Addition of fluoride to acrylic bone cement does not improve fixation of a total hip arthroplasty stem.
Improved fixation to bone is vital for improving the long term success of cemented implants. Addition of fluoride to acrylic bone cement may be one way to improve the quality of the bone cement interface and thereby reduce the risk of loosening. Ninety patients (97 hips) with a median age of 70 years (range, 31-81 years) scheduled for total hip arthroplasty were randomized to receive a stem fixed with fluoride-containing acrylic bone cement or conventional acrylic bone cement. Fixation and bone remodeling around the femoral component was studied with radiostereometry and dual-energy xray absorptiometry up to 5 years after the operation in 73 patients (77 hips). Radiostereometric evaluation at 5 years revealed no differences in stem migration (subsidence/lift-off) or rotations. The stem subsidence inside the mantle was similar in the two groups. At 5 years the study group had lost more bone mineral in Gruen regions 5 and 7 than the controls. The Harris hip and pain score did not differ. Use of fluoride containing bone cement did not improve the stem fixation compared with a conventional cement used up to 5 years, but resulted in more pronounced loss of bone mineral density in the medial cortex.


METHODS
Therapeutic Level I. See Guidelines for Authors for a complete description of levels of evidence.
Digas
Georgios
G
Department of Orthopaedics, Institute of Surgical Science, Sahlgrenska University Hospital, Göteborg University, Sweden. georgios.digas@vgregion.se
Kärrholm
Johan
J
Thanner
Jonas
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001843:Bone Cements; D004338:Drug Combinations; D005260:Female; D005459:Fluorides; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D007593:Joint Instability / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D019904:Polymethyl Methacrylate; D011474:Prosthesis Design; D013997:Time Factors; D016896:Treatment Outcome
D001843:Bone Cements; D004338:Drug Combinations; D019904:Polymethyl Methacrylate; D005459:Fluorides