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Lordosis, kyphosis, and scoliosis
Osteomalacia and rickets
Paget disease of bone
Calcium pyrophosphate deposition disease (pseudogout)
Juvenile idiopathic arthritis
Inclusion body myopathy
Degenerative disc disease
Spinal disc herniation
Achilles tendon rupture
Anterior cruciate ligament injury
Iliotibial band syndrome
Patellar tendon rupture
Patellofemoral pain syndrome
Carpal tunnel syndrome
Thoracic outlet syndrome
Radial head subluxation (Nursemaid elbow)
Rotator cuff tear
Lambert-Eaton myasthenic syndrome
Limited systemic sclerosis (CREST syndrome)
Mixed connective tissue disease
Systemic lupus erythematosus
Developmental dysplasia of the hip
Osgood-Schlatter disease (traction apophysitis)
Slipped capital femoral epiphysis
Back pain: Pathology review
Bone disorders: Pathology review
Bone tumors: Pathology review
Gout and pseudogout: Pathology review
Muscular dystrophies and mitochondrial myopathies: Pathology review
Myalgias and myositis: Pathology review
Neuromuscular junction disorders: Pathology review
Pediatric musculoskeletal disorders: Pathology review
Rheumatoid arthritis and osteoarthritis: Pathology review
Scleroderma: Pathology review
Seronegative and septic arthritis: Pathology review
Sjogren syndrome: Pathology review
Systemic lupus erythematosus (SLE): Pathology review
Osteomalacia & Rickets
Bone softening caused by a faulty process of bone mineralization manifests as either rickets in children or osteomalacia in adults.
Inadequate bone mineralization could be due to a deficient or impaired metabolism of vitamin D, phosphate or calcium.
But first, a bit about bones. Now, long bones, like the femur, are made up of two epiphyses, which are its ends, and the diaphysis, which is the shaft.
Between each epiphysis and the diaphysis, there’s a region called the metaphysis.
And the metaphysis contains the epiphyseal plate, or the growth plate, which is the part of the bone that grows during childhood.
Once growth stops, the growth plate is replaced by an epiphyseal line, and this is known as epiphyseal closure.
Now, for bones to grow and develop properly, special bone cells, called osteoblasts, are hard at work.
To build bone, osteoblasts secrete osteoid, which is an organic matrix made of type 1 collagen.
These collagen fibers are the framework for the osteoblasts' work.
Osteoblasts then deposit calcium and phosphate crystals into the framework.
This process is called bone mineralization, and it confers strength to the growing bones.
Bone mineralization is dependent on an enzyme called alkaline phosphatase - which increases in response to osteoblast activity.
So, at the end of the day, bones are like a storage warehouse for calcium and phosphate.
Now, the levels of calcium and phosphate in the bone, but also in the blood, are regulated by vitamin D and parathyroid hormone, or PTH.
Vitamin D-wise, two steps are necessary for optimal metabolism: first, there must be enough vitamin D in the body, either from food, or created in the skin in response to sunlight exposure.
Rickets and osteomalacia are conditions characterized by bone softening due to a calcium deficiency or lack of vitamin D. The main difference between the two is the age at which they occur. Osteomalacia affects adults, whereas rickets affects children.
The key symptoms are diffuse bone and joint pain, proximal muscle weakness, bone fragility, and increased risk of fractures with minimal trauma. For rickets, there may also be craniotabes( softening and thinning of skull bones). The treatment typically involves vitamin D supplementation and treating the underlying cause.
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