Total knee replacement in juvenile chronic arthritis

Area of Science:

• Orthopedic Surgery
• Rheumatology
• Biomedical Engineering

Background:

• Juvenile chronic arthritis (JCA) can cause severe knee joint damage.
• Total knee replacement (TKR) is a surgical option for end-stage knee arthritis.

Purpose of the Study:

• To evaluate the outcomes of primary knee replacements in JCA patients.
• To assess the long-term efficacy and complications of TKR in this population.

Main Methods:

• Retrospective analysis of 18 primary knee replacements in 12 JCA patients (1975-1981).
• Follow-up averaged six years, assessing patient satisfaction, ambulation, range of motion, and radiographic findings.
• Radiographic analysis included hip-knee-ankle (HKA) angle and bone-cement interface evaluation.

Main Results:

• Eight of twelve patients (67%) experienced improved functional capacity and increased range of motion.
• Four knee joints required revision surgery due to component malposition or loosening.
• Radiographs revealed radiolucent zones exceeding 2 mm at the bone-cement interface in 8 joints, with migration signs in 4.

Conclusions:

• Despite patient satisfaction and functional improvement in most cases, TKR in JCA patients is associated with a high rate of revision and radiographic signs of component loosening.
• Standardized radiographic measurements are crucial for prosthesis selection in JCA.
• A cautious approach to knee replacement in JCA patients is warranted due to potential long-term failure risks.