Which step is not part of the trial reduction process?

• A. Assess soft tissue balance
• B. Assess ROM
• C. Assess stability
• D. Place final components without trial

Answer: (D)

In a trial reduction, the surgeon uses temporary, or trial, components to mimic the final knee prosthesis so they can check how the knee will function before committing to the actual implants. The goal is to assess three key aspects: soft tissue balance, range of motion, and joint stability. Soft tissue balance means the ligaments and surrounding tissues have the right tension in both full extension and at flexion, so the knee isn’t too tight or too loose in either position. Assessing ROM involves moving the knee through its functional arc to ensure there’s smooth articulation without impingement or restriction. Assessing stability means checking for unwanted laxity or instability in varus/valgus and anterior-posterior directions across different degrees of flexion. These checks guide any necessary releases or adjustments before final components are implanted. Placing final components without the trial would skip this essential verification step, risking poor balance, limited motion, or instability after the final implants are in place. Once the trial is satisfactory, the surgeon proceeds to insert the final prosthetic components with the appropriate fixation method.