Patellar instability in Indian population: relevance of tibial tuberosity and trochlear groove distance.

Sourabh Kulkarni,Saurabh Talekar,Vijay D Shetty,Amith P Shetty,Karan K Alva

doi:10.1051/sicotj/2016008

Abstract

Introduction: The tibial tuberosity to trochlear groove (TTTG) distance in the western population is extensively studied through various modalities such as X-rays, computerised tomography and magnetic resonance imaging. However, to our knowledge there is very little or no literature support to indicate that TTTG distance has been studied in the Indian population. Methods: We therefore undertook a study to measure the TTTG distance in 100 MRI scans of normal Indian knees. Patients with the following co-morbidities were excluded from the study; ligamentous laxity, patellofemoral instability, mal-alignment and osteoarthritis. We measured TTTG distance on the axial MRI slices using OsiriX software. Results: The mean value for females was found to be 14.07 mm and that for male was found to be 13.34 mm. Our study indicates that the TTTG distance, using MRI scans as measurement modality, in the Indian population is significantly different when compared to the published western data. Discussion: We believe that this study can form the basis for future studies on the relationship between TTTG distance and patellar instability in Indian population.

Highlights

The tibial tuberosity to trochlear groove distance (TTTG distance) is an important parameter to determine the degree of external tibial torsion or lateralisation of the tibial tuberosity
It is known that excessive tibial torsion can result in patellar maltracking and that a TTTG distance greater than 20 mm can lead to patellar instability [2]
TTTG distance in the western population is extensively studied through various modalities such as X-rays, computerised tomography and magnetic resonance imaging (MRI)

Summary

Introduction

The tibial tuberosity to trochlear groove distance (TTTG distance) is an important parameter to determine the degree of external tibial torsion or lateralisation of the tibial tuberosity. It was initially described by Goutallier et al in 1978 on axial radiographs taken with the knee in 30 degrees of flexion and neutral rotation [1]. There is very little or no literature support to indicate that TTTG distance has been studied in the Indian population. We undertook a study to measure the TTTG distance in 100 MRI scans of normal skeletally matured Indian knees

Methods

Results

Conclusion