We conducted extensive histological examination of the tissues that were adjacent to the prosthesis in 9 hips that had a failed total arthroplasty. The prostheses were composed of titanium alloy (Ti-6Al-4V) and ultra-high molecular weight polyethylene. The average time that the prosthesis had been in place in the tissue was 33.5 months (range, 11 to 57 months). 7 arthroplasties were revised because of aseptic loosening and 2, for infection. In 8 hips cement had been used and in one (that had a porous-coated implant for 52 months) no cement had been utilized.
Intense histiocytic and plasma-cell reaction was noted in the pseudocapsular tissue. There was copious metallic staining of the lining cells. Polyethylene debris and particles of cement with concomitant giant-cell reaction were present in 5 hips. Atomic absorption spectrophotometry revealed values for titanium of 56 to 3700 micrograms per gram of dry tissue (average, 1047 micrograms per gram; normal, zero micrograms per gram), for aluminum of 2.1 to 396 micrograms per gram (average, 115 micrograms per gram; normal, zero micrograms per gram), and for vanadium of 2.9 to 220 micrograms per gram (average, 67 micrograms per gram; normal, 1.2 micrograms per gram). The highest values were found in the hip in which surgical revision was performed at 57 months. The concentrations of the 3 elements in the soft tissues were similar to those in the metal of the prostheses.
The factors to which failure was attributed were: vertical orientation of the acetabular component (five hips), poor cementing technique on the femoral side (three hips), infection (two hips), and separation of a sintered pad made of pure titanium (one hip). A femoral component that is made of titanium alloy can undergo severe wear of the surface and on the stem, where it is loose, with liberation of potentially toxic local concentrations of metal debris into the surrounding tissues. It may contribute to infection and loosening.
Copyright remains with the authors and publisher.
We conducted extensive histological examination of the tissues that were adjacent to the prosthesis in 9 hips that had a failed total arthroplasty. The prostheses were composed of titanium alloy (Ti-6Al-4V) and ultra-high molecular weight polyethylene. The average time that the prosthesis had been in place in the tissue was 33.5 months (range, 11 to 57 months). 7 arthroplasties were revised because of aseptic loosening and 2, for infection. In 8 hips cement had been used and in one (that had a porous-coated implant for 52 months) no cement had been utilized.
Intense histiocytic and plasma-cell reaction was noted in the pseudocapsular tissue. There was copious metallic staining of the lining cells. Polyethylene debris and particles of cement with concomitant giant-cell reaction were present in 5 hips. Atomic absorption spectrophotometry revealed values for titanium of 56 to 3700 micrograms per gram of dry tissue (average, 1047 micrograms per gram; normal, zero micrograms per gram), for aluminum of 2.1 to 396 micrograms per gram (average, 115 micrograms per gram; normal, zero micrograms per gram), and for vanadium of 2.9 to 220 micrograms per gram (average, 67 micrograms per gram; normal, 1.2 micrograms per gram). The highest values were found in the hip in which surgical revision was performed at 57 months. The concentrations of the 3 elements in the soft tissues were similar to those in the metal of the prostheses.
The factors to which failure was attributed were: vertical orientation of the acetabular component (five hips), poor cementing technique on the femoral side (three hips), infection (two hips), and separation of a sintered pad made of pure titanium (one hip). A femoral component that is made of titanium alloy can undergo severe wear of the surface and on the stem, where it is loose, with liberation of potentially toxic local concentrations of metal debris into the surrounding tissues. It may contribute to infection and loosening.
Copyright remains with the authors and publisher.