Evaluation of persistent pain after hip resurfacing.

Evaluation and treatment of pain following hip resurfacing arthroplasty can be challenging, even for the most experienced arthroplasty surgeon. As in any total hip replacement, there are a number of investigative tools at the disposal of orthopaedic surgeons to elicit the underlying causes of pain for diagnosis and treatment. A detailed history and physical examination are the most important first steps in the differential diagnosis of the intrinsic and extrinsic etiologies of hip pain. Serial radiographs from the time of surgery also should be reviewed and compared for changes indicative of loosening, migration, and osteolysis, in combination or alone. Diagnostic injections with local anesthetic agents additionally can be performed to localize the origin of pain. Bone scintigraphy, hip joint aspiration, and laboratory tests, including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), should be requested routinely to exclude an occult infection. The use of ultrasound (US), magnetic resonance imaging (MRI), and even hip arthroscopy has been suggested as potential diagnostic tools when metal sensitivity is suspected. Relative to cause, femoral neck fractures and the possibility of metal hypersensitivity as sources of persistent groin pain should always be considered in metal-on-metal hip resurfacing. Additionally, iliopsoas tendinopathy and anterior impingement of the femoral neck are well-recognized causes of pain and should be included in the differential diagnosis. Surface arthroplasty is becoming an acceptable alternative to standard total hip replacement in young patients. It is increasingly essential to recognize the different causes of pain following resurfacing in order to make an accurate diagnosis and initiate timely, appropriate treatment.