Distúrbios de coagulação em pacientes com osteonecrose da cabeça femoral / Coagulation disorders in patients with femoral head osteonecrosis

Objetivo: Comparar a ocorrência de trombofilias em pacientes com osteonecrose idiopática da cabeça femoral em relação aos pacientes com osteonecrose secundária da cabeça femoral. Métodos: Um total de 24 pacientes consecutivos foram avaliados, sendo oito portadores de osteonecrose idiopática e 16 de osteonecrose secundária. Os exames realizados na detecção de trombofilias foram as dosagens de proteína C, proteína S e antitrombina e as pesquisas de mutações nos genes da protrombina e do fator V. Comparamos estatisticamente os resultados através do cálculo da razão de chances ou odds ratio das diferentes trombofilias entre os dois grupos. Resultados: O odds ratio para a deficiência da proteína S e deficiência da proteína C entre os grupos idiopático e secundário foram respectivamente 5 e 2,14. Desta maneira, um indivíduo com osteonecrose idiopática possui uma chance 5 vezes maior de apresentar deficiência da proteína S e 2,14 vezes maior de apresentar deficiência da proteína C do que um indivíduo com osteonecrose secundária. Conclusão: Pacientes com osteonecrose idiopática têm maiores chances de apresentar trombofilias do que aqueles com osteonecrose secundária, sugerindo que estes distúrbios de coagulação podem desempenhar um papel importante na patogênese dos casos de osteonecrose onde não há inicialmente nenhum fator de risco identificável. Nível de Evidência III, Estudo de Caso-Controle.

Objective: To compare the occurrence of thrombophilic disorders in patients with idiopathic osteonecrosis of the femoral head and patients with secondary osteonecrosis of the femoral head. Methods: Twenty-four consecutive patients were enrolled, with eight of them presenting idiopathic osteonecrosis and 16 presenting secondary osteonecrosis. The tests for detection of thrombophilic disorders were measurements of protein C, protein S and antithrombin levels and detection of prothrombin and factor V gene mutations. We compared the results using the odds ratio statistics for the thrombophilic disorders between the two groups. Results: The odds ratio for the protein S deficiency and protein C deficiency between the idiopathic and secondary groups were 5 and 2.14, respectively. Thus, an individual with idiopathic os teonecrosis has 5 times more chance of presenting protein S deficiency and 2.14 times more chance of presenting protein C deficiency than an individual with secondary osteonecrosis. Conclusion: Patients with idiopathic osteonecrosis have more chances of presenting thrombophilias than those with secondary osteonecrosis, suggesting these coagulation disorders can play an important role in the pathogenesis of the osteonecrosis in cases where there was no initial risk factor recognized. Level of Evidence III, Case-Control Study.

[Core decompression in stage 1 idiopathic necrosis of the femoral head]

The osteonecrosis of the femoral head is a progressive multi-etiologieal disease; its prim urn inoveizs is circulatory and the pathophysiology is still unexplained. Ficat and Arlet classified this disease into 5 stages from 0 to IV. The progression from one stage to another is inevitable if surgical treatment is not performed early. The MRI is currently the investigation of choice in detecting infraradiological stage I necrosis. The core decompression as proposed by Ficat and Arlet allows to excise the necrotic zone, confirm the histological diagnosis, decompress the intramedullary increased pressure and favor the ncovascularization of the femoral head. The aim of this study is to present the mid-term results of the core decompression in a series of 17 hips in 16 patients with an average age of 46 years that were operated upon in stage I idiopathic necrosis of the femoral head, 4 to 6 weeks after the symptoms appeared. The MRI demonstrated the zone of necrosis iii 16 hips. The histological examination confirmed the diagnosis of necrosis in 16 hips including the one which was negative on MRI. The Merle d'Aubigne hip score was used for the clinical evaluation and showed to be less than 15 in all hips preoperatively. This score improved to 18 [full value] after a mean follow-up of 8 years, ranging from 3 to 13 years. The X-rays of the operated hips remained normal at the final follow-up in all cases. The very high percentage [100%] of recovery and healing in stage I femoral head necrosis hi this series may be explained by the absence of obvious etiological factors [idiopathic necrosis] and moreover by the short delay between the onset of the symptoms and the operative treatment. We believe that the MRI is the examination of choice that should be done early hi patients with a painful hip and normal X-rays and that core decompression performed soon is an excellent procedure to treat stage I idiopathic necrosis of the femoral head