Simple bone cysts (SBCs) are cysts filled with fluid that occur most frequently in the long bones (arms or legs) of children. There are many ways to treat SBCs but it is unclear if one is better than another. The purpose of this research trial is to compare the effectiveness of two common treatments that are used by surgeons today.

In general, few randomized clinical trials have been undertaken in paediatric orthopaedics, and only one to date has addressed the problem of simple bone cysts (SBCs). Also known as unicameral bone cysts, they are the commonest bone lesion in children. Despite general opinion, these cysts do not resolve at skeletal maturity.

Many forms of treatment have been recommended but none, including the popular methods of corticosteroid or bone marrow injections, have reliably eradicated SBC. Although the lesions are considered benign (non-cancerous), they cause pain, frequently interfere with function, dramatically restrict play activity, may re-fracture leading to growth arrest and/or deformity, and cause enormous anxiety for children and their families.

With a well-developed network of surgeons and researchers, we will provide evidence comparing the effectiveness of two treatment interventions for SBC. More specifically, our goals for this study are:

1. to compare the rate of radiographic healing between two standard treatments including curettage with puncture alone, and curettage with puncture followed by injection with Vitoss morsels;
2. to identify prognostic radiographic factors associated with simple bone cyst healing and fracture;
3. to determine the impact of simple bone cyst on children/family functioning.

Inclusion Criteria:

• Patients with a confirmed simple bone cyst in a long bone (ie. arm or leg) within last 3 months
• At least 3 weeks must have elapsed since last fracture
• At least 3 months must have elapsed since last cyst treatment
• Patients and/or their legal representatives willing to provide written informed consent (and assent, when appropriate)
• Patients with stabilizing implants in the bone where the cyst is located

Exclusion Criteria:

• Patients with bone disease (ie. osteogenesis imperfecta, cancer, osteoporosis, Paget's disease)
• Pregnant or breastfeeding female
• Patients with cysts crossing the growth plate (area where bone grows)