Sequelae & Complications
Secondary consequences of the disease
Sequelae: Lasting or long-term effects of the condition
Complications: Unexpected consequences or outcomes that result due to the disease or treatment
Cranial Complications
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Temporomandibular joint ankylosis: stiffening or immobility of jaw due to fusion of joint
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Trouble eating or speaking
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​​​Severe weight loss
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Common in late stages of FOP
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Hearing impairment
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Seen in ~50% of FOP patients
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Usually occurs in childhood or adolescence
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Possible causes: middle ear ossification or neurologic
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Treat with hearing aid
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Hair loss or mild cognitive delay in major forms of FOP
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Mobility and Pain​
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Progressive stiffness and pain in affected joints and areas
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As disease progresses, patients experience increased limited mobility, which can result in:
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balance issues​
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difficulty walking/sitting
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restricted movement
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Can result in complete immobilization
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Entrapment​ neuropathies: abnormal bony growths compress nerves, causing pain, numbness, and/or weakness in areas
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Usually confined to a wheelchair in 30s and require lifelong assistance
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Other Sequelae & Complications​​
​Progressive Spine Deformity
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Scoliosis: side-to-side curvature​
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Kyphosis: front-to-back curvature
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Kyphoscoliosis: excessively abnormal curvature in multiple planes - combination of scoliosis, kyphosis, and spinal rotation
Kidney Stones
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Immobilization with increased bone turnover is a significant risk factor​
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Source: Wix.com
Submandibular Heterotopic Ossification & Swelling
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Relatively uncommon
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Swelling can be life-threatening, especially when associated with massive anterior neck swelling and difficulty swallowing
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Recommend efforts to reduce swelling, including treatment with glucocorticoids and respiratory support
​Thoracic Insufficiency Syndrome (TIS)
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Life-threatening complication of cardiopulmonary function
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​​Increased susceptibility to respiratory infection or right sided congestive heart failure
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Associated with fusion of joints between ribs and spine, ossification of muscles around ribs and spine, and progressive spinal deformity
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Ways to reduce morbidity and mortality from TIS in patients with FOP:
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Maximize pulmonary function and minimize respiratory compromise using prophylactic measures
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Prevent and treat any infections via vaccinations (subcutaneous injection) and antibiotics
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Use positive pressure assisted breathing without the use of supplemental oxygen
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Avoid upper abdominal surgery as it interferes with diaphragmatic respiration
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Avoid unmonitored supplemental oxygen - can cause death by sudden correction of oxygen tension
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Fatal Sequelae and Complications
Source: DALL-E AI Image Generator
Knowledge Check
Questions
Question 1.​​ What is a common sequelae/complication of abnormal bone development in FOP?
A) Increased joint flexibility
B) Stiffness and limited movement
C) Faster healing of fractures
D) Strengthened muscles
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Question 2. Why can FOP lead to severe weight loss?​
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A) Increased metabolism
B) Difficulty digesting food
C) Ankylosis of the jaw
D) Increased mobility
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Question 3.​ What is a major complication that results from thoracic insufficiency syndrome (TIS)?
A) Kidney failure
B) Right-sided heart failure
C) Liver damage
D) Brain hemorrhage​​​​​
Question 4.​ True or False.
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Patients with FOP should receive vaccinations via subcutaneous injection instead of intramuscular injection.​
Question 5.​ True or False.
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Surgery is a reliable and effective treatment for people with FOP.​