Clinical Evaluation of the Access Socket Flexible Socket for Transtibial Prosthesis

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

Interventions

DEVICE

Rigid Socket (RS)

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

DEVICE

Access Socket (AS)

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.

Sponsors & Collaborators

• Institution Nationale des Invalides

  collaborator OTHER

• Hôpital Filieris de Freyming-Merlebach

  collaborator UNKNOWN

• Ortho Access

  collaborator UNKNOWN

• H20 Orthopedie

  collaborator UNKNOWN

• Otto Bock France SNC

  collaborator INDUSTRY

• Hôpital d'Instruction des armées Percy

  collaborator UNKNOWN

• Clinical Investigation Center - University Hospital Grenoble

  collaborator UNKNOWN

• Union de Gestion des Etablissements des Caisses d'Assurance Maladie - Nord Est

  lead OTHER

Principal Investigators

• Isabelle Loiret, MD · Institut Régional de Médecine Physique et de Réadaptation (IRR), Nancy, France

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-04-27

Primary Completion

2027-04-27

Completion

2027-10-30

Countries

• France

Study Locations