Less invasive TKA: extramedullary femoral reference without navigation.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Surgical Instrumentation

Background:

• Femoral intramedullary referencing is standard in knee arthroplasty but can cause complications like fat embolism.
• Alternative referencing methods are needed to improve safety and outcomes in total knee arthroplasty.

Purpose of the Study:

• To evaluate a novel extramedullary device for femoral referencing in primary total knee arthroplasty.
• To compare the accuracy and safety of the extramedullary device against standard intramedullary instruments.

Main Methods:

• A randomized study of 100 patients undergoing primary total knee arthroplasty.
• Comparison between standard intramedullary (IM) femoral instruments and a new extramedullary (EM) device.
• EM device calibrated with preoperative templated data and intraoperative checks.

Main Results:

• Similar coronal alignment (84% IM vs. 86% EM) and improved sagittal alignment (78% IM vs. 90% EM) with the EM device.
• No significant difference in operative time or postoperative blood loss between groups.
• Extramedullary referencing demonstrated comparable safety and efficacy to intramedullary referencing.

Conclusions:

• Extramedullary referencing with preoperative templating is a safe and viable alternative for femoral component placement in total knee arthroplasty.
• The new extramedullary device provides accurate alignment and comparable outcomes to traditional methods.
• This approach may mitigate risks associated with intramedullary canal reaming.