Is it advantageous to strengthen the cement-metal interface and use a

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collar for cemented femoral components of total hip replacements? Harris-W-H. Orthopaedic Biomechanics Laboratory, Massachusetts General Hospital, Clin-Orthop. 1992 Dec. (285). P 67-72. The mechanism of initiation of loosening of cemented femoral components is now known. It is debonding at the cement-metal interface. Current data strongly support the concept that a collar and improvement of the cement-metal interface are valuable. Precoating and having a roughened surface proximally and distally on the stem contribute to extended longevity of the cement-metal interface. Using contemporary instrumentation, collar-calcar contact can be achieved regularly and, once achieved, is well maintained for years. Author-abstract.