Assessing accuracy requirements in high tibial osteotomy: a theoretical, computer-based model using AP radiographs

Area of Science:

• Orthopedic surgery
• Biomechanical engineering

Background:

• High tibial osteotomy (HTO) is a popular surgical treatment for medial compartment knee arthritis.
• Preoperative planning aims to realign the weight-bearing line (WBL) using standing AP radiographs.
• Clinical outcomes of HTO can be unpredictable, potentially due to inaccuracies in executing the surgical plan.

Purpose of the Study:

• To determine the theoretical accuracy of medial wedge opening required for high tibial osteotomy (HTO).
• To assess the precision needed to achieve a preoperative target for the weight-bearing line (WBL) on the tibial plateau.

Main Methods:

• A theoretical 2-D osteotomy model was developed.
• The model calculated the radiological wedge opening accuracy necessary to position the WBL at 62-66% of the tibial plateau width.

Main Results:

• The theoretical medial wedge opening requires an accuracy of ±0.9 mm to achieve the preoperative WBL target on plane radiographs.
• This level of precision is essential for accurate preoperative plan delivery.

Conclusions:

• Current surgical systems may not reliably achieve the ±0.9 mm accuracy needed for HTO.
• Improved surgical accuracy aids or patient stratification are necessary to enhance clinical outcomes in HTO.
• Surgical accuracy is a critical factor for both short- and long-term results in HTO procedures.