Abstract
Total hip arthroplasty following pelvic or femoral trauma presents the joint surgeon with challenges not dissimilar to that of revision surgery. Careful preoperative evaluation and planning, and realistic assessment of risks and expectations is necessary.
Complex acetabular fractures present the surgeon with a variety of challenges in conversion to total hip replacement (THR). Bone stock is the critical factor in achieving a stable acetabular reconstruction, particularly with regard to the posterior column. In patients who have undergone prior open reduction and internal fixation, routine radiographic examination will often be inconclusive as to the status of healing of fractures due to the presence of metal, and CAT scans will be similarly obfuscated by metal artefact. Therefore, the surgeon must be prepared for the possibility of bone stock deficiency at the time of reconstruction.
Subclinical infection following ORIF is possible; all patients should be screened for this possibility with preoperative determination of the ESR and C-reactive protein. If these studies are elevated, aspiration of the hip under x-ray or ultrasound guidance should be considered. At the time of surgery, it is suggested that cultures be obtained prior to the administration of systemic antibiotics, and consideration given to intraoperative frozen section examination of tissue if infection is suspected. Removal of internal fixation devices, debridement, and second stage reconstruction after appropriate antibiotic therapy will be necessary in these cases.
Exposure of the hip will be complicated by scar tissue. Particular care is required to avoid sciatic nerve injury during the exposure and hardware removal. Extension of the hip and knee during posterior exposure of the acetabulum and internal fixation devices will aid in retraction and avoidance of neuropraxic sciatic injury.
Stainless steel screws and plates should not contact titanium alloy implants in order to avoid the possibility of fretting wear and corrosion of dissimilar metals. Intraarticular exposure of screws or plates mandates removal of the device. In the absence of such exposure, hardware may be left in place.
Post-traumatic hip arthritis is frequently associated with avascular necrosis of the femoral head. It is not unusual to see advanced bone loss and collapse of the femoral head, with associated limb shortening. If internal fixation has been performed in the proximal femur, consideration of the appropriate femoral component length is necessary to bypass any stress risers. Calcar replacement implants will be necessary in the face of proximal femoral deficiency.
The risk of dislocation following THR in the setting of post-traumatic arthrosis is increased in the presence of soft tissue defects, abductor dysfunction, or neuromuscular deficit. Postoperative bracing may be necessary to assure stability of the reconstruction. The use of a THR orthosis set at 10–15° abduction, 30–60° flexion for 12 weeks following surgery has been successful in preventing dislocation in the setting of abnormal soft tissues.
The abstracts were prepared by Mrs Dorothy L. Granchi, Course Coordinator. Correspondence should be addressed to her at PMB 295, 8000 Plaza Boulevard, Mentor, Ohio 44060, USA.
