Cidex-induced synovitis

Area of Science:

• Orthopedics
• Biomaterials Science
• Toxicology

Background:

• Glutaraldehyde (Cidex) is a high-level disinfectant used in arthroscopic surgery.
• Concerns exist regarding potential intra-articular toxicity from residual disinfectant.
• Understanding Cidex's effects on synovial tissue is crucial for patient safety.

Purpose of the Study:

• To evaluate the synovial response to varying concentrations of glutaraldehyde (Cidex).
• To determine the relationship between Cidex concentration and the severity of induced synovitis.
• To assess the effectiveness of different rinsing protocols in mitigating Cidex toxicity.

Main Methods:

• Rabbit knees were injected with different concentrations of Cidex (10 ppm to 100+ ppm).
• Synovial tissue was examined microscopically for inflammatory changes.
• Intraoperative rinse solutions were analyzed for Cidex concentrations.
• The impact of single versus double rinsing techniques was investigated.

Main Results:

• Microscopic inflammation, including hypertrophy and edema, was observed at 10 ppm Cidex.
• Higher concentrations (100+ ppm) induced necrosis, hemorrhage, and diffuse synovitis.
• Inflammation severity correlated directly with Cidex concentration.
• Single-use rinse solutions reached up to 300 ppm, increasing to 1000 ppm with reuse.
• Double-rinsing protocols reduced second rinse concentrations to below 10 ppm.

Conclusions:

• Glutaraldehyde induces a dose-dependent chemical synovitis, not an allergic reaction.
• Single-use rinsing protocols can lead to significant intra-articular Cidex exposure.
• Double-rinsing, with changes between cases, effectively minimizes residual Cidex and prevents joint inflammation.