Does final component alignment correlate with alignment of the bone resection surfaces in cemented total knee...

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiology

Background:

• Total knee arthroplasty (TKA) aims for optimal component alignment to ensure long-term success.
• Navigation-assisted surgery is increasingly used to improve surgical accuracy.
• Understanding factors influencing alignment deviation is crucial for improving TKA outcomes.

Purpose of the Study:

• To investigate the correlation between bone resection surface alignment and final component alignment in navigation-assisted TKA.
• To identify factors contributing to alignment deviations (outliers) in TKA.

Main Methods:

• Retrospective review of 276 knees from 222 patients undergoing navigation-assisted TKA for osteoarthritis.
• Measurement of deviation between bone resection alignment and final component alignment.
• Evaluation of factors such as patient demographics, bone mineral density, joint contractures, and gap differences for association with >2° alignment deviation.

Main Results:

• Outliers occurred in 8.6% of femoral coronal, 1.4% of tibial coronal, and 17.4% of tibial sagittal planes.
• Coronal plane outliers were linked to preoperative/postoperative flexion contractures, a ≥3mm medial-lateral gap difference in extension, and poor bone quality (T-score <-2.5).
• Tibial sagittal plane outliers were associated with preoperative/postoperative flexion contractures.

Conclusions:

• A notable deviation exists between bone resection alignment and final component alignment in TKA.
• Increased flexion contractures, significant medial-lateral gap differences, and poor bone quality are associated with higher risks of alignment outliers.
• Awareness of these factors can guide surgeons to minimize alignment deviations and improve TKA results.