Background: Bone cysts are tumor-like formations with varying fluid contents that resembled cavities. In flat bones, it is frequently asymptomatic until it is unintentionally found during imaging.

Objective: This study aimed to evaluate clinical and radiological results in management of benign bone cyst by using bone marrow and bone substitute composite.

Patients and methods: This study included 30 patients with benign bone cystic lesion were discovered accidentally or come with pathological fracture who were admitted to Orthopedic department, Zagazig University Hospitals. Plain radiographs were reviewed to determine the anatomic location, presence of pathological fracture, cyst size (cyst index), postoperative osseous healing, and the presence of local recurrence.

Results: Age was distributed as 17.64±6.3 and males represented 66.6%. Unicameral bone cyst was 50% then aneuresmal bone cyst type was 26.6%. The majority site was tibia with (53%). All patients were without nail except one case only fixed with nail. Only 3 cases had complication with 10% (one case with delay healing, one case with infection and one case with nonunion). Regarding progress distribution; the majority of patients were good (96.7%). There was no significant association except between complication and bad progress there was significant association between them.

Conclusion: Bone marrow and bone replacement composite management of bone cysts is a useful technique with numerous benefits as a reconstructive and reparative therapy.