Surgeons who held a biased view of independent treatment centres caused the unnecessary recall of more than 600 patients, a new report claims.

NHS South West ordered a review of the performance of Weston Area Health Trust’s independent treatment centre after an earlier British Orthopaedic Association study claimed revision rates for surgery were five percentage points too high.

However the NHS South West review found the BOA’s figures were inaccurate and blamed a “bias” for the original finding.

Professor Brian Toft of Warwick University, who chaired the review, said the BOA report had “very serious flaws in it” and that a “cognitive bias” affected the BOA reviewers predisposing them “to see things that were wrong even if they were not”.

The Weston NHS Treatment Centre was established at the Somerset trust in 2002, staffed by Scandinavian surgeons who were flown in to carry out knee and hip replacements. It was also used by patients from Cardiff and Vale Trust.

The programme was strongly opposed by surgeons at North Bristol and Cardiff and Vale trusts, Professor Toft’s report found. A member of the Welsh commissioning team told the review the use of independent centres was “seen by some in the Welsh medical community as an assault on private practice”.

A senior manager from Weston Area said Bristol surgeons had been “very vigorous in telling us [the centre] how we got it all wrong, and it was never going to work, and it wasn’t fair”.

Welsh surgeons refused follow-up treatment to patients operated on at the centre.

The two senior surgeons who carried out the BOA’s review recommended all patients who had undergone surgery at the centre be reviewed.

As a result the Rhondda Cynon Taff local health board recalled all 683 Welsh patients treated at the centre. The trust asked for support from NHS South West, which then ordered its own review.

That review panel found the revision rate was closer to 3 per cent, not statistically high enough above the normal revision rate of 1-2 per cent to merit the recall.

NHS South West and Weston Area welcomed the findings. In a statement BOA president Peter Kay said the organisation had “significant areas of disagreement with the report” but the “episode is effectively closed”.