Association Between Two Anatomical Landmark Measurements and Tibial Osteotomy Thickness in Total Knee Arthroplasty

This study preliminarily explores the statistical association between measurements derived from the apex of the tibial tubercle and the most lateral point of the fibular head, as anatomical reference landmarks, and tibial osteotomy thickness in total knee arthroplasty (TKA), while also evaluating the limitations of their predictive value.

We analyzed the computed tomography (CT) scan data from 20 patients in the TKA Group and 30 patients in the Non-surgical Group. Key anatomical measurements were performed: the distance from the tibial tubercle apex to the osteotomy surface in the sagittal plane (tibial tubercle distance [TD]), and the distance from the most lateral point of the fibular head to the osteotomy surface in the coronal plane (fibular head distance [FD]). Statistical analysis was performed using SPSS 22.0 software. The primary aim was to assess the association between these measurements and the tibial osteotomy thickness and to evaluate the strength and limitations of this association for exploratory estimation of tibial osteotomy thickness.

Measurements showed good to excellent inter-observer reliability (intraclass correlation coefficient [ICC]: 0.89-0.91). A modest inverse association was observed. The multiple regression model combining both landmarks was significant (F = 3.303, p = 0.041), but demonstrated very limited explanatory power (adjusted R² = 0.041), and neither landmark emerged as an independent significant predictor (normalized tibial tubercle distance [TDJ]: p = 0.078; normalized fibular head distance [FDJ]: p = 0.098). In an exploratory time-series analysis, an Auto Regressive Integrated Moving Average (ARIMA) (0,1,0) model demonstrated a high goodness-of-fit on the historical data (R² = 0.896, Mean Absolute Percentage Error [MAPE] = 1.137%), whereas its near-zero stationary R² suggests that its goodness-of-fit may be attributed more to the intrinsic continuity of the data series rather than the predictive utility of the anatomical landmarks.

This study demonstrates a modest inverse association between the measurements derived from the tibial tubercle apex/the most lateral point of the fibular head and the tibial osteotomy thickness. However, linear regression reveals that these variables are weak standalone predictors, and their clinical predictive utility likely depends on integration into multifactorial models.