Patellar Clunk Syndrome: A Systematic Review of Risk Factors and Treatment.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering

Background:

• Patellar Clunk Syndrome (PCS) is a recognized complication following total knee arthroplasty (TKA).
• Previous research identified potential risk factors such as male sex, patellar size, and implant characteristics.
• A systematic review assessing PCS risk factors and treatment outcomes was lacking.

Purpose of the Study:

• To systematically review and synthesize existing literature on risk factors associated with Patellar Clunk Syndrome (PCS) after total knee arthroplasty (TKA).
• To evaluate the treatment outcomes for PCS following TKA.
• To identify key factors influencing PCS development and treatment efficacy.

Main Methods:

• A systematic literature search was conducted across four online databases following PRISMA guidelines.
• Studies published from 2000 onwards, focusing on PCS as a primary outcome of TKA, were included.
• Risk factors and treatment outcomes were extracted, and study quality was assessed using the Newcastle-Ottawa Scale (NOS).

Main Results:

• Twenty-four articles were included in the analysis, with 19 assessing risk factors and 5 evaluating treatment outcomes.
• Identified risk factors for PCS include specific implant designs (e.g., mobile-bearing, posterior stabilized), retained patella, smaller patellar thickness, and higher postoperative knee flexion.
• Arthroscopic treatment for PCS demonstrated satisfactory outcomes in all assessed studies.

Conclusions:

• Key risk factors for PCS in TKA patients involve implant design, patellar characteristics, and postoperative knee mechanics.
• Arthroscopic intervention is supported by strong evidence for effectively improving functional outcomes in symptomatic PCS patients.