Podium (General) 03

Comparison Of Neutral and Mild Residual Coronal Alignment Correction And Functional Outcome In Patient With Primary Total Knee Arthroplasty

Astrawinata Guatama, MD
Resident Orthopedic & Traumatology Department
Faculty of Medicine, University of Hasanuddin, Makassar, Indonesia

Background: Total knee arthroplasty (TKA) is one of the most successful operations in terms of patient satisfaction, improvement in function, alleviation of pain and suffering. Coronal alignment after the surgery is important determinant of functional outcome in TKA. This study was intended to prove whether neutral alignment post operative will bring better patient satisfaction and functional outcome compared to mild residual alignment.

Method: A retrospective analytic study was conducted to patients underwent unilateral primary TKA from January 2018 – December 2020. We excluded patients with history of neurologic disorders, post-operative infection, ipsilateral femur or tibial malunion, and who performed one-stage bilateral TKA. Post-operative knee X-ray was measured and grouped into “neutral alignment” (0±3°) and “mild residual alignment” (-6˚ to +6°). Functional outcome was assessed using SF-KSS and WOMAC Score questionnaires. Statistical data was proceed using independent-T-test, Wilcoxon Signed Rank test, Chi square and Mann-Whitney test. Significant result was drawn at p-value <0.05.

Result: There were 111 patients that grouped into “neutral” (n=65) and “mild” (n=46). Mean age was 64 years old (range 48 to 92), more female gender (76.6%) and resemblant knee location (50.5% right vs 49.5% left). Functional outcome improvement was 51.8% vs 51.4% according to SF-KSS score with highest enhancement in “satisfaction” on both groups; and 69.1% vs 70.6% according to WOMAC score with highest enhancement in “stiffness” on both groups. Both groups finding is statistically insignificant (p>0.05).

Conclusion: Since there was no significant differences, this study result may convinces surgeon to preserve more bone stock and soft tissue to achieve only mild residual alignment while balancing gap; rather than aggressively release to insist neutral alignment, especially on extremely deformed knee.

Keywords: coronal alignment, residual, total knee arthroplasty, functional outcome