Safety and Early Clinical Performance of High-Purity Type I Collagen Augmentation in Arthroscopic Meniscal Repair: A Prospective Feasibility Study
Phase: NA
Conditions: Meniscus Tear, Knee Meniscus Injury, Meniscal Repair, Knee Arthroscopy (for Diagnostic or Therapy)
Sponsor: Adichunchanagiri Institute of Medical Sciences, B G Nagara

Title: Safety and Early Clinical Performance of High-Purity Type I Collagen 
Augmentation in Arthroscopic Meniscal Repair: A Prospective Feasibility 
Study 
 
NCT No: NCT07352410 
 
Date: March 08, 2026 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

INTRODUCTION 
Meniscal tears are among the most frequently encountered intra-articular knee injuries and 
represent a significant cause of pain, functional limitation, and early degenerative change in 
active adults. Contemporary orthopaedic practice increasingly favors meniscus-preserving 
arthroscopic repair techniques over partial meniscectomy, given the well-established role of 
the meniscus in load transmission, joint stability, and long-term cartilage protection [1,2]. 
Despite improvements in arthroscopic instrumentation and suture constructs, healing rates 
following meniscal repair remain variable, particularly in tears extending into avascular zones 
or those with complex morphology [3,4]. 
Failure of meniscal repair is multifactorial and influenced by tear pattern, vascularity, 
mechanical stability, biological milieu, and patient-related factors. Even under optimal 
mechanical conditions, biologic healing remains a limiting factor, especially in the inner two-
thirds of the meniscus where vascular supply is poor [5]. Reported failure rates for 
arthroscopic meniscal repair range from 10% to 30%, with higher rates observed in isolated 
repairs and degenerative tear patterns [6,7]. These limitations have driven interest in biologic 
augmentation strategies aimed at enhancing intrinsic healing potential. 
Collagen-based scaffolds and biologic matrices have emerged as promising adjuncts in 
meniscal surgery. These materials are designed to provide a biocompatible framework that 
supports cell migration, extracellular matrix deposition, angiogenesis, and tissue remodelling 
at the repair site [8]. Experimental and early clinical studies have suggested that collagen 
augmentation may improve meniscal healing, reduce pain, and enhance functional recovery, 
particularly in tears with limited intrinsic healing capacity [9,10]. However, heterogeneity in 
collagen processing, scaffold architecture, and clinical application techniques has limited the 
generalizability of existing evidence. 
High-purity type I collagen is a bioengineered collagen matrix composed of more than 97% 
native type I collagen, manufactured to remove immunogenic proteins, elastin, and lipids 
while preserving the native triple-helical structure. Unlike cross-linked or chemically 
modified scaffolds, high-purity type I collagen remains un-crosslinked, allowing controlled 
enzymatic degradation and progressive replacement by organized host tissue [11]. Its 
phosphorylated collagen structure has been shown to enhance bioactivity, angiogenesis, and 
early granulation, properties that are advantageous in environments with limited intrinsic 
vascularity such as the meniscus. 

The clinical performance of high-purity type I collagen has been demonstrated across 
multiple surgical disciplines, including chronic wound management, reconstructive surgery, 
scar modulation, and tissue regeneration [12, 13]. Prospective studies and randomized trials 
have consistently reported favourable safety profiles, improved tissue quality, reduced 
inflammation, and enhanced functional outcomes with its use [14, 15]. These reproducible 
biological effects provide a strong rationale for exploring its application in meniscal repair, 
where biologic failure remains a major challenge. 
Before undertaking large randomized controlled trials, feasibility studies play a critical role in 
evaluating procedural practicality, safety, early clinical signals, and variability of outcomes. 
Such studies are particularly important when introducing biologic adjuncts into technically 
demanding procedures such as arthroscopic meniscal repair [16]. Feasibility data inform 
study design, sample size estimation, outcome selection, and refinement of surgical technique 
for subsequent trials. 
The present prospective single-arm feasibility study was therefore designed to evaluate the 
safety, handling characteristics, and early clinical performance of high-purity type I collagen 
augmentation in arthroscopic meniscal repair of the knee. Secondary objectives included 
exploratory assessment of pain reduction, functional improvement, and early radiological 
healing trends. The findings of this study are intended to generate preliminary clinical signals 
and inform the design of a future randomized controlled trial comparing high-purity type I 
collagen augmentation with standard meniscal repair. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

MATERIALS AND METHODS 
Study Design and Setting 
This study was designed as a prospective, single-arm feasibility study evaluating the safety, 
procedural practicality, and early clinical outcomes of high-purity type I collagen 
augmentation in arthroscopic meniscal repair of the knee. The study was conducted at a 
tertiary care orthopaedic centre with expertise in sports medicine and arthroscopic knee 
surgery. The primary intent of the study was exploratory, aimed at generating preliminary 
clinical signals and feasibility data to inform the design of a future randomized controlled 
trial [17]. 
The study was approved by the Institutional Ethics Committee prior to patient enrolment and 
was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice 
guidelines. Written informed consent was obtained from all participants after detailed 
explanation of the study objectives, procedures, potential benefits, and risks. 
 
Patient Selection 
Adult patients aged 18 to 45 years presenting with symptomatic, repairable meniscal tears of 
the knee were screened for eligibility. Inclusion criteria comprised longitudinal, vertical, or 
bucket-handle meniscal tears involving the red-red or red-white zones, deemed suitable for 
arthroscopic repair based on preoperative magnetic resonance imaging and intraoperative 
assessment. Both medial and lateral meniscal tears were included. 
Exclusion criteria included complex degenerative meniscal tears, root tears, radial tears 
extending into the avascular zone, advanced osteoarthritis (Kellgren–Lawrence grade ≥ 2) 
[18], inflammatory arthropathy, active infection, prior surgery on the index knee, concurrent 
ligament reconstruction, systemic illness affecting wound healing, known hypersensitivity to 
collagen, pregnancy, or inability to comply with postoperative rehabilitation and follow-up. 
 
Arthroscopic Surgical Technique 
All procedures were performed under spinal or general anaesthesia with the patient 
positioned supine and a pneumatic tourniquet applied to the proximal thigh. Standard 
anterolateral and anteromedial arthroscopic portals were established. Diagnostic arthroscopy 
was performed to confirm tear morphology, location, and reparability. 
Meniscal tears were carefully debrided at the margins using a shaver or rasp to promote 
vascular ingress and enhance healing potential. Care was taken to preserve meniscal tissue 

and avoid excessive removal of fibrocartilaginous material. Meniscal repair was performed 
using an all-inside, inside-out, or hybrid suture technique based on tear location and surgeon 
preference, ensuring stable fixation and restoration of meniscal contour. 
 
Application of High-Purity Type I Collagen Augmentation 
Following completion of meniscal suturing, high-purity type I collagen was prepared 
according to manufacturer instructions. The collagen matrix was rehydrated in sterile normal 
saline and trimmed into thin strips suitable for arthroscopic delivery. Using a grasping 
instrument or cannula-assisted technique, the collagen matrix was placed directly over the 
repaired meniscal tear site, ensuring intimate contact with the repair interface. 
The collagen was gently moulded to conform to the meniscal surface and secured through 
inherent adherence and contact pressure from the surrounding synovial fluid environment. No 
additional fixation devices were used. Care was taken to avoid displacement during final 
inspection and joint lavage. The arthroscopic portals were closed in standard fashion. 
 
Postoperative Rehabilitation Protocol 
All patients followed a standardized postoperative rehabilitation protocol. Partial weight-
bearing with crutches was initiated immediately after surgery and continued for four weeks. 
Knee range of motion was restricted to 0–90 degrees for the first four weeks, followed by 
gradual progression to full range of motion by six weeks. 
Closed-chain strengthening exercises were initiated at six weeks, with gradual return to low-
impact activities by three months. Return to pivoting or high-impact sports was deferred until 
after six months, based on clinical and imaging assessment. 
 
Outcome Measures 
The primary feasibility outcomes included procedural safety, absence of collagen-related 
adverse events, and completion of the surgical technique without technical difficulty. 
Secondary exploratory clinical outcomes included pain assessed using the Visual Analog 
Scale [19], knee function assessed using the Lysholm Knee Scoring Scale [20] and the 
International Knee Documentation Committee (IKDC) subjective score [21], and patient 
satisfaction. Outcomes were assessed preoperatively and at six weeks, three months, and six 
months postoperatively. 

Radiological assessment of meniscal healing was performed using magnetic resonance 
imaging at six months. Healing was graded using a modified MRI meniscal healing score 
based on signal intensity, continuity, and tear morphology. 
 
Data Collection and Management 
All clinical data were collected prospectively using standardized case report forms. Data were 
anonymized using unique study identifiers and entered into a secure electronic database. Data 
quality checks were performed periodically to ensure completeness and accuracy. 
Radiological assessments were performed by a musculoskeletal radiologist blinded to clinical 
outcomes. 
 
Statistical Analysis Plan 
Given the feasibility nature of the study, no formal hypothesis testing or sample size 
calculation for efficacy was performed. The sample size was determined pragmatically to 
allow assessment of safety, procedural feasibility, and variability of outcomes [22]. 
Continuous variables were summarized as mean ± standard deviation or median with 
interquartile range, depending on distribution. Changes in clinical outcome scores over time 
were analysed using paired t-tests for normally distributed variables or Wilcoxon signed-rank 
tests for non-normally distributed variables. Ninety-five percent confidence intervals were 
calculated for mean changes to provide estimation of effect size rather than definitive 
efficacy. 
 
 
 
 
 
 
 
 
 
 
 

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