General orthopedics shoulder Flashcards
anatomy of bone
-Diaphysis—shaft/hollow tube of compact bone
-Epiphysis—end plates of bone
-Metaphysis—area that connects diaphysis to epiphysis
-Articular cartilage—thin layer of hyaline cartilage covering the epiphysis at the articulation
-Periostium—surface of bone not covered by cartilage
-Medullar cavity—semi hollow space in diaphysis containing yellow marrow
-Endosteum—lining of medullary cavity
-Sharpey’s fibers- predominately type III collagen, perforating fibers from periosteum to cortical bone and extending to endosteum. Also, more commonly noted in tooth sockets attaching tooth base to bone. Have decreased mineralization, therefore, are not susceptible to resorption/calcification.
bone growth / histology
-Bone growth in length~~Endochondral ossification
-Bone growth in width~~Intramembranous ossification
-3 types of Bone:
-Long- Diaphysis, metaphysis, epiphysis. Cortical and trabecular bone.
-Short- Bones of the hands and feet. Cortical and trabecular bone.
-Flat- Pelvis, scapula, skull, and mandible. Varies from purely cortical to mix of cortical and thin region of trabecular bone.
**Bone mass and structure change considerably during growth, remain fairly constant during adulthood, and deteriorate in the elderly. **
bone composition
-One tissue consists of cells embedded in a fibrous organic matrix -> primarily collagen 90%, and 10% amorphous ground substance (primarily glycosaminoglycan and glycoproteins)
-Rigidity and strength of bone is derived from mineral salts that permeate the organic matrix.
-Biochemically:
-Organic substances~~35%
-Inorganic substances~~45%
-Water~~20%
-Organic (Osteoid) ~ bone cells, intracellular matrix (90% collagen fibrils)
-Inorganic (Minerals) ~ calcium phosphate, calcium carbonate, phosphorous, magnesium, sodium, hydroxyl, carbonate, fluoride
bones: cell types
-Bone contains-
-99% of total body calcium
-90% of total body phosphorus.
-Cell types :
-Osteoprogenitor
-Osteoblast ~ Bone surface cells that form bone matrix and regulate osteoclastic activity. Osteoblasts secrete type 1 collagen
-osteocyte
-Osteoclast ~ Multinucleated bone resorbing cells.
-Bone Homeostasis- Balanced bone formation and bone resorption
-Bone is not solid
-contains many spaces/channels for lymphatics, blood vessels, nerves.
-From periosteum neurovascular structures penetrate compact/cortical bone via Volkmann’s canals (horizontally), they then run vertically through the lamellae in the Haversian canal
bone remodeling
-ongoing replacement of old bone by new bone
-prevents microdamage accumulation
-bone resorbing osteoclast and bone forming osteoblasts.
-Osteoclasts- phagocyte activity prepares bone surface for remodeling -> secrete enzymes which digest collagen, and acids which dissolves minerals.
-Osteoblasts follow after resorptive process stops
-Osteoblast deposit osteoid and mineralize it to form new bone.
-Calcium and phosphorous make up hydroxyapatite ~ the primary salt that acts to harden bone
hormonal regulation of remodeling
-Human growth hormone
-Sex hormones (estrogen & testosterone)
-Insulin
-T3 and T4
-Parathyroid
-Calcitonin (regulates calcium)
bone reactions (localized)
-Stress Reaction- Precursor to stress fracture. Localized insult to bone causing inflammatory response/edema without trabecular injury. Repetition injury.
-Stress Fracture- Localized insult to bone causing significant trabecular injury. Repetition injury.
-Avascular Necrosis/Osteonecrosis- Bone death/destruction secondary to ischemia. Will see reactive/remodeling changes at area of insult which will lead to bone collapse and eventual bone death.
-Bone deposition > bone resorption = osteophyte formation
-Bone deposition < bone resorption = disuse atrophy , “spongy”
bone reactions (generalized)
-Bone deposition > bone resorption = osteopetrosis (overly dense bones), Acromegaly ( too much growth hormone)
-Bone deposition < bone resorption = osteoporosis (bone mineral density & mass decreases), rickets (Vit D deficiency), osteomalacia.
epiphysial plates
-Highly specialized cartilaginous structure through which longitudinal growth occurs.
-3 necessities for normal growth:
-Plate must be intact
-Blood supply intact
-Physical activity / pressures
reactions at growth plate: increase: generalized and localized
-Generalized:(increase)
-Gigantism
-Marfan’s syndrome
-Pituitary gigantism
-Localized:
-Chronic inflammation
-Congenital A/V malformation
-Fracture of shaft of long bone (temporary)
reactions of growth plate: decrease: generalized and localized
-Generalized: (decrease)
-Dwarfism (achondroplasia(affects fibroblast growth factor receptor) / skeletal dysplasia)
-Rickets (Vitamin D deficiency causing softening of bone)
-Localized:
-Disuse retardation
-Physical injury
-Thermal injury
-Ischemia
types of joints
-Syndesmosis~ bound by fibrous tissue, i.e. Tibiofibular, skull sutures
-Synchondrosis~ bound by cartilage, i.e. growth plate
-Symphysis~ boney ends covered by cartilage, fibrous tissue, little movement …i.e. pubic symphysis
-Synostosis~ a joint that at some point fuses and forms a bony union…most syndesmosis and all synchondrosis become synostosis
-Synovial~ hyaline cartilage, synovial capsule, free movement, fairly unstable
imaging used in ortho
-X-Ray (Best for Bones, often combined with other imaging)
-MRI
-CT Scan
-Ultrasound
-Nuclear Medicine
Adequacy, Alignment, Bones, Cartilage, Soft tissue (ABCS): Adequacy
-2 views minimum AP & Lateral (3 views preferred (oblique))
-If targeting the SHAFT (get Joint above & below)
-If targeting a JOINT (get Midshaft above & midshaft below)
-All x-rays should have an adequate number of views.
-All x-rays should have adequate penetration
test
-cells
-remodeling
-deposition > remodeling vice versa
Adequacy, Alignment, Bones, Cartilage, Soft tissue (ABCS): Alignment
-compare to contralateral side
-Alignment relative to proximal & distal bones
-Fractures & dislocations may affect alignment
-describe distal part in reference to proximal part. e.g: Valgus means the distal part is lateral to the proximal part.
-2 things to comment on -> 1. The distal part of the bone relative to the proximal part. 2. At the level of the joint, the distal bone relative to proximal bone. E.g.: Genu valgus- tibia is lateral relative to the femur
Adequacy, Alignment, Bones, Cartilage, Soft tissue (ABCS): Bones
-Identify Bone
-Examine the whole bone for:
-Discontinuity- factures or lytic changes at the cortex
-Change in bone shadow consistency = change in density
-Describe Bone abnormality
-Location
-Shape
-In deformity we describe 2 elements:
-1. Angulation (magnitude - direction)
-2. Translation (3 components):
-a. Magnitude (0%-90%-100%)
-b. Direction - On AP (Medial or Lateral translation). On Lateral view (Anterior or Posterior) Remember describe distal relative to proximal.
-c. On AP view: deformity is described as either Varus or Valgus
-If apex of angle lateral = varus deformity
-If apex of angle medial = valgus deformity
-On Lateral view: deformity is described as either Extension of Flexion.
-If apex of angle anterior = extension deformity
-If apex of angle posterior = flexion deformity
Adequacy, Alignment, Bones, Cartilage, Soft tissue (ABCS): Cartilage
-Joint spaces on x-rays. You cannot actually see cartilage on X-ray.
-Widening of joint spaces = ligamentous injury &/or fractures.
-Narrowing of joint spaces = Arthritis
Adequacy, Alignment, Bones, Cartilage, Soft tissue (ABCS): Soft tissue
-implies to look for soft tissue swelling & joint effusions.
-Signs of:
-Trauma
-Occult fracture
-Infections
-Tumors
anterior and posterior fat pad sign:
-Represents possible fracture
-Usually not seen unless trauma
-Kids= Supracondylar fx.
-Adults= Radial head fx
-represent a trauma
-pushed out of joint
-flexed to the shaft of the radius
-apex where they meet is pointing medially (draw lines to continue each bone and see where they meet)
-complete spiral fracture
-distal part is lateral -> valgus
-this is the right knee
-varus deformity - towards midline
-A: Not Adequate. No joint above
B: Right transverse Mid-shaft fracture of the femur.
AP view: Apex of angle is lateral, varus deformity.
Lateral view: Approx: 25% posterior angulation. (Use goniometer)
C: Insignificant
S: Insignificant
intra-articular fracture of base of 1st metacarpal
A: Inadequate because only one view
B: Multiple intra-articular fragmental fracture of base of 1st metacarpal
C: Insignificant
S: Insignificant
If fracture is intra-articular the joint has to be reduced early to avoid OA.
-Often surgical.
fracture types
-“a complete or incomplete break in the continuity of bone”
-Transverse
-Avulsion
-Oblique
-Spiral
-Comminuted
-Compression
-Butterfly
-Segmented
-Greenstick
dislocation
-at the joint
-named by the position of the distal segment
-this is posterior dislocation
-ortho emergency
-affects blood and nerves
-tibia slid backward past femur
bayonet apposition
-note overlap of 2 fracture fragments
-2 segments break and overlap
angulation of fracture
fracture descriptions
-Angulated
-Distracted
-Displaced
-Impacted
-Intra articular vs. non articular
-Open vs. Closed
-AP view
-fracture line directly through falynx
-not displaced
-no angulation
-Left oblique fracture of the midshaft of the 2nd proximal phalanx with no displacement and no angulation.
-Fracture is also extra articular
fractures and healing
-broken blood vessels in periosteum, and medullary cavity
-clot or “fracture hematoma” is formed around site 6-8 hours after
-Infiltration of capillaries into the fx. hematoma organize it into granulation tissue called a Procallus.
-The Procallus is then invaded by fibroblasts and osteoprogenitor cells
-Fibroblasts produce finger like fibers in the fx. site while osteoprogenitor cells turn into chondroblasts in a vascular area just outside the fx. site. These chondroblasts produce fibro-cartilage.
-The Procallus is transformed into a fibrocartilage callus ~lasts about 3 weeks
-At this point the fibrocartilage is converted into spongy bone ~ now known as bony callus which lasts about 3-4 months
-Generally, it takes 6-8 weeks for complete fracture healing.
-Lastly the process of remodeling occurs to the bone callus for about 6 months
shoulder instability/sublux exam, work up, tx
-Exam
-Apprehension test -Ant pain vs post pain & palpable clunk (labrum tear)
-Inferior distraction - Sulcus formed & apprehension
-Anterior displacement - Assoc, pain & clunk
-Posterior displacement- Posterior pain & clunk
-X-rays - AP, Y Scapula, Axillary (birds eye to see in humerus is in socket)
-MRI / MR Arthrogram
-Treatment - Physical Therapy, Surgery (for recurrent instability)
-right picture is Y scapula view- normal
anterior glenohumeral dislocation
-Etiology: M.C.= traumatic with external rotation & abduction.
-P/E: Arm held in abduction & external rotation. Prominent acromion with loss of normal contour.
-Studies: X-rays: AP, Y Scapula, Axillary
-Hill Sachs Lesion; groove fracture of the humerus (from when the humerus traumatically hit the glenoid)
-Bankart Lesion; glenoid rim fracture
-Treatment: Reduction & Immobilization (Check deltoid pinprick for axillary nerve injury (m.c.) sensation pre & post), Physical Therapy
-Recurrent dislocations: Incidence decreases as age increases
35 year old female presents to urgent care after falling off her bike landing directly on the top of her right shoulder. She comes in complaining of pain localized over shoulder with pain at all attempts of range of motion.
P/E:
Local tenderness
Pain with motion especially adduction
Obvious deformity (sometimes)
AC joint separation
-acromion and clavicle
AC joint separation
-Acromioclavicular ligament provides horizontal stability.
-Coracoclavicular ligament provides vertical stability.
-Grade I: Normal XR. Ligament sprain
-Grade II: Slight widening. AC lig ruptured, CC lig sprained.
-Grade III: Significant widening. AC & CC lig ruptured.
-Grade IV: AC & CC ruptured. Displacement of clavicle into trapezius.
-Grade V: Class IV +disruption of clavicular attachments.
-Grade VI: Clavicle falls underneath coracoid (Very rare)
-tx-
-nothing- 1,2,3
-surgery - 4,5,6
clavicle fractures
-M.C. fx. In children, adolescents & newborns @ birth.
-Group I: midshaft, middle ⅓ (m.c)
-Group II lateral, distal third
-Group III: proximal, medial third
-Mechanism
-FOOSH (fall on outstretched hand)
-No fall think malignancy, child abuse
-P/E
-Pain with ROM
-+deformity
-Often holds arm against chest
-Tx:
-Nonoperative: Sling immobilization. Clinical union usually achieved in 6-12 weeks in adults & 3-6 weeks in children.
-Operative: open fractures, displaced with skin tenting, subclavian artery or vein injuries, severe displacement, shortening
-Complications: Brachial plexus injury=peripheral neuropathy
proximal humerus fracture
-Mechanism
-FOOSH
-Metastatic breast ca
-DX:
-X-ray
-CT for preop planning
-Tx:
-Majority are nondisplaced and treated sling immobilization, p.t.
-Complications: Axillary & subscapular nerve (weakness with abduction & ER) injuries
biceps tendonitis
-Inflammation of the long head of the biceps tendon.
-Overuse injury - repetitive overhead activities, lifting
-Signs & Symptoms
-Pain or tenderness anteriorly, which worsens with overhead lifting or activity
-Pain or achiness that is referred distally
-An occasional snapping sound or sensation
-Treatment
-Non - Operative- Rest, Ice, NSAIDs, Steroid injection, Physical Therapy
-Operative- In refractory cases - Biceps Tenodesis
humeral shaft fracture
-Mechanism- FOOSH
-P/E:
-Arm pain & swelling, ecchymosis, decreased ROM
-Rule out Radial Nerve Injury (wrist drop, weakness with wrist, finger & thumb extension, decreases sensation dorsal web space between thumb & index
-Tx:
-Non-operative: Majority. Coaptation splint
-Operative: open, vascular or nerve injury
