Orthopaedic Hospital

Implant Retrieval Lab

J. Vernon Luck, Sr., MD Orthopaedic Research
Center, Orthopaedic Hospital.
Pat Campbell, Ph.D.
Scott D. Nelson, MD, Chief of Pathology
Santa Monica UCLA and Orthopedic Hospital
1250 16th Street, Santa Monica, CA 90404

• Summary
• General Information
• Case Studies
• Histological Examples
• Diagnosing Metal Sensitivity

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This website was made possible by funding from the Los Angeles Orthopaedic Hospital Doctors' Education Research Fund

Case Studies

Case Histories provided by Mr. D. Fern of the Royal Cornwall Hospitals, England and Mr J. Latham, Southampton University Hospitals, England.

Case 1.

A 70-year-old woman received a large diameter metal-on-metal total hip replacement. Within several months, an expansive lytic lesion developed on the inner wall of the pelvis and the patient reported groin pain.  An acetabular revision was required for aseptic loosening at 1 year post-operatively. At that surgery, copious amounts of sterile fluid were present in the joint and extensive osteolysis and necrosis of the joint tissues were noted.  ESR and CRP were normal and bacterial cultures were negative.  Tissues taken at that surgery are shown in the figures.

Case 2.

This 51-year-old male patient had a total hip replacement with 28mm Metasul metal-on-metal bearings implanted for osteoarthritis. The patient returned to normal activity levels and despite some persisting trochanteric region pain, functioned well with a good range of motion. At approximately 2 years post-operatively, the patient complained of a large swelling in the groin and a trochanteric bursa was removed.  Another effusion occurred and an arthrogram confirmed that there was communication with the joint, and there was radiographic suspicion that there was impingement between the acetabular rim and the psoas bursa.  The bursa was removed and a large volume of serous fluid and necrotic debris were noted in the joint. Four months later, the hip dislocated atraumatically and a second operation was performed to exchange the cobalt chrome acetabular bearing to polyethylene.  Again, a large amount of serous fluid was noted in the joint. There were no signs of infection and minimal synovial thickening.  Bacterial and fungal cultures were negative. There was no apparent metal staining and measurements of the removed Metasul bearings verified low wear. The ESR varied from 29 to 7.  Tissue taken at that surgery is shown in the figures. The patient continued to have effusions and the bearings were changed to ceramic on polyethylene.

Case 3.

This 53-year-old woman received a 42mm metal-on-metal surface arthroplasty for osteoarthritis. At 1 year post-operatively, she underwent an ultrasound to investigate the cause of a painful groin lump. A synovial cyst was aspirated but cultures of the fluid were negative.  The swelling reappeared and a CT scan showed swelling of the psoas bursa. This was aspirated several times.  A skin patch test was positive for cobalt. The implants were removed at 2.5 years after the original surgery. Tissues taken at that time are shown in the figures. Retrieval analysis showed that the bearing wear was minimal, and that the resurfaced femoral head was viable.