Treatment of first-time traumatic anterior shoulder dislocation: the UK TASH-D cohort study

Shoulder dislocations are the most common joint dislocations seen in emergency departments. Most traumatic cases are anterior and cause recurrent dislocations. Management options include surgical and conservative treatments. There is a lack of evidence about which method is most effective after the first traumatic anterior shoulder dislocation (TASD). To produce UK age- and sex-specific incidence rates for TASD. To assess whether or not surgery within 6 months of a first-time TASD decreases re-dislocation rates compared with no surgery. To identify clinical predictors of recurrent dislocation. A population-based cohort study of first-time TASD patients in the UK. An initial validation study and subsequent propensity-score-matched analysis to compare re-dislocation rates between surgery and no surgery after a first-time TASD. Prediction modelling was used to identify potential predictors of recurrent dislocation. UK primary and secondary care data. Patients with a first-time TASD between 1997 and 2015. Stabilisation surgery within 6 months of a first-time TASD (compared with no surgery). Stabilisation surgery within 12 months of a first-time TASD was also carried out as a sensitivity analysis. Re-dislocation rate up to 2 years after the first TASD. Eligible patients were identified from the Clinical Practice Research Datalink (CPRD) (1997-2015). Accuracy of shoulder dislocation coding was internally validated using the CPRD General Practitioner questionnaire service. UK age- and sex-specific incidence rates for TASD were externally validated against rates from the USA and Canada. A propensity-score-matched analysis using linked CPRD and Hospital Episode Statistics (HES) data compared re-dislocation rates for patients aged 16-35 years, comparing surgery with no surgery. Multivariable Cox regression models for predicting re-dislocation were developed for the surgical and non-surgical cohorts. Shoulder dislocation was coded correctly for 89% of cases in the CPRD [95% confidence interval (CI) 83% to 95%], with a 'primary' dislocation confirmed for 76% of cases (95% CI 67% to 85%). Far fewer patients than expected received stabilisation surgery within 6 months of a first TASD, leading to an underpowered study. Around 20% of re-dislocation rates were observed for both surgical and non-surgical patients. The sensitivity analysis at 12 months also showed little difference in re-dislocation rates. Missing data on risk factors limited the value of the prediction mode