Radiological diagnosis of screw penetration of the hip joint in acetabular fracture reconstruction.

Screw penetration of the hip joint following acetabular fracture reconstruction is a relatively uncommon complication but, if not corrected, may have a catastrophic effect on the postoperative function of the hip joint. Intraoperative radiographs and postoperative standard anteroposterior (AP) radiographs frequently show super-imposition of the screws and acetabulum. Computed tomographic (CT) scanning has been the only diagnostic technique available allowing documentation of screw penetration into the hip joint. CT scan, however, can be performed only after termination of surgery. In search for a radiological view that will help in diagnosing screw penetration into the hip joint both intra- and postoperatively, we undertook a controlled study of 25 patients having either a posterior or extensile lateral surgical approach and six cadaveric specimens. A combination of a cross-table lateral view of the hip and a Judet iliac view proved more informative than AP or Judet obturator views in demonstrating absence or presence of the screw in the hip joint (if the screws were placed along the posterior wall or column). Intraoperative AP radiographs projected as a Judet obturator view were the least helpful in making this determination. When screw penetration is suspected, we recommend the use of intraoperative fluoroscopy in multiple projections or intraoperative arthrogram in the lateral projection of the pelvis. Also, Judet iliac and cross-table lateral radiographs in the operating room while the patient is still under anesthesia might exclude any screw penetration into the hip joint.