Non-spinal Hydatid Disease of Bone: A Series of Nine Cases.

Background: Extra-spinal osseous hydatid disease is reported in a small number of case series. In the present study, we report our experience with extra-spinal hydatid disease of the bone in a series of nine patients. Methods: In this retrospective study, the patients who were diagnosed with an extra-spinal osseous hydatid disease were included. All patients were treated surgically. Preoperative anthelmintic drugs were employed for the cysts that were diagnosed before the operation. Postoperative chemotherapy was performed for all patients. Results: The study population included nine patients, including seven males and two females, with a mean age of 45.2±7.9 years and an average follow-up of 4.1±2.7 years. Non-specific pain was the most common symptom at presentation. Pelvic bones were the most frequent site of involvement. Serologic tests were false negative in seven patients. The disease was diagnosed preoperatively in five patients, and all of them were located in flat bones. The cysts were treated by radical excision in four patients, extended curettage in four patients, and amputation in one patient. The recurrence of the lesion was recorded in two patients who were treated by intralesional curettage. One case of suppuration was the only postoperative complication of this series. Conclusion: Osseous hydatid disease is a serious disease with challenging diagnosis, difficult treatment, and significant morbidity. Preoperative diagnosis is generally easier in flat bones. Radical resection is the optimal treatment of this disease, while non-radical resection is associated with a higher risk of recurrence.