L5 radiculopathy secondary to migration of a revision stemmed acetabular cup.

Abstract

Stemmed acetabular components are used in patients undergoing revision total hip arthroplasty in cases with major acetabular defects or pelvic discontinuity. Conflicting results relating to the survival of the component, and complication rates are reported in the literature. We present a case of L5 radiculopathy secondary to proximal migration of this device. A 79-year-old man was admitted to our department in 2012 with increasing pain and paresthesias, initially diagnosed as left L5 radiculopathy. In 2002, he had undergone revision surgery due to aseptic loosening of the acetabular component with a stemmed acetabular cup. Radiological findings were severe osteolysis around the acetabular cup with proximal migration. MRI showed osteolysis involving the left L5/S1 facet joint and evidence of soft tissue in the left foramina encasing the L5 radicular nerve. Nerve conduction and electromyography studies revealed chronic L5 radiculopathy. This case report illustrates the importance of considering acetabular loosening in a patient presenting with radicular symptoms. If a stemmed acetabular cup is chosen for an acetabular reconstruction, careful surgical technique should be employed in order to achieve durable fixation. If the patient has pelvic discontinuity, other options of reconstruction have showed better outcomes in the literature.