NAVIGATED VERSUS MECHANICAL KNEE REPLACEMENT: COMPARISON BETWEEN INITIAL NAVIGATED AND CONVENTIONAL CASES PERFORMED...

Area of Science:

• Orthopedic surgery
• Biomechanical engineering

Background:

• Accurate postoperative alignment is crucial for total knee arthroplasty (TKA) success.
• Traditional mechanical alignment (MA) techniques may lead to outliers.
• Navigated alignment (NA) systems offer potential for improved precision.

Purpose of the Study:

• To compare the postoperative mechanical axis in TKA using navigated and mechanical alignment systems.
• To evaluate the learning curve and outcomes for a surgical team new to navigated techniques.

Main Methods:

• A comparative study of 36 TKAs (25 navigated, 11 mechanical) performed between 2008-2010.
• Postoperative panoramic X-rays were used to measure axis deviation.
• The same surgeon and team, beginners in NA and experienced in MA, performed all surgeries.

Main Results:

• Navigated TKA resulted in a mean axis deviation of 1.32° (SD 1.57°), compared to 3.18° (SD 2.99°) for mechanical TKA.
• A significantly lower proportion of navigated cases exceeded a 3° axis deviation.
• The navigated technique showed a tendency towards better alignment, favoring statistical significance.

Conclusions:

• Navigated TKA achieved better limb alignment and fewer outliers compared to the mechanical technique, even for a novice team.
• The navigated technique was safely integrated without additional complications.
• NA offers a promising alternative for achieving optimal TKA alignment.