Posterior dislocation of hip leads to the attitude of the lower leg:

Usually, the head of the femur is dislocated posterior to the acetabulum when the thigh is flexed, for example, as may occur in a head-on automobile collision when the knee is driven violently against the dashboard. The significant clinical findings are shoening, adduction, and internal rotation of the extremity. Anteroposterior, lateral and, if fracture of the acetabulum is demonstrated, oblique radiographic projections (Judet views) are required. Common associated injuries include fractures of the acetabulum or the femoral head or shaft and sciatic nerve injury. Ref: Smith W.R., Agudelo J.F., Parekh A., Shank J.R. (2006). Chapter 3. Musculoskeletal Trauma Surgery. In H.B. Skinner (Ed), CURRENT Diagnosis & Treatment in Ohopedics, 4e.