Patellar clunk syndrome in a current high flexion total knee design

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering

Background:

• Patellar clunk syndrome is a potential complication following total knee arthroplasty.
• High-flex posterior stabilized prostheses are designed to improve range of motion.

Purpose of the Study:

• To evaluate the incidence of patellar clunk syndrome in two types of high-flex posterior stabilized knee prostheses: mobile bearing and fixed bearing.
• To compare the incidence between the two prosthesis designs and identify associated risk factors.

Main Methods:

• Retrospective study of 208 total knee arthroplasties (204 patients).
• Evaluation of patellar clunk and component position over a two-year follow-up period.
• Comparison of incidence between high-flex mobile bearing and fixed bearing prostheses.

Main Results:

• The mobile bearing prosthesis group had a significantly higher incidence of patellar clunk (15%) compared to the fixed bearing group (0%; p < 0.001).
• Males showed a significantly higher incidence (34.1%) than females (8.6%; p < 0.01).
• Surgical treatment for fibrous nodules was required in 11 knees with patellar clunk.

Conclusions:

• The design of this specific mobile bearing knee prosthesis appears to contribute to patellar clunk syndrome.
• Prosthesis design and patient sex are significant factors in the occurrence of patellar clunk.