Assessing Tibial Tray Rotation in TKA: A Cadaveric Study

Area of Science:

• Orthopedics
• Biomechanical Engineering
• Surgical Innovation

Background:

• Accurate transverse plane rotation of the tibial tray is crucial for optimal outcomes in total knee arthroplasty (TKA).
• Current methods for validating tibial anatomical landmarks for rotation lack sufficient evidence.
• Establishing precise tibial component alignment is essential for restoring knee function and patient satisfaction.

Purpose of the Study:

• To validate the use of the anterior tibial center point of rotation (ATCPR) and the femoral trochlear groove (FTG) for determining ideal tibial tray rotation in TKA.
• To assess the impact of precise tibial tray alignment on knee range of motion (ROM) and component positioning.
• To establish a reliable method for achieving maximal tibial rotation and knee ROM during TKA.

Main Methods:

• Proposing a novel alignment technique using the ATCPR and FTG to guide tibial tray placement in TKA.
• Measuring preoperative and postoperative knee range of motion (ROM) and tibial rotation range.
• Evaluating the effects of medial and lateral tibial component malrotation (5 mm) on knee ROM and patellar tracking.

Main Results:

• Aligning the tibial tray centerline with ATCPR and FTG lines resulted in a mean ROM of 144.3° (preoperatively 145°) and tibial rotation of 22.8 mm (preoperatively 24.9 mm).
• Medial rotation of the tibial component by 5 mm decreased knee ROM in flexion and caused patellar subluxation.
• Lateral rotation by 5 mm decreased knee ROM in extension.

Conclusions:

• The proposed method of aligning the tibial tray with ATCPR and FTG provides an accurate means to achieve ideal tibial tray rotation in TKA.
• This technique maximizes tibial rotation and knee ROM while avoiding component impingement or maltracking.
• Validated anatomical landmarks offer a reproducible approach to optimizing TKA surgical outcomes.