2015 ISAKOS Biennial Congress ePoster #2016

MRI Pre Operative Planning of Tibial Tunneling in Posterior Cruciate Ligament Reconstruction

Robson Souza Santos, MD, Feira De Santana, BA BRAZIL
João Espregueira-Mendes, MD, PhD, Porto PORTUGAL
Abner Portugal Tavares, PT, Feira De Santana, Bahia BRAZIL
Franklin Cajaiba Dultra, PT, Feira De Santana, Bahia BRAZIL
George Felipe Araujo Neves, MD, Feira De Santana, Bahia BRAZIL
Hospital Ortopedico, FEIRA DE SANTANA, BA, BRAZIL

FDA Status Not Applicable

Summary: Preoperative planning of the reconstruction of the PCL through MRI showed to be an effective and safest way to realization of the surgical procedure.

Abstract:

Introduction

Posterior Cruciate Ligament (PCL) injuries may lead to functional disability such that surgical repair is at times indicated. Due to the proximity between the PCL insertion and the surrounding neurovascular bundle, special care must be taken during surgical reconstruction to avoid injury during tibial tunneling.
Objectives: This study sought to use MRI to identify the anatomical position of the neurovascular bundle and measure safe angles for the tibial tunneling during PCL reconstruction.

Materials And Methods

This is an observational retrospective study in which 200 MRIs (100 from each knee) were randomly selected. We measured the distance between the PCL insertion and the neurovascular bundle, and delineated imaginary 10mm tunnels centered on the PCL insertion point both on medial to lateral or lateral to medial paths. We then identified angles in which these imaginary tunnels intersected the neurovascular bundle. Additionally, 20 MRIs were also evaluated with the knee at 90° flexion. Statistical significance was set at p<5% and the paired t test was utilized for our analysis.

Results

Out of the 200 MRIs of knees in extension, 35% were male. For tunnels delineated on a medial to lateral path, the range of angles in which intersection with the neurovascular bundle occurred was 0° to 85° for both knees with mean values of 18,85 ± 15,6° and 62,69 ± 10,98° for the right knee and 21,85 ± 17,34° and 60,8 ± 11,69° for the left knee. For tunnels delineated on a lateral to medial path, the range of angles intersecting the neurovascular bundle was de 0° to 60° for the right knee de 0° to 45° for the left knee with mean values of 0° ± 0,0° and 14,15 ± 15,46° for the right knee and 0,1 ± 1,0° and 13,8 ± 13,91° for the left knee. The distance between the neurovascular bundle and the insertion of the PCL was also assessed in a soubgroup of 20 MRIs with knees in flexion as well as in extension yielding mean measurements of 1,85 ± 0,50cm for the flexed right knee and 2,07 ± 0,51cm for the flexed left knee versus 1,31 ± 0,27cm for the extended right knee and 1,36 ± 0,20cm for the extended left knee. This represents a statistically significant difference in the posterior tibial cortex to neurovascular bundle distance (p<0,01 and p<0,03 for right and left knees respectively). Our results indicate that in 91% of knees and tunneling can be safely be performed on a lateral to medial path. Additionally, in 8% of the knees analyzed, tunneling can be safely performed in medial to lateral path without risk of injury. 9% of the knees analyzed presented high risk of injury for tunneling in either direction.

Conclusion

Our study demonstrates that tunneling on a lateral to medial path is safer than on a medial to lateral path as long as adequate technique is observed .And that MRI of knees in extension is useful for pre-operative planning as measurements obtained with knees in flexion yielded increased distance measurements.