A chronically dislocating prosthetic patella. A case report

• Published in: Orthopedics (Thorofare, N.J.) Vol. 11; no. 3; pp. 457 - 460
• Main Authors: FLANDRY, F, HARDING, A. F, KESTER, M. A, COOK, S. D, HADDAD, R. J. JR
• Format: Journal Article
• Language: English
• Published: Thorofare, NJ Slack 01.03.1988; SLACK INCORPORATED
• Subjects: Biological and medical sciences; Equipment Failure; Female; Humans; Joint Dislocations - etiology; Knee Prosthesis; Medical sciences; Middle Aged; Orthopedic surgery; Patella - surgery; Prosthesis Failure - etiology; Reoperation; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Knee; Orthopedic surgery; Luxation; Prosthesis; Patella; Diseases of the osteoarticular system; Lower limb
• ISSN: 0147-7447; 1938-2367
• DOI: 10.3928/0147-7447-19880301-10

A 63-year-old white woman was evaluated for a chronically dislocating right patella 6 months following total knee arthroplasty. At the time of our initial evaluation, her knee would not extend beyond 35 degrees and her patella was dislocated and irreducible. At arthrotomy, when the patella was everted, the patellar component was oriented with the facet ridge rotated 90 degrees to the trochlear groove of the femoral component. The patellar template guide indicated that the fixation pegs had been drilled properly, and thus, the patellar component had been assembled improperly during manufacturing. After dome-type patellar prosthesis replacement and proximal and distal extensor realignments were performed, 2 months post-revision the patient had a range of motion from 5 degrees to 95 degrees and ambulated with no patellar instability or pain.