Osseointegrated (bone-anchored) prosthesis for below-knee (transtibial) amputation

Transtibial Osseointegration Surgery Study (TOSS)

This trial tests whether the OPRA bone-anchored implant helps people aged 22–65 with transtibial (below-knee) amputations who cannot use or do not benefit from socket prostheses.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 30 (estimated)
• Ages: 22 Years to 65 Years
• Sex: All
• Sponsor: Walter Reed National Military Medical Center (fed)
• Locations: 2 sites (Bethesda, Maryland and 1 other locations)
• Trial ID: NCT06636136 on ClinicalTrials.gov

What this trial studies

The protocol implants the OPRA osseointegration system into the tibia of eligible transtibial amputees and follows them with standardized clinical and radiologic exams and performance testing. Outcomes include soft-tissue complications and infections, patient-reported function, quality of life and pain scores, physical performance measures, and biomechanical and bone-quality metrics. Assessments occur preoperatively and at 6, 12, 24, 36, 48 and 60 months after surgery, with data recorded on electronic case report forms. Procedures are performed by experienced investigators at participating centers including Walter Reed and Penn Medicine.

Who should consider this trial

Good fit: People aged 22–65 with traumatic or cancer-related transtibial amputations who are skeletally mature and have failed or cannot tolerate conventional socket prostheses, and who are eligible for care at the participating military treatment facility(ies).

Not a fit: Patients with incomplete skeletal growth, active uncontrolled infection, inadequate bone quality or other medical contraindications to surgery, or those who do well with conventional socket prostheses are unlikely to benefit.

Why it matters

Potential benefit: If successful, the OPRA system could reduce socket-related problems and improve mobility, comfort, and quality of life for people with below-knee amputations.

How similar studies have performed: Osseointegration for transfemoral amputees has shown improved mobility and quality-of-life in prior programs but also higher rates of soft-tissue complications and infection, so transtibial application builds on that experience.

Eligibility criteria

Inclusion Criteria:

* Diagnosis of a transtibial amputation age 22-65.
* The OPRA™ Implant System is indicated for patients who have transtibial amputation due to trauma or cancer and who have or are anticipated to have rehabilitation problems with, or cannot use, a conventional socket prosthesis. The OPRA™ Implant System is intended for skeletally mature patients.
* The patient failed to receive benefit from socket prostheses or is expected to not tolerate socket use due to problems such as:

  * Recurrent skin infections and ulcerations in the socket contact area
  * Pain
  * A short stump preventing the use of socket prosthesis
  * Volume fluctuation in the stump
  * Soft tissue scarring
  * Extensive area of skin grafting
  * Socket retention problems due to excessive perspiration
  * Restricted mobility
* Eligible to receive care at Military Treatment Facility ( WRNMMC only)
* DEERS-eligible ( WRNMMC only)

Exclusion Criteria:

* The patient's skeletal growth is not complete. Completed skeletal growth is defined through the finding of generally closed epiphyseal zones on X-ray.
* The patient has atypical skeletal anatomy which may affect treatment with OPRA™.

  * Examples of atypical skeletal anatomy.
  * Skeletal dimensions outside defined interval.
  * Development anomalies.
  * Conditions which are not amenable to device insertion such as deformities, fracture, infection.
* The patient would have less than 2 mm of remaining cortex bone available around the implant, if implanted.
* Osteoporosis.
* The patient is older than 65 years and younger than 22 years.
* BMI over 35.
* Do not treat patients with the following concurrent diseases:

  * Severe peripheral vascular disease.
  * Diabetic mellitus with complications.
  * Neuropathy or neuropathic disease.
  * Active infection or dormant bacteria.
  * Metabolic bone disease and/or metastatic lesions in the residual tibia.
* Pregnancy before the surgery female patients will take a pregnancy test) Note: Patients who become pregnant, after surgery stage I, surgery stage II will be delayed until safe to do so by their doctor. The patient will remain in the study, unless they would like to withdrawal.
* The patient is not expected to be able to comply with treatment and follow up requirements.
* Participants unable to sign their own consent (No legally authorized representatives may provide consent)

Where this trial is running

Bethesda, Maryland and 1 other locations

• Orhopaedic Surgery Service, Walter Reed National Military Medical Center — Bethesda, Maryland, United States (RECRUITING)
• Department of Orthopaedic Surgery and Department of Anesthesiology & Critical Care Penn Medicine University City — Philadelphia, Pennsylvania, United States (RECRUITING)

Study contacts

• Principal investigator: Christopher H Renninger, MD — Walter Reed National Military Medical Center
• Study coordinator: Emma L Stewart

Conditions: Amputation, Traumatic, Leg, Lower, Transtibial, Osseointegration