Sagittal component alignment is less reliable than coronal component alignment in a Chinese population undergoing...

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiology

Background:

• Total knee arthroplasty (TKA) aims to restore knee function and alignment.
• Component alignment is crucial for TKA success.
• Computer-assisted navigation is an evolving technique in TKA.

Purpose of the Study:

• To compare postoperative sagittal component alignment in primary TKA between conventional and navigated techniques.
• To assess if navigation systems increase femoral component hyperextension in Chinese patients.

Main Methods:

• Retrospective review of 36 patients (72 knees) undergoing simultaneous bilateral primary TKAs.
• One knee treated with computer-assisted navigation, the contralateral with conventional technique.
• Radiographic and clinical outcomes were compared, analyzing component alignment and preoperative angles.

Main Results:

• Significant differences in femoral coronal and sagittal component alignment between navigated and conventional groups.
• Navigated TKA showed less sagittal deviation and a tendency towards hyperextension (-0.35°) compared to conventional (2.77°).
• No significant difference in Knee Society Score (KSS) at 2 years postoperatively.

Conclusions:

• Conventional and navigated techniques yield significantly different sagittal component alignments in primary TKA.
• Navigated TKA is associated with a higher risk of femoral component hyperextension in Chinese patients.