Unicameral Bone Cyst: Diagnosis, Treatment, and Follow-Up Methods, a Multicenter Study

Background and Objectives: Unicameral bone cyst (UBC) is a benign cystic lesion originating from the metaphysis, often extending toward the diaphysis as the individual grows. It is more common in boys aged 5-15 years, typically affecting long bones like the humerus and femur. UBC is usually asymptomatic and found incidentally on imaging, with pathological fractures being a common complication. Treatment options include conservative observation, percutaneous injection, and surgery. This study aims to compare the diagnostic, treatment, and follow-up processes of UBC cases across multiple centers in our country. Materials and Methods: This study reviewed 180 UBC cases in patients aged 0-20 from seven clinical centers in our country. Patient demographics, symptoms, diagnostic methods, treatment approaches, and follow-up data were collected. Radiological and histopathological diagnostic accuracy, treatment methods (conservative, percutaneous injection, surgical), and recovery were analyzed using Musculoskeletal Tumor Society (MSTS) scores and Capanna criteria. Results: Among 180 patients, 50% had pain. Most diagnoses were made through radiographic imaging, with 96.1% diagnostic accuracy. The humerus (44.7%) and femur (30.7%) were the most commonly affected bones. Pathological fractures were found in 35% of cases. Treatment included conservative (19%), percutaneous injection (31.8%), and surgery (49.2%). The average follow-up period was 81 months, with early complications being skin issues and late complications primarily limb shortening. Conclusions: The study highlights the effectiveness of different treatment approaches for UBC, showing that surgical treatment offers the best clinical outcomes, while percutaneous injection is a less invasive option. Treatment should be tailored to individual patient needs.