The medial femoral wall can play a more important role in unstable intertrochanteric fractures compared with lateral femoral wall: a biomechanical study

Abstract

BackgroundThe major objective of the present study is to investigate the differences in the load and strain changes in the intertrochanteric region of human cadaveric femora between the loss of medial or lateral wall and after treatment with proximal femoral nail antirotation (PFNA).MethodsAfter measuring the geometry of the proximal femur region and modeling the medial or lateral wall defect femoral models, six pairs of freshly frozen human femora were randomly assigned in the medial or lateral wall group. According to a single-leg stance model, an axial loading was applied, and the strain distribution was measured before and after PFNA implantation. The strains of each specimen were recorded at load levels of 350, 700, and 1800 N and the failure load. Paired t test was performed to assess the differences between two groups.ResultsThe failure mode of almost all defect model femora was consistent with that of the simulated type of intertrochanteric fractures. After the PFNA implantation, the failure mode of almost all stabilized femora was caused by new lateral wall fractures. The failure load of the lateral wall group for defect model femora was significantly higher than that of the medial wall group (p < 0.001). However, the difference disappeared after the PFNA was implanted (p = 0.990). The axial stiffness in all defect model femora showed the same results (p < 0.001). After the PFNA implantation, the axial stiffness of the lateral wall group remained higher than that of the medial wall group (p = 0.001). However, the axial stiffness of the lateral wall group showed that the femora removed from the lateral wall were higher than the PFNA-stabilized femora (p = 0.020). For the axial strain in the anterior wall after the PFNA implantation, the strain of the lateral wall group was significantly lower than that of the medial group (p = 0.003). Nevertheless, for the axial strain of the posterior wall after the PFNA implantation, the strain of the medial wall group was significantly lower than that of the lateral group (p < 0.001).ConclusionsIn summary, this study demonstrated that PFNA is an effective intramedullary fixation system for treating unstable intertrochanteric fractures. Compared with the lateral wall, the medial femoral wall is a more important part in the intertrochanteric region. We suggest that in treating intertrochanteric femoral fractures with medial wall fractures, the medial wall fragment should be reset and fixed as much as possible.

Locking compression plate fixation of femoral intertrochanteric fractures in patients with preexisting proximal femoral deformity: a retrospective study

“…Due to the relatively poor bone quality and quantity in the affected side, premature weight-bearing could result in failed internal fixation and screw loosening. Some authors [ 12 , 21 ] have reported that coxa vara deformity often occurs after locking compression plate internal fixation due to severe osteoporosis and weight-bearing activity before the internal femoral cortex establishes adequate buttress function. For this reason, the standing timing and weight-bearing for such patients needs to be determined according to the type of fracture, osteoporosis, and fracture healing conditions.…”

The Lateral Femoral Wall Thickness on the Risk of Post-Operative Lateral Wall Fracture in Intertrochanteric Fracture: A Finite Element Analysis

“…The medial wall consisted of the medial cortex and medial calcar located in its deep side. The loss of the medial support had been proven to cause coxa varus postoperatively due to the hinge [23]. When a lateral wall fracture occurred, the medial support played a important role in maintaining the stability of the intertrochanteric fracture.…”

Fixation with Cephalic Intramedullary Nail Versus Sliding Hip Screw for Fractured Lesser Trochanter with Completeness of Lateral Wall

“…Studies have proven that the condition of the lateral wall most signi cantly affects the e cacy of the device used for unstable ITFs, followed by the integrity of the medial and lateral wall of the trochanteric region [4][5][6] . While cephalic intramedullary nails have been regarded as more reliable than Dynamic Hip Screws for unstable ITFs, there is still controversy when encountering fractures with preserved lateral walls.…”