week 3.1 disorders Metabolic, rheumatic and degenerative muscle and bone disorders

myopathy - def + common symptoms, treatment

• Definition: disease of the muscles → muscle fibres do not function properly

• Symptoms:

  • Proximal, symmetric limb weakness (reflexes & sensation preserved)

  • Muscle pain

  • Muscle enlargement or atrophy

• Treatment: symptom management → cause-specific therapy

Inherited myopathies – main types? (5)

• Dystrophies: cycles of muscle degeneration & regeneration

• Congenital myopathies: microscopic muscle changes

• Mitochondrial myopathies: defects in mitochondrial function

• Inflammatory myopathies: autoimmune-mediated

• Metabolic myopathies: biochemical metabolism defects affecting muscle

Acquired myopathies – main types?

• Drug/alcohol-induced myopathy

• Glucocorticoid myopathy: steroids ↑ muscle protein breakdown → atrophy

• Other toxic agents

• Inflammatory:

  • Dermatomyositis: muscle weakness + skin changes

  • Polymyositis: inflammation of many muscles

  • Inclusion body myositis: slow progressive → hand grip & knee weakness

muscular dystrophy - def and key features

• Definition: hereditary, progressive muscle diseases

• Features:

  • Progressive skeletal muscle weakness

  • Defects in muscle proteins

  • Death of muscle cells/tissue

  • Often multi-system involvement

what are the types of muscular dystrophy

• Duchenne: onset before 5 years → rapid progression

• Becker: onset early childhood → adulthood → slower progression

fibromyalgia - def + key features

• Definition: chronic muscle and connective tissue pain

• Other symptoms:

  • Debilitating fatigue

  • Sleep disturbances

  • Joint stiffness

  • swallowing bad

myasthenic gravis def, cause?

• Definition: autoimmune neuromuscular disease → fluctuating muscle weakness & fatiguability

• Cause: antibodies block acetylcholine receptors

• Pattern: muscles weaken with activity, improve after rest

Osteogenesis Imperfecta – definition & cause?

• defective type I collagen synthesis → brittle bones weak connective tissue

Osteogenesis Imperfecta – key manifestations?

• Extreme skeletal fragility → frequent fractures

• Thin, poorly developed bones

• Short limbs

• Soft cranium with bifrontal prominences

• Other connective tissue problems (e.g., joint laxity, blue sclera)

Osteogenesis Imperfecta – treatment strategies?

• Bisphosphonates: ↑ cortical bone width → increased bone strength

• Physiotherapy: strengthen muscles, improve mobility

Osteochondrosis – definition & key feature?

• joint/bone diseases in children & adolescents

• interrupted blood supply to bone,

Osteochondrosis – main classifications & examples?

• Spinal: Scheuermann’s disease

• Articular: Legg-Calvé-Perthes disease

• Non-articular: Osgood-Schlatter disease

Scheuermann’s Disease – definition & pathology?

• vertebrae grow unevenly i

• Results in “wedged” vertebrae → thoracic kyphosis

• Loss of vertebral height may occur

Scheuermann’s Disease – clinical features?

thoracic vertebrae deform, back pain, hunchback

legg-calve-perthes disease- def + pathology

bone death of proximal femoral epiphisis

unkown cause
Manifestations: short stature; hip, knee, or groin pain worsened by movement; reduced hip ROM;
Treatment:, braces, physiotherapy, surgical intervention

Osgood-Schlatter Disease – definition & pathology?

Condition: microfractures at the patellar tendon insertion on the tibial tubercle
“ growth periods”

Osgood-Schlatter Disease – manifestations & treatment?

Manifestations:

anterior knee pain; inflammation/thickening of patellar tendon; swelling, tenderness, prominent tibial tubercle

Treatment:

activity limitation; tibial bands/braces; anti-inflammatories and cold therapy

Scoliosis – definition

lateral deviation of the spine, may include rotation/deformity

Scoliosis – congenital & neuromuscular types?

• Congenital: vertebral formation/segmentation defects (hemivertebra, wedge vertebra)

• Neuromuscular: cerebral palsy, myelodysplasia, Duchenne MD

Scoliosis – manifestations, treatment?

Manifestations: deformity, usually painless, may cause shortness of breath

Treatment: braces, surgery, physiotherapy

Osteopenia – definition

reduction in bone mass greater than expected for their age, race, or gender

Osteoporosis – definition & pathology?

loss of mineralised bone mass and increased bone porosity
due to

imbalance between bone resorption and formation

Osteoporosis – risk factors?

• Personal: advanced age, female, postmenopausal, family hx

• Lifestyle: sedentary, low calcium/nutrition, smoking, excess alcohol & caffeine

• Drugs/disease: diabetes, malignancy

primary feature of an osteoporotic bone?

low bone mass with microarchitectural deterioration
→ increased porosity and fragility
→ reduced bone strength and higher fracture risk

Osteoporosis – manifestations?

loss of trabeculae, cortical thinning, increased fractures, vertebral compression, wedging

Osteoporosis – diagnosis?

Bone mineral density (BMD) assessment using DEXA scan

Osteomalacia vs Rickets – definition?

softening of bones due to undermineralisation (no bone loss)
Feature: ↓ bone mineral content
Rickets: children
Osteomalacia: adults

Osteomalacia – causes?

• ↓ calcium absorption,

• phosphate deficiency,

• malnutrition

Osteomalacia – manifestations?

weak, soft bones;

bone pain;

muscle weakness
Hypocalcemia
Fractures

Osteomalacia – treatment?

• Treat underlying cause

• vitamin D supplementation

Rickets – cause?

vitamin D deficiency

Rickets – manifestations?

• Bone pain/tenderness

• muscle weakness,

• increased fractures

• Skeletal deformities: bowed legs, knock-knees, “windswept knees”

• Cranial,

• Hypocalcemia

Rheumatoid Arthritis – definition & pathology?

Condition:

• systemic inflammatory disease,attacks synovial joints
  women more likely

• Pathology:

• inflammation of joint capsule - , excess synovial fluid, and fibrous tissue formation → joint damage

Rheumatoid Arthritis – what is it + pathogenisis

• autoimmine disease where immune system attacks synovial joints

• synovial inflamation leads to joint erosion and deformity

Rheumatoid Arthritis – what joints, what level of inflamaiton

small joints , high inflamaiton

Rheumatoid Arthritis –manifestations?

• morning stiffness

• swollen joints

• fatiugue

• progressive decrease in ROM

Rheumatoid Arthritis – diagnosis?

morning stiff
swelling of >3 joints for >6 weeks
X-ray changes

Rheumatoid Arthritis – treatment?

rest, splints, ROM exercises, hot/cold therapy surgury

Spondyloarthropathies – definition

inflammatory disorders primarily affecting axial skeleton/spine with the absense of the rhumatoid factor

Ankylosing Spondylitis – definition & pathology?

• pain + stiffening of the spine
  - late adolescence

• inflammatory erosion of sites where tendons attach to bone, leading to fusion of the spine.

Ankylosing Spondylitis – manifestations?

low back pain, stiffness, buttocks & hip discomfort fatigue, weight loss, low-grade fever

Ankylosing Spondylitis – diagnosis & treatment?

diagnosis: patient Hx, physical exam, xray

treatment: control pain, maintian mobility, muscle strengthening, heat, hydrotherapy

Osteoarthritis – definition

progressive loss of articular cartilage

leads to inflamation of synovial membrane

OA- risk factors?

age, gender, race, obesity

OA- joint involvement and level of inflamation

big joints, mild inflamtion

Osteoarthritis – pathogenesis?

• Cartilage changes: disruption of smooth surface, surface cracks, erosion

• Subchondral bone exposed → fragments/free bodies

• Osteophytes: abnormal bony spurs at joint margins

Osteoarthritis – manifestations?

• limit ROM

• joint instability/enlagement

• Pain: aching, poorly localized, worsens with use, relieved by rest

• Night pain in later stages

• Crepitus (joint grinding)

OA - diagnosis

patient Hx

physical examination

xray: narrowed joint space, osteophytes

OA - treatment

• no cure

• symptom relief

• some meds for pain relief

• surgical joint replacement

• physio: support joint, reduce weight, hot/cold therapy