Laser subtotal meniscectomy in rabbits

Area of Science:

• Orthopedics
• Regenerative Medicine
• Biomedical Engineering

Background:

• Meniscal injuries are common, impacting knee function.
• Current treatments for meniscal tears vary, with healing potential being a key factor.
• Laser surgery offers a minimally invasive approach for meniscal resection.

Purpose of the Study:

• To evaluate the healing capacity of the rabbit meniscus peripheral rim after laser subtotal meniscectomy.
• To assess the histological changes and regenerative processes post-procedure.
• To determine the efficacy of laser resection on meniscal repair.

Main Methods:

• Thirty rabbits underwent laser subtotal meniscectomy (23 bilateral, 7 sham controls).
• Histological analysis of meniscus peripheral rims was performed up to 6 months post-operation.
• Evaluation focused on tissue devitalization, chondrocyte viability, collagen structure, neovascularity, and cell proliferation.

Main Results:

• A superficial devitalized layer (17 microns) indicated minimal thermal damage from laser energy (20-38 W).
• Chondrocytes and collagen structure remained largely intact within 20-50 microns of the free margin.
• Significant healing observed by 2 weeks with vascular bud proliferation and increased ground substance.
• By 10 weeks, the meniscus free margin was sealed with organized collagen and increased chondrocytes.

Conclusions:

• The peripheral rim of the rabbit meniscus demonstrates unimpaired healing potential after laser subtotal meniscectomy.
• Meniscal repair is driven by chondrocyte proliferation and supported by neovascularization.
• Laser resection of the central meniscus allows for effective regeneration of the peripheral rim.