Introduction: Hip resurfacing has been increasingly used procedure for physiologically young and active patients. Wear properties of the implants are considered to be excellent. We present a case of tumor like swelling of the thigh following metal on metal hip resurfacing.

Case report: 56 year old lady underwent metal on metal hip resurfacing for idiopathic osteoarthritis of right hip. Implant size: 38 mm head with 44 mm cup.

After 18 months of successful surgery she presented with short duration (2 weeks) history of thigh swelling with pain and stiffness in hip and knee. Clinically gross circumferential swelling of right thigh from inguinal ligament to the knee joint. She had increased serum cobalt chromium levels. Aspiration of hip revealed high levels of cobalt and chromium. Biopsy and intra operative samples at revision revealed “no infection or tumor but non specific inflammatory reaction.”

The patient underwent revision surgery to ceramic-plastic bearing.(THR).

12 months post operative, the swelling has reduced with painless mobile hip and knee joints.

Discussion: The metal on metal hip resurfacing could have produced high metal ion wear reaction leading to swelling. Which could be because of small diameter prosthesis with valgus position of femoral component with open cup angle of 49 degrees.