BESS/BOA patient care pathways: atraumatic shoulder instability

Key points

1. 01Physiotherapy, targeting proprioception, rotator cuff, and scapula muscles, is first-line treatment for all patients regardless of whether structural pathology is present
2. 02Most patients (50-80%) can achieve successful outcomes without surgery if the correct rehabilitation programme is followed with good compliance
3. 03Surgery carries real risks of poor outcomes in this population; arthroscopic capsulorrhaphy alone is not recommended due to failure rates of 16-59%
4. 04Open and arthroscopic capsular shift procedures show lower re-dislocation rates (7.5% and 7.8% respectively) but evidence quality remains low
5. 05Complex cases with psychological, central sensitisation, or muscle patterning features need early multidisciplinary team involvement including psychology, pain services, and rheumatology

How it was conducted

Design

BESS/BOA consensus patient care pathway with narrative literature review

Evidence search

MeSH search to April 2017, approximately 400 publications screened

Evidence base

Mainly Level IV retrospective cohort studies; three Level II publications, all from a single prospective cohort with controls

Condition

Atraumatic shoulder instability (Stanmore Polar Type II and III), including multidirectional and muscle patterning subtypes

Setting

Tiered primary, secondary, and tertiary care pathways for the UK NHS

Surgical procedures reviewed

Open capsular shift, arthroscopic capsular shift, arthroscopic capsulorrhaphy, laser and thermal capsulorrhaphy, Bankart repair, bone block procedures

What they found

• Atraumatic instability accounts for approximately 4% of all shoulder instability presentations, although the true burden may be higher
• Non-operative treatment achieves successful outcomes in 50-80% of cases; the pathway states 80% of patients should respond to non-operative measures
• Burkhead and Rockwood reported good-to-excellent Rowe scores after physiotherapy alone in 80% of their cohort, though no pre-intervention scores were reported
• Warby RCT: the Watson Multi-Directional Instability rehabilitation programme produced significantly better outcomes over 24 weeks compared with the Rockwood programme (no exact effect size reported in the reviewed text)
• Longo review: recurrence rates of 22% for laser capsulorrhaphy and 24.5% for thermal capsulorrhaphy; other authors reported higher recurrence rates of 59% with thermal capsulorrhaphy
• Re-dislocation rate was 7.5% for open capsular shift and 7.8% for arthroscopic capsular shift
• Post-operative Rowe scores for open capsular shift ranged from 90.6 to 94 across included studies (10-38 shoulders per study)
• Arthroscopic capsulorrhaphy failure rates ranged from 16 to 59% across studies; complication rates included neurological injury and adhesive capsulitis
• 40% of patients over 40 years old with a traumatic anterior glenohumeral dislocation have a rotator cuff tear

Limitations

• No universal definition of atraumatic shoulder instability exists across the reviewed studies, making comparison of outcomes difficult
• The three Level II (best available) publications were all derived from a single cohort, severely limiting the independence of higher-quality evidence
• Studies are small (typically 10-54 shoulders), use heterogeneous outcome measures, and mix traumatic and atraumatic pathologies, preventing pooled analysis
• No long-term follow-up studies exist for either physiotherapy or surgical interventions in this population, so durability of outcomes is unknown

Why it matters

For patients

Most people with atraumatic shoulder instability will improve with the right physiotherapy programme without needing surgery, but recovery can take up to six months and requires consistent effort.

For clinicians

Identify and classify atraumatic instability early to avoid inappropriate surgery; refer complex cases (psychological features, central sensitisation, persistent A and E attendance, school or work absence over three months) early to a tertiary multidisciplinary team.

For readers

This BESS/BOA pathway provides a tiered management algorithm based on limited evidence and expert consensus, highlighting an urgent need for well-designed RCTs on both exercise and surgical interventions in this population.