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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Negative pressure wound therapy (NPWT) versus conventional wound dressings in Total Knee Arthroplasty
Scientific title
In individuals undergoing knee replacement, is negative pressure wound therapy more cost effective than conventional wound dressings.
Secondary ID [1] 282704 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
knee replacement 289416 0
Condition category
Condition code
Musculoskeletal 289742 289742 0 0

Study type
Description of intervention(s) / exposure
There will be two phases to our study.
Phase 1 will be purely observational to elucidate a baseline costing. The patients will be treated with the conventional dry dressings regularly utilised by the surgeons. This phase will last 2 months. Unilateral and bilateral total knee Arthroplasty patients will be recruited into this phase. ‘
Phase 2 will be a randomised controlled trial comparing patient satisfaction and cost between negative wound pressure therapy and conventional dry dressings. Patients undergoing bilateral knee arthroplasty will be recruited and have each knee randomised to either receiving NPWT or CDD. We expect this phase to last 8-12 months to recruit the required number of patients. The negative pressure dressing will be left intact till wound review between 10-12 days in outpatient clinic.

Surgical wounds in these patients will be managed with negative pressure wound therapy (NPWT). Negative Pressure Wound Therapy (NPWT) has been used for many years for treatment of chronic wounds and more recently for post arthroplasty wound management. Orthopaedic surgeons are proactive in their consideration on surgical dressings in attempts to avoid costly post arthroplasty wound infections; at face value the closed, portable dressing system appears to provide an attractive option for wound care. NPWT consists of a closed, sealed system that applies negative pressure (suction) to the wound surface. The dressing is suggested to support primary intention to heal by improving local blood flow, facilitate oedema and exudate removal, reducing bacterial contamination, and promoting incision healing.The dressing will be applied by the surgeon at completion of surgery and left intact until the post-operative review appointment at 2 weeks post op. The patients will be discharged from hospital with a small canister attached to the dressing for collection of excess fluid.
Intervention code [1] 287362 0
Treatment: Devices
Comparator / control treatment
The conventional dressings are changed as necessary on the ward and once discharged from inpatient stay, they will be left intact until clinic review between 10-12 days post-operatively. If there is excessive wound ooze, they will be changed on the ward or in clinic earlier than expected. There is significant variation between the type of dressings utilised by the three surgeons and this will affect the number of dressings each of their patients undergo. The other aspect that differs among the 3 surgeons is regular use of intra-articular drains post-op to decrease haemarthrosis. Removal of these drains will be taken into account as they will require separate dressing changes as well.
Control group

Primary outcome [1] 289830 0
Cost of dressings changes- assessed by real time review of dressings and disposables used at time of change.
Timepoint [1] 289830 0
The cost of disposables and dressings will be accumulated at time of surgery and at each dressing change as an inpatient usually between Day one post-operative and Day four post-operatively as well as on review in outpatient clinic up to day 12. This outcome will be assessed in both Phase one and Phase two of the study,
Primary outcome [2] 296804 0
Patient satisfaction- assessed by a wound diary that requires patients to give us their opinion on different aspects pertaining to the dressings utilised for each of their knees.
Timepoint [2] 296804 0
The wound diary will be started from day of surgery till review in clinic between day 10-12.
his outcome measures will only be assessed in phase two only
Secondary outcome [1] 303336 0
Patient preference- assessed by a final evaluation form at their follow up at 10-12 days where they will pledge their favoured dressing type.
Timepoint [1] 303336 0
The final evaluation form will be provided at day 10-12 in clinic follow up. This outcome measures will only be assessed in phase two.
Secondary outcome [2] 319273 0
Patient morbidity assessment- assessed using American Society of Anaesthesiologist Physical status classification and Charlson Comorbidity Index.
Timepoint [2] 319273 0
This information will be gathered pre-operatively for patients recruited to both phases.

Key inclusion criteria
Patients undergoing Total knee Arthroplasty for treatment of knee Arthritis,
Male and non-pregnant females.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Previous joint replacement.
Known allergy to active ingredients in the drape adhesives used in dressings, both conventional dry dressings and Negative Pressure Wound Therapy devices.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed- Surgeons recruiting participants for Phase two were aware that these participants would have one knee treated with the conventional dry dressing and the other with the negative pressure wound therapy.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The randomisation was performed using a list generated from a randomisation computer program. The study will not affect the order of which knee is performed first; this will be decided by the surgeon in collaboration with the anaesthetist and or an existing participant preference
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
In Phase one- all participants receive the same intervention
In Phase two- all participants receive both interventions at the same time to separate knee surgical sites. .
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
No statistical calculations were performed to predict sample size. Participant numbers were based on similar studies as well as resources and access to the negative pressure wound dressings.
Statistical analysis will be performed with IBM SPSS software. Mean will be compared via ANOVA statistical testing to assess significance. General Linear model multivariate testing was utilised to compare patient evaluation scores.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 8530 0
4810 - Townsville
Recruitment postcode(s) [2] 8529 0
4812 - Pimlico

Funding & Sponsors
Funding source category [1] 289763 0
Commercial sector/Industry
Name [1] 289763 0
KCI Medical
Address [1] 289763 0
KCI Medical Australia
Level 7, 15 Orion Road
Lane Cove West NSW 2066
Country [1] 289763 0
Primary sponsor type
Other Collaborative groups
Orthopaedic Research institute of Queensland
Orthopaedic Research Institute
Suite 102, Level 2, Mater Medical Centre,
21-29 Fulham Rd,
Pimlico 4812, Queensland, Australia
Secondary sponsor category [1] 288452 0
Commercial sector/Industry
Name [1] 288452 0
Acelity/ KCI
Address [1] 288452 0
KCI Medical Australia
Level 7, 15 Orion Road
Lane Cove West NSW 2066
Country [1] 288452 0

Ethics approval
Ethics application status
Ethics committee name [1] 291493 0
Mater Health Services North Queensland Ltd
Ethics committee address [1] 291493 0
Mater Health Services North Queensland Ltd
21-37 Fulham Rd
Pimlico QLD 4812
Ethics committee country [1] 291493 0
Date submitted for ethics approval [1] 291493 0
Approval date [1] 291493 0
Ethics approval number [1] 291493 0

Brief summary
A Randomised control single centre trial for patients undergoing bilateral TKR for the treatment of osteoarthritis performed at the Mater Health Services North Queensland between December 2013 and June 2015. The trial is comprised of 2 phases, phase 1 focuses on the economics of Conventional Dry Dressings (CDD) for patients undergoing TKR. Phase 2 captures the cost of Negative Pressure Wound Therapy (NPWT) vs CDD as well as patient satisfaction in patients undergoing Bilateral TKR under three surgeons. Each knee shall be randomised to receive either dry dressings or negative pressure wound dressings. Surgeons and patients will be blinded to which leg will receive the CDD and the NPWT until wound closure and the dressings are to be applied. Patient satisfaction will be assessed in the form of a diary and questionnaire. Economy of dry dressing changes on the ward and in clinic is to be calculated with ward checklists. Data in regards to BMI, American Society of Anaesthesiologist Physical status classification, and Charlson Comorbidity Index will be collated as well. The follow up period is two weeks or untill the first outpatient review as per surgeons standard of care.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 40906 0
Dr Varaguna Manoharan
Address 40906 0
Orthopaedic Research Institute of Queensland
7 Turner Street
Pimlico, Queensland 4812
Country 40906 0
Phone 40906 0
Fax 40906 0
Email 40906 0
Contact person for public queries
Name 40907 0
Mrs Andrea Grant
Address 40907 0
Orthopaedic Research Institute of Queensland
7 Turner Street
Pimlico, Queensland 4812
Country 40907 0
Phone 40907 0
Fax 40907 0
Email 40907 0
Contact person for scientific queries
Name 40908 0
Dr Varaguna Manoharan
Address 40908 0
Orthopaedic Research Institute of Queensland
7 Turner Street
Pimlico, Queensland 4812
Country 40908 0
Phone 40908 0
Fax 40908 0
Email 40908 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary