Dynamic bone study in total prosthesis of the hip (RM isoelastic type)

Over a period of 33 months, an evaluation was made of the development of 78 asymptomatic patients (average age: 62.27 ± 8.12 years), fitted with uncemented total prostheses of the hip, and a control group of 30 patients without prostheses (average age: 64.12 ± 10 years). All of them underwent bone scintigraphy modified three times: angioscintigraphy, sequenced scintigraphy and static scintigraphy. The following areas of interest were evaluated qualitatively: in the first phase, the gluteal, articular and diaphyseal regions; in the second and third phases, the cotyloid region, the trochanter, the intermediate area of the stem and the vertex of the prosthesis. The presence of any calcifications in the articular interface was sought. The natural development of bone repair activity in patients with hip prostheses showed that the areas of maximum stress, in decreasing order, are the following regions: trochanteric, cotyloid, vertex and intermediate area of the stem; the early presence of articular calcifications was observed in 20.5% of the cases studied. On the other hand, perfusion of the periprosthetic tissue showed no significant changes with respect to the control group. On the contrary, sequential scintigraphy was very sensitive in the detection of changes in the rate of bone repair, differentiating between the post-surgical period proper and the subsequent period in which the prothesis was stabilized; this was not the case with static scintigraphy, the sensitivity of which is inferior. (author). 14 refs, 3 figs