Custom TKA combined with personalised coronal alignment yield improvements that exceed KSS substantial clinical...

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiographic Imaging

Background:

• Total knee arthroplasty (TKA) aims to restore function and alleviate pain in patients with knee osteoarthritis.
• Custom implants and personalized alignment strategies are emerging to optimize TKA outcomes.
• Assessing outcomes using standardized metrics like the Knee Society Scores (KSS) is crucial for evaluating treatment efficacy.

Purpose of the Study:

• To report 12-month Knee Society Scores (KSS) following custom total knee arthroplasty (TKA) with personalized alignment.
• To determine if custom TKA achieves substantial clinical benefits (SCB) in KSS Knee and Function scores.
• To investigate associations between radiographic alignment parameters and KSS outcomes.

Main Methods:

• A consecutive series of 266 custom, computed tomography (CT)-based, posterior-stabilised cemented TKAs were analyzed.
• Knees were aligned to preserve constitutional alignment within specific femoral mechanical angle (FMA), tibial mechanical angle (TMA), and hip-knee-ankle (HKA) angle ranges.
• KSS Knee and Function scores were collected preoperatively and at 12-month follow-up. Uni- and multivariable analyses were performed.

Main Results:

• Mean improvements in KSS Knee and Function scores at 12 months exceeded SCB thresholds (61.0 ± 13.0 and 42.7 ± 16.7, respectively).
• No significant differences in KSS scores were observed between knees within vs. outside the target alignment zones.
• Worse KSS Knee scores were associated with a preoperative FMA > 95° (p=0.023).

Conclusions:

• Custom TKA utilizing personalized alignment successfully achieved improvements exceeding substantial clinical benefits.
• The findings support the feasibility of custom TKA with personalized alignment.
• Further comparative studies with longer follow-up are warranted to validate these results.