Clinical Evaluation of the Access Socket Flexible Socket for Transtibial Prosthesis

NCT07592325 | Recruiting

• 1 other identifier: 2026-A00019-42
• Study Type: interventional
• Target: 25
• Locations: 1 country
• Sites: 5

Brief Summary

Transtibial amputation significantly impacts patient autonomy and quality of life, primarily due to the limitations of conventional rigid sockets, which restrict comfort and joint range of motion. The Access Socket (AS) is an innovative prosthetic socket combining a rigid carbon-fiber structure in key load-bearing areas with flexible urethane-resin (ProtheFLEX®) zones in regions typically rigid in conventional sockets. This hybrid design aims to improve comfort and pressure distribution while preserving the mechanical properties required for ambulation. The AS has already demonstrated benefits in transfemoral amputees and is now reimbursed in France for that population. A preliminary uncontrolled study in 12 transtibial amputees suggested significant improvements in perceived function, comfort, satisfaction, and mobility. This multicenter, randomized, open-label, two-arm crossover study aims to compare the (AS) with the standard rigid socket (RS) in 25 adults with transtibial amputation. Participants will wear each socket for approximately 4 weeks (after a 1-2 week adaptation period) in a randomized order. The primary outcome is the Patient Specific Functional Scale (PSFS). Secondary outcomes include comfort (SCS), satisfaction (OPUS), psychosocial adjustment (TAPES-R), mobility (PLUS-M), prosthesis utility (PEQ-U), and the proportion of patients electing to keep the AS at study completion.

Conditions

Transtibial Amputation; Lower Limb Amputation Below Knee

Keywords

Transtibial prosthesis; Prosthetic socket; Flexible socket; Access Socket; Comfort; Quality of life; Rehabilitation; cross over trial; Patient Specific Scale

Outcome Measures

Primary Outcomes (1)

• Patient Specific Functional Scale (PSFS) score

  Patient-centered self-report tool. The patient identifies 3-5 specific activities they have difficulty performing, then rates their ability on a 0-10 scale (0 = unable to perform, 10 = able to perform at pre-injury level). The final score is the mean of the ratings

  One time at the end of each 4-week wear period (V1, V2 and V3)

Secondary Outcomes (5)

• Socket Comfort Scale (SCS) score

  One time at the end of each 4-week wear period (V1, V2 and V3)

• Orthotics Prosthetics Users Survey (OPUS) score

  One time at the end of each 4-week wear period (V1, V2 and V3)

• Trinity Amputation and Prosthesis Experience Scale - Revised (TAPES-R) score

  One time at the end of each 4-week wear period (V1, V2 and V3)

• Prosthesis Evaluation Questionnaire - Utility subscale (PEQ-U) score

  One time at the end of each 4-week wear period (V1, V2 and V3)

• Proportion of participants electing to keep the Access Socket at study completion

  Through study completion, an average of 10 weeks

Study Arms (2)

Group 1 (RS -> AS)

ACTIVE COMPARATOR

Participants wear their standard rigid socket (RS) for 4 weeks, complete evaluation, then switch to the Access Socket (AS) for 1-2 weeks of adaptation followed by 4 weeks of wear, with a second evaluation.

Device: Access Socket (AS); Device: Rigid Socket (RS)

Group 2 (AS -> RS)

ACTIVE COMPARATOR

Participants receive the Access Socket (AS) first, with 1-2 weeks of adaptation followed by 4 weeks of wear and evaluation. They then switch to the standard rigid socket (RS) for 1-2 weeks of adaptation and 4 weeks of wear, with a second evaluation.

Device: Access Socket (AS); Device: Rigid Socket (RS)

Interventions

Access Socket (AS) DEVICE

Hybrid prosthetic socket combining a rigid carbon-fiber structure in load-bearing areas (lateral, postero-inferior, inferior) with flexible urethane-resin (ProtheFLEX®) zones in regions typically rigid in conventional sockets. Manufactured from the same plaster mold as the rigid socket to ensure identical internal geometry.

Group 1 (RS -> AS); Group 2 (AS -> RS)

Rigid Socket (RS) DEVICE

Conventional definitive carbon-fiber rigid socket, currently the only socket type reimbursed in France for transtibial amputation (LPPR-listed). Standard of care comparator.

Group 1 (RS -> AS); Group 2 (AS -> RS)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Unilateral or bilateral transtibial amputation
• Currently fitted with a definitive carbon rigid socket
• Any residual-limb shape
• Any etiology
• Able to understand simple instructions, read, write, and provide informed consent - or able to be accompanied by a trusted person in case of inability to read/write autonomously
• Provided free written informed consent
• Aged 18 years or older
• Affiliated to a social security system

You may not qualify if:

• Use of hydroalcoholic solution (HAS) for socket donning
• Currently fitted with a provisional socket
• Neurological pathology limiting capacity to participate in activities
• Orthopedic pathology limiting capacity to participate in activities
• Pregnant or breastfeeding women
• Minors
• Persons not under legal protection or unable to express consent
• Persons under guardianship or curatorship
• Persons under judicial protection

Sponsors & Collaborators

• Institution Nationale des Invalides: collaborator
• Hôpital Filieris de Freyming-Merlebach: collaborator
• Ortho Access: collaborator
• H20 Orthopedie: collaborator
• Union de Gestion des Etablissements des Caisses d'Assurance Maladie - Nord Est: lead
• Otto Bock France SNC: collaborator
• Hôpital d'Instruction des armées Percy: collaborator
• Clinical Investigation Center - University Hospital Grenoble: collaborator

Study Sites (5)

Hôpital National d'Instruction des Armées (HNIA) Percy

Clamart, 92140, France

RECRUITING

Hôpital Filieris de Freyming-Merlebach

Freyming-Merlebach, 57804, France

RECRUITING

CHU Grenoble Alpes - Hôpital Sud

Grenoble, 38434, France

RECRUITING

Institut Régional de Médecine Physique et de Réadaptation (IRR) - Filière Locomoteur

Nancy, 54000, France

RECRUITING

Insititution Nationale des Invalides

Paris, 75007, France

RECRUITING

Study Officials

• Isabelle Loiret, MD

  Institut Régional de Médecine Physique et de Réadaptation (IRR), Nancy, France

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Isabelle Loiret, MD

CONTACT

+33383529950; isabelle.loiretpro@gmail.com

Jonathan Pierret, PhD

CONTACT

jonathan.pierret@ugecam.assurance-maladie.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Double-blinding not feasible: participants can perceive differences in socket rigidity and prosthesis weight
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Open-label, two-arm randomized crossover trial. Each participant wears both sockets sequentially in a randomized order. Each socket period includes a 1-2 week adaptation/adjustment phase followed by a 4-week wear period before evaluation.

Study Record Dates

• First Submitted: May 5, 2026
• First Posted: May 18, 2026
• Study Start: April 27, 2026
• Primary Completion (Estimated): April 27, 2027
• Study Completion (Estimated): October 30, 2027
• Last Updated: May 18, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

FR (5)