Safety and Efficacy Clinical Trial of the Vessel-X® Bone Filling Container System (CMT-VX)

Background and Rationale:

Osteoporotic vertebral compression fractures (OVCFs) are a common and serious complication of osteoporosis, particularly among elderly and postmenopausal patients. OVCFs may result in severe pain, functional impairment, spinal deformity, and reduced quality of life. Conventional conservative treatments, including bed rest, analgesics, and bracing, may provide limited symptom relief. Minimally invasive vertebral augmentation procedures, such as vertebroplasty and kyphoplasty, have been widely used to improve clinical outcomes; however, risks including bone cement leakage and incomplete vertebral restoration remain concerns.

The Vessel-X® Bone Filling Container System, manufactured by Central Medical Technologies Inc. (CMT), is a third-generation vesselplasty technology designed for percutaneous vertebral augmentation procedures. The system utilizes an implantable biocompatible polyethylene terephthalate (PET) container with a microporous structure for controlled bone cement delivery. The implant remains within the vertebral body after cement injection and is designed to reduce cement leakage while maintaining vertebral height restoration and pain relief.

This is a prospective, open-label, randomized, parallel-controlled, non-inferiority clinical trial conducted in Taiwan to evaluate the safety and clinical effectiveness of this system (Model: BVFT-UP01-D20, Approved No. 005889) compared with conventional vertebroplasty performed using manual orthopedic surgical instruments (Approved No. 005698), both manufactured by CMT. Both groups will utilize the same radiopaque bone cement ("Tecres" Osteopal V) for the therapeutic procedures.

Hypothesis:

The study is designed as a non-inferiority trial. The primary hypothesis is that the incidence of unanticipated serious adverse device effects (USADEs) in the Vessel-X® group is not higher than that in the control group. For efficacy, the experimental group is hypothesized to be non-inferior to the control group regarding pain relief, disability improvement, and radiographic parameters, with a pre-specified non-inferiority margin of -15% for the difference in fused effective rates between the two groups.

Patient Enrollment and Site Allocation:

To achieve the clinical evaluation objectives, a total of up to 146 subjects will be recruited across participating medical centers in Taiwan. The target sample size is allocated specifically as 86 subjects from Tri-Service General Hospital (TSGH) and 60 subjects from Taoyuan General Hospital (TYGH). Subjects at each site will be allocated to the experimental and control groups using a 1:1 randomization scheme.

Surgical Procedure Protocol:

All surgical procedures will be performed under real-time fluoroscopic (C-arm) guidance using a standard unilateral transpedicular approach:

Experimental Group: The Vessel-X® PET biocompatible microporous container will be deployed into the vertebral body, and bone cement will be injected in a controlled manner, allowing partial cement interdigitation through the micropores. The container remains as a permanent implant.

Control Group: Conventional vertebroplasty will be performed using CMT's standard manual orthopedic surgical instruments to deliver the bone cement directly.

In both groups, fluoroscopic monitoring is maintained throughout the injection, and cement delivery will be discontinued immediately if any cement leakage or breach is observed.

Clinical Evaluation Timelines:

Subjects will participate in the study for a total duration of 13 months, consisting of a 1-month screening period, the surgical intervention (Day 1), and a 12-month post-operative follow-up period. Follow-up visits are scheduled at Day 8 (8±2 days), Month 1 (31±2 days), Month 3 (91±15 days), Month 6 (181±15 days), Month 9 (271±15 days), and Month 12 (361±15 days).

Outcome Assessments:

Safety Assessment (Primary Endpoint, ITT Population): Evaluated by the incidence of adverse events, complications, bone cement leakage, and new-onset neurological deficits.

Efficacy Assessment (Secondary Endpoints, PP & FAS Populations): Evaluated by changes from baseline to each follow-up timepoint in Visual Analogue Scale (VAS) scores for pain, Oswestry Disability Index (ODI) scores for functional disability, and radiographic parameters (anterior vertebral height, midline vertebral height, and kyphotic Cobb's angle)