Pipkin subclassified Epstein-Thompson type 5 fracture-dislocations into four additional subtypes according to head fragment location and presence of neck, acetabulum fracture. Hougaard and Thomsen reviewed 203 posterior hip dislocations and found that 13 patients with a fracture of the femoral head(Pipkin type 1,2). 1 with fractures of femoral head and neck(Pipkin type 3), 2 with fractures of femoral had and acetabulum(Pipkin type 4). Epstein, Wiss, and Cozen reported that 11 cases of Pipkin type 1,26 of type 2,8 of type 3, and 10 of type 4.

We experienced 2 cases of Pipkin type 3 and 3 of type 4 from January, 1990 and the results obtained were as follows.

1. By Pipkin classification, type 3 was 2 cases and type 4 was 3 cases.

2. In 2 cases of type 3, was treated by primary bipolar endoprosthesis due to comminution of head, neck and the other was by emergency open reduction of dislocation, multiple Knowles pinning of neck fracture, screw fixation of large head fragmnt, multiple knowles pinning of neck fracture, screw fixation of large head fragment, and quardratus femoris pedicled bone graft.

3. In 3 cases of type 4, one was reduced successfully by manipulation and treated conservatively. Two cases were initially treated by closed reduction and delayed open screws fixation of large acetabular rim fragments, during which head fragments were not removed.

4. There had been no clinical or radiological evidence of avascular necrosis of femoral head at 17 months follow up, but increased isotope uptake on bone scanning in type 3 patient.

5. All type 4 patients had not complained of hip pain and no evidence of radiological avascular necrosis of femoral heads at average 29 months follow up.