Multidirectional instability of the glenohumeral joint: an unstable classification resulting in uncertain evidence-based practice

A systematic review to compare physiotherapy treatment programmes for atraumatic shoulder instability

Background

Optimal physiotherapy treatment is uncertain for atraumatic shoulder instability (ASI), the primary aim of this systematic scoping review was to compare physiotherapy treatment programmes for people with ASI. The secondary aims were to evaluate outcome measures used and to compare the effectiveness of these programmes.

Methods

CINAHL, EMBASE and Medline databases were searched for studies, except single case studies, published between 1950 and July 2021. 12 critical appraisal items covered three domains; internal validity, transferability to wider population and reporting.

Results

Ten studies were included; one randomised controlled trial, 6 cohort studies and 3 case series. There were 491 participants. Treatment programmes included education, movement re-education, static posture correction, shoulder muscle strengthening, functional training, and adjuncts. All studies used patient reported outcome measures (PROMs), 7 of which reported a statistically significant improvement (p < 0.05) post-treatment. There was no clear relationship between programmes and outcomes. PROMs specific to shoulder instability were all found to detect statistically significant differences post-treatment.

Discussion

There does not appear to be one optimal physiotherapy treatment programme for ASI. Future studies should use PROMs that are valid in the shoulder instability population and use more outcome measures that are specific to impairments being targeted.

Advances in the Non-Operative Management of Multidirectional Instability of the Glenohumeral Joint

Multidirectional instability (MDI) of the glenohumeral joint refers to symptomatic subluxations or dislocations in more than one direction. The aetiology of MDI is multifactorial, which makes the classification of this condition challenging. A shoulder rehabilitation program is the initial recommended treatment for MDI, however available rehabilitation programs have varying levels of evidence to support their effectiveness. In 2016, we published the details of an evidence-based program for MDI that has been evaluated for efficacy in two single-group studies and a randomised controlled trial. In 2017, we published a clinical commentary on the aetiology, classification, and treatment of this condition. The aim of this paper is to provide an update on the components of these publications with a particular focus on new advances in the non-operative management of this condition.

Muscle activity and scapular kinematics in individuals with multidirectional shoulder instability: A systematic review

BACKGROUND

Several studies reported the importance of glenohumeral and scapular muscle activity and scapular kinematics in multidirectional shoulder instability (MDI), yet a systematic overview is currently lacking.

OBJECTIVE

This systematic review evaluates and summarizes the evidence regarding muscle activity and shoulder kinematics in individuals with MDI compared to healthy controls.

METHOD

The electronic databases PubMed and Web of Science were searched in September 2020 with key words regarding MDI (population), muscle activity, and glenohumeral and scapular movement patterns (outcomes). All studies that compared muscle activity or scapular kinematics between shoulders with MDI and healthy shoulders were eligible for this review, except for case reports and case series. All articles were screened on the title and abstract, and remaining eligible articles were screened on full text. The risk of bias of included articles was assessed by a checklist for case-control data, as advised by the Cochrane collaboration.

RESULTS

After full text screening, 12 articles remained for inclusion and one study was obtained by hand search. According to the guidelines of the Dutch Institute for Healthcare Improvement, most studies were of moderate methodological quality. We found moderate evidence that MDI individuals show increased or prolonged activity of several rotator cuff muscles that control and centre the humeral head. Furthermore, we found evidence of decreased and/or shortened activity of muscles that move or accelerate the arm and shoulder girdle as well as increased and/or lengthened activity of muscles that decelerate the arm and shoulder girdle. The most consistent kinematic finding was that MDI individuals show significantly less upward rotation and more internal rotation of the scapula during elevation of the arm in the scapular plane as compared with controls. Finally, several studies also suggest that the humeral head demonstrates increased translations relative to the glenoid surface.

CONCLUSION

There is moderate evidence for altered muscle activity and altered humeral and scapular kinematics in MDI individuals as compared with controls.

Epidemiology of the Frequency, Etiology, Direction, and Severity (FEDS) system for classifying glenohumeral instability

HYPOTHESIS

The purpose of this multicenter epidemiologic study was to determine the distribution of patients within the Frequency, Etiology, Direction, and Severity (FEDS) classification system to determine which categories are of clinical importance.

METHODS

Shoulder instability patients were identified using International Classification of Diseases, Ninth Revision coding data from 3 separate institutions from 2005-2010. Data were collected retrospectively. Details of instability were recorded in accordance with the FEDS classification system. Each patient was assigned a classification within the FEDS system. After all patients were assigned to a group, each group was individually analyzed and compared with the other groups.

RESULTS

There are a total of 36 possible combinations within the FEDS system. Only 16 categories were represented by at least 1% of our patient population. Six categories captured at least 5% of all patients with shoulder instability. Only 2 categories represented greater than 10% of the population: solitary, traumatic, anterior dislocation, with 95 patients (24.8%), and occasional, traumatic, anterior dislocation, with 63 patients (16.4%).

CONCLUSIONS

There are 16 categories within the FEDS classification that are clinically significant. Solitary, traumatic, anterior dislocation and occasional, traumatic, anterior dislocation were the most frequently observed in our cohort.

Multidirectional instability of the glenohumeral joint: Etiology, classification, assessment, and management

Multidirectional instability of the shoulder is a type of glenohumeral joint shoulder instability. There are discrepancies in the definition and classification of this condition, which can make diagnosis and treatment selection challenging. Knowledge of contributing factors, the typical clinical presentation, and current best evidence for treatment options can assist in the diagnosis and appropriate treatment selection for this pathology. The purpose of this article is to present an overview of the current literature regarding the etiology, classification, assessment, and management of multidirectional instability of the glenohumeral joint.