol for the first 2 months, which included immobilisation in a suspension sling for 3 weeks, and light household activities. The experimental intervention was started 2 months after the surgery. All follow-up assessments (including control group and exercise group participants) were performed individually. The first follow-up was completed 2 weeks after starting the experimental intervention (ie, 10 weeks postsurgery). The second follow-up was 6 weeks after starting the experimental intervention, with subsequent follow-ups at 4 and 6 months after starting the experimental intervention.
Outcomes for each group of muscles tested were compared, as follows:
Grip strength—outcomes in favour of EBI alone, but not statistically significant (Hedge’s g −0.26, 95% CI −0.83 to 0.32, p=0.38);
External rotation strength—outcomes in favour of EBI alone, however, but not statistically significant (Hedge’s g 0, 95% CI −0.57 to 0.57, p=1.00).
Internal rotation strength—outcomes in favour of EBI alone (Hedge’s g −1.05, 95% CI −1.67 to −0.44).
Overall, strength outcomes were not statistically significant (Hedge’s g −0.43, 95% CI −1.78 to 0.93, p=0.31). The heterogeneity was moderate with I2=69.48% (figure 6) (online supplemental figure 5).
Supplemental material
Forest plot from the meta-analysis showing head-to-head comparisons between strength outcomes following EBI in conjunction with surgery and EBI alone. EBI, exercise-based intervention.
Physical function: ROM
Active AROM
Of the total 75 participants, 38 underwent EBI in conjunction with surgery and 37 underwent EBI alone (figure 7) (online supplemental figure 6).
Supplemental material
Forest plot from the meta-analysis showing head-to-head comparison between AROM outcomes following EBI in conjunction with surgery and EBI alone. AROM, active range of motion; EBI, exercise-based intervention.
The meta-analysis for Forward flexion AROM was based on two studies with a total of 75 participants. Of the total, 38 participants underwent EBI in conjunction with surgery and 37 underwent EBI alone. The outcomes were in favour of EBI in conjunction with surgery, but were not statistically significant (Hedge’s g 0.32, 95% CI −0.12 to 0.77, p=0.16). Outcomes for the movements tested for AROM were compared, as follows:
Abduction AROM—The meta-analysis was based on one study with a total of 30 participants. Of the total, 15 participants underwent EBI in conjunction with surgery and 15 underwent EBI alone. The outcomes were in favour of EBI alone, but not significant (Hedge’s g −2.27, 95% CI −3.18 to −1.37).
External rotation AROM: The meta-analysis was based on one study with a total of 45 participants. Of the total, 23 participants underwent EBI in conjunction with surgery and 22 underwent EBI alone. The outcomes were in favour of EBI alone but not statistically significant (SMD −0.40, 95% CI −0.99 to 0.18, p=0.17).
Internal rotation AROM: The meta-analysis was based on one study with a total of 45 participants. The outcomes were in favour of EBI alone but not statistically significant (Hedge’s g −0.14, 95% CI −0.71 to 0.44, p=0.64).
Overall, AROM outcomes were in favour of EBI alone, but were not statistically significant (Hedge’s g −0.40, 95% CI −1.70 to 0.89, p=0.44). The heterogeneity was high with I2=89.68% (figure 7) (online supplemental figure 6).
Passive range of motion
Overall, the passive range of motion (PROM) outcomes were in favour of EBI in conjunction with surgery when compared with EBI alone. However, the outcomes were not statistically significant (Hedge’s g 0.07, 95% CI −0.74 to 0.89, p=0.86). Outcomes for the movements tested for PROM were compared, as follows:
Abduction PROM—The meta-analysis was based on one study with a total of 30 participants. Of the total, 15 participants underwent EBI in conjunction with surgery and 15 underwent EBI alone. The outcomes were in favour of EBI alone, and were statistically significant (Hedge’s g −1.13, 95% CI −1.89 to −0.38, p<0.001).
External rotation PROM—The meta-analysis was based on two studies with a total of 75 participants. Of the total, 38 participants underwent EBI in conjunction with surgery and 37 underwent EBI alone. The outcomes were in favour of EBI in conjunction with surgery, and were statistically significant (Hedge’s g 0.89, 95% CI 0.29 to 1.49, p<0.001).
Forward flexion PROM—The meta-analysis was based on one study with a total of 30 participants. Of the total, 15 participants underwent EBI in conjunction with surgery and 15 underwent EBI alone. The outcomes were in favour of EBI in conjunction with surgery, but were not statistically significant (Hedge’s g 0.19, 95% CI −0.51 to 0.89, p=0.59).
Internal rotation PROM: The meta-analysis was based on two studies with a total of 75 participants. Of the total, 38 participants underwent EBI in conjunction with surgery and 37 underwent EBI alone. The outcomes were in favour of EBI in conjunction with surgery, but were not statistically significant (Hedge’s g 0.27, 95% CI −0.31 to 0.84, p=0.37).
The heterogeneity was high with I2=84% (figure 8) (online supplemental figure 7).
Supplemental material
Forest plot from the meta-analysis showing head-to-head comparison between PROM outcomes following EBI in conjunction with surgery and EBI alone. EBI, exercise-based intervention; PROM, passive range of motion.
Qualitative synthesis
Primary outcomes:
Recurrence
Eleven included studies evaluated recurrence following ASD.37–47 In one study,37 the mean (±SD) age of participants was 23.49±7.3 years, with a recurrence rate of 18.2% following an arthroscopic repair and EBI. Another study43 included 20 naval officers who underwent a 4-month EBI, of whom five sustained a recurrence (three of these occurring within 6 months of the ASD). This suggests that clearance of participants to unrestricted sporting or occupational activities must be cautiously recommended during the first 6 months following an initial episode of ASD. Another study44 followed 30 athletes who sustained an ASD. All participants underwent the same course of physical therapy that included strength and mobility training.
On average, there were 1.4 in-season recurrences per season, per athlete. The chances of recurrence were higher in athletes who returned to sport within the same season, an important consideration for return to play decisions. A case series of 42 consecutive patients38—who, on average, participated in sports for 2 hours a day, 3 days a week before they sustained an anterior-inferior shoulder dislocation—reported an overall recurrence rate of 22.5%, mostly occurring within the first year following arthroscopic capsulo-labral reconstruction. All of these except one were contact or overheard athletes. Overhead athletes were more at risk of recurrence compared with other included participants. A negative relationship between the University of California at Los Angeles Shoulder Score (UCLA) and rate of recurrence was observed: that is, lower functional rating on UCLA was accompanied by higher rates of recurrence (33.1% in the low UCLA group vs 29.1% in the high UCLA group). Overall, recurrence was higher within a year of the initial episode in young active males, and in individuals who returned to their preinjury level of activity within 6 months.
Return to activity
Of the included studies, 12 looked at RTA following ASD.9 39 41–46 48–51 The studies used a range of EBIs including postsurgical EBI,39 41 42 45 46 48–51 multimodal EBI9 and EBI alone.43 44 48 50 The majority of studies among non-athletes reported RTA at 3–4 months following ASD, whereas one study of athletes51 reported an average RTA of 8.4 months following arthroscopic stabilisation and postoperative EBI. Most of the included studies report successful RTA (as high as 80%–90%) indicating that EBI can help to facilitate successful RTA. As outlined above, this finding is supported mostly by studies (n=9) that included surgery and postoperative EBI.
Secondary outcomes: self-report measures
Rowe score
The Rowe score (0–100; where higher scores reflect greater function) was reported in seven studies,37–40 52–54 of which four37 39 52 54 reported follow-up scores. Studies reported Rowe scores after 13 years37 (median±SD= 90.0±20.5), 6 weeks54 (mean±SD=81.8±24.9 and 84.8±23.3 for dominant and non-dominant), and 2 years (mean=96.5). Archetti Netto et al 52 compared outcomes of open and arthroscopic Bankart repairs (each with postsurgical EBI), and reported the following outcomes: 79% excellent, 14% good and 7% fair Rowe scores (descriptive data not provided). Three studies reported changes from surgery plus EBI from baseline to follow-up including statistically significant improvements (all p≤0.001) in mean scores from preoperative (range: 24–64) to postoperative (range: 80–90).38 40 53 Interventions for each included: arthroscopic Bankart repair plus EBI,38 open reconstruction plus EBI40 and open Bankart repair plus multimodal EBI.53
Western Ontario, Shoulder Instability Index
The WOSI was used as a QOL outcome measure in six studies with 446 participants.5 9 31 42 55 The WOSI is a 21-item scale assessing physical symptoms, sport/recreation/work function, lifestyle function and emotional function (higher score indicates worse QOL). Participants in one study55 demonstrated an improvement in their WOSI scores (mean±SD), 4.5±2.5 years following shoulder reconstruction. They underwent a 4-week postoperative rehabilitation programme (ROM exercises, dynamic strengthening) and returned to activity at 6 months, with a 15%±15% improvement in their WOSI scores at follow-up. Participants in another study9 underwent two different forms of EBI (neuromuscular rehabilitation, or home-based exercises). This study found no statistically significant difference in total or subdomain WOSI scores. Another study among athletes (n=62)56 investigated enhanced-EBI (ie, functional rehabilitation programme comprising supervised ROM, strengthening and plyometric exercises) following arthroscopic Bankart repair. Mean WOSI scores preoperatively were 1578.0±60.9 and 178.9±32.3 postoperatively at 2 years (Δ 1399.1±63.2, p<0.001).
One study57 investigated outcomes cross-sectionally following three to 6 weeks of enhanced-EBI only for both ASD and recurrent-ASD (most-recent occurrence). Those who had experienced an ASD (n=34) had a mean±SD WOSI score of 1064±373.2, compared with 1048.3±371.5 among individuals with recurrent-ASD (n=22). Though no comparison was drawn between a control, or EBI in conjunction with surgery, this study demonstrated that there was no statistically significant between group difference. A second study58 investigated the effectiveness of three EBI only protocols: traditional (ie, resistance band-based exercise), Bodyblade (ie, resisted vibration exercise), and a mixed programme of both—over an 8-week period. All three groups improved significantly at 8 weeks follow-up, with no significant difference between them. At the 8-week follow-up a 59.4% improvement in WOSI score was observed in the traditional EBI group, a 56.5% improvement in the Bodyblade group, and 43.3% improvement in the mixed group. A third study,42 compared two types of surgical management for ASD (traditional vs immediate arthroscopic stabilisation). One group underwent a 3-week immobilisation period followed by physiotherapy, while another group underwent a 4-month rehabilitation programme. All participants demonstrated a significant improvement in WOSI scores at the 24-month follow-up with the immediate surgical group showing significantly better results (287.01±290.19) than the traditional group (633.93±547.25) (p=0.03). In another study,5 252 participants underwent sling immobilisation and a 12-week rehabilitation programme. There was no significant improvement in WOSI score at the 1-year and 2-year follow-up assessments. Overall, the included studies reported on a range of ASD management approaches, and had varying lengths of follow-up and rehabilitation programmes. WOSI scores improved in participants who underwent a well-structured EBI, in conjunction with surgery.
Constant Murley Score
The Constant Murley Score (0–100; where higher scores reflect greater function) was reported in two studies.37 57 This study reports on a 13-year follow-up of patients who underwent arthroscopic Bankart repair with postoperative EBI. Except for a standardised postoperative ROM protocol, a physiotherapist determined an appropriate rehabilitation programme. While no preintervention data are reported, the Constant Murley Score (mean±SD) of 104 participants was 94.0±9.1 at 13-year follow-up, similar to those not reporting recurrence. The Constant Murley Score was also used in the aforementioned study57 cross-sectionally comparing 3–6 weeks of enhanced-EBI for ASD (initial occurrence) and recurrent-ASD (most recent occurrence), respectively. Scores were 70.4±19.4 for the recurrent-ASD group, and 64.4±19.1 for the ASD group. Again, no significant between group difference was observed.
American Shoulder and Elbow Surgeon’s shoulder score
The ASES was used to measure postoperative QOL in six studies with a total of 336 participants.36 37 53 55 59 60 With 100 maximum points, this scale weighs 50% of its questions to assess pain and 50% to assess function. Participants from two studies with a 1-year follow-up reported an improvement of 16 points (95% CI 10 to 23)36; and (64±19.7 to 92.1±3.5 at follow-up p<0.001), following arthroscopic Bankart repair with multimodal EBI.53 Similarly, 83 participants from a study,60 demonstrated an improvement in ASES scores at 33 months following arthroscopic Bankart repair plus multimodal EBI 75.4±17.6 to 94.9±9.6). Another study investigating multimodal-EBI following arthroscopic Bankart repair56 reported significant ASES score improvements. Preoperatively ASES scores were 45.5±3.4, and 2 years postoperatively were 89.3±3.2 (Δ 43.8±4.0, p<0.001). Participants in one study55 reported their satisfaction level (with respect to pain and function) as extremely satisfied following capsule repair (92±12, range: 60–100), with a mean follow-up period of 4.5 years. Another study37 reported ASES scores 93±17.6, but with a longer follow-up period of 13 years following arthroscopic Bankart repair plus EBI. Further, participants who experienced a recurrent episode of shoulder instability during the follow-up period reported lower ASES scores (87.9±15.9) when compared with participants who did not have a recurrent episode of shoulder instability (93.2±9.1). Overall, ASES outcomes were observed to improve through surgical intervention in combination with EBI. All the studies reported an improvement that exceeded the minimal clinically important difference range of 6.4–17 points.61
Disabilities of the Arm, Shoulder and Hand questionnaire
The DASH outcome measure (0–100; 0=no disability; 100=severe disability) was reported in two studies.52 62 Outcomes were reported at the following time points (mean±SD): preoperatively (14±14.6), 3 months (11.8±9.2), 4.5 months (5.7±4.4), 6 months (7.5±9.7), 9 months (4.1±4.7), 12 months (3.5±4.2) and 24 months (2.1±3.3). Netto et al 52 compared postoperative outcomes between arthroscopic and open Bankart repair procedures (n=50), both with postoperative EBI. Final follow-up was completed at mean time point of 37.5 months on a total of 42 study participants. Mean±SD were reported for both open (4.22±5.8) and arthroscopic (2.65±7.3) cohorts, with a significant difference between groups (p=0.031).
Pain intensity
Use of a VAS (VAS; 0=no pain; 10=maximal pain) for pain intensity was reported in four studies.37 53 54 63 Hwan and So63 reported improvements in pain intensity of 8.0 at baseline (initial, postinjury) to 2.0 at 5 months following rehabilitation with EBI alone. Additionally, Rhee and Lim53 reported an improvement in pain intensity from 2.8 at baseline (preoperative) to 1.30 at 1 year following open Bankart repair. Two studies only presented data for 13-year37 and 6-week54 follow-up, without including any baseline data. One study used the numerical pain rating scale.57 This previously detailed cross-sectional study compared ASD (initial occurrence) with recurrent-ASD (most recent-occurrence) following 3–6 weeks of multimodal-EBI only. No significant difference was observed between groups.
Shoulder Rating Questionnaire
The Shoulder Rating Questionnaire (SRQ),64 a joint-specific questionnaire comprising five domains (VAS of overall function, pain, activities of daily living, recreational life and work), was reported in one study only.65 For that study,65 data were reported at baseline and at 9 months follow-up (lower scores reflected better function). Scores for the SRQ were significantly different between conditions at baseline (t=8.77, p<0.001) and the two time points (t=3.59, p<0.001). Despite this, when using a cut-off score of 11% change (indicating those who reported being ‘much better’), there was a sensitivity value of 55% and specificity of 86% (AUC 0.68 via ROC curve). This indicates that the SRQ may be effective at excluding those with worse function but less effective at identifying those classified as ‘much better’.
Lysholm score
One study included functional assessment of the shoulder via the Lysholm Score.66 This scoring system67 includes pain during activity, after activity and at rest using the VAS (0=no pain; 10=maximal pain). Assessments were undertaken in this study at 1-month, 6-month and 12-month follow-up with no statistically significant differences observed between arthroscopic and non-surgical treatment groups. However, the proportion of scores in the ‘excellent’ group (94–100 points) increased from 1-month to 6-month follow-up in both the arthroscopic (7%–53%) and non-surgical (7%–40%) treatment groups. There appeared to be a decrease in Lysholm Score from 6 months to 12 months.
University of California at Los Angeles Shoulder Score
Archetti Netto et al 52 report on the UCLA score (0–35; excellent=30–35, good=28–33, fair=21–27, poor=0–20) for 42 participants at a mean time point of 37.5 months. Results were categorised as good/excellent and fair/poor. Of the participants who underwent an open procedure, 23 (92.0%) reported a rating of either good or excellent, while 2 participants (8.0%) reported ratings of either fair or poor. Of the participants who underwent an arthroscopic procedure, 16 (94.1%) reported ratings of either good or excellent, and 1 participant (5.9%) fair or poor.
Oxford Instability Shoulder Score
Two studies reported on the Oxford Instability Shoulder Score (OISS) (12=best function, 60=worst function). Moser et al 65 assessed the outcomes for patients who participated in EBI for shoulder instability. Scores were reported at baseline and at 9 months. The OISS scores were reported as a percentage (mean±SD) and 95% CI’s at different time points: baseline=45±20, 41–49; 9 months=21±19, 16–26; differential=−22±18, 17–26. Jakobsen et al 41 compared exercise-based rehabilitation with open Bankart repair in 76 patients following diagnosis via arthroscopy. The OISS was determined at 10 years following intervention. A total of 37 patients underwent surgical repair and 39 were managed non-surgically. Results were categorised as ‘excellent’ for 19 (53%) participants, and ‘good’ for 6 (17%) participants. In the non-surgically managed group, 24 (62%) participants experienced recurrence. The majority of these participants (n=19, 80%) underwent subsequent open or arthroscopic repair, with 63% reporting a ‘good’ or ‘excellent’ outcome according to the OISS. Overall, 29 (38.1%) of the participants managed non-surgically reported experiencing both pain and recurrence, yielding an OISS rating of ‘unsatisfactory’. In the context of self-reported shoulder instability, EBI in conjunction with stabilising surgery, led to improved results.
Secondary outcomes: physical function
Strength
Strength measures were reported in seven studies in which rotator cuff strength was assessed using isokinetic dynamometers at varied angular velocities. A study of 79 patients62 evaluated the weight-standardised peak torque (PT/W as %) at different time points (from 1.5 to 24 months postsurgery). Strength returned to presurgical values and was equal with the uninjured side at 6 months for external rotation (ER) and 4.5 months for internal rotation (IR). Another study68 assessed rotator cuff strength at 12 weeks following the operation across three different velocities (90°/s, 210°/s and 300°/s). Unilateral external rotator and internal rotator ratio was regained in 9/20 at the slower velocity (90°), 5/20 at 210° and 4/20 at 300°, representing an anterior to posterior force couple at 60%–66% capacity. Lee et al 69 also found that neuromuscular factors (including strength, endurance and control) were suboptimal following arthroscopic Bankart repair, compared with those without ASD (IR strength: 670±1 vs 718±2 Joules, p=0.002, ER strength: 422±6 J vs 501±2 J, p=0.044). Following a 4-week upper-body wobble-board training programme (10 min duration, 5–6 days per week), Naughton et al 70 found that perceived stability and strength of the affected shoulder significantly improved (torque=10.95, p<0.001 and torque=6.17, p<0.001, respectively). Collectively, these findings indicate improvements in rotator cuff strength following both surgical and non-surgical interventions, and highlight the importance of the anterior to posterior force couple in post-ASD rehabilitation.
Range of motion
Glenohumeral ROM measures were reported in eleven studies18 39 42 47 52 53 55 63 66 68 71 including ER, IR, flexion and abduction movements. Three studies assessed rotation ROM with the arm at 90° of abduction,47 55 68 two measured it with arm in neutral39 63 and one study measured elevation and ER ROM in the scapular plane.52 All studies measured ROM in supine with one exception42 where ROM was measured in sitting. Predominantly, ROM returned to presurgical values at follow-up. However, one study68 found ROM deficits in 70% of the participants at 12 weeks postoperatively; while ER ROM deficits (mean loss: 11°, range: 5°–20°) at 6 weeks following an open Bankart repair were observed elsewhere.39 Another study42 noted a trend of ER ROM deficits following arthroscopic stabilisation. In contrast, Gaballah et al reported 90% improvement in ROM outcomes after a 6-week rehabilitation protocol. This study used a non-surgical approach to manage ASD, indicating that the mode of management (ie, surgical vs non-surgical) influences objectively measured ROM (particularly ER) outcomes.
Discussion
This review aimed to investigate the effectiveness of EBI in the management of ASD by comparing the outcomes surgery with postoperative EBI versus EBI alone. Recurrence rates were lower, and there was more successful RTA following surgery with postoperative EBI. Improvements in self-reported outcomes were found for the ASES, CMS and Rowe score following surgery with postoperative EBI, compared with EBI alone. Considering that these outcomes include activities of daily living, behaviour, functional mobility, general health, life participation, mental health, pain and QOL—these improvements have clinical implications. There is a trend towards better shoulder strength and AROM outcomes following EBI alone, however, this was not statistically significant. Also, PROM outcomes were better following surgery with postoperative EBI but were not statistically significant. For some outcomes (CMS, VAS, WOSI, abduction AROM and forward flexion AROM) we compared multimodal EBI with standard EBI and found that these outcomes were better with multimodal EBI. Multimodal EBI included additional approaches such as neuromuscular exercise and therapeutic ultrasound with elastic resistance training.
Recurrence
The lower recurrence rates following EBI in conjunction with surgery align with normal ranges reported in previous literature.72–74 The recurrence was especially high in young active males, competing in collision sports, overhead sports or involved in overhead occupations. This is an interesting insight given 2009 of the 3848 (52.2%) of the total participants included across 56 studies were males, a finding also consistent with previous studies.4 75 76 Further, another systematic review which focused on young active males concluded that early surgical stabilisation has the advantage of preventing recurrence of ASD.77 Our findings support the notion that surgery in conjunction with EBI reduce the risk of complications and improve functional recovery. However, several factors determine the prognosis following ASD including age, activity level and sport participation.78 Our findings highlight that surgical management of ASD with arthroscopic or open Bankart repair can help to reduce the rate of recurrence. However, the time required for recovery can impact readiness for athletic and/or occupational participation.79 Conversely, the risks of not considering surgery and subsequent EBI include high recurrence rates,80 bone loss and subsequent decline in QOL.80 It is therefore imperative that clinicians present their clients with evidence-based information on risks and benefits of non-surgical and surgical intervention to facilitate the decision-making process.81 Relevant factors include: the natural history of shoulder instability, clinical and imaging findings, sport-specific and activity-specific demands, the duration of treatment and the individual’s motivation.19 Age is another key factor as younger adolescents aged <14 years are at a high risk of recurrence; and primary surgical treatment has been demonstrably effective in young individuals older than 14 years.82 83 Furthermore, the nature of functional demands, as seen in young individuals who participate in throwing or overhead sports, can increase risk of recurrence.84
Return to activity
Previous studies on patient expectations for treatment of shoulder instability indicate that RTA is a primary concern, with one study showing that 95% of participants wanted to return to a preinjury level of activity.79 The present investigation found that EBI in conjunction with surgery appeared 1.81 times more likely to facilitate successful RTA compared with EBI alone. There is no consensus as to the appropriate time for RTA83 though it is agreed that participants should have minimal pain, symmetrical shoulder strength and sport-specific ROM capability to successfully RTA.85–87 Further, there is discussion of a 90%–100% strength regain being appropriate prior to returning to sport.80 86–88 Therefore, the decision to permit RTA following any form of management (EBI alone or EBI in conjunction with surgery) must consider progression at each stage of the intended RTA process. The findings of this study suggest that EBIs in conjunction with surgery improve the likelihood of successful RTA. However, the decision to permit this must be criteria-driven, and informed by detailed clinical examination.
Self-report measures
This review meta-analysed self-report measures as secondary outcomes in the management of ASD, comprising ASES, CMS and Rowe scores. From this analysis, improvements were only observed for the CMS score following surgery with postoperative EBI. This measure comprehensively assesses shoulder function and has the ability to detect change following injury.86 89 This self-report measure has been previously used in a range of settings including on the sporting field and in orthopaedic practice.89 This finding is not without limitation as it is based on a single study, and the CMS is not a specific scale to measure functional outcomes following ASD.90 The included studies reported on a range of self-report measures, including: the Rowe score, the WOSI and the Constant Murley score, ASES, UCLA, Lysholm score, Tampa scale of kinesiophobia, pain intensity. The studies had varying lengths of follow-up and rehabilitation programmes, but overall, results suggest that EBI, including multimodal programmes, in conjunction with surgery can improve self-reported function as measured by the Rowe score and WOSI, while the Constant Murley Score appears to remain stable over time. However, more studies are needed to provide a more definitive conclusion on the effectiveness of different management approaches for anterior shoulder instability.
Physical function
Strength
We investigated comparisons between EBI alone and EBI in conjunction with surgery to determine their effectiveness on strength outcomes. The improvements in shoulder IR strength were significant, which could be explained by the specific characteristics of the muscle strengthening programmes. A focus on shoulder IR strength is commonplace in post-ASD rehabilitation programmes given the role that the related musculature (ie, subscapularis and pectoralis muscles) play in anterior stability of the shoulder.91 As well as strength deficits, surgical interventions are often associated with postoperative pain which may also contribute to weakness due to reflex neuromuscular inhibition. Furthermore, immobilisation following surgery contributes to weakness associated with disuse atrophy.87 92 This is not surprising as strength deficits following surgery often do not recover until at least 7–8 months.80
Range of motion
We included comparisons between EBI in conjunction with surgery and EBI alone for the following movements: shoulder flexion, abduction, ER, and IR AROM and PROM. Significant improvements in abduction PROM following EBI alone were demonstrated. The included study had a rehabilitation protocol that focused on mobility, which demonstrated overall improvements in abduction PROM. There was also significant improvement in ER PROM following EBI in conjunction with surgery. Prolonged immobilisation in IR may result in restricted ER ROM, which may have prompted a greater focus on improving ER ROM, and explain the ER PROM improvements.
Additionally, the secondary comparison between standard EBI and multimodal EBI AROM outcomes showed significantly better results following multimodal EBI. The multimodal EBIs included strategies such as neuromuscular exercises9 and elastic resistance training combined therapeutic ultrasound.34 While beyond the scope of our study, these findings raise interest in the mechanisms underlying the greater efficacy demonstrated by multimodal EBI, and opportunities to maximise outcomes of ASD patients through conservative management.
Limitations
This study has some limitations. Initially, our search was restricted in several ways (ie, four databases, from 1990 and in English language only). Given the databases that we selected, our search not only included the academic peer-reviewed literature but also the grey literature (ie, via Web of Science and Google Scholar). Most articles in this area were published since 1990 and hence the bias with the selection of databases and date limitations is considered low. By selecting English language only, we acknowledge the potential of selection bias. Future studies would benefit from not restricting to English only, particularly given a range of translation options now available. Second, EBI for ASD is multifaceted, and can include combinations of shoulder strengthening, mobility, proprioception and endurance training approaches. It is possible that differences in EBI methodology contributed to different effects on outcomes, and this may explain the considerable heterogeneity demonstrated in the present analysis, which ranged from low to high (I2=0%–89.21%), with >75% rated as high.93 The components and dosage of EBI varied depending on the patient goals and level of performance. There is no consensus on, or an established clinical practice guideline, for prescribing EBI to ASD patients. Hence, the impact of EBI observed in this study may be influenced by the training level and preinjury status of the affected individual. For example, prolonged morbidity secondary to rotator cuff tear is more prevalent in older than in a younger population.94 Additionally, the follow-up times of the included studies varied from as low as 3 weeks to as high as 7 years. This was another factor that may have contributed to the considerable heterogeneity. Nevertheless, only comparable studies were included in this review, which is a strength of the assessment of EBI on functional outcomes post-ASD. While this review included more studies than a previous meta-analysis by Longo et al,73 only a few studies included specific settings (athletic, occupational, motor vehicle accidents etc), which may affect the translation of our findings to different contexts. There is evidence of certain measures (eg, WOSI, Oxford Shoulder Score) being specific and sensitive to measuring changes in the ASD population however, the majority of the self-report measures included in our analysis need further investigation.95 As such, these measures may have limited ability to detect changes between groups (ie, EBI in conjunction with surgery, and EBI alone); and is important context when interpreting these findings.
Further to the above limitations regarding characteristics of the included studies, our analysis was limited by a number of key factors. One, studies that included a head-to-head analysis (ie, experimental in design) were few and included low sample sizes with substantial heterogeneity in their features and outcomes. Two, carrying out a random effects analysis (using the Sidik-Jonkman model) was able to highlight some important findings in relation to non-recurrence, RTA, self-report measures and functional measures, however, was predisposed to ‘sparse data bias’26 27 96 as only a certain number of studies could be included in the analysis. Further, data were not always normally distributed, and alongside the sparse data bias, further options such a subgroup analyses, meta-regression and investigation of non-reporting bias were outside the scope of this review. Lastly, the tertiary findings on the success of multimodal EBI for ASD were based on limited number of studies.
Our findings highlight a need for future studies to clearly describe EBI parameters such as number of sets and/or repetitions, intensity, and session duration and frequency—enabling direct comparison of dose–response effects on function post-ASD. Given that multiple components make up a typical EBI for ASD, the aforementioned factors require additional investigation, to assess whether (and to what extent) these determinants of EBI influence outcomes.
Implications for practice, policy and future research
This review assessed the effectiveness of EBI in conjunction with surgery compared with EBI alone for ASD. Following EBI in conjunction with surgery, recurrence rates were lower and there was more successful RTA. Together with improvements in self-reported outcomes, strength and ROM, these findings show the clinically meaningful effects of EBI in conjunction with surgery for ASD; and provide evidence to directly inform clinical management decisions. In terms of management following ASD, this review provides evidence that further supports a combined surgical and EBI approach. Although there is evidence that multimodal EBI may provide additional benefits beyond standard rehabilitative practice, further research investigating such methods is required. Despite the low certainty of evidence, recommendations can be made for increased implementation of EBI in conjunction with surgery for the management of ASD.
Data availability statement
No data are available as the data extracted for this systematic review and meta-analysis is available in the published literature.
Ethics statements
Patient consent for publication
References
Supplementary materials
Supplementary Data
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Footnotes
Twitter @DrRdeZoete, @TimLathlean
Contributors TL conceived and designed the research project. VC and TL searched and screened the studies. VC and RMJdZ carried out the risk of bias assessment. CD and TL carried out the data extraction. TL analysed the data and interpreted the results of the analysis, over successive revisions and is responsible for the overall content as the guarantor. All authors drafted the manuscript and assisted in the interpretation of the data. All authors critically reviewed the manuscript, provided significant input to the initial submission and subsequent revisions and approved the final version.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.