Intrapelvic Pseudotumor Causing Neuropathy and Vascular Obstruction After Revision Total Hip Arthroplasty: A Case Report

Background: There is a growing body of recent literature regarding the occurrence of pseudotumors associated with modular junctions and various bearing surfaces after total hip arthroplasty (THA). Revision surgery is often technically challenging and high complication rates have been reported. The optimal management of these patients and outcomes after operative treatment remain poorly understood. Methods: We report the case of a 77-year-old male with progressive unilateral lower extremity swelling, pain, and neuropathy 9 years after revision THA for polyethylene liner wear. Imaging and biopsy confirmed a massive intrapelvic pseudotumor exerting compressive effects. Radiographs demonstrated extensive femoral and pelvic osteolysis without evidence of component loosening. Debulking of the intrapelvic portion of the pseudotumor was performed via the lateral window of the ilioinguinal approach with component retention. Results: Debulking of the intrapelvic mass resulted in resolution of symptoms. One year postoperatively the patient reported pain free ambulation using a walker and no recurrence of symptoms. Radiographs demonstrated stable THA components in comparison with preoperative films. Discussion and Conclusion: This case demonstrates a rare finding of intrapelvic pseudotumor causing neurovascular compression after revision THA. Clinicians should be aware of intrapelvic pseudotumor as a possible cause of limb swelling and neuropathy, and that debulking of the mass is a potential treatment option in the setting of well-fixed implants.