Transverse Tibial Bone Transport (TTT) in the Management of Chronic Diabetic Lower Extremity Wounds

SMILE - TTT: Surgical MIcrovascularization of Lower Extremities for Diabetic Foot Ulcers - Transverse Tibial Transport Study

The purpose of this study is to evaluate the safety and clinical performance of transverse tibial bone transport in patients with chronic ischemic and diabetic lower extremity ulcers. This study will assess wound healing outcomes and limb preservation in a population with limited therapeutic alternatives.

Diabetic lower extremity ulcers are associated with impaired blood flow, delayed wound healing, high morbidity, and an increased risk of limb loss. In some patients, conventional treatments such as wound care, revascularization procedures, or adjunctive therapies are ineffective or not feasible, leaving limited options short of major amputation.

Transverse tibial bone transport (TTT) is a surgical technique that applies controlled distraction to the tibial cortex and has been reported in prior clinical studies to stimulate angiogenesis, improve local perfusion, and support wound healing in ischemic conditions.

Inclusion Criteria:

• Adults (>=22 years).
• Chronic diabetic foot ulcer wound persisting >=12 weeks and less than 104 weeks refractory to standard wound care.
• Wound location within distal 1/3 tibia and below including foot.
• Wound stages: WiFi >= 3
• At least one patent lower extremity tibial vessel (after revascularization if needed).
• Able to provide informed consent and comply with study procedures.

Exclusion Criteria:

• Active systemic infection (positive blood cultures)

• Severe sepsis (2 out of 4 SIRS criteria with impact on organ dysfunction)

• Subacute lower extremity wound <12 weeks with or without standard wound cares

• Internal hardware within 10cm of possible TTT placement

• Most proximal aspect of wound within 10cm of most distal pin of possible TTT placement

• End Stage Renal Disease requiring dialysis

• Renal function values

  • eGFR: <15ml/min and
  • Creatinine: >6mg/dL and
  • BUN: >50 mg/dL

• Wounds less than 1 cm3 or greater than 30 cm3

• Corticosteroids >10mg prednisone equivalent daily for >2 weeks

• Patients with osteomyelitis in the ipsilateral tibia at planned corticotomy site

• Cognitive or social limitations precluding consent or follow-up

• Current participation in another investigational study (drug or device)

• Immunocompromised (WBC <4) or undergoing active chemotherapy

• Hemoglobin A1c >12

• BMI <18.5 kg/m2

• Pregnant, lactating, or planning to become pregnant

• Life expectancy less than 12 months

• Severe hepatic impairment defined by patient on a transplant list, MELD > 20, Child's class C.

• A history of conditions that may impair wound healing in the opinion of the Investigator, for example, autoimmune disorders, renal failure patients on dialysis, or medications that impair the healing process.