In fracture acetabulum of hip which of the following is late complication ?-

*In the longer term, the common problem is the development of hip osteoahritis. Other possible problems include AVN of femoral head and heterotopic ossification ( bone formation). Early complications: 1-Venous Thromboembolism. 2-Neurovascular injury: Sciatic nerve, the lateral femoral cutaneous nerve, Femoral nerve, Superior gluteal bundle and the iliofemoral vessels. 3-Intraaicular hardware . 4-Malreducton. 5-Failure of fixation. 6-Infection. Late complications: 1-Avascular necrosis: femoral or acetabular. 2-Posttraumatic Ahritis. 3-Heterotopic Ossification. 4-Nonunion. Ref: Apley's 9th/e 840,841