Introduction: Lag screw cut-out in gamma nailing is reported between 1,1% and 7.1% in the literature. Searching for predictive factors we performed a retrospective study, and we analyzed our cut-out cases.

Material & Methods: We reviewed our first 1000 gamma nailings. A detailed analysis of the cut-out cases was performed. We focused on fracture type and the technical failures of the primary surgery. Fractures were classified according to AO. Timing of surgery, implant type and an estimated value of osteoporosis on x-ray was investigated. Distance of the tip of the lag screw from the cortical bone, from the ideal central line of the neck and head in AP and lateral view, and precision of reduction was measured and classified. We recorded the direction of cut-out and the occurrence of secondary varus displacement.

Results: We had 29/1000 (2,9%) cut-outs. Average age was: 76 years. 14/29 (48%) AO A2.2 type and 8/29 (28%) A3.3 type fractures were found in the cut out group. Normal collo-diaphyseal angle was achieved in all cases primarily. In 21/29 (72%) the gap between main fragments was narrower than 5 mm, and in 8/29 (28%) it was bigger. The subjective evaluation of the reduction was 2/29 excellent, 9/29 good, 12/29 satisfactory and 6/29 bad. Primary position of the lag screw tip was caudal in 13/29, central in 10/29 and cranial in 6/29 cases. The distance of the lag screw from the central line in frontal/dorsal direction was 0–4 mm in 5/29, 5–9 mm in 12/29, 10–14 mm in 7/29 and 15–19 mm in 5/29 cases. The numbers of too short or too long lag screws were not high in this patient group. The cut out was cranial in 24/29 (83%) cases and central at 5/29 (17%) patients. We recorded 20/29 (68%) secondary varus displacement. We found 2/29 (7%) patients where none of the above mentioned technical problems could be justified.

Conclusion: AO A2.2 and A3.3 fracture type is a predisposing factor. Cut-out appears relatively early. Correct positioning of the lag screw in both views is essential. Leaving the fracture in a significantly displaced position increases the risk of cut out, too. The lag screw migrates mainly cranial with a secondary varus dislocation. With adequate technique the majority of cut-outs can be avoided, but there is a little percentage of the cases when the primary mistake is not obvious. A possible explanation could be osteoporosis, but further investigation is necessary to clarify these unknown factors.

Purpose: Open reduction and internal fixation (ORIF) is considered the treatment of choice in dislocated acetabular fractures. However ORIF has several drawbacks, such as intra operative blood loss, operative trauma and septic complications. To overcome these problems we applied percutaneous cannulated screw fixation in some cases.

Methods: 198 acetabular fractures were treated between 1996 and 2003 in our department. According to the AO classification there were: 74 type A, 99 type B and 25 type C cases. The causes of the trauma were fall from high at 29, traffic accident at 112 and simple drop with osteoporosis in 57 patients. There were 29 polytraumatized and 46 multitraumatized patients. The 89 non-displaced fractures were treated conservatively: 8–12 weeks non-weight bearing were applied. The other cases were treated surgically: the simple wall fractures with screws, the column fractures with plates. The ilioinguinal approach was used in 11 and the Kocher-Langenbeck in 92 patients. Recently we have started to apply a percutaneous technique with cannulated screws. We used them at the fractures of the roof of the acetabulum and at elderly patients who had moderately dislocated anterior column fracture. We applied this technique in 6 cases.

Results: In the cannulated screw group there was no intra- or postoperative complication, and the functional results have been excellent or good. In those cases, where the fracture involved the posterior wall or the posterior column, and percutaneous reduction could not have been achieved; we made open reduction, and ORIF.

Conclusions: Percutaneous cannulated screw technique can be useful in the treatment of the fractures of the anterior column and the dome of the acetabulum.