Smart Crutch Tips for Guided Weight-Bearing in Patients Recovering From Extra-Articular Distal Tibia Fractures
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-80
SponsorComeback Mobility Inc
About this trial
The goal of this clinical trial is to learn whether personalized weight-bearing prescriptions using Smart Crutch Tips™ can improve recovery after surgery for extra-articular distal tibia fractures. The study will also assess how safe and practical this approach is in daily outpatient use.
Can a personalized weight-bearing program based on CT and finite element analysis help the fracture heal faster? Can it help patients return to full weight-bearing sooner? Can it reduce the fear of movement during recovery? Researchers will compare standard rehabilitation, AO Foundation-based recommendations, and personalized weight-bearing programs derived from finite element analysis (FEA) to determine which approach leads to faster healing, earlier mobility, and better outcomes.
Participants will:
Use Smart Crutch Tips™ during walking for up to 24 weeks; Follow a personalized weight-bearing prescription based on CT scans and biomechanical modeling; Follow a specific walking plan with real-time audio and visual feedback; Attend eight follow-up visits over 36 weeks for clinical exams, x-rays, and CT scans; Complete online questionnaires about pain, activity, and fear of movement.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Signed informed consent was provided after being fully informed about participation in the study.
Age: 18 to 80 years for both males and females (pre-menopausal).
Body weight between 40 and 120 kg.
Diagnosed with a closed tibial shaft fracture (AO/OTA classification: 43- А1, 43-А2, 43-А3) requiring surgical treatment.
Disqualifiers
Presence of open or high-energy fractures, multiple lower-limb fractures, or use of bone grafts.
Fractures classified as 41-A, 41-B, or 42 -A,B according to AO/OTA.
Chronic alcoholism (defined as >14 standard drinks per week for men or >7 for women).
Presence of metabolic disorders, including uncontrolled thyroid dysfunction, severe renal or hepatic pathology.
Trial design
Design model
Parallel
Treatments tested in this trial
Smart Crutch Tips™
DeviceSmart Crutch Tips™ are sensor-equipped crutch attachments that measure real-time axial loading during ambulation. The devices connect via Bluetooth to a mobile application and deliver auditory and visual feedback to guide patients toward prescribed weight-bearing levels. The devices continuously record loading and step-count data for clinical monitoring and analysis.
Finite Element Analysis (FEA)
Procedure/SurgeryFinite Element Analysis (FEA) is performed up to four times postoperatively to generate individualized weight-bearing prescriptions during rehabilitation. Simulations are based on CT scans and include segmentation and biomechanical modeling of the bone-fixator system. Assessments occur at: 8 days (baseline), 6 weeks, 12 weeks, and 15 weeks. Three regions are segmented: fixation system (screws and nail), bone fragments, and fracture gap. Materials: fixator (Titanium Grade 5), bone (mapped into cortical, trabecular, soft tissue, air), and fracture gap (early connective tissue). FEA calculates personalized safe loading based on: (1) Fixator safety (stress \< 290 MPa), (2) Interfragmentary motion (target: 0.5-2.0 mm), and (3) Strain in the fracture gap (octahedral: 0.001-0.05; hydrostatic: 0.001-0.02), supporting biological healing. Output informs weight-bearing prescriptions and step-count targets, delivered via Smart Crutch Tips™ with real-time fee
Iterative walking
BehavioralParticipants will perform iterative walking sessions as part of their rehabilitation program. These sessions will be repeated throughout the day, with a minimum 2-hour rest interval between sessions. Step count will be progressively increased over time, according to the individualized rehabilitation plan.
Lower Limb Rehabilitation Exercise Program
Procedure/SurgeryThe program consists of a structured set of isometric and dynamic exercises targeting the quadriceps, hamstrings, gluteal muscles, and ankle/foot mobility. Exercises are performed in a supine, prone, or seated position, as appropriate, with 2 sets of 5-12 repetitions or sustained holds of 20-30 seconds, progressing gradually according to the rehabilitation plan. All movements are conducted within a pain-free range (not exceeding 4/10 on the VAS scale), with additional hourly ankle mobility work prescribed to reduce swelling and prevent thrombosis.
Orthopedic shoes for use during rehabilitation period
DevicePatients are provided with orthopedic shoes to be worn during the rehabilitation period (up to 6-10 weeks).
Treatment groups
30 Participants
are divided into 3 treatment groupsGroup A: Control Group (Standard of Care)No intervention 0 interventions
Group B: Controlled Mechanical Stimulation According to AO GuidelinesExperimental treatment 3 interventions
Group C: Personalized Controlled Mechanical Stimulation (FEA)Experimental treatment 5 interventions
Trial outcomes
Primary outcomes
1
Time to Radiographic Fracture Union
X-rays will be performed at Visit 1, Visit 2, Visit 3, Visit 4, Visit 5 and Visit 6, Visit 7 postoperatively. CT will be conducted at Visit 0, Visit 1, Visit 2, and Visit 3 to assess fracture union progression and load adaptation. Fracture Consolidation Assessment Procedure: CT and X-ray data will be evaluated separately. CT criteria include qualitative parameters (fracture line presence, edge clarity, cortical bridging) and quantitative parameters (Hounsfield units at the fracture site). Radiographic assessment will follow the modified RUST scale: Score 1 - no callus, visible line; Score 2 - callus without bridging, visible line; Score 3 - callus with bridging, visible line; Score 4 - callus with bridging, no visible line. The total score ranges from 4 to 16. Fracture is united if at least three cortices are bridged. Delayed union is defined as a visible fracture line and no callus after 3 months.
Time frame
12 - 24 weeks post-surgery ± 7 daysSecondary outcomes
1
mRUST Score
The modified Radiographic Union Scale for Tibial fractures (mRUST) is used to assess bone healing based on radiographs of the fracture site. Four cortices are evaluated, with scores assigned according to callus formation and visibility of the fracture line. The total score ranges from 4 to 16, with higher scores indicating more advanced bone healing. mRUST scores will be compared between intervention and control groups at each follow-up visit to determine the impact of the intervention on bone healing
Time frame
at 6, 12, 15, 18, 21, 24, 36 weeks after surgery (+- 7 days)2
Adherence to Prescribed Axial Loading
The percentage of steps taken within the prescribed range of axial loading. Higher percentages indicate better adherence to the prescribed loading regimen. This is measured through continuous monitoring using the Smart Crutch Tips™ device and analyzed at each follow-up visit (from 0 to 36 weeks).
Time frame
from 0 to 36 weeks post-surgery3
Lower Extremity Functional Status (LEFS)
Assessed using the Lower Extremity Functional Scale (LEFS) - a validated instrument designed to measure a patient's ability to perform everyday physical activities involving the lower limbs. The questionnaire consists of 20 items, each scored from 0 (extreme difficulty or unable to perform) to 4 (no difficulty). The total score ranges from 0 to 80, with higher scores indicating better functional status.
Time frame
0-8 days post-surgery and at 6, 12, 15, 18, 21, 24, 36 weeks after surgery (+- 7 days)4
Recording of AEs/SAEs AR/SAAR/SUSARs, including Postoperative Complications
The following types of postoperative complications will be recorded and analyzed: residual pain; delayed union; nonunion; malunion; implant failure; need for reoperation. Assessment will be performed clinically at each visit and supplemented with radiological evaluation (X-ray and CT), according to the visit schedule. All adverse events (AEs), serious adverse events (SAEs), adverse reactions (ARs), serious adverse reactions (SAARs), and suspected unexpected serious adverse reactions (SUSARs) identified during the study will also be recorded, described, and analyzed.
Time frame
0-8 days post-surgery and at 6, 12, 15, 18, 21, 24, 36 weeks after surgery (+- 7 days)Other outcomes
1
Time to Full Weight-Bearing (FWB)
Time to full axial loading on the injured limb will be assessed using both clinical evaluation and finite element analysis (FEA). The measure reflects the time required for participants to achieve full weight-bearing. Assessment will be performed during follow-up visits (evaluation of pain, mobility, swelling, radiological confirmation) or via the CBM system (three consecutive days without crutches/cane and without complications, confirmed at a follow-up visit). The variable is measured on a ratio scale.
Time frame
From surgery until full weight-bearing, assessed up to 24 weeks2
Analgesic Consumption
Recorded use of analgesics (yes/no) during scheduled clinical visits.
Time frame
0-8 days post-surgery and at 6, 12, 15, 18, 21, 24, 36 weeks after surgery (+- 7 days)3
Antidepressant Consumption
Recorded use of antidepressants (yes/no) during scheduled clinical visits
Time frame
0-8 days post-surgery and at 6, 12, 15, 18, 21, 24, 36 weeks after surgery (+- 7 days)4
Psychotherapy Visits
Number of psychotherapy visits recorded during follow-up
Time frame
From surgery through 36 weeksSponsors and contacts
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Source ClinicalTrials.gov