Correlation between component alignment and short-term clinical outcomes after total knee arthroplasty

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Radiology

Background:

• Accurate component alignment in total knee arthroplasty (TKA) is critical for successful patient outcomes.
• Understanding the relationship between specific alignment parameters and clinical results can guide surgical technique improvements.

Purpose of the Study:

• To investigate the correlation between various component alignments and short-term clinical outcomes following TKA.
• To identify which alignment parameters most significantly influence patient satisfaction and functional recovery.

Main Methods:

• Radiological data from 50 TKA patients were analyzed within one week post-surgery to measure hip-knee-ankle angle (HKA), medial distal femoral angle (MDFA), medial proximal tibial angle (MPTA), femoral flexion-extension angle (FEA), tibial slope angle (TSA), femoral rotational angle (FRA), and tibial rotational angle (TRA).
• Clinical outcomes were assessed after one year using the Hospital for Special Surgery (HSS) knee scoring system, categorizing patients into excellent, good, and not good groups.
• Statistical analyses included difference analysis and linear correlation analysis to determine relationships between alignment parameters and HSS scores.

Main Results:

• Significant differences in MDFA and FEA were observed among the patient outcome groups (p=0.050 and p=0.001, respectively).
• FEA showed a moderate correlation with overall HSS scores (r=0.572, p<0.001) and significant linear correlations with pain, function, range of motion (ROM), muscle, and stability scores.
• Larger MDFA correlated with lower FE deformity scores (r=-0.289, p=0.042), TSA positively influenced ROM (r=0.436, p=0.002), FRA changes affected FE deformity scores (r=0.312, p=0.027), and increased TRA correlated with higher muscle strength scores (r=0.402, p=0.004).

Conclusions:

• The femoral flexion-extension angle (FEA) is a significant factor influencing clinical outcomes after total knee arthroplasty (TKA).
• Improvements in surgical techniques and instrumentation are recommended to enhance the accuracy of FEA adjustment, thereby optimizing joint functionality and patient satisfaction.