CSAW

Arthroscopic subacromial decompression for subacromial shoulder pain (CSAW): a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial.

Beard DJ, Rees JL, Cook JA, et al. Lancet (London, England) 2018 · PMID 29169668 · doi:10.1016/s0140-6736(17)32457-1

Question

Does arthroscopic subacromial decompression improve subacromial pain more than diagnostic arthroscopy alone or no treatment?

Design

Pragmatic, placebo-controlled, three-arm multicentre RCT in NHS hospitals in the UK.

Patients

Adults with at least three months of subacromial pain, intact rotator cuff, who had completed non-operative care including physiotherapy and an injection.

Intervention

Arthroscopic subacromial decompression (removal of bone and soft tissue)

Comparison

Investigational arthroscopy only (placebo surgery) or no treatment with specialist review

Primary outcome

Oxford Shoulder Score at 6 months

Key result

Both surgical arms improved slightly more than no treatment, but decompression gave no clinically important benefit over arthroscopy alone. The difference between the two surgical groups was not significant.

Limitations

Substantial crossover and non-adherence to allocation, and the difference versus no treatment fell below the minimal clinically important difference.

Impact on practice

Undermined routine decompression for subacromial pain; together with FIMPACT it led to restricted commissioning of the procedure in England and an emphasis on physiotherapy-led care.