Intra-articular histopathologic changes secondary to local lead intoxication in rabbit knee joints

Area of Science:

• Orthopedic research
• Toxicology
• Biomaterials science

Background:

• Joint injuries, such as those from gunshot wounds, can result in intra-articular lead fragment retention.
• The physiological effects of retained intra-articular lead fragments on joint tissues are not fully understood.

Purpose of the Study:

• To investigate the impact of intra-articular lead fragments on articular cartilage, synovium, and menisci in a rabbit knee model.
• To compare the degenerative effects of lead implants with stainless steel implants and surgical controls.

Main Methods:

• A rabbit knee model was utilized.
• Cylindrical lead implants were placed in a non-weight-bearing area of the medial femoral condyle.
• Control groups included stainless steel implants (to account for mechanical effects) and arthrotomy (to account for surgical effects).

Main Results:

• Rabbit knees with lead implants showed significantly greater articular degeneration compared to steel implants, arthrotomy controls, and untreated knees (p=0.0625 and p=0.0325, respectively).
• Synovial changes were more pronounced in knees with lead implants than in all other groups.
• No significant degenerative changes were observed in the menisci of any experimental group.

Conclusions:

• Intra-articular lead fragments are not physiologically inert and can induce degenerative changes in joint tissues.
• These lead-induced changes may represent early signs of degenerative joint disease and could lead to chronic damage.
• Surgical removal of intra-articular lead fragments may be advisable to prevent the development of early arthropathies in humans, even in the absence of mechanical impingement.