A sophisticated fracture classification system of the proximal femur trochanteric region (AO/OTA-31A) based on 3D-CT images

Abstract

ObjectiveFracture classification evolves dynamically with new and enhanced imaging modalities. This paper aims to introduce a novel hypothesis of a sophisticated fracture classification system for the proximal femur trochanteric region (AO/OTA-31A) based on 3D-CT images and accommodate the clinical requirement of the worldwide outbreak of geriatric hip fractures with large amounts of surgical operations.MethodsIn the current practice of widely preoperative 3D-CT application and cephalomedullary nailing, we attempt to propose a new comprehensive classification system to describe the fracture characteristics in a more detailed and sophisticated architecture, and pay the most important concern to the parameters that contribute to fracture stability reconstruction in osteosynthesis.ResultsThe new four-by-four comprehensive classification system, followed the structure of the AO/OTA system, incorporates many fracture characteristics as dividing indexes into multiple grade levels, such as fracture line direction, the number of fragments, the lesser trochanter fragment and its distal extension (>2 cm), the posterior coronal fragment and its anterior expansion (to the entry portal of head–neck implant at the lateral cortex), the lateral wall and anterior cortex fracture, and the anteromedial inferior corner comminution. From a panoramic perspective, there are four types and each type has four subtypes. A1 is simple two-part fractures (20%), A2 is characterized by lesser trochanter fragment and posterior coronal fractures (62.5%), A3 is reverse obliquity and transverse fractures with complete lateral wall broken (15.5%), and A4 is medial wall comminution which further lacks anteromedial cortex transmission of compression force (2%). For subtypes, A2.2 is with a banana-like posterior coronal fragment, A2.4 is with distal cortex extension >2 cm of the lesser trochanter and anterior expansion of the posterior coronal fragment(s) to the entry portal of head–neck implants, A3.4 is a primary pantrochanteric fracture, and A4.4 is a concomitant ipsilateral segmental fracture of the neck and trochanter region.ConclusionClassification represents diversity under consistency. The four-by-four sophisticated classification system delineates fracture characteristics in more detail. It is applicable in the time of rapid outbreak of trochanteric fractures in the older population, the large amounts of surgical operations, and incorporates various rare and/or more complicated subtypes which is unclassifiable before.

The remnant axial cortical length of the proximal femur in pertrochanteric fractures: a three-dimensional computed tomography study and its clinical implications

“…CT has been used in trochanteric fractures for assessing the reliability of classification systems [ 10 , 11 ]. In 2016, Sharma et al [ 7 ] reported that 51 patients with AO/OTA 31-A2 pertrochanteric fractures were evaluated using a pre-operative CT scan, and found that AO/OTA 31-A2 pertrochanteric fractures with a lateral wall height of > 1.68 cm and an anterior component of > 2.10 cm in circumference are not likely to sustain a lateral wall fracture when treated with a dynamic hip screw (DHS).…”

Role of Anteromedial Cortical Support for Unstable Intertrochanteric Fractures Being Treated With Cephalomedullary Nails

“…Unstable fractures, however, can be due to communition or reverse obliquity, which brings translational forces into action responsible for post-operative construct collapse. Current evolving evidence has elaborated the morphological characteristics and fracture line mapping of these intertrochanteric fractures with the help of 3D-computed tomography [ 5 ]. It has helped surgeons gain better insight into the fracture pattern, pre-operative planning, and execution of surgical techniques.…”

Proximal Femur Fracture: Common Doubts on Frequently Used Terminologies

“…Nowadays, it must be said that it is necessary to have computed tomography with 3D reconstructions at the hospital emergency level because it helps to better preoperative classification of intertrochanteric fractures, especially in a selected group of fractures where stability and sidewall integrity, among other things, are difficult to assess [21].…”