Proposal of new classification of femoral trochanteric fracture by three-dimensional computed tomography and relationship to usual plain X-ray classification

Abstract

Purpose: Classification of femoral trochanteric fractures is usually based on plain X-ray findings using the Evans, Jensen, or AO/OTA classification. However, complications such as nonunion and cut out of the lag screw or blade are seen even in stable fracture. This may be due to the difficulty of exact diagnosis of fracture pattern in plain X-ray. Computed tomography (CT) may provide more information about the fracture pattern, but such data are scarce. In the present study, it was performed to propose a classification system for femoral trochanteric fractures using threedimensional CT (3D-CT) and investigate the relationship between this classification and conventional plain X-ray classification. Methods: Using three-dimensional (3D)-CT, fractures were classified as two, three, or four parts using combinations of the head, greater trochanter, lesser trochanter, and shaft. We identified five subgroups of three-part fractures according to the fracture pattern involving the greater and lesser trochanters. In total, 239 femoral trochanteric fractures (45 men, 194 women; average age, 84.4 years) treated in four hospitals were classified using our 3D-CT classification. The relationship between this 3D-CT classification and the AO/OTA, Evans, and Jensen X-ray classifications was investigated. Results: In the 3D-CT classification, many fractures exhibited a large oblique fragment of the greater trochanter including the lesser trochanter. This fracture type was recognized as unstable in the 3D-CT classification but was often classified as stable in each X-ray classification. Conclusions: It is difficult to evaluate fracture patterns involving the greater trochanter, especially large oblique fragments including the lesser trochanter, using plain X-rays. The 3D-CT shows the fracture line very clearly, making it easy to classify the fracture pattern.

Reverse wedge effect following intramedullary nailing of a basicervical trochanteric fracture variant combined with a mechanically compromised greater trochanter

“…Considering the complexity of the fracture morphology, a three-dimensional classification system originating from Evans' would be more pragmatic [16]. The principle from Babhulkar and Shoda's classifications of GT fracture [2,7] could be incorporated to further classify basicervical TF variants according to the morphology of the PLF.…”

“…Therefore, each case could be defined as either a 3-fragmentary or 4-fragmentary pattern. Then, the rationale of Shoda's 3D-CT classification of the proximal femur was borrowed to further classify it into one of four subgroups [7]. The 3-fragmentary S was the first subgroup, where "S" referred to a small PLF fragment combined with cephalocervical and shaft fragments ( Fig.…”

“…On the 3D-CT, the morphological feature of the primary fracture line was specifically studied [7]. As the GT of the injured limb was routinely comminuted and the normal spatial relationship between the main fragments was altered, we utilized the mirrored image of the contralateral uninjured proximal femur as a template for the injured hip to precisely evaluate the distribution primary fracture line.…”

A novel three-dimensional classification system for intertrochanteric fractures based on computed tomography findings

“…Some previous studies introduced the concept of three-dimensional classification of intertrochanteric fractures. Nakano et al (22) and Shoda et al (23) proposed a three-dimensional CT classification that defined an intertrochanteric fracture as that containing 4 major fragments and evaluated each greater trochanter fragment by its size. However, in the present study, 30.5% of fractures (n = 29) included the GA fragment, suggesting that intertrochanteric fractures can be classified more accurately by dividing the fracture into 5 fragments.…”

Reverse Wedge Effect Following Intramedullary Nailing of a Basicervical Trochanteric Fracture Variant Combined with a Mechanically Compromised Greater Trochanter

“…Therefore, each case could be defined as either a 3fragmentary or 4-fragmentary pattern. Then, the rationale of Shoda's 3D-CT classification of the proximal femur was borrowed to further classify it into one of four subgroups [7] . The 3-fragmentary S was the first subgroup, where "S" referred to a small PLF fragment combined with cephalocervical and shaft fragments ( Figure 3A).…”