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BackgroundAlthough valgus-impacted fractures don't displace obviously, a larger valgus angle and posterior tilt of the femoral head can cause hip joint dysfunction and femoral head necrosis. The optimal surgical approach for valgus-impacted femoral neck fractures remains controversial. This study compared the biomechanical characteristics of different treatment strategies based on nite element analysis. MethodsTen valgus-impacted femoral neck fractures were analyzed in terms of posterior tilt and valgus angle measured on X-ray radiographs. Using these data, we generated 7 nite element models that were compared in terms of von Mises stress distribution and displacement. ResultsIn the intact femur, von Mises stress was concentrated at the medial and inferior sides of the femoral neck. In valgus-impacted femoral neck fractures, von Mises stress was at the same locations but was 5.66 times higher than that in the intact femur. When 3 cannulated screws were used for internal xation, anatomic reduction diminished the stress at the fracture end from 140.6 to 59.14 MPa, although displacement increased from 0.228 to 0.450 mm. When the fracture was xed with a sliding hip screw (SHS) + cannulated screw, there was less stress at the fracture end and greater displacement with anatomic reduction than that without reduction (stress: 15.9 vs 37.9 MPa; displacement: 0.329 vs 0.168 mm). ConclusionsThe SHS + cannulated screw has superior biomechanical stability than 3 cannulated screws, and is recommended following anatomic reduction to treat valgus-compacted femoral neck fractures. BackgroundA valgus-impacted femoral neck fracture classi ed as Garden type I[1] has a posteriorly tilted femoral head, is relatively stable, associated with mild symptoms, and easily misdiagnosed. The optimal treatment approach for this type of fracture is controversial. Because of their stability (minimal displacement) they are treated conservatively sometimes. However, there is a high risk of further displacement and the relatively short femoral neck can lead to complications such as hip dysfunction and pain. [2][3][4] The necessity of reduction and method of internal xation are also debated. Some studies suggest that for Garden I and II fractures-in particular, valgus-impacted femoral neck fracturesintraoperative reduction does not in uence the success of the surgery. [5,6] It has also been argued that as valgus-impacted fractures can destabilize after reduction, there is no need for anatomic reduction. [7] Others recommend anatomic reduction because the fact that malreduction signi cantly increases the risk

BackgroundAlthough valgus-impacted fractures don’t displace obviously, a larger valgus angle and posterior tilt of the femoral head can cause hip joint dysfunction and femoral head necrosis. The optimal surgical approach for valgus-impacted femoral neck fractures remains controversial. This study compared the biomechanical characteristics of different treatment strategies based on finite element analysis.MethodsTen valgus-impacted femoral neck fractures were analyzed in terms of posterior tilt and valgus angle measured on X-ray radiographs. Using these data, we generated 7 finite element models that were compared in terms of von Mises stress distribution and displacement.ResultsIn the intact femur, von Mises stress was concentrated at the medial and inferior sides of the femoral neck. In valgus-impacted femoral neck fractures, von Mises stress was at the same locations but was 5.66 times higher than that in the intact femur. When 3 cannulated screws were used for internal fixation, anatomic reduction diminished the stress at the fracture end from 140.6 to 59.14 MPa, although displacement increased from 0.228 to 0.450 mm. When the fracture was fixed with a sliding hip screw (SHS) + cannulated screw, there was less stress at the fracture end and greater displacement with anatomic reduction than that without reduction (stress: 15.9 vs 37.9 MPa; displacement: 0.329 vs 0.168 mm).ConclusionsThe SHS + cannulated screw has superior biomechanical stability than 3 cannulated screws, and is recommended following anatomic reduction to treat valgus-compacted femoral neck fractures.

BackgroundFemoral head fractures are rare but potentially disabling injuries, and classifying them accurately and consistently can help surgeons make good choices about their treatment. However, there is no consensus as to which classification of these fractures is the most advantageous; parameters that might inform this choice include universality (the proportion of fractures that can be classified), as well as, of course, interobserver and intraobserver reproducibility.Questions/purposes(1) Which classification achieves the best universality (defined as the proportion of fractures that can be classified)? (2) Which classification delivers the highest intraobserver and interobserver reproducibility in the clinical CT assessment of femoral head fractures? (3) Based on the answers to those two questions, which classifications are the most applicable for clinical practice and research?MethodsBetween January 2011 and January 2023, 254 patients with femoral head fractures who had CT scans (CT is routine at our institution for patients who have experienced severe hip trauma) were potentially eligible for inclusion in this study, which was performed at a large Level I trauma center in China. Of those, 9% (23 patients) were excluded because of poor-quality CT images, unclosed physes, pathologic fractures, or acetabular dysplasia, leaving 91% (231 patients with 231 hips) for analysis here. Among those, 19% (45) were female. At the time of injury, the mean age was 40 ± 17 years. All fractures were independently classified by four observers according to the Pipkin, Brumback, AO/Orthopaedic Trauma Association (OTA), Chiron, and New classifications. Each observer repeated his classifications again 1 month later to allow us to ascertain intraobserver reliability. To evaluate the universality of classifications, we characterized the percentage of hips that could be classified using the definitions offered in each classification. The kappa (κ) value was calculated to determine interrater and intrarater agreement. We then compared the classifications based on the combination of universality and interobserver and intraobserver reproducibility to determine which classifications might be recommended for clinical and research use.ResultsThe universalities of the classifications were 99% (228 of 231, Pipkin), 43% (99 of 231, Brumback), 94% (216 of 231, AO/OTA), 99% (228 of 231, Chiron), and 100% (231 of 231, New). The interrater agreement was judged as almost perfect (κ 0.81 [95% CI 0.78 to 0.84], Pipkin), moderate (κ 0.51 [95% CI 0.44 to 0.59], Brumback), fair (κ 0.28 [95% CI 0.18 to 0.38], AO/OTA), substantial (κ 0.79 [95% CI 0.76 to 0.82], Chiron), and substantial (κ 0.63 [95% CI 0.58 to 0.68], New). In addition, the intrarater agreement was judged as almost perfect (κ 0.89 [95% CI 0.83 to 0.96]), substantial (κ 0.72 [95% CI 0.69 to 0.75]), moderate (κ 0.51 [95% CI 0.43 to 0.58]), almost perfect (κ 0.87 [95% CI 0.82 to 0.91]), and substantial (κ 0.78 [95% CI 0.59 to 0.97]), respectively. Based on these findings, we determin...