Open Reduction by Fenestration to the Ilium for Central Acetabular Depression Fracture: A Case Report and Operative Technique

Abstract

We reported a case of the acetabular depression fracture in conjunction with a central fracture dislocation of the hip that was treated with a unique surgical technique. CASE REPORT: A 76-year-old man suffered a left acetabular fracture with severe left hip joint pain and walking disability. Acetabular fracture was not apparent on the initial radiographs including anteroposterior and oblique views of the pelvis. However, computed tomography (CT) scanning showed displaced acetabular depression fracture (a third fracture fragment) in the center of the weight-bearing area with fracture of the ilium and spontaneous reposition of central dislocation of the hip (Fig. 1, 2). It seemed that this fracture fragment created incongruity of the acetabular articular surface and the potential for hip joint instability. Therefore, the patient was treated with open reduction and internal fixation. SURGICAL TECHNIQUE: To perform the procedure, the patient was placed in the lateral decubitus position. A direct lateral approach to the hip was used for exposure. The vastus lateralis was released 1 cm distal from its origin, trochanteric osteotomy was done by the Gigli saw. To observe the hip articular surface and to identify the fracture fragment, the femoral head was posterior dislocated with excision of teres ligamentum after T-shaped capsulotomy. The depressed fragment in the acetabulum was identified under direct vision but could not be reduced. Therefore, the outer cortex of the ilium was fenestrated in a size of 2 × 2 cm so that a 1-cm-wide levator was inserted to the depressed fragment at 2 cm proximal from the hip articular surface through the fenestrated window (Fig. 3). Subsequently, the displaced bone fragment was pushed down by using the levator to the adequate articular joint level. The fragment was stabilized with packed cancellous bone graft harvested from the osteotomized greater trochanter. The removed outer cortex of the ilium from fenestrated site was repositioned and fixed by a reconstruction plate and screws. The osteotomized greater trochanter was reattached and fixed with two cannulated cancellous hip screws. RESULTS: At 9-month follow-up, he was pain-free and continued to function well without the use of external supports. The acetabular depression fracture was completely reduced and healed in the CT scanning evaluation. The patient had no signs of posttraumatic osteoarthritis in radiographs. DISCUSSION and CONCLUSION: In acetabular fracture dislocations of the hip joint, the precise pathological anatomy is not easily demonstrated by routine radiographs with classification of acetabular fractures. In our case, however, details of acetabular fracture were not well visible on conventional radiographs. It has been shown that computed tomography is useful method in precise evaluation of the fracture type with bone damage and integrity of joint configuration. Concerning approach to the fracture fragment which existed in the center of the weight bearing area of acetabulum, we performed to fenestrate on the intact bony cortex of the ilium just proximal to the fracture site. It was convenient and useful to gain good reduction of the central acetabular depression fracture, although there was no report on such a ‘fenestration’ method.