Fourty-nine patients with 50 complex acetabular fractures were treated with open reduction and internal fixation from August 1993 to February 1996 in a prospectively documented study. The fractures were fixed with small fragment implants through a modified extensile iliofemoral approach (Maryland approach). Thirty-seven patients were polytraumatized with an ISS of 20 pts. on average. In 10 patients the ISS was > 25 pts. Good or anatomic initial fracture reduction with a fragment stepoff K 2 mm could be achieved in 48 fracturers (96 %). Thirty-six patients with 37 fractures could be evaluated after 25 months on average. In 28 fractures (76 %) the functional outcome was good or excellent according to the d'Aubigne and Harris scores. Radiological results were excellent in 21 fractures (57 %) and satisfactory in 12 fractures (Heeg score). In 7 cases (14 %) a postoperative subcutaneous seroma had to be treated surgically. No wound infections, however, were observed. Further complications were secondary a loss of reduction in 4 cases (11 %), relevant heterotopic ossifications (Brooker III/IV) in 5 cases (14 %), and aseptic femoral head necrosis in 2 cases (5 %). In two cases a total hip replacement (THR) for posttraumatic arthritis had to be performed. Two more cases are scheduled for THR due to symptomatic femoral head necrosis. A good joint reconstruction can be achieved through the modified extensile iliofemoral approach (Maryland) in complex fractures of the acetabulum. However, the approach related morbidity seems to be worrisome. In complex fractures with comminution in the roof of the acetabulum the prognosis remains uncertain even in cases where initial anatomic joint reconstruction can be achieved.