Impingement of metal-polyethylene hip prostheses
- PDF / 1,335,424 Bytes
- 6 Pages / 595 x 792 pts Page_size
- 83 Downloads / 175 Views
hristoph Lutter · Daniel Klüß · Andreas Enz · Wolfram Mittelmeier Department of Orthopedics, University Medical Center Rostock, Rostock, Germany
Impingement of metalpolyethylene hip prostheses Potential cause of high systemic titanium levels?
Case report Medical history In 2006 the female patient underwent implantation of a hip joint replacement (right side) in another hospital after suffering from osteoarthritis. At that time the patient was 57 years old and highly physically active (body weight 54 kg). A cementless prosthesis (Aesculap Bicontact SD 13, BBRaun Aesculap, Tuttlingen, Germany, metal head 32XL, Plasmacup 54, PE insert symmetric 32) was implanted according to the specifications and approvals of the components used. In the following years, the patient was free of complaints and largely unrestrictedly active. In 2016 the patient fell and suffered a periprosthetic femoral fracture (type Vancouver A), which could be successfully treated conservatively in another hospital. In February 2019, the patient now 70 years old, presented at our orthopedic outpatient clinic and reported progressive pain in the area of the right hip, especially under load. Furthermore, the patient complained of fatigue and concentration problems.
Clinical findings The physical examination revealed pronounced pain during rotation and compression of the right hip and a distinct limping of the right lower extremity. Further radiographical examinations showed a large osteolysis in the acetabular roof (. Fig. 1a). For a more precise evaluation, we analyzed metal ion levels in the patient’s blood, which revealed
significantly elevated systemic metal concentrations; in particular cobalt (Co) and titanium (Ti) were found to be greatly increased. (. Fig. 2).
Diagnosis In summary of the findings, we diagnosed a pronounced metallosis and a loosening of the acetabulum cup based on bony defects in the acetabular roof. Metal abrasion and/or polyethylene (PE) abrasion were suspected to be the cause of these defects [1]. Based on our findings, we recommended the bony reconstruction of the acetabulum and a two-stage replacement of the inserted endoprosthesis.
Treatment and follow-up After appropriate presurgical preparation the acetabular cup was removed in April 2019, the pelvic defect was filled with allogenic cancellous bone (impaction grafting; 2 × femoral head plus 12 mm3 cancellous bone) and a large metal head spacer (outer diameter 60 mm, Exactech, Kiel, Germany) was temporarily implanted (. Fig. 1b,c). The stem/cone (12 mm/14 mm) of the prosthesis proved to be solid and undamaged and was thus left in situ. Intraoperatively, large quantities of metallic dark discolored granulomatous periarticular tissue were noticeable, which were resected in the best possible way and submitted for histopathological processing (pathological finding periprosthetic membrane of the abrasion-induced type I of the consen-
sus classification) (. Fig. 3d). The explanted prosthesis components showed a pronounced destruction caused by a cup head impingement, with both the p
Data Loading...
