Michel Franco

Lipoma arborescens of the knee: report of a case managed by arthroscopic synovectomy.

We report a case of lipoma arborescens treated with an arthroscopic procedure. Lipoma arborescens is an uncommon pseudo-tumoral synovial lesion usually located in the suprapatellar pouch of the knee. This diagnosis should be considered, particularly in patients with chronic joint effusion. Magnetic resonance imaging confirms the lipomatous nature of the synovial proliferation. When limited to the anterior compartment of the knee, lipoma arborescens can be treated by arthroscopic synovectomy.

Radiographic follow-up of a phalangeal brown tumor

We report the 6-year radiographic follow-up of a phalangeal brown tumor in a patient with severe hyperparathyroidism secondary to chronic renal failure treated with hemodialysis. The phalangeal lesion increased in size during the first 3 years, until the patient finally accepted to undergo parathyroidectomy. The initial radiographic change was a small intracortical lytic area. Two years later, an expansile cystic lesion was visible in the phalanx, and computed tomography showed a cortical defect. Ossification of the lesion occurred over the 2.5 years following parathyroidectomy. The epidemiology, radiographic changes and post-treatment evolution of brown tumor in dialysed patients is reviewed. Surgical parathyroidectomy is the standard treatment for brown tumor complicating secondary hyperparathyroidism. The usefulness and limitations of treatment with vitamin D analogs, recently reported in a few case reports, are discussed.

Tacrolimus pain syndrome in renal transplant patients: report of two cases

We report two renal transplant patients who experienced onset of severe bilateral knee pain 1 and 3 months after transplantation, respectively, while on tacrolimus therapy. Tacrolimus, like cyclosporine A, is an immunosuppressive agent that inactivates the enzyme calcineurin phosphatase. A bone pain syndrome was reported in 1989 in organ transplant recipients treated with cyclosporine A. Our cases suggest that tacrolimus may induce the same syndrome. Technetium 99m bone scanning shows increased uptake in the affected areas, and magnetic resonance imaging changes are consistent with bone marrow edema. The tacrolimus dosage need not be reduced unless trough levels are too high. The symptoms resolve completely within a few months. Imaging studies should be done to rule out avascular necrosis. The pathophysiology of this syndrome is discussed. Since tacrolimus was introduced recently, similar cases should be published.

Longitudinal bone insufficiency fracture of the tibia in a renal transplant recipient.

We report a case of longitudinal tibial fracture as the first manifestation of bone insufficiency in a 50-year-old patient who had received a renal transplant 12 years earlier. The epidemiological, clinical, and imaging features of these fractures are reviewed. Bone loss occurs in the long term in about half of renal transplant recipients. The main causes are preexisting renal osteodystrophy; glucocorticoid therapy; and hyperparathyroidism, whether residual or secondary to imperfect graft function. The effects of cyclosporine therapy on bone metabolism remain unclear. Identification of patients at very high risk of fracture and available options for early prophylaxis are discussed.

Lipome arborescent du genou traité par synovectomie arthroscopique

Resume Les auteurs rapportent un cas de lipome arborescent du genou traite par synovectomie arthroscopique. Il s’agit d’une pseudotumeur rare de la synoviale, d’etiologie inconnue, surtout observee au genou, en particulier dans le recessus suprapatellaire. Si le diagnostic est evoque, notamment devant un epanchement chronique, les sequences adaptees d’imagerie par resonance magnetique peuvent confirmer la nature graisseuse de la proliferation. En cas d’extension limitee au compartiment anterieur du genou, la synovectomie arthroscopique est une alternative possible a l’arthrotomie.

Douleurs osseuses épiphysaires et tacrolimus après transplantation rénale : à propos de 2 cas

Resume Nous rapportons 2 cas de greffes renaux sous tacrolimus ayant presente un syndrome douloureux des genoux au premier et troisieme mois de greffe. Le tacrolimus est un immunosuppresseur agissant, comme la cyclosporine, par inhibition de l’activite phosphatasique de la calcineurine. Ce syndrome semble similaire a celui decrit en 1989 avec la cyclosporine. La scintigraphie osseuse montre des hyperfixations des epiphyses douloureuses, et l’imagerie par resonance magnetique des modifications du signal en faveur d’un œdeme medullaire. Si les taux residuels de tacrolimus ne sont pas trop eleves, la diminution de posologie ne semble pas toujours necessaire. L’evolution est favorable en quelques mois. La surveillance radiologique doit eliminer une osteonecrose. Les hypotheses pathogeniques sont evoquees. L’utilisation du tacrolimus etant encore recente, il est utile que les observations similaires soient rapportees.

Fracture de contrainte longitudinale du tibia et insuffisance osseuse après transplantation rénale

Resume Nous rapportons un cas de fracture de contrainte longitudinale du tibia revelant une insuffisance osseuse chez un patient de 50 ans, transplante renal a l’âge de 38 ans. Les particularites epidemiologiques et cliniques de ce type de fracture de contrainte sont resumees, ainsi que les indications de l’imagerie. L’insuffisance osseuse apres transplantation renale est un probleme frequent, concernant jusqu’a 1 patient sur 2 a long terme. Les principales causes sont l’osteodystrophie renale preexistante, la corticotherapie, l’hyperparathyroidie residuelle ou secondaire a une fonction imparfaite du greffon. Le role de la ciclosporine sur le metabolisme osseux reste encore imprecis. Les criteres de selection des patients les plus a risque de fracture et les possibilites de traitement preventif precoce sont discutes.

Brachydactylie et ostéocondensation des phalanges distales au cours d’une hyperparathyroïdie secondaire

Resume Les auteurs rapportent un cas d’hyperparathyroidie severe, responsable d’acroosteolyse des phalanges distales, chez une patiente en insuffisance renale chronique. La recuperation apres parathyroidectomie s’est accompagnee d’un raccourcissement d’environ 1/3 de la longueur des phalanges distales, avec osteocondensation globale de certaines phalanges et deformation en forme de bec des pouces. Il s’agit d’un aspect radiographique devenu rare du fait de la meilleure prise en charge therapeutique actuelle de l’osteodystrophie renale. Les auteurs discutent la physiopathologie de ces modifications osseuses et rappellent brievement les autres causes d’osteocondensation phalangienne distale.

Distal phalangeal brachydactyly and osteosclerosis in a case of secondary hyperparathyroidism.

A case of severe hyperparathyroidism (HPT), secondary to chronic renal failure, with massive distal phalangeal osteolysis is reported. After parathyroidectomy, brachydactyly and osteosclerosis of the distal phalanges were observed; the phalanx of the thumbs healed with shortened and sclerotic beaked appearance. These radiographic findings are actually uncommon because of more efficient treatment of renal osteodystrophy. Pathophysiology of this bone sclerotic lesion is discussed, and other causes of distal phalangeal osteosclerosis are mentioned.