Iatrogenic Anterior Tibial Artery Pseudoaneurysm – A Rare Case Report

Introduction: Interlocking tibia nail fixation for tibia shaft fracture treatment is one of the most commonest procedures performed in orthopedic trauma practices. We report one such case of a rare complication of anterior tibial artery (ATA) pseudo-aneurysm caused by the proximal coronal locking bolt performed by an unusual entry from lateral to medial side during shaft of tibia fracture fixation. Case Report: A 86- years old female sustained a road traffic accident and was diagnosed with a closed tibia shaft fracture of the right leg for which she underwent intramedullary interlocking nail IMIL nailing elsewhere. She presented to us three 3 weeks after primary surgery with persistent pain and swelling in the right leg proximally. We investigated and diagnosed her as having a pseudoaneurysm of the Anterior Tibial Artery on color Doppler and magnetic resonance imaging (MRI) angiography. The pseudoaneurysm of ATA was clipped without any complications. To avoid the rupture of the pseudoaneurysm during manipulation of nail and bolts, their positions were not changed as they were supporting the fracture well and the fracture was also not united at that time. Conclusion: Though Although interlocking nailing of tibia shaft fracture is a commonly performed procedure, it can lead to disastrous vascular complications if the procedure is not performed with utmost care. ATA injury by proximal locking bolts of the tibia nail mandates the need for reconsideration of the nail design with better screw hole positions. We recommend preferring standard AO manual instructions for proximal tibia locking bolt direction. Keywords: Pseudo-aneurysm, tibia nail, locking bolt, anterior tibial artery.

Extraction of Broken Tibial Interlock Nail with a Retrograde Hooked Guide Wire: A Novel Surgical Technique

Introduction: Removal of a distal piece of a broken nail often possesses a technical challenge. Several methods have been described in the past to extract a distal piece by using specialized instruments like such as hooks, olive wires, and talwalkar radial square nail etc. It is difficult to extract a distal piece from a proximal incision site and often fracture or the nonunion site has to be opened. In this article, we describe a novel technique to extract a distal piece of broken intramedullary tibia nail by retrograde manner using a guide wire with a “‘U”’ shaped bend at its distal end to hook the tip of a distal piece of broken nail and help in extraction. Case Report: A 43- year-s old male presented with complain of pain in left leg since 3 months. Patient had sustained left- sided compound Grade 2 tibia shaft fracture in a road traffic accident 4 years back. He was operated with tibia interlock nail followed by skin grafting for wound coverage in a different facility. On clinical examination: There was tenderness around distal tibia, no swelling, no coronal or sagittal plane fracture mobility, and no crepitus or loss of transmitted movements which suggested fracture union clinically. Radiographs confirmed complete union of tibia shaft fracture with hypertrophic nonunion of distal fibula with broken intramedullary nail IMN at the level of proximal most screw hole of distal locking holes with both distal locking screws broken. As fracture was united, we planned for removal of broken nail without opening fracture site. For extraction for distal tibial broken nail part, we used this new Retrograde Hooked Guide Wire technique. Conclusion: It is a simple, cost effective, minimally invasive procedure with minimal blood loss and decrease time of surgery that can be used before attempting more invasive extraction methods and hence should be included in standard procedures for extraction. Keywords: Tibia, interlock nail, broken nail, retrograde guide wire, nail removal.

Finite Element Analysis of Different Pin Diameter of External Fixator in Treating Tibia Fracture

Biomechanical perspective of external fixator is one of the biggest elements that should be considered in treating fracture bone. This is due to the mechanical behavior of the structure could be analyzed and optimized in order to avoid failure, increase bone fracture healing rate and prevents preterm screw loosening. There are three significant factors that affect the stability of external fixator and those are the placement of pin at the bone, configuration and components of external fixator. All these factors contribute to a question, what is the optimum pin diameter which exerts good stress distribution? To date, the research on the above-mentioned factors are limited in the literature. Therefore, this study was conducted to evaluate the unilateral external fixator with different pin sizes in treating tibia shaft fracture via the finite element method. First and foremost, the development of the tibia shaft fracture was conducted using Mimics software. The computed tomography (CT) data image was utilized to develop three-dimensional tibia bone followed by crafting fracture on the bone. Meanwhile, the unilateral external fixator was developed using SolidWorks software. In this study, five pin diameters (4.5, 5.0, 5.5, 6.0 and 6.5 mm) were developed and analyzed. Both tibia bone and external fixator were meshed in 3-matic software. Simulation of this configuration took place in a finite element software, Marc.Mentat. From the findings, it is shown that the larger diameter of pin demonstrated the lowest stress distribution. The size of the 5.5mm pin shows optimum diameter in terms of stress distribution with the value of 21.50 MPa in bone and 143.33 MPa in fixator. Meanwhile the displacement value of 1.42mm in bone and 1.20mm in fixator. In conclusion, it is suggested that the pin diameter of 5.5 mm is the most favorable option in treating tibia shaft fracture in terms of mechanical perspective.