Implant failures in patients with proximal fractures of the femur treated with a sliding screw device

Biomechanical evaluation of a new augmentation method for enhanced screw fixation in osteoporotic proximal femoral fractures

“…Conventional hip screw fixation of a proximal femoral head fragment (group 2) was compared with the new modified fixation method using additional PMMA augmentation of the previously irrigated trabecular bone structure in the contrallateral femoral head (group 1). Bone mineral density (BMD) was measured by qCT (DensiScan 1000, Scanco Medical, Bassersdorf, Switzerland; group 1: 0.382 AE 0.058 g/cm 3 ; group 2: 0.376 AE 0.060 g/cm 3 ; average AE standard deviation). BMD was measured at the center of the femoral head at the location of the later screw position.…”

“…[1][2][3][4][5][6][7] The rate of implant cut-out was significantly reduced in the past by changing from mostly rigid fixation principles to dynamically acting devices such as the dynamic hip screw. The failure rates remain high, however, for comminuted fractures in osteoporotic proximal femurs.…”

Tribology of Hemiarthroplasty

“…Some studies have shown that DHS is also less likely to cut out if put into the lower half of the femoral head (Mainds and Newman , 1989). Technical failure of fixation can cause prolonged bed rest and follow-up, or complete failure of the fixation (Heyse- Moore et al, 1983;Moller et al, 1984).…”

Clinical Outcome Following Treatment Of Pertrochanteric Fractures With Dynamic Hip Screw In A Nigerian Rehabilitation Hospital

“…Although many devices can achieve rigid fixation, the dynamic hip screw (DHS) is currently the most frequently used device for intertrochanteric hip fracture [6][7][8] . The DHS is based on tension band principle and allow the screw to slide within the barrel to enable compression of the fracture when the patient begins to bear weight.…”

“…The DHS is based on tension band principle and allow the screw to slide within the barrel to enable compression of the fracture when the patient begins to bear weight. The principle only works in the presence of intact posteromedial wall in the region of the lesser trochanter and so cannot be successful in unstable patterns such as reverse oblique fractures, fractures with large posteromedial fragment and fractures with sub trochanteric extension [7,8].…”