3D-CT evaluation of femoral trochanteric fracture - Relationship to clinical results -

Objectives Femoral trochanteric fracture is usually classified by plain X-ray findings, such as AO/OTA classification, Evans classification and Jensen classification. However, it is sometimes difficult to classify the fracture because the fragment of greater trochanter is not clear in plain X-ray. We classified the fracture with 3D-CT findings. In this study, we examined the relationship between fracture type in 3D-CT and clinical results.

Methods Using 3D-CT, fractures were classified as two, three, or four parts using combinations of the head, greater trochanter (GT), lesser trochanter (L), and shaft. We identified five subgroups of three-part fractures according to the fracture pattern involving the greater and lesser trochanters (small fragment of GT: Gs, big fragment of GT: Gb., large fragment of GT including lesser trochanter:G-L, whole greater trochanter is one big fragment:Gw, fracture of lesser trochanter:L). 91 cases over 65 years old treated with PFNA-II (2011 April - 2014 December) and followed at least 6 months are included in this study. These cases were classified with this 3D-CT classification. Non-union cases at 6 months and sliding distance in each group were examined.

Results and Conclusion In 3D-CT classification, number of each group was as follows; 2 part: 20 cases, 3 part Gs: 9 cases, Gb: 14 cases, G-L: 31 cases, Gw: 5 cases, L: 5 cases, 4 part: 7 cases. Non-union cases were 29 cases. 2 part: 5 cases (25%), 3 part Gs:1 case (11%), Gb:3 cases (21%), G-L: 11 cases (36%), Gw:4 cases (80%), L:1 case (57%), 4 part:4 cases (32%). In 3 part Gw and3 part L, many cases were not united at 6 months. However, there was no statistical difference. Sliding distance in each group are as follows; 2 part: 4.0mm, 3 part Gs: 3.9mm, Gb: 4.2mm, G-L: 5.8mm, Gw: 4.4mm, L: 8.7mm, 4 part: 6.2mm. Sliding distance of 3 part L is significantly larger than those of 2 part and 3 part Gs.

According to recent AO/OTA classification, 2 part and 3 part Gs type in 3D-CT classification are only stable type fracture. However, there was no significant difference in non-united cases and sliding distance of blade in each group except sliding distance of 3 part L type. Although our preliminary data are limited, further evaluation in a large series may clarify the clinical results difference in each group.

Stichwörter femoral trochanter fracture, 3D-CT

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Artikel online veröffentlicht:
15. Oktober 2020