Outer, hard covering of bones
Cortical or compact bone
Inner, mesh-like region of the bone
Trabecular or spongy bone
Stronger deposition of collagen in bone. Collagen fibers vary in orientation to better withstand stress
Lamellar
irregular arrangement of collagen fibers leads to weaker bone; found during embryonic development and fracture healing; later converts to lamellar form
Woven
deposition of calcium crystals that harden the bone, giving it strength
Mineralization
mesenchymal origin, secrete matrix and alkaline phosphatase, activateosteoclasts. Ultimately form periosteum or become osteocytes within matrix
Osteoblasts
originate from monocytes/myeloid lineage—fuse into multinucleated cells that travel along bone surface until reaching microfractures; carry out bone resorption, creating a cavity—after which they die by apoptosis
Osteoclasts
Fracture type-communicates with air through skin or mucous membrane
Open
Fracture type-skin may be broken, but bone does not communicate with air
Closed
Fracture type-one fracture line, two bone fragments
Simple
Fracture type-more than one fracture line, multiple fragments
Comminuted
Fracture type-bone segments are out of alignment
Displaced
Fracture type-slowly develops upon repeated increased loads
Stress fracture
Fracture type-periosteum remains intact on one side
Greenstick
Fracture type-in context of preexisting osteoporosis, osteomyelitis, tumor invasion
Pathologic fracture (spontaneous, noninjury induced)
Fracture type-piece of bone comes off with attached tendon
Avulsion
Stages of fracture healing
1. inflammation and fracture hematoma 2. Fibrocartilaginous callus 3.Bony callus formation 4. Bone remodeling
Timeline for complete fracture healing
up to 1 year
Fracture complication- failure of fracture healing
disunion/pseudoarthrosis. Usually due to excessive load or deficient blood supply
Fracture complication-Infection of fracture site
Associated with open fractures, malnutrition and immune compromise
Fracture complication- Reduced mobility
Atrophy of muscles after casting. Rapid loss after injury is followed by slow recovery after activity can be resumed
Fracture complication-result of prolonged immobility
Muscle contractures
Assessment of joints during physical examination
1.Active and passive range of motion 2.degrees of movement 3.pain 4.laxity 5.instability
Components of Synovial Joints- Basic components
2 articulating bones and cartilage
Purpose of cartilage
Reduces friction between articulating bones
Components of Synovial Joints-holds the joint together, is lined by the synovial membrane
Articular capsule
Components of Synovial Joints-Lubricates the joints
synovial fluid
Components of Synovial Joints-Extends from one bone to the other across the joint, for stabilization
Ligament
Components of Synovial Joints-small pouches of fluid for cushioning (in some joints)
Bursae
Components of Synovial Joints-surround muscle tendons, protecting them during movement
Tendon sheaths
Components of Synovial Joints-additional fibrocartilage pad in some joints—additional cushioning
Menisci
Joint movement-away from the midline of the body
Abduction
Joint movement-Toward the midline of the body
Adduction
Joint movement-circular or cone shaped movement available at ball and socket joints.
Circumduction
Joint movement-the angle of the joint increases or the return from flexion
Extension
Joint movement-the angle of the joint decreases or the return from extension
Flexion
Joint movement-Rotating towards the midline
Medial or internal rotation
Joint movement-rotating away from the midline of the body
Lateral or external rotation
Joint movement-foot moves toward the shin
Dorsiflexion
Joint movement-foot moves away from the shin
Plantar flexion
Joint movement-sole of the foot faces the midline
Inversion
Joint movement-sole of the foot faces away from the midline
Eversion
Joint movement-palm of the hand facing downward
Pronation
Joint movement-palm of the hand facing upward
Supination
stretching injury to a musculotendinous unit
Strain
stretching injury that tears ligaments
Sprain
Grade of sprain-ligament microtears, little swelling, no instability, littlefunctional loss
Grade 1
Grade of sprain-partial ligament tear, more swelling, tenderness, disability
Grade 2
Grade of sprain-complete ligament rupture, severe swelling and tenderness,joint instability, and functional loss
Grade 3
Difference between strain and sprain
Quickness of recovery. Strain is faster than sprain. Joint laxity is a good evaluation for grade of sprain
Most common ankle sprain
Lateral, due to foot inversion
Knee anatomy-within the joint, provide stability
Anterior and posterior cruciate ligaments (ACL and PCL) hold bones together
Knee anatomy-cushioning
Medial and lateral menisci
Knee anatomy-Additional support
Medial and lateral collateral ligaments
Knee sprains
Medial or lateral collateral ligaments (hinging on side of injury). Cruciate ligaments (ACL or PCL) give positive drawer sign (on side of injury)
Meniscus injuries
Caused: rotational flex when knee is semi-flexed and bearing weight
Symptoms: joint line tenderness, effusion and locking
Diagnosis: MRI or arthroscopy
Where spinal nerves exit the spine
Intervertebral foramen
Awkward positions for prolonged times, coupled to movements that overuse some muscles and underuse others, lead to inflammation, decreased blood supply, nerve damage, and tendon irritation
Repetitive stress injury or cumulative trauma disorders
A repetitive stress injury of the wrist, culminating in compression neuropathy of the median nerve within the carpal tunnel, findings in the median nerve distribution
Carpal Tunnel Syndrome
Symptoms of Carpal Tunnel Syndrome
Pain, paresthesia, thenar muscle atrophy and weakness of thumb abduction
Hallmark of trigger finger
Finger may have “catching” sensation before it locks
Hallmark of hip bursitis
Worse at night and when lying on affected side . Common among runners and people who spend long periods of time on their feet
Concern with epiphyseal fractures
Growth plate (epiphysis) fracture can result in short bone length
Inflammation of tendon/physis connection
Apophysitis
Repetitive stress injuries produce apophysitis
at tibial tubercle-Osgood-schlatter disease at inferior patella-jumper's knee
Absent production or abnormal forms of dystrophin, a muscle cell cytoskeletalprotein
Muscular dystrophy (MD)
Two types of muscular dystrophy
Duchenne MD-more severe, earlier progression to death Becker MD-less severe, slow progression
bone disease that develops when bone mineral density and bone mass decreases, or when the structure and strength of bone changes. Common in both men and women
Osteoporosis
gradual loss of muscle mass
Sarcopenia
Factors contributing to sarcopenia include:
• Myosteatosis—fat accumulation in muscles• Decreased mitochondrial function• Degradation of myofibrils• Decreased innervation• Metabolic alterations
Complex form of arthritis caused by too much uric acid that crystallizes and is deposited in joints
Gout
Major factor in gout
imbalance of uric acid production and uric acid excretion
Symptoms and diagnosis of gout
Monosodium urate crystals are deposited in joints, eliciting robust inflammation with swelling, pain, and redness. Synovial fluid sampling can demonstrate crystals
Axial skeleton inflammation (likely autoimmune in origin) with predominant low back pain, though pain can be felt anywhere in the body d/t nerve inflammation
Spondyloarthritis
Joints most affected by spondoyloarthrits
sacroiliac and zygapophyseal