The proximal tibia anthropometry in adult Nigerians: Correlation to tibial components of total knee replacement and equations for estimation of its dimensions

Abstract

Background: The knee joint is commonly affected by osteoarthritis. Total Knee Replacement (TKR) is usually considered for knee osteoarthritis after failure of conservative management. The total knee prostheses used during this procedure are fashioned from bony dimensions of Westerners.
Objective: This study compared some of the available tibial baseplate with the proximal tibiae dimension of Nigerians. It also provided equations that can be used to estimate dimensions of different parts of proximal tibia.
Design: This was a prospective descriptive study.
Methods: Fifty four matured tibiae, comprising 23 right and 31 left bones were measured. Ten parameters were measured and documented. Dimensions of proximal tibia bones from other regions of the world were retrieved from published articles. The dimensions of tibial baseplates were extracted from product monographs. Analyses were done with Microsoft excel 2010 (Microsoft Corporation, Redmond, Washington, United States) and STATA version 13 (Stata Corp, Texas. USA). Statistical significance was set at p ≤ 0.05.
Results: There were no significant differences between the left and right tibiae. The average proximal tibia dimension differs from between racial groups. The average aspect ratio calculated was 1.51 ± 0.11. Three of the four implants have sizes that were far larger than the tibiae dimensions, with increment in sizes that were far steep compared to the dimensions of the proximal tibiae. There was
a mismatch of aspect ratio of the tibiae and those of the tibial baseplates. Equation to estimate the anteroposterior dimension for each tibia condyle was generated and tested on published values.
Conclusion: This study provided equations that can be used to estimate the anteroposterior dimensions of tibial plateau, the medial and the lateral condyles with the estimated values within ±5mm of the actual value. This can be used as part of pre-operative planning. It also provided data that can be considered in the designing of a suitable tibial baseplate component of total knee prosthesis for Nigerians.

Key words: Total knee replacement, Pre-operative, Planning, Proximal tibia, Tibia bone fixation, Nigerians, Africans, Anthropometry, Knee prosthesis