Acute anterior shoulder dislocation is an injury in which the top end of the upper arm bone is pushed out of the joint socket in a forward direction. Afterwards, the shoulder is less stable and is prone to re-dislocation or subluxation (partial re-dislocation), especially in active young adults. Initial treatment involves putting the joint back in place. This is called 'closed reduction' when it is done without surgery. Subsequent treatment is often conservative (non-surgical) and generally involves placement of the injured arm in a sling or in another immobilising device followed by specific exercises.
After a comprehensive search, completed in September 2013, for randomised controlled trials that compared different methods of conservative management of these injuries we included only four trials, one of which was not truly randomised. These trials involved a total of 470 participants (371 male). All had primary traumatic anterior dislocation of the shoulder reduced by various closed methods. Three studies evaluated mixed populations; in the fourth study, all participants were male and 80% were soldiers. All trials were at some risk of bias (systematic errors that could lead to overestimation or underestimation of treatment effectiveness), with two trials in particular being at high risk of bias in a number of aspects. Overall, the quality of the evidence was very low, meaning that we are very uncertain about the direction and size of effect.
All four trials compared immobilisation of the arm in external rotation (when the arm is orientated outwards with the forearm away from the chest) versus immobilisation in internal rotation (the usual sling position, where the arm rests against the chest) following closed reduction. Investigators followed patients for at least two years. The results showed no difference between the two groups in any of our pre-defined outcomes. These included re-dislocations, scores on validated shoulder function questionnaires, return to pre-injury activity or sport, and any instability. Other pre-defined outcomes (patient satisfaction with the intervention, and health-related quality of life outcome data) were not reported. Adverse events were poorly recorded.
In our recommendations for future research, we point out the importance of completing and publishing the eight other trials making the same comparison as the four included trials. We also note that other important questions need to be studied, such as how long the shoulder should be immobilised for the best outcomes. In conclusion, current evidence from randomised controlled trials is insufficient to inform choices for conservative management following closed reduction of traumatic anterior dislocation of the shoulder.
Numerous conservative strategies may be adopted after closed reduction of a traumatic anterior dislocation of the shoulder, and many warrant investigation. However, our review reveals that evidence from randomised controlled trials is only available for a single approach: immobilisation in external rotation versus immobilisation in the traditional position of internal rotation. Moreover, this evidence is insufficient to demonstrate whether immobilisation in external rotation confers any benefit over immobilisation in internal rotation.
We identified six unpublished trials and two ongoing trials that compare immobilisation in external versus internal rotation. Given this, the main priority for research on this question consists of the publication of completed trials, and the completion and publication of ongoing trials. Meanwhile, increased attention to other interventions is required. Sufficiently powered, good quality, well reported randomised controlled trials with long-term surveillance should be conducted to examine the optimum duration of immobilisation, whether immobilisation is necessary at all (in older age groups particularly), which rehabilitative interventions work best and the acceptability to participants of different care strategies.
Acute anterior dislocation, which is the most common type of shoulder dislocation, usually results from an injury. Subsequently, the shoulder is less stable and is more susceptible to re-dislocation, especially in active young adults. This is an update of a Cochrane review first published in 2006.
To assess the effects (benefits and harms) of conservative interventions after closed reduction of traumatic anterior dislocation of the shoulder. These might include immobilisation, rehabilitative interventions or both.
We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (September 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 8), MEDLINE (1946 to September 2013), EMBASE (1980 to Week 38, 2013), CINAHL (1982 to September 2013), PEDro (1929 to November 2012), OTseeker (inception to November 2012) and trial registries. We also searched conference proceedings and reference lists of included studies.
Randomised or quasi-randomised controlled trials comparing various conservative interventions versus control (no or sham treatment) or other conservative interventions applied after closed reduction of traumatic anterior dislocation of the shoulder.
All review authors independently selected trials, assessed risk of bias and extracted data. Study authors were contacted for additional information. Results of comparable groups of trials were pooled.
We included three randomised trials and one quasi-randomised trial, which involved 470 participants (371 male) with primary traumatic anterior dislocation of the shoulder reduced by various closed methods. Three studies evaluated mixed populations; in the fourth study, all participants were male and 80% were soldiers. All trials were at some risk of bias but to a differing extent. One was at high risk in all domains of the risk of bias tool, and one was at unclear or high risk in all domains; the other two trials were deemed to have predominantly low risk across all domains. Overall, reflecting both the risk of bias and the imprecision of findings, we judged the quality of evidence to be "very low" for all outcomes, meaning that we are very uncertain about the estimates of effect.
The four trials evaluated the same comparison - immobilisation in external rotation versus internal rotation - and each of our three primary outcomes (re-dislocation, patient-reported outcome measures (PROMs) for shoulder instability and resumption of activities) was reported by one or more of the trials, with two-year or longer follow-up. Pooling was possible for "re-dislocation" (three trials) and for aspects of "resumption of sport/activities at pre-injury level" (two trials).
There was no evidence to show a difference between the two groups in re-dislocation at two-year or longer follow-up (risk ratio (RR) 1.06 favouring internal rotation, 95% confidence interval (CI) 0.73 to 1.54; P value 0.77; 252 participants; three trials). In a low-risk population, with an illustrative baseline risk of 247 re-dislocations per 1000, these data equate to 15 more (95% CI 67 fewer to 133 more) re-dislocations per 1000 after immobilisation in external rotation. In a medium-risk population, with an illustrative baseline risk of 436 re-dislocations per 1000, the data equate to 26 more (95% CI 118 fewer to 235 more) re-dislocations after immobilisation in external rotation.
Nor was evidence found to show a difference between the two groups in return to pre-injury levels of activity at two-year or longer follow-up (RR 1.25 favouring external rotation, 95% CI 0.71 to 2.2; P value 0.43; 278 participants; two trials). In a low-risk population, with an illustrative baseline risk of 204 participants per 1000 returning to pre-injury levels of activity, this equates to 41 more (95% CI 59 fewer to 245 more) participants per 1000 resuming activity after immobilisation in external rotation. In a high-risk population, with an illustrative baseline risk of 605 participants per 1000 returning to pre-injury levels of activity, this equates to 161 more (95% CI 76 fewer to 395 more) participants per 1000 resuming activity after immobilisation in external rotation.
One trial reported that the difference between the two groups in Western Ontario Shoulder Instability Index scores, analysed using non-parametric statistics, was "not significant (P = 0.32)". Of our secondary outcomes, pooling was possible for "any instability" (two trials) and for important adverse events (three events, two trials). However, adverse event data were collected only in an ad hoc way, and it is unclear whether identification and reporting of such events was comprehensive. No report addressed participant satisfaction or health-related quality of life outcome measures.
There was no evidence confirming a difference between the two positions of immobilisation in any of the primary or secondary outcomes; for each outcome, the confidence intervals were wide, covering the possibility of substantial benefit for each intervention.