David Johnson

David Johnson

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2019 in The Knee
Verified
Journal Article
Closed access
DJDavid Johnson
David Johnson
PTPhilip Gartside Turner
Philip Gartside Turner

13 April 2020 in Osteoarthritis and Cartilage Open
Verified
Journal Article
Open access
BSBodor Bin sheeha
Bodor Bin sheeha
MGMalcolm Granat
Malcolm Granat
AWAnita Williams
Anita Williams
DJDavid Johnson
David Johnson
RJRichard Jones
Richard Jones
Total knee arthroplasty (TKA) is the gold-standard treatment for end-stage knee osteoarthritis, and the primary expectations are reduced pain and improved function. However, there is conflicting evidence regarding functional changes post-TKA. Commonly, functional changes are measured using Oxford Knee Score (OKS). No previous study has investigated physical behaviour (PB) changes in terms of volume and patterns post-TKA. The aims of this study were to explore volume and pattern changes in PB following TKA using an objective tool and to assess the correlation between this and OKS. An activPAL measured the PB of individuals on a waiting list for TKA for a period of 7–8 days pre-TKA, and for the same length of time at 12 months post-TKA. OKS was completed at similar follow-up time points. Thirty-three individuals completed the study, where stepping time, the number of steps and the time spent on moderate to vigorous physical activity (MVPA) (>100 steps/minute) improved significantly post-TKA p = 0.0001. Steps at 12 months post-TKA improved by 45.6% (from 4240 to 6174) and stepping time increased by 38.8% (from 0.98 to 1.36 h). MVPA improved by 35 min at 12 months (from 6.6 to 41.7 min). There were no significant correlations between PB and OKS. This is the first study to explore PB volumes and event-based patterns post-TKA. Activity improved in terms of volume and patterns. No correlation was found between OKS and ActivPAL, which emphasises the need to use objective methods in addition to patient-reported outcome measures.

1 December 2019 in The Knee
Verified
Journal Article
Closed access
DJDavid Johnson
David Johnson
PTPhilip Gartside Turner
Philip Gartside Turner

23 June 2020 in Journal of Bone and Joint Surgery
Verified
Journal Article
Closed access
BSBodor Bin sheeha
Bodor Bin sheeha
AWAnita Williams
Anita Williams
DJDavid Johnson
David Johnson
MGMalcolm Granat
Malcolm Granat
ANAhmad Bin Nasser
Ahmad Bin Nasser
RJRichard Jones
Richard Jones
Background: The Oxford Knee Score (OKS) is a reliable, valid, and sensitive assessment tool for individuals undergoing a total knee arthroplasty (TKA). The published psychometric assessment of the Arabic version of the OKS (OKS-Ar) is limited to male patients and has not been assessed for responsiveness following TKA. The aim of this study was to assess the reliability, validity, and responsiveness of the OKS-Ar in an inclusive population of patients undergoing TKA. Methods: One hundred Arabic-speaking patients awaiting TKA were assessed with the OKS-Ar, the Arabic version of the Knee injury and Osteoarthritis Outcome Score (KOOS-Ar), and a visual analogue scale for pain (VAS-P) in order to assess the correlation between the OKS-Ar and the KOOS-Ar and VAS-P and determine the construct validity. Repeat assessments were completed 7 to 10 days after the first assessment and 6 months after TKA. Results: Questionnaires were completed by 80 female and 20 male participants with a mean age of 62 ± 8 years. The test and retest median scores showed no significant difference from one another, with a strong Spearman correlation between the 2 measurements (rs = 0.94). Bland-Altman limits of agreement showed no significant bias. The Cronbach alpha was 0.85 indicating high internal consistency. There was no floor or ceiling effect before TKA, and the post-TKA ceiling effect was only 2%. The OKS-Ar pain component correlated strongly with the KOOS-Ar pain subscale (rs = 0.73). The OKS-Ar effect size was 3.09, which was larger than that of all of the KOOS subscales at 6 months after TKA. Conclusions: To our knowledge, this is the first study to assess reliability, validity, and responsiveness of the OKS-Ar after TKA. The validity and reliability results are similar to those found for both the original English-language OKS and the OKS translated into other languages. We believe that this is also the first study to assess OKS-Ar responsiveness after TKA and to show a large effect size. We found that the OKS-Ar is a feasible, valid, reliable, and sensitive measurement tool to assess pain and function in TKA-treated individuals whose main language is Arabic.

1 February 2023 in The Annals of The Royal College of Surgeons of England
Verified
Journal Article
Closed access
ABAj Berg
Aj Berg
TNT Naylor
T Naylor
DJDavid Johnson
David Johnson
TCThe PATHS Study Collaborators
The PATHS Study Collaborators
Introduction Neck of femur fractures (NOFF) are associated with significant morbidity and mortality, exacerbated by anaemia. Evidence indicates tranexamic acid (TXA) administration in NOFF surgery reduces blood loss and transfusion requirements, without increasing complications. The aim of this study was to establish current TXA administration practice in patients undergoing surgery for NOFF in the UK. Methods We conducted a multicentre prospective study within the UK over a two-week period in March 2019. Pre-, intra- and postoperative data were collected locally and analysed centrally. Results Data for 917 patients were submitted from 66 institutions. Of those eligible, 48.0% received TXA perioperatively. Administration rates varied from 0 to 100%. Significantly greater numbers undergoing arthroplasty received TXA (57.6%) compared with internal fixation (38.4%, p<0.01). Some 15.2% of institutions had a protocol for TXA use in NOFF. Patients treated in these units were significantly more likely to receive TXA (86.7%) than those who were not (41.2% p<0.01). Of those receiving TXA, 92.3% were given 1g intravenously (IV) at anaesthetic administration. Conclusions Despite supportive evidence for its use, a wide variation in the administration of TXA between hospitals and procedures has been demonstrated. Administration rates were higher for arthroplasty than for fixation procedures. Most centres do not have a protocol guiding TXA administration. We recommend administration of 1g IV TXA perioperatively for patients undergoing NOFF surgery, where not contraindicated, unless future randomised controlled trials support an alternative regimen. We recommend units include their own locally agreed TXA policy within a written protocol for the care of NOFF patients.

16 May 2025 in The Surgeon
Verified
Journal Article
Closed access
HSHannah Sevenoaks
Hannah Sevenoaks
JRJoanna Richards
Joanna Richards
SHSophie Howles
Sophie Howles
LMLouise McMenemy
Louise McMenemy
RBRobyn Brown
Robyn Brown
DJDavid Johnson
David Johnson