Hydatid Disease of the Knee Joint: Osseous and Extraosseous Involvement

Tibial hydatidosis: a case report

“…However, bone hydatidosis is a very rare entity accounting for 0.5 to 2.5% of total cases, as most larvae are trapped by the liver and lung upon release of embryo in to the portal circulation [1–5]. It occurs most commonly in the spine (35%) and pelvis (21%), with long bone involvement of the femur (16%) and tibia (10%) seen less commonly [3, 4, 6]. …”

“…Diagnosing bone hydatid disease is more challenging and often made at an advanced stage intraoperatively, as most cases do not have a specific clinical features and imaging characteristics, and are often asymptomatic [1, 2, 5, 6, 9, 10]. Preoperative diagnosis is primarily made by imaging studies like X-ray, Computed tomography (CT) scans and Magnetic Resonance Imaging (MRI) [3–5].…”

“…Progression of the disease takes place in 2 forms: formation of diverticuli and exogenous vesiculation [5]. Although CT scan is valuable in depicting hydatid cysts, MRI is the most helpful technique, especially in the soft tissue involvement and spine [1, 6]. However, sometimes it is not possible to differentiate hydatid cyst appearance from malignancy [6].…”

“…Although CT scan is valuable in depicting hydatid cysts, MRI is the most helpful technique, especially in the soft tissue involvement and spine [1, 6]. However, sometimes it is not possible to differentiate hydatid cyst appearance from malignancy [6]. CT scan shows well-defined single or multiple cystic lesions that may cause cortical thinning without contrast enhancement.…”

“…Once they escape the filtering action of the lungs and the liver, the embryos finally reach the general circulation to involve the brain, kidneys, bones, and other tissues [2]. Echinococcosis of the bone is extremely low as most larvae are trapped by the liver and the lungs upon release of embryo in to the portal circulation [1, 3–6]. This accounts for only 0.5 to 2.5% of all human hydatidosis [1, 3–5].…”