Comparative Effectiveness of Socket Casting Methods: Improving Form and Fit

The overall objective is to compare hand casting to standing hydrostatic pressure casting using a water cylinder in persons with lower limb amputation. Our overall hypothesis is that standing hydrostatic pressure casting with a water cylinder will lead to more consistent and efficient residual limb shape capture and improved initial socket fit and comfort compared to hand casting.

Study Overview

• Status: Completed
• Conditions: Lower Limb Amputation
• Intervention / Treatment: Procedure: Hand Casting; Device: Symphonie Aqua SystemTM

Detailed Description

One of the most important components of restoring function in persons with lower limb amputation is the precise fitting of the prosthetic socket to the residual limb. However, this is challenging because the residual limb is dynamic in shape and volume. Additionally, prosthetic socket fabrication processes influence socket fit. These processes typically consist of residual limb shape capture, positive mold rectification, initial diagnostic socket fitting, and definitive prosthesis delivery. The most prevalent residual limb shape capture method involves a negative wrap cast in a non-weight bearing position and manual manipulation of the cast to conform to the residual limb shape. With this technique it is challenging to accurately capture the bony contours and distribute pressure evenly around the residual limb. To improve shape capture, techniques that rely less on manual manipulation by the prosthetist, such as standing hydrostatic pressure casting with a water cylinder have been developed. Given the use of physics to shape the residual limb, it has been proposed that pressure casting results in better fitting and more comfortable sockets, however this has not yet been demonstrated. The overall objective is to compare hand casting to standing hydrostatic pressure casting using a water cylinder in persons with lower limb amputation. Our overall hypothesis is that standing hydrostatic pressure casting with a water cylinder will lead to more consistent and efficient residual limb shape capture and improved initial socket fit and comfort compared to hand casting.

• Study Type: Interventional
• Enrollment (Actual): 80
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Italy
  • Emilia-Romagna
    • Bologna, Emilia-Romagna, Italy, 40139
      • INAIL
• United States
  • Illinois
    • Chicago, Illinois, United States, 60611
      • NUPOC
  • Minnesota
    • Minneapolis, Minnesota, United States, 55417
      • Minneapolis VA Heath Care System

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• unilateral lower limb amputation (transtibial and transfemoral)
• current prosthesis users

Exclusion Criteria:

• poor residual limb sensation
• a superficial neuroma that is painful to pressure
• an open sore on the residual limb
• a residual limb circumference or body weight that exceeds the size or weight limits of the Symphonie Aqua SystemTM (i.e., >58cm and 170kg for persons with transtibial amputation and >78cm and 170kg for persons with transfemoral amputation
• persons who are unable to stand for the 4-6 minutes required for casting (e.g. persons with bilateral amputations).
• persons with new amputations (i.e., have been an amputee for less than 1 year)
• persons with transfemoral amputation who have a known silicone allergy or a femur length less than 5 inches

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Hand Casting; hand cast will be taken using a circumferential plaster of Paris or fiber glass wrap of the residual limb with the subject in a seated position	Procedure: Hand Casting; plaster of Paris or fiberglass bandages are wrapped around the residual limb
Active Comparator: standing hydrostatic pressure casting with a water cylinder; hand cast will be taken using a circumferential plaster of Paris wrap of the residual limb with the subject in a seated position. The residual limb is then placed into the Symphonie Aqua System while in a weight bearing standing position.	Device: Symphonie Aqua SystemTM; a water filled cylinder that can be pressurized around the residual limb to support body weight

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Socket Comfort Score	Score from 0-10, with 0 being the least comfortable socket and 10 being the most comfortable socket	at study completion, 1 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cast/Socket volume	digitized volume and shape of cast and socket	at every study visit, up to 1 month
Procedure time	Time to cast, rectify and fit the socket	at every study visit, 1 month
Socket Fit	checklist will be used to assess fit of socket	at study completion, 1 month
Socket preference	subject's preference for socket to continue wearing	at study completion, 1 month

Collaborators and Investigators

• Sponsor: Northwestern University
• Collaborators: Minneapolis Veterans Affairs Medical Center; University of Washington; INAIL (Istituto Nazionale per L'Assicurazioni contro gli Infortune sul Lavoro)
• Investigators: Principal Investigator: Steven Gard, PhD, Northwestern University

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2020
• Primary Completion (Actual): September 1, 2023
• Study Completion (Actual): September 1, 2023

Study Registration Dates

• First Submitted: October 21, 2019
• First Submitted That Met QC Criteria: October 25, 2019
• First Posted (Actual): October 28, 2019

Study Record Updates

• Last Update Posted (Actual): September 19, 2024
• Last Update Submitted That Met QC Criteria: September 16, 2024
• Last Verified: September 1, 2024

More Information

Terms related to this study

• Keywords: shape capture; prosthetic sockets
• Other Study ID Numbers: W81XWH1910835

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data generated by the funded research will be made available to the research community and to the public under the auspices of the PI. Prior to sharing, data will be de-identified and redacted to reduce the risk of subject identification.
• IPD Sharing Time Frame: Data will be shared after acceptance for publication of the main findings from the final dataset.
• IPD Sharing Access Criteria: The PI will share data upon request with anyone via a unique link to a file or folder within Northwestern Box. A data-sharing agreement will be used to ensure that the data is only used for the purpose described, users acknowledge the data source in any use of the data, agree to provide the PI with copies of any presentation or publication that uses the data, prohibit sharing of the data with others without those parties having their own data use agreement, and prohibit manipulation of data for the purposes of identifying subjects.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No