Smart Crutch Tips for Guided Weight-Bearing in Patients Recovering From Tibial Shaft 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 tibial shaft 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? Does iterative walking in the early postoperative period support faster or better bone healing? Researchers will compare standard rehabilitation to different types of personalized weight-bearing programs to see which 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 six 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.
Body Mass Index (BMI) between 18.5 and 29.9 kg/m².
Disqualifiers
Presence of open or high-energy fractures, multiple lower-limb fractures, or use of bone grafts.
Fractures classified as 43-B or 43-C 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: 7 days (baseline), 6 weeks, 12 weeks, and optionally at 16 weeks if healing isn't confirmed. 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. In the intervention arms, walking sessions will be guided by real-time auditory and visual feedback from Smart Crutch Tips™.
Lower Limb Rehabilitation Exercise Program
Procedure/SurgeryA structured exercise program prescribed postoperatively to promote functional recovery after tibial shaft fracture surgery. Exercises target quadriceps, hamstrings, gluteal muscles, and ankle/foot mobility to maintain muscle tone, prevent stiffness, and improve circulation. The program includes isometric and dynamic exercises such as: static quadriceps and hamstring contractions, straight leg raises, hip abduction, knee extension, hamstring curls, heel slides, ankle dorsiflexion/plantarflexion, ankle inversion/eversion, ankle circles, toe spreading, and passive ankle stretching using a strap or towel. Exercises are performed in pain-free ranges with gradual progression in repetitions and sets according to the rehabilitation plan. Certain ankle and foot mobility exercises (dorsiflexion/plantarflexion) are also performed hourly during the day to prevent swelling and thrombosis.
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 and Activity (Optimal Interfragmentary Motion)Experimental treatment 4 interventions
Group C: Controlled Mechanical Stimulation and Activity According to the Claes-Heigele TheoryExperimental treatment 4 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 postoperatively. CT will be conducted at Visit 0, Visit 1, Visit 2, and optionally at 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, 16, 20, 24, and 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
0-7 days post-surgery and at 6, 12, 16, 20, 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
0-7 days post-surgery and at 6, 12, 16, 20, 24, 36 weeks after surgery (+- 7 days)Other outcomes
1
Device Usability (System Usability Scale, SUS)
Assessment of Smart Crutch Tips™ usability, reliability, and patient satisfaction using the validated SUS questionnaire.
Time frame
Week 6 post-surgery2
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 weeks3
Analgesic Consumption
Recorded use of analgesics (yes/no) during scheduled clinical visits.
Time frame
At all follow-up visits up to 36 weeks4
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