Evidence map›Paper›PMID 33483447›Full record

Trial reportBMJ open2021

Tourniquet use in total knee replacement surgery: a feasibility study and pilot randomised controlled trial (SAFE-TKR study).

Peter David Henry Wall, Imran Ahmed, Claire Edwin, Muhamed M Farhan-Alanie, Helen Parsons, Andrew James Price, Jane Warwick, Charles E Hutchinson, Martin Underwood, Andrew Metcalfe and 2 more

Open access · goldAbstract readMulticenter StudyRandomized Controlled Trial
In one paragraph

Trial report in BMJ open, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed, 1 pooled it
0.4field-weighted citation impact, top 49% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

5 citing papers in PubMed, 1 synthesis or guideline pooled it, 9 citations in OpenAlex.

  1. Total knee arthroplasty with or without a tourniquet: a meta-analysis of randomized controlled trials.European journal of orthopaedic surgery & traumatology : orthopedie traumatologie · 2025
    Pooled it
  2. Trial
  3. Article
  4. Article
  5. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors at 3 institutions in 1 country.

Peter David Henry WallWarwick Clinical Trials Unit, University of Warwick Warwick Medical School, Coventry, UK p.d.h.wall@warwick.ac.uk.ORCID 0000-0003-3149-3373
Imran AhmedWarwick Clinical Trials Unit, University of Warwick Warwick Medical School, Coventry, UK.ORCID 0000-0003-2774-9954
Claire EdwinWarwick Clinical Trials Unit, University of Warwick Warwick Medical School, Coventry, UK.
Muhamed M Farhan-AlanieTrauma and Orthopaedic, Warwick Clinical Trials Unit, Coventry, UK.ORCID 0000-0002-9209-0108
Helen ParsonsDivision of Health Sciences, University of Warwick, Coventry, Warks, UK.
Andrew James PriceNuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK.ORCID 0000-0002-4258-5866
Jane WarwickWarwick Clinical Trials Unit, University of Warwick Warwick Medical School, Coventry, UK.
Charles E HutchinsonWarwick Medical School, University of Warwick, Coventry, UK.
Martin UnderwoodWarwick Medical School, University of Warwick, Coventry, UK.
Andrew MetcalfeWarwick Clinical Trials Unit, University of Warwick Warwick Medical School, Coventry, UK.ORCID 0000-0002-4515-8202
SAFE-TKR Study Group
the SAFE-TKR study group
University of Warwick · GBNuffield Orthopaedic Centre · GBUniversity Hospitals Coventry and Warwickshire NHS Trust · GB

Funding

Department of Health DRF-2018-11-ST2-030Department of Health PDF-2015-08-108
6 · The paper itself

Abstract

introductionTourniquets are routinely used during total knee replacement (TKR) surgery. They could increase the risk of thromboembolic events including cerebral emboli, cognitive decline, pain and other adverse events (AEs). A randomised controlled trial to assess whether tourniquet use might safely be avoided is therefore warranted but it is unclear whether such a trial would be feasible.

methodsIn a single-site feasibility study and pilot randomised controlled trial, adults having a TKR were randomised to surgery with an inflated tourniquet versus a non-inflated tourniquet. Participants underwent brain MRI preoperatively and within 2 days postoperatively. We assessed cognition using the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA) and Oxford Cognitive Screen (OCS) and thigh pain using a Visual Analogue Scale at baseline and days 1 and 2, and 1 week postsurgery. AEs related to surgery were recorded up to 12 months.

resultsWe randomised 53 participants (27 tourniquet inflated and 26 tourniquet not inflated). Fifty-one participants received care per-protocol (96%) and 48 (91%) were followed up at 12 months. One new ischaemic brain lesion was detected. Of the cognitive tests, MoCA was easy to summarise, sensitive to change with lower ceiling effects compared with OCS and MMSE. There was a trend towards more thigh pain (mean 49.6 SD 30.4 vs 36.2 SD 28 at day 1) and more AEs related to surgery (21 vs 9) in participants with an inflated tourniquet compared with those with a tourniquet not inflated.

conclusionA full trial is feasible, but using MRI as a primary outcome is unlikely to be appropriate or feasible. Suitable primary outcomes would be cognition measured using MoCA, pain and AEs, all of which warrant investigation in a large multicentre trial. TRIAL REGISTRATION NUMBER: ISRCTN20873088.

Indexed as

Arthroplasty, Replacement, KneeTourniquetsAdultFeasibility StudiesFemaleHumansPilot ProjectsTreatment Outcomeadult surgerykneeorthopaedic & trauma surgery

Identifiers

PMID33483447
PMCPMC7825264
OpenAlexW3124443594

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.