Chronic Bone Disease in Pediatric Sickle Cell Disease Including a Case of Successful Bisphosphonate Therapy

Chelsey Grimbly; Rose Girgis; Jacob L Jaremko; Aisha Bruce

Background: Avascular necrosis (AVN) is common in Sickle Cell Disease (SCD), frequently involving the femoral and humeral head and less commonly involving the spine. AVN leads to joint collapse, chronic pain and disability, and often requires joint replacement in early adulthood. There are no medical therapies for AVN in SCD despite the high burden of disease and there are no published reports of bisphosphonate therapy in this condition.

Methods: We performed a retrospective review of our centre's cohort, looking at bone disease in pediatric patients with sickle cell disease.

Results: In our tertiary care centre, we have a pediatric cohort of 97 patients with sickle cell disease. Of these, 57% were male; age at youngest presentation was 2 years old; 86% are HgSS, 15% have bone abnormalities including AVN of the femur, humerus, and vertebral bodies. We had rare bone diseases including orbital hematoma, subgaleal hematoma, lytic and sclerotic lesions of the femur and pelvis, and vaso occlusive crisis of the jaw resulting in facial neuropathy. We highlight the radiographic findings and a case of successful bisphosphonate therapy.

Successful Case of Bisphosphonate Therapy:

An adolescent male with HbSS had spontaneous orbital hematoma and significant bone comorbidity including AVN of the humerus and femur. He had chronic back pain and recurrent vaso occlusive crises localized to the lumbar region. Spine XRay and MRI demonstrated avascular necrosis of multiple vertebral body involvement and significant loss of vertebral height. The patient was treated with intravenous bisphosphonate. He reported decreased pain and imaging of the vertebral bodies showed stabilization of vertebral bodies without additional deterioration.

Table 1: Summary of bone disease in a tertiary cohort
N =14 (%)	Type of bone disease
9 (64%)	Vertebral avascular necrosis including H shaped vertebral bodies, wedged vertebral bodies, and endplate irregularity
1 (7%)	Humeral AVN (unilateral)
4 (29%)	Femoral head AVN (all cases were bilateral)
5 (36%)	Other: lytic sclerotic lesions of the femurs and pelvis, orbital hematoma, subgaleal bleed, vaso occlusive crisis of the jaw causing neuropathy
Radiologic findings will be presented visually

Conclusion: Sickle Cell AVN develops in childhood and may affect the femur, humerus and spine, and joint involvement is often bilateral. In children with SCD and chronic back pain or vaso-occlusive crises localized to the back, consider avascular necrosis of the spine. There may be a role of intravenous bisphosphonates in arresting the progression of AVN in children with sickle cell disease

ESPE Abstracts

P2-34