BACKGROUND: Several factors are known to influence osseous union of @entity2249 . Numerous clinical studies have reported different results, hence with different recommendations regarding treatment of @entity174 : @entity2249 with a more vertically oriented @entity174 line. The current study aimed to analyze biomechanically whether this @entity174 poses a higher risk of nonunion. OBJECTIVES: To analyze the influence of one designated factor, authors believe that a computerized @entity174 model, using a finite element Finite Element Method (FEM), may be essential to negate the influence of other factors. The current study aimed to investigate a single factor, i.e. orientation of the @entity174 line toward a horizontal line, represented by Pauwels classification. It was hypothesized that a model with a vertically oriented @entity174 line maintaining parity of all other related factors has a higher stress at the @entity174 site, which would delay @entity174 healing. This result can be applicable to other types of pinning. @entity1 AND METHODS: The finite element models were constructed from computed tomography data of the femur. Three @entity174 models, treated with pinning, were constructed based on Pauwels classification: Type I, 30   between the @entity174 line and a horizontal line; Type II, 50  ; and Type III, 70  . All other factors were matched between the models. The Von Mises stress and principal stress distribution were examined along with the @entity174 line in each model. RESULTS: The peak Von Mises stresses at the medial femoral neck of the @entity174 site were 35, 50 and 130 MPa in Pauwels @entity174 , respectively. Additionally, the peak Von Mises stresses along with the @entity174 site at the lateral femoral neck were 140, 16, and 8 MPa in Pauwels @entity174 , respectively. The principal stress on the medial femoral neck in Pauwels @entity174 was identified as a traction stress, whereas the principal stress on the lateral femoral neck in Pauwels @entity174 was a compression stress. CONCLUSIONS: The most relevant finding was that hook pinning in Pauwels @entity174 may result in delayed union or nonunion due to significantly increased stress of a traction force at the @entity174 site that works to displace the @entity174 . However, in a Pauwels @entity174 , increased compression stress contributes to stabilize it. Surgeons are recommended not to treat Pauwels @entity2249 by pinning.

Biomechanical Study Using the Finite Element Method of Internal Fixation in Pauwels XXXX .

@entity1 :: ('9606', 'Species') :: ['PATIENTS'] @entity2249 :: ('MESH:D005265', 'Disease') :: ['type III femoral neck fractures', 'femoral neck fractures'] @entity174 :: ('MESH:D050723', 'Disease') :: ['Pauwels III fractures', 'type III fracture', 'type I fracture', 'type I, II, and III fractures', 'fracture']
@entity2249 :: (MESH:D005265,Disease) :: ['Type III Vertical Femoral Neck Fractures']
