A RCT of Collagen Scaffold for the Repair of Talus Cartilage Injury

Microfracture to repair cartilage defect is a minimally invasive procedure that is usually done arthroscopically. The doctor first cleans the damaged cartilage area, and then uses a special microfracture cone to drill vertically in the subchondral bone plate, forming multiple tiny holes, allowing mesenchymal stem cells and growth factors in the bone marrow to overflow, forming a blood clot rich in repair components, and finally stimulating fibrocartilage regeneration to fill the defect area.

The collagen cartilage scaffold(COLTRIX® CartiRegen) used in this study consist of an injection needle, a syringe, and a collagen gel prefilled in a syringe. The collagen gel contains phosphate buffer and type I collagen which the telopeptides are removed.. After the product is implanted in the body, it forms a degradable three-dimensional scaffold to provide an environment for cells to adhere, proliferate, migrate, differentiate and secrete, thereby promoting cartilage repair. At present, it has been commercially applied to clinical repair of knee cartilage defect.

Microfracture to repair cartilage defect is a minimally invasive procedure that is usually done arthroscopically. The doctor first cleans the damaged cartilage area, and then uses a special microfracture cone to drill vertically in the subchondral bone plate, forming multiple tiny holes, allowing mesenchymal stem cells and growth factors in the bone marrow to overflow, forming a blood clot rich in repair components, and finally stimulating fibrocartilage regeneration to fill the defect area.

The MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) scoring system includes multiple dimensions such as the morphology of the repaired tissue, the thickness of the repaired cartilage, the signal intensity of the repaired tissue, the integration of the repaired cartilage with normal cartilage, the bone quality under the repaired cartilage, the accumulation or inflammation of the joint cavity, and the coverage of cartilage defects. Morphology and its integration with the surrounding normal cartilage.

The range of motion (ROM), measured in degrees (°) using the neutral-zero method, includes: sagittal plane dorsiflexion (0°-20°) and plantarflexion (0°-50°) at the talocrural joint, and frontal plane/horizontal plane inversion (0°-35°) and eversion (0°-15° to 20°) at the subtalar joint. Anatomically, the neutral reference position is 90° between the foot and leg, with the goniometer axis placed inferior to the lateral malleolus or midpoint of the bimalleolar line, the stationary arm aligned with the fibular/leg axis, and the moving arm aligned with the 5th metatarsal or calcaneus axis. Active and passive ROM should be documented separately, with unilateral findings compared to the contralateral side to assess restriction.

A Visual Analogue Scale (VAS) is a straight-line measurement tool where respondents mark their perceived intensity of a symptom-such as pain-along a continuous 0-100 mm continuum.

The Kellgren-Lawrence (KL) grade is a standardized radiological scoring system (grades 0-4) used to classify the severity of osteoarthritis based on features such as joint space narrowing, osteophytes, and subchondral sclerosis.

The Tegner score is a clinician-reported scale (0-10) that rates a patient's activity level by linking knee function to the demands of specific sports and occupational activities.

The AOFAS score is a clinician-based 100-point ankle-foot rating system that evaluates pain, function, and alignment to assess outcomes in foot and ankle disorders.