Ultrasound machine was no longer approved for use by Health Canada therefore study was closed prior to patients being enrolled on study.

Simple bone cysts (SBCs), also known as unicameral bone cysts (UBCs), are benign bone lesions. Literature to date describes little agreement between clinicians on specific prognostic criteria for the prediction of cyst healing, recurrence or fracture. Evidence has shown that bone mineral density (BMD) is a reliable indicator of risk to SBC patients given its association with the mechanical properties of bone. There has been further exploration into the use of quantitative ultrasound to assess bone density by measuring the velocity of the ultrasound transmission over the bone. To determine whether the QUS can provide prognostic information with respect to cyst healing, recurrence or fracture with a SBC, further study is needed.

Arm 1 - Simple Bone Cyst Patients

Inclusion Criteria

1. Patients ≥ 2 and ≤ 21 years
2. Patients with a diagnosis of simple bone cyst located in a long bone confirmed by imaging within 3 months prior to registration
3. All patients and/or their parents or legally authorized representatives must sign a written informed consent. Assent, when appropriate, will be obtained according to institutional guidelines.

Exclusion Criteria

1. Patients with implants to stabilize the bone where the cyst is located.
2. Patients with bone disease (i.e. osteogenesis imperfecta, cancer, osteoporosis, Paget's disease)
3. Patients who are pregnant or breastfeeding
4. Patients with a simple bone cyst crossing the growth plate

Arm 2 - Healthy Controls

Inclusion Criteria

1. Patients ≥ 2 and ≤ 21 years
2. All patients and/or their parents or legally authorized representatives must sign a written informed consent. Assent, when appropriate, will be obtained according to institutional guidelines.

Exclusion Criteria

1. Patients with bone disease (i.e. osteogenesis imperfecta, cancer, osteoporosis, Paget's disease)
2. Patients receiving any bone-modifying agents (i.e. steroids, bisphosphanates, etc.)
3. Patients who are pregnant or breastfeeding

Arm 3 - Fracture patients

Inclusion Criteria

1. Patients ≥ 2 and ≤ 21 years
2. Patients who have undergone any type of casting or surgical treatment for their fracture
3. All patients and/or their parents or legally authorized representatives must sign a written informed consent. Assent, when appropriate, will be obtained according to institutional guidelines.

Exclusion Criteria

1. Patients with bone disease (i.e. osteogenesis imperfecta, cancer, osteoporosis, Paget's disease)
2. Patients receiving any bone-modifying agents (i.e. steroids, bisphosphanates, etc.)
3. Patients who are pregnant or breastfeeding