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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
Clinical outcomes of the pressure cast technique to create low-cost prosthetic sockets for Vietnamese participants with below knee amputations
Scientific title
Clinical evaluation of a hydrocast technique for transtibial socket fit in Vietnamese participants with below knee amputations
Secondary ID [1] 292886 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Transtibial amputation 304732 0
Condition category
Condition code
Physical Medicine / Rehabilitation 304047 304047 0 0
Other physical medicine / rehabilitation

Study type
Description of intervention(s) / exposure
Intervention Name: Pressure cast (PCAST) Prosthetic Socket
This study was conducted at the Vietnamese Training Centre for Orthopaedic Technologists (VIETCOT) clinic in Hanoi, Vietnam. VIETCOT staff with International Society for Prosthetics and Orthotics (ISPO) category II qualifications cast, fabricated and fitted the PCAST sockets. Briefly, the PCAST technique involved wrapping participants’ residual limb, wearing a cotton sock, in plaster wrap uniformly; followed by placement of the limb into the PCAST tank (made of polyvinyl chloride) filled with water, separated from the limb by a polyethelene diaphragm. The water pressure was increased until the participants could stand with 50% of their weight supported by the pressurised water. Once the plaster wrap hardened, the tank was depressurised and the plaster removed. No rectifications to the positive socket mould based on the plaster wrap were performed with the exception of the smoothing of obvious rough edges. The hard socket was manufactured using standard International Committee of the Red Cross (ICRC) techniques using ICRC polypropylene technology. The casting and initial fitting of the prosthetic socket took approximately 2 hours. The socket was manufactured once, after which the participants completed a usage period of approximately 5 months. During this time they were under no obligation to use the prosthesis and could replace it with their original prosthesis at any time. There were no strategies to monitor adherence to the study or use of the socket until the participants self-reported use when they returned after the extensive usage period
Intervention code [1] 299124 0
Treatment: Devices
Comparator / control treatment
The clinical outcomes of the participants were initially assessed using their current or original limb. This data was used to compare the relative outcomes of the intervention socket (the PCAST socket).
Control group

Primary outcome [1] 303378 0
Six-minute-walk-test (distance a participant is able to walk in a 6 minute window)
Timepoint [1] 303378 0
Before receiving PCAST limb (with current limb), 15 minutes after receiving PCAST limb, and approximately 5 months after receiving PCAST limb.
Primary outcome [2] 303379 0
Timed-up-and-go Test (the time a participant takes to rise from a chair, walk three meters, turn around, walk back to the chair, and sit down).
Timepoint [2] 303379 0
Before receiving PCAST limb (with current limb), 15 minutes after receiving PCAST limb, and approximately 5 months after receiving PCAST limb.
Primary outcome [3] 303380 0
Spatio-temporal gait data (the participant walks over an instrumented 4.57 m walkway (Gaitrite). Spatio-temporal gait data is a composite outcome and data collected included speed, cadence, step length, stride length, support base, swing time, stance time and single and double support times.
Timepoint [3] 303380 0
Before receiving PCAST limb (with current limb), 15 minutes after receiving PCAST limb, and approximately 5 months after receiving PCAST limb.
Secondary outcome [1] 338773 0
Satisfaction with Prosthesis questionnaire (SATPRO). Validated survey (composite outcome) with 19 survey items to evaluate the most significant criteria used by the person when selecting a technical aid. Includes factors relating to comfort, ease of use and aesthetics.
Timepoint [1] 338773 0
Before receiving PCAST limb (with current limb), 15 minutes after receiving PCAST limb, and approximately 5 months after receiving PCAST limb.
Secondary outcome [2] 338774 0
Socket Comfort Score (SCS). Validated survey instrument to determine the users perceived socket comfort. Participants rated the comfort of their socket on a 0–10 scale where 0 represented the most uncomfortable and 10 the most comfortable sockets imaginable
Timepoint [2] 338774 0
Before receiving PCAST limb (with current limb), 15 minutes after receiving PCAST limb, and approximately 5 months after receiving PCAST limb.
Secondary outcome [3] 338786 0
Pressure profile at the interface of the socket and participants residual limb. The pressure data was collected using the F-socket residual limb/socket interface pressure measurement system (Tekscan Inc., USA).
Timepoint [3] 338786 0
Before receiving PCAST limb (with current limb), 15 minutes after receiving PCAST limb, and approximately 5 months after receiving PCAST limb.

Key inclusion criteria
Eligibility for the study dictated that participants were 18 years or older, active wearers and long-term users of their prosthesis.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Significant co-morbidities which affect their ability to provide quality feedback comparing their previous prostheses to that of the PCAST or complete the physical function tests. In addition, they will require minimal physiotherapy or gait training prior to limb use or require walking aids additional to a prosthetic limb (e.g. canes or walkers).

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Single group
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Descriptive statistics were calculated. Data sets were assessed for normality by measures of skewness and kurtosis. Repeated measures multivariate analyses of variance (RM MANOVA) with contrast testing (two-tailed) were used to compare original and PCAST (pre) data, collected after 15 minutes of a familiarisation, and PCAST (post) data, collected following a usage-period of about 5 months. Three separate RM MANOVAs were conducted on the 1) physical function and SATPRO data, 2) spatial gait data and 3) temporal gait data. Statistical calculations were performed with SPSS (version 17) with the alpha level set at 0.05. Effect sizes were calculated using Cohen’s d for all comparisons with p < 0.05. The pressure magnitude data exhibited high right skewness and the location data distribution was non-parametric. As such, Mann-Whitey U tests were used to compare the HighSCS and LowSCS group pressure data, with the effect size calculated using the Glass rank-biserial correlation, r.

It was planned that a total of 50 subjects would participant in the study. However, it would be conducted in three phases consisting of 15, 15 and 20 subjects respectively. By conducting the project in phases, there are opportunities for phase two and three to be improved on depending on the results of the preceding phases. In a study of similar aims, Hafner et al. performed tests to determine the evaluation of function, performance and patient preference as transfemoral amputees’ transition from one lower-limb prostheses to another. Hafner performed these tests on 17 subjects with significant power, thus 15-20 subjects was deemed appropriate for the current study.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 9213 0
Viet Nam
State/province [1] 9213 0
Ha noi

Funding & Sponsors
Funding source category [1] 297514 0
Name [1] 297514 0
CASS Foundation
Address [1] 297514 0
2/111 Collins St, Melbourne VIC 3000
Country [1] 297514 0
Funding source category [2] 297533 0
Name [2] 297533 0
Rotary Club of Richmond
Address [2] 297533 0
PO Box 138 Richmond Vic 3121
Country [2] 297533 0
Primary sponsor type
The University of Melbourne
Grattan St, Parkville VIC 3010
Secondary sponsor category [1] 296519 0
Name [1] 296519 0
Address [1] 296519 0
Plenty Rd, Bundoora VIC 3083
Country [1] 296519 0
Other collaborator category [1] 279730 0
Name [1] 279730 0
Jim Lavranos
Address [1] 279730 0
The Royal Melbourne Hospital, 300 Grattan St, Parkville VIC 3050
Country [1] 279730 0

Ethics approval
Ethics application status
Ethics committee name [1] 298613 0
The University of Melbourne Human Research Ethics Committee
Ethics committee address [1] 298613 0
Grattan St, Parkville, VIC, 3010
Ethics committee country [1] 298613 0
Date submitted for ethics approval [1] 298613 0
Approval date [1] 298613 0
Ethics approval number [1] 298613 0
Ethics committee name [2] 298615 0
University of Labour and Social Affairs - Research Ethics
Ethics committee address [2] 298615 0
43 Tran Duy Hung, Trung Hoà, Cau Giay, Hà Noi, 123002, Vietnam
Ethics committee country [2] 298615 0
Viet Nam
Date submitted for ethics approval [2] 298615 0
Approval date [2] 298615 0
Ethics approval number [2] 298615 0

Brief summary
The most important part of the artificial limb is the socket, which forms the interface between the amputee’s residual limb and prostheses. The design and fitting of the socket is a difficult task due to the uniqueness of each amputee’s residual limb. Every fitting requires much attention from the prosthetist. Although there exists some guidelines to design and fit sockets for different levels of amputation, a successful fitting is still highly dependent on the skill and experience of the prosthetist. The purpose of this study is to examine the comfort of a socket made by an new technique known as pressure casting (PCAST). The aim of this study is to examine the comfort and function of the PCAST socket. This will be done by measuring the walking pattern and level of mobility with the PCAS Tlimb and the pressure between the residual limb and the PCAST socket during walking. Walking patterns and pressures will be recorded by high-tech “state of the art” non-invasive measurement systems located at the Vietnamese Training Centre for Orthopaedic Technologists (VIETCOT) in Hanoi. A total of 50 people will participate in this study.
Trial website
Trial related presentations / publications
Lee PV, Lythgo N, Laing S, Lavranos J, Thanh NH. Pressure casting technique for transtibial prosthetic socket fit in developing countries. J Rehabil Res Dev. 2014;51(1):101-10. 10.1682/JRRD.2012.10.0191
Public notes
Attachments [1] 2056 2056 0 0
/AnzctrAttachments/373649-ULSA ethics approval.pdf (Ethics approval)

Principal investigator
Name 77654 0
Prof Peter Vee Sin Lee
Address 77654 0
The University of Melbourne, Grattan St, Parkville, VIC, 3010
Country 77654 0
Phone 77654 0
+61 3 83444426
Fax 77654 0
Email 77654 0
Contact person for public queries
Name 77655 0
Prof Peter Vee Sin Lee
Address 77655 0
The University of Melbourne, Grattan St, Parkville, VIC, 3010
Country 77655 0
Phone 77655 0
+61 3 83444426
Fax 77655 0
Email 77655 0
Contact person for scientific queries
Name 77656 0
Prof Peter Vee Sin Lee
Address 77656 0
The University of Melbourne, Grattan St, Parkville, VIC, 3010
Country 77656 0
Phone 77656 0
+61 3 83444426
Fax 77656 0
Email 77656 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