Arthroscopic subacromial decompression versus placebo surgery for subacromial pain syndrome: 10 year follow-up of the FIMPACT randomised, placebo surgery controlled trial.

OBJECTIVE

To assess the long term efficacy of arthroscopic subacromial decompression (ASD) versus placebo surgery (diagnostic arthroscopy) and exercise therapy in patients with subacromial pain syndrome.

DESIGN

Randomised, placebo surgery controlled trial.

SETTING

Orthopaedic department of three public hospitals in Finland.

PARTICIPANTS

210 adults aged 35 to 65 years with symptoms consistent with subacromial pain syndrome for more than three months, enrolled from 1 February 2005 with 10 year follow-up to 20 September 2023. Participants and outcome assessors were blinded to group allocation in the primary (ASD versus placebo surgery) comparison.

INTERVENTIONS: ASD, placebo surgery, and exercise therapy (1:1:1). Exercise therapy was used as a pragmatic comparator.

MAIN OUTCOME MEASURES: The primary outcomes were shoulder pain at rest and on arm activity, both assessed at 10 years using a visual analogue scale (VAS, ranging from 0 to 100, with 0 denoting no pain). The minimally important difference was defined as 15. A mixed model repeated measures analysis of variance was used, treating participants as random factors, incorporating baseline values as covariates.

RESULTS

Participants were randomly assigned to ASD (n=59), placebo surgery (n=63), and exercise therapy (n=71). Of these, a total of 168 participants (87%) completed the 10 year follow-up. In the primary intention-to-treat analysis (ASD versus placebo surgery), no between group differences were observed for the two primary outcomes at 10 years: the mean difference between groups (ASD minus placebo surgery) was -1.5 points (95% confidence interval (CI) -8.6 to 5.6) in VAS pain score at rest and -3.2 points (-13.0 to 6.5) in VAS pain score on arm activity. No significant between group differences were found for any of the secondary outcomes or adverse events. In the pragmatic comparison, the mean difference between groups (ASD minus exercise therapy) was -4.0 points (-11.0 to 3.0) in VAS pain score at rest and -9.4 points (-19.0 to 0.3) in VAS pain score on arm activity. No significant between group differences were observed for the secondary outcomes or adverse events.

CONCLUSION

In patients with subacromial pain syndrome, ASD offered no benefit over placebo surgery or exercise therapy during 10 year follow-up.

TRIAL REGISTRATION: ClinicalTrials.gov NCT00428870.