A 44 year old female with a primary diagnosis of Sickle Cell Disease presented with a one month history of lumbar back pain
A 44 year old woman with a primary diagnosis of sickle cell disease presented to her GP with a one month history of lower back pain after a sickle crisis. She was already known to the Orthopaedic team, whom she was under 5 years previously, with chronic left hip pain.
The GP suspected possible disc disease and sent the patient for a MRI of her lumbar spine.
Questions:
1) What signs can be seen on MRI in a patient the Sickle Cell Disease
2) What is the cause of her lower back pain?
3) What was the nature of her previous left hip pathology
1) Sickle Cell anaemia causes destruction of red blood cells stimulating greater production. This occurs within the bone marrow, specifically red marrow, which is present in large quantities in children. As we age, our red bone marrow is converted to yellow or fatty marrow. Sickle Cell causes the persistence and expansion of the body's red marrow. This can be seen with the vertebral bodies on MRI
Fig. 1a is a T1 weighted sagittal image of the lumbar spine and shows some of the musculoskeletal manifestations of sickle cell disease. It shows intermediate to low signal bone marrow, similar to the signal produced by the intervertbral discs. This is a sign of a hypercellular marrow. The marrow should be fatty so return high signal on T1 (Fig 1b)
This hypercellular marrow leads to cortical thinning and bone softening. In this case it results in multiple end plate changes (Schmorl's nodes).
2) The sickling of red blood cells in the bone marrow can lead to infarction and this can happen anywhere in the skeleton. Infarcts often occur in medullary cavities and the epiphyses of children. Infarcts commonly affect the hands and feet of children causing dactylitis and the long bones leading to pathchy intramedullary sclerosis and lucency.
The spine is more often affected in adults and causes vertebral endplate ischaemic changes. Fig. 3 demonstrates abnormal heterogenous signal and oedema of the L5 inferior endplate from a subacute infarction. Specifically the imaging shows asymmetrical endplate change which has a serpiginous quality, characteristic for avascular necrosis. These asymmetrical findings help differentiate AVN from simple Modic endplate change.
The second important differential diagnosis to consider in Sickle Cell patients is discitis or infection of the intervertebral disc, to which these patients are prone. The findings in discitis include high signal in the intervertebral disc on T2WI or STIR, endplate irregularity, oedema or destruction and often a surrounding soft tissue element. Neither of these are present in this case.
Finally the patient's back pain could be due to the small disc bulge shown on the sagittal T2WI. With the onset of pain after the last sickle crisis and the evidence of AVN elsewhere, the patients symptoms were thought most likely to be secondary to the demonstrated infarct than the visualised disc extrusion.
3) Epiphyseal ischaemic necrosis of the femoral heads is common and leads to avasular necrosis by the age of 35 years in 50% of those affected. This patient has undergone a left total hip replacement (Fig. 4) at an early age due to AVN of the left femoral head. This is another complication of an infarct caused by sickle cell disease.
Vertebral body infarct secondary to a sickle cell crisis
Based on the provided lumbar MRI and pelvic X-ray images, and in combination with the patient’s past medical history (sickle cell disease), the following main findings are noted:
Based on the above imaging findings and the patient’s history of sickle cell disease, the following differential diagnoses are suggested:
Considering the patient’s age, known history of sickle cell disease, current clinical symptoms (low back pain starting after the last sickle cell crisis), and the imaging findings showing hyperproliferative bone marrow changes in the vertebral bodies along with subacute endplate infarction (ischemic necrosis) signals, the most appropriate diagnosis is:
“Ischemic endplate necrosis (bone infarction) of the lumbar vertebrae due to sickle cell disease.”
There is no imaging evidence suggestive of infection or malignancy. To further clarify, one may correlate with serum inflammatory markers (e.g., CRP, WBC count, ESR) and follow-up MRI imaging changes.
Rehabilitation should follow a gradual and individualized approach, considering the relative fragility of bone structures, potential anemia, and limited cardiopulmonary function in these patients:
Throughout all training stages, monitoring the patient’s pain, anemia, and heart rate is critical. If any significant discomfort or signs of fractures or infection appear, discontinue exercise immediately and seek medical evaluation.
This report is based on the currently provided medical history and imaging information for reference analysis only, and cannot replace professional clinical diagnosis and physician advice. The specific diagnosis and treatment plan should be determined by a professional medical team, taking into account the patient’s actual condition.
Vertebral body infarct secondary to a sickle cell crisis
