A hip joint prosthesis that has a strap plate and a hollow, tapered femoral neck subassembly. The femoral neck includes a flanged force plate that radiates from a head stem base and abuts the femur. Several longitudinal ridges and/or an annular recess or other surface treatment at the head stem base facilitates retention in the femur. Shaped surfaces of a femoral neck at the strap plate interlock in non-rotational engagement with a bore of the head stem base. A tapered stem projects from the force plate and supports a ball head. The strap plate includes laterally and longitudinally displaced elongated fastener holes and stress relieving recesses and/or channels. Fasteners anchor the strap plate to the femoral shaft. A shouldered bolt mounts through the femoral neck to engage the ball head base and draw the ball head base and ball head toward the strap plate and contain the prosthesis to the femur.