Background With the advent of an aging society, osteoporotic fractures—particularly hip fractures—are increasing, with a 1-year mortality rate of 17%. Achieving stable fixation that enables early ambulation is essential but remains challenging because complex intertrochanteric (IT) fracture patterns are often underestimated on plain radiographs. Using three-dimensional computed tomography (3D-CT), this study analyzed whether the anterior fracture line lies medial or lateral to the IT line and examined its relationship with displacement or distal medullary canal engagement, highlighting the potential influence of the joint capsule and capsular ligaments on fracture morphology and fixation stability.
Methods A retrospective review was conducted on 96 osteoporotic IT fractures in patients aged ≥60 years treated between April 2013 and December 2022 at National Police Hospital and Asan Medical Center, Seoul, Korea. Fractures were classified as engaged, completely displaced, and partially displaced based on 3D-CT findings. The anterior fracture-line position (medial or lateral to the IT line) and the status of the lesser trochanter (LT) were evaluated. The chi-square or Fisher exact test was used for statistical comparisons.
Results In total, 96 patients were analyzed. Of these, 49 cases (51.0%) were classified as engaged type, 27 cases (28.1%) as completely displaced type, and 20 cases (20.8%) as partially displaced type. When comparing fracture pattern with anterior fracture-line position, the completely displaced type showed a significantly higher proportion of lateral anterior fracture lines than the other two types (P<0.001). However, no significant association was identified between fracture pattern and LT displacement. When the anterior fracture-line position and LT displacement were evaluated together, only the engaged type demonstrated a possible association between a lateral anterior fracture line and LT displacement, though the statistical significance was weak (P=0.047).
Conclusions Fracture lines lateral to the IT line were strongly associated with displacement in IT fractures; however, their relationship with LT involvement, reflecting iliopsoas tendon traction, was not clearly demonstrated. Although the factors contributing to the engaged-type fracture remain uncertain, the statistical association between fracture pattern and anterior fracture-line position suggests that capsular structures may play a stabilizing role in select fracture configurations. Further studies are needed to clarify these anatomical interactions.
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Objectives This study aimed to assess fracture verticality in both coronal and axial planes after eliminating projection error in femoral neck fractures among non-older adults, and to demonstrate its clinical utility using computed tomography (CT)-based modeling at actual size.
Methods This retrospective observational study enrolled 57 patients (30 males and 27 females), aged 20–65 years, with displaced femoral neck fractures. Based on CT images, an actual-size fracture model was constructed. The CT scanning plane was reformatted with the neck-shaft fragment realigned vertically to the ground and parallel to the femoral neck axis. Three consecutive images were used to generate coronal reformats at the centerline and posterior border to measure central and posterior coronal plane verticality as Pauwels’ angle (PA). The central image of the reformatted axial plane was used to assess axial plane verticality. Differences in verticality were analyzed using analysis of variance.
Results Three coronal morphology types were identified: linear (n=30), concave (n=25), and convex (n=2). Two axial morphology types were observed: cephalad (n=35) and trochanteric (n=22). The mean central PA, posterior PA, and axial verticality were 55.43°±13.79°, 51.44°±11.13°, and 85.74°±18.41°, respectively. Only the central PA showed a significant difference (P<0.001). The PA was significantly higher in the linear coronal type between images (P<0.05) and in the trochanteric axial type (P<0.05).
Conclusions After reformatting the scanning plane, the central PA showed significant variation between images. Femoral neck fractures of the linear type in the coronal plane and the trochanteric type in the axial plane demonstrated greater verticality than other morphological types.
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Background Posterior malleolar fractures frequently accompany rotational ankle fractures. However, the morphological relationship between lateral and posterior malleolar fractures in supination-external rotation (SER) ankle fractures remains unclear. This study aimed to classify lateral malleolar fracture patterns in SER type 3 and 4 ankle fractures and investigated their associations with posterior malleolar fracture morphology.
Methods We retrospectively reviewed 132 patients with SER type 3 or 4 ankle fractures and concurrent posterior malleolar fractures between January 2016 and December 2021. Lateral malleolar fractures were categorized as fibular fractures extending <4.5 cm proximal to the ankle joint (102 ankles) or fibular fractures extending ≥4.5 cm proximal to the ankle joint (30 ankles) based on posterior cortex height measured using three-dimensional computed tomography (3D-CT). Posterior malleolar fracture morphology was assessed using the Haraguchi and Bartonicek classifications. Quantitative parameters—including fracture height, angle, and articular involvement—were analyzed using 3D-CT imaging.
Results Fibular fractures extending ≥4.5 cm proximal to the ankle joint were associated with a significantly higher frequency of Haraguchi type II and Bartonicek types 3 and 4 posterior malleolar fractures. This group also exhibited greater articular involvement (19.2% vs. 12.0%) and posterior cortical height (55.4 mm vs. 24.8 mm) compared to the <4.5 cm group (all P<0.001).
Conclusions In SER type 3 and 4 ankle fractures, a fibular fracture extending ≥4.5 cm proximal to the ankle joint may be associated with posterior malleolar fractures exhibiting greater articular involvement and medial extension. Preoperative evaluation of the lateral malleolar fracture pattern may provide useful insights into posterior malleolar morphology and assist in surgical planning. However, these findings should be interpreted with caution due to inherent study limitations.
Level of evidence: IV