Prevention of Pernicious Vascular Event: Acetabular Component Screw Impinging on External Iliac Vessels - A Unique Case Report

Abstract

Introduction: Revision total hip arthroplasty requires meticulous planning and execution to achieve the desired outcome. Pelvic vessel injury following total hip arthroplasty is rare, but a well-known and serious complication, having a very high morbidity (15%) and mortality (7%). This case demonstrates the rare occurrence of acetabular screw abutment to the external iliac vessels, which if removed during revision hip surgery without releasing the adhesions around it, will lead to avulsion injury of the vessels and a catastrophic event.

Case report: We present this challenging and unique case of a 64-year-old female patient where the acetabular component screw was found to be adherent to the external iliac vessels, with vascular injury imminent. During revision surgery, the iliac vessels were first released free of all adhesions with the intrapelvis screw using an ilioinguinal incision and retroperitoneal approach. The prosthesis was removed using a posterior approach to the hip joint. Definitive surgery was performed after 2 weeks.

Conclusion: Surgeons should be cognizant of the possibility of an avulsion vascular injury in revision cases having intrapelvic screws or implants. The proximity of such an implant with the intrapelvic vasculature must be confirmed preoperatively. Management should be individualized. Dual approach and staged procedure help in a favorable outcome. Vascular injury, revision total hip arthroplasty, screw abutting iliac vessel, external iliac vessel, computed tomographic angiography.

Keywords: Vascular injury; computed tomographic angiography; external iliac vessel; revision total hip arthroplasty; screw abutting iliac vessel.

Figure 1

Anteroposterior view of pelvis with both hips at the time of presentation – Shows left hip acetabular component loosening with superior migration and two screws protruding into the pelvic cavity (Arrowhead).

Figure 2

Special views of the pelvis – obturator view (left) showing excessively long screws pointing into the pelvic cavity. Furthermore, note the thinned-out anterior column of the acetabulum (arrowheads) and iliac view (right) showing a broken screw (arrow). Note the posterior intact but thinned out acetabulum column (arrowheads).

Figure 3

3D CT of the pelvis showing the three screws when seen from the inner aspect of the pelvis. They have been arbitrarily labeled as Screw 1 for the superior most screw, Screw 2 for the anterior screw, and Screw 3 for the posterior most screw (Broken Screw).

Figure 4

Axial cut of CT Angiography of the pelvis – The screw tip in extreme proximity to the external iliac vessels can be seen.

Figure 5

3D reconstructed CT Angiography of the pelvis – A better visualization of the screw previously labeled as Screw 2, abutting the external iliac artery.

Figure 6

Intraoperative picture (First stage surgery) – Shows the screw tip which is separated away from the external iliac artery and vein through the ilioinguinal incision.

Figure 7

Post-operative radiograph of pelvis with both hips after Stage 1 surgery – Antibiotic laden cement filler in the left acetabulum and proximal femur seen. Prophylactic wiring of the proximal femur was done to prevent fracture during stem removal.

Figure 8

Intraoperative picture of the ilioinguinal incision (Before final Closure) – shows uninjured iliac artery and vein after screw and prosthesis removal.

Figure 9

Post-operative radiograph of pelvis with both hips after the definitive surgery – Total hip arthroplasty performed using trabecular metal augment for tackling the acetabular bone loss. Note the correction of limb length discrepancy depicted by parallel interischial and intertrochanteric line.