[Translated article] Total hip arthroplasty with shelf acetabuloplasty in dysplastic coxarthrosis, mean follow-up of 7 years.

INTRODUCTION: Developmental dysplasia of the hip is the cause of approximately one third of secondary coxarthrosis. Anatomy alterations make it difficult to place a total hip prosthesis in its anatomical position and for it to be stable in the long term; there are several techniques to achieve this goal. In the present work, we used autograft of the femoral head (shelf graft or reinforced roof), to improve the coverage of the acetabular component with favourable results. MATERIALS AND METHODS: Sixteen cases were included in 14 patients with a diagnosis of developmental dysplasia of the hip (13 women and one man), the mean age was 44.3 years (range 35-68 years), with a mean follow-up of 7 years (range 1-15 years). All the cases were evaluated clinically and radiographically, to demonstrate the osseointegration of the graft and the functional results in the medium term. RESULTS: All the acetabular components were placed in anatomical position (Ranawat technique), the mean percentage of host bone coverage was 54.53% (range 43.28-79.05%), obtaining additional coverage with the bone graft of 45.13%. Osseointegration of the graft of 100% at 12 weeks, resorption of the graft from the sixth month, stabilising in the third postoperative year. Only one case of dislocation is reported, no cases of infection, loosening, heterotopic ossification or revision. CONCLUSION: This procedure has shown good functional results in the medium term with 100% osseointegration, despite cases of severe bone resorption of the graft that does not compromise the stability of the prosthesis.

Total hip arthroplasty with shelf acetabuloplasty in dysplastic coxarthrosis, mean follow-up of 7 years. / Artroplastia total de cadera no cementada con techo armado en coxartrosis displásica, seguimiento medio de 7 años.

Developmental dysplasia of the hip is the cause of approximately one third of secondary coxarthrosis. Anatomy alterations make it difficult to place a total hip prosthesis in its anatomical position and for it to be stable in the long term; there are several techniques to achieve this goal. In the present work, we used autograft of the femoral head (shelf graft or reinforced roof), to improve the coverage of the acetabular component with favorable results. MATERIALS AD METHODS: Sixteen cases were included in 14 patients with a diagnosis of developmental dysplasia of the hip (13 women and one man), the mean age was 44.3 years (range 35-68 years), with a mean follow-up of 7 years (range 1-15 years). All the cases were evaluated clinically and radiographically, to demonstrate the osseointegration of the graft and the functional results in the medium term. RESULTS: All the acetabular components were placed in anatomical position (Ranawat technique), the mean percentage of host bone coverage was 54.53% (range 43.28-79.05%), obtaining additional coverage with the bone graft of 45.13%. Osseointegration of the graft of 100% at 12 weeks, resorption of the graft from the sixth month, stabilizing in the third postoperative year. Only one case of dislocation is reported, no cases of infection, loosening, heterotopic ossification or revision. CONCLUSION: This procedure has shown good functional results in the medium term with 100% osseointegration, despite cases of severe bone resorption of the graft that does not compromise the stability of the prosthesis.

Progesterone effects on the acquisition of conditioned avoidance responses an other motoric behaviors in intact and ovariectomized rats.

This study demonstrates a significant impairment in the acquisition of conditioned avoidance responses in female rats during their estrus phase. Progesterone (PROG 5 mg) injected 6 h prior to the test, significantly enhanced the performance exhibited by rats at estrus, but not at diestrus. In ovariectomized rats, the acquisition of conditioned avoidance responses was similar to the exhibited during diestrus and this behavior was depressed by a single dose of estradiol benzoate (EB 2 micrograms) injected 48 h prior to the test. PROG antagonized the avoidance depression induced by EB, but it was not able to induce changes in the acquisition of conditioned avoidance response in ovariectomized rats without EB pretreatment. Estradiol appears to be the principal ovarian steroid modulating the acquisition of an avoidance task, whereas PROG seems to have a secondary role in this behavior, regulating the actions of estradiol on the brain. PROG failed to induce consistent changes in some spontaneous motor behaviors in intact and ovariectomized rats.

Behavioral effects of a LHRH antagonist in intact and ovariectomized rats.

The effects of the LHRH antagonism on the acquisition of conditioned responses (CARs) and spontaneous motility were studied in intact and ovariectomized rats. A synthetic antagonist of LHRH, [N-acetyl-D-p-chloro-Phe1,2,D-Trp3,D-Arg6,D-Ala10]-LHRH, was injected in a single dose (10 micrograms/rat, SC) at noon on the day of proestrus in the normally cycling rat, and behavioral experiments were carried out on the morning of estrus or metestrus. Two procedures were followed in the ovariectomized rats: in the first, the antagonist was injected 1 h before estradiol, and in the second, at noon on the day after estradiol replacement. The experiments were carried out 24 and 48 h after estradiol, respectively. The LHRH antagonist facilitated the acquisition of CARs in both experimental groups, thus reversing the impairments observed during estrus and metestrus and those induced by estradiol replacement. The antagonist decreased the number of head shakes during estrus, whereas it induced an increase in total motility and rears in ovariectomized control animals. On the other hand, the antagonist increased the number of rears and reversed the decrease in grooming behavior induced by estradiol. The results led to the idea of a role of LHRH in behaviors not apparently related to sex, which could explain the behavioral changes observed across the estrous cycle and those induced by estradiol replacement in ovariectomized rats.

Effects of estradiol replacement in ovariectomized rats on conditioned avoidance responses and other behaviors.

The acquisition of conditioned avoidance responses along with spontaneous behaviors were studied in ovariectomized rats. Fourteen days after ovariectomy, they were injected subcutaneously with one of the following doses of estradiol benzoate: 0.2, 2 or 20 microgram/rat. Behavioral tests were applied 3, 24, 48 or 72 hours after estradiol treatment. Although estradiol 2 microgram/rat induced a decrease in acquisition of conditioned avoidance responses at all times tested, this effect was maximum at 48 h. Estradiol 0.2, and 20 microgram/kg decreased and stimulated, respectively, the acquisition performance, as tested 3 h after injection. All doses increased global motility and rearing behavior. This hypermotility disappeared at 24 h, but it was observed again at 48 and 72 h after estradiol 0.2 and 20 microgram/rat. The hormone also induced an increase in head shaking and a decrease in grooming. Although the behavioral changes are more significant in presence of very low serum levels of estradiol, they seem to be triggered by the previous increase in the estradiol levels. The possible sites and mechanisms of action of estradiol on behavior are discussed.