Influence of Prosthetic Foot Stiffness on Transtibial Osseointegrated Bone-Anchored Limb Outcomes (TBAL)

University of Colorado Denver (CU Denver)

Status and phase: Enrolling; Phase 1

Conditions: Bone Anchored Devices; Amputation; Transtibial Amputation - Unilateral; Osseointegration

Treatments: Device: A prosthetic foot that is two prosthetic foot stiffness categories softer than the stiffness of the as-prescribed prosthetic foot; Device: As-prescribed prosthetic foot stiffness; Device: A prosthetic foot that is two prosthetic foot stiffness categories stiffer than the stiffness of the as-prescribed prosthetic foot

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT07263945

25-0854

1R01HD119003-01 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

A clinical trial utilizing cross-over study design in which individuals with transtibial amputation using either a bone-anchored limb or standard socket prosthesis will perform activities of daily living with varying prosthetic foot stiffness categories to complete the following 4 Specific Aims: 1) Determine the influence of prosthetic foot stiffness on dynamic bone-implant loading, 2) Determine how prosthetic foot stiffness influences function, pain, and multi-joint biomechanics outcomes, 3) Establish how prosthetic foot stiffness influences osseoperception and fall risk, and 4) Establish target ranges of optimal foot stiffness based on the sensitivity biomechanical outcomes to variability in foot stiffness.

Full description

This will be a clinical trial with two groups (individuals with a unilateral transtibial amputation using either an osseointegrated bone-anchored limb or socket prosthesis that will implement a cross-over design. The objective of this clinical trial is to determine how changes in prosthetic foot stiffness influence clinical and biomechanical outcomes in patients with transtibial osseointegrated bone-anchored limbs compared to patients with transtibial amputation using a standard socket-suspended prosthesis. Although proper loading between the bone and implant is pivotal to promote and maintain osseointegration, which is required for physiological loading and thus positive outcomes, evidence surrounding the role of how prosthetic componentry influences force transmission and functional outcomes in this population currently does not exist. The findings of this clinical trial will address a critical knowledge gap pertaining to the role of componentry on multi-loading domain outcomes. Outcomes will be assessed in each participant in the same three conditions: one with their clinical prescribed prosthetic foot, one with a soft prosthetic foot (-2 stiffness categories less than prescribed), and one with a stiff prosthetic foot (+2 stiffness categories more than prescribed). This data will be used to test/develop the following aims: 1) Does foot stiffness change loading between the bone and implant during activities of daily living? 2) Does foot stiffness influence measures of function, pain, and biomechanics in patients with transtibial osseointegrated bone-anchored limbs differently than a socket prosthesis? 3) Does foot stiffness influence sensitivity, balance, and fall risk in patients using an osseointegrated bone-anchored limb different than a socket prosthesis? and 4) (exploratory) develop an optimization platform using computer models to determine the optimal foot stiffness that maximizes joint loading symmetry and minimizes metabolic cost.

Enrollment: 60 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Unilateral transtibial amputation due to traumatic, congenital, or cancer-related causes
• > 12-months bone-anchored limb implantation surgery (Bone Anchored Limb group)
• > 12-months limb amputation (Socket Control group)
• Non-vascular amputation etiology
• Low profile prosthetic foot (nominal)
• Can walk unassisted for 5-minutes
• > 18 years old

Exclusion criteria

• Major amputation on contralateral limb
• Vascular amputation etiology
• Neurologic pathology that impairs coordination/balance
• Regular assistive device use required for community ambulation
• Inflammatory diseases or diabetes
• Pregnancy or breastfeeding

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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60 participants in 3 patient groups

Two prosthetic foot stiffness categories stiffer than the as-prescribed prosthetic foot stiffness

Active Comparator group

Description:

A prosthetic foot that is two prosthetic foot stiffness categories stiffer than the stiffness of the as-prescribed prosthetic foot. The prosthetic foot type, including the manufacturer and length, will remain the same as the nominal (as-currently prescribed) foot.

Treatment:

Device: A prosthetic foot that is two prosthetic foot stiffness categories softer than the stiffness of the as-prescribed prosthetic foot

Two prosthetic foot stiffness categories softer than the as-prescribed prosthetic foot stiffness

Active Comparator group

Description:

A prosthetic foot that is two prosthetic foot stiffness categories softer than the stiffness of the as-prescribed prosthetic foot. The prosthetic foot type, including the manufacturer and length, will remain the same as the nominal foot.

Treatment:

Device: A prosthetic foot that is two prosthetic foot stiffness categories stiffer than the stiffness of the as-prescribed prosthetic foot

As-prescribed prosthetic foot stiffness

Active Comparator group

Description:

The prosthetic foot that is currently prescribed and used by each participant daily.

Treatment:

Device: As-prescribed prosthetic foot stiffness