~ 29 ~ International Journal of Orthopaedics Sciences 2019; 5(4): 29-31 E-ISSN: 2395-1958 P-ISSN: 2706-6630 IJOS 2019; 5(4): 29-31 © 2019 IJOS www.orthopaper.com Received: 16-08-2019 Accepted: 20-09-2019 Dr. Chander Mohan Singh Department of Orthopaedics, Armed Forces Medical College, Pune, Maharashtra, India Dr. Rajiv Kaul Department of Orthopaedics, Military Hospital, Kirkee, Maharashtra, India Dr. Mohammed Schezan Iqbal Department of Orthopaedics, Armed Forces Medical College, Pune, Maharashtra, India Correspondence Dr. Rajiv Kaul Department of Orthopaedics, Military Hospital, Kirkee, Maharashtra, India Prophylactic curettage and internal fixation for a benign cystic lesion of the proximal femur: A case report Dr. Chander Mohan Singh, Dr. Rajiv Kaul and Dr. Mohammed Schezan Iqbal DOI: https://doi.org/10.22271/ortho.2019.v5.i4a.1642 Abstract Unicameral bone cyst (UBC) is a benign, expansile, non-neoplastic bony lesion characterized by spaces that are separated by fibrous septae. These sometimes may threaten the architectural strength of the proximal femoral trabaecular arrangement because of the destructive effect of the cyst on the bone and the propensity to develop into a pathological fracture, especially under the influence of weight-bearing. We report a case of a solitary bone cyst in the proximal femur in a 15 year old girl, which was treated with curettage, synthetic bone grafting and prophylactic internal fixation with a dynamic hip screw (DHS). At 2 years follow-up, the lesion had completely healed and patient was pain-free and without any deformity. We suggest this method of treatment to be ideal for UBCs at this site, especially in the skeletally immature. Keywords: Proximal femur, unicameral bone cyst, curettage, prophylactic fixation Introduction The proximal femur is a common site of occurrence of a number of benign bony lesions like unicameral (UBC) and aneurysmal (ABC) bone cysts. UBCs are true cysts with unknown origins. They occur more frequently in males and are usually diagnosed in the first 2 decades [1] . Pathological fractures and incidental finding are the most common presentations. Frequent locations include the proximal humerus and proximal femur in children [2] . Radiographically, they appear as radiolucent central metaphyseal lesions with mild expansion and a narrow zone of transition. UBCs often abut growth plates and move away with skeletal growth. A ‘fallen leaf’ sign, where a fracture fragment falls to the dependent portion of the lesion, is seen in approximately 5% of lesions [3, 4] . Loculations and pathologic fracture can best be appreciated on CT. MRI shows low T1 and high T2 signal with rim enhancement typical of a cyst. A single layer of mesothelial cells comprises the cyst wall and is seen in conjunction with pressurized serous fluid on histology [5] . UBCs tend to elongate with skeletal growth and then spontaneously fill-in at maturity. Patients with large lesions at a young age or pathological fractures should be considered for surgical treatment. Aspiration of the fluid for cytologic diagnosis, followed by injection of various substances like sclerosants, steroids, bone marrow aspirate, and demineralized bone matrix can be done to try and stimulate healing and spontaneous filling [6] . Curettage and grafting with or without internal fixation is performed in older children and adolescents. UBCs in high-risk locations such as the femoral neck are treated with weight bearing and/or activity restrictions, aspiration and injection, or curettage with either placement of allograft cortical strut (younger patients) or internal fixation (Postpubertal) [7] . Case report A young female, aged 15 years, presented to our tertiary care center in western Maharashtra with insidious onset, dull aching pain in the right hip, aggravated by walking and physical activity and relieved by rest, without any history of constitutional symptoms. On examination, she had painfully restricted hip abduction and internal rotation.