How to manage Orthapaedic conditions Flashcards
What are the different bone cells and their roles?
- Osteogenic cells “stem cells”
precursors to the more specialized bone cells (osteocytes and osteoblasts)- found in the bone marrow - Osteoblast “Bone forming”
- secretes osteoid
- Catalyse mineralisation of osteoid - Osteoclast “Bone breaking”
- dissolve and reabsorb bone by phagocytosis
- Derived from bone marrow - Osteocytes “mature” bone cell
- Formed when an osteoblast becomes embedded in it’s secretions
- sense mechanical strain to direct osteoclast and osteoblast activity
What are the 2 main bone types in the body?
- flat bones
- Long bones
What is the subdivision from flat/ long bones that can be used to describe it’s structure?
Flat and long bones can be either:
- cortical/compact (weight bearing)
- cancellous/ spongy (not weight bearing)
Describe the structure of compact/ cortical bone
- Compact bone have “osteons”
- repeated structural units “osteons” provide protection, support and resists stresses produced by weight of movement - “Osteons” are made up of:
- concentric “lamellae” around a central “Haversian canal”
- “Haversian canal”- contain blood vessels, nerves and lymphatics - “Volkmans canal” these are transeverse perforating canals that connect the Haversian canals
- Lacunae- small paces containing osteocytes
- tiny canaliculi radiate from lacunae filled with extracellular fluid
Describe the structure of long bones
- Periosteum: connective tissue covering
- Outer cortex: compact bone
- Cancellous/ spongy bone at the end (proximal epiphysis)
- Medullary cavity: contains yellow bone marrow
- Nutrient artery
- Articular cartilage: on surface of bone at a joint only
(Diaphysis long stick part, metaphysis, physis/ epiphyseal line/ growth plate, epiphysis (end)
What are the different mechanisms that can cause a fracture?
- Trauma:
- low energy
- high energy - Stress (bone breaking from a marathon)
- abnormal stresses on normal bone - Pathological (osteoporosis, cancers)
- normal stresses on abnormal bone
What are the different pathologies that can cause fractures?
- Osteoporosis (soft bone)
- Malignancy (primary or bone mets)
- Vit D deficiency (presents as Osteomalacia in adults or rickets in kids)
- Osteomyelitis (bone infection)
- Osteogenesis Imperfecta (genetic)
- Pagets
What different things do you make note of when describe a fracture pattern?
- Soft tissue integrity:
- open
- closed - Bony fragments:
- Greenstick (not broken all the way)
- Simple
- Multifragmentary - Movement:
- displaced
- undisplaced
What is the process for fracture healing?
- INFLAMMATION:
- Haematoma formation
- Release of Cytokines
- Granulation tissue and blood vessel formation - REPAIR:
- Soft Callus formation
(Type II Collagen - Cartilage)
- Converted to hard callus
(Type I Collagen - Bone) - REMODELLING:
- Callus responds to activity, external forces, functional demands and growth
- Excess bone is removed
What is Wolff’s law?
Bone Grows and Remodels in response to the forces that are placed on it
What are the clinical features of a fracture?
- Pain
- Swelling
- Crepitus (cracking of bone)
- Deformity
- Adjacent structural injury:
Nerves/vessels/ligament/tendons
How are fractures investigated?
- Radiograph
- Bone scan
- MRI scan
- CT scan
(need at least 2 different views perpendicular to each other to detect/ identify a fracture)
How do you describe a fracture image from a radiograph?
Location: which bone and which part of bone?
Pieces: simple/multifragmentary?
Pattern: transverse/oblique/spiral
Displaced/undisplaced?
Translated/angulated?
X/Y/Z plane
How do you describe the X/Y/Z plane of a fracture?
in terms of
a) TRANSLATION:
X= Medial/ lateral
Y= Proximal/ distal
Z= Anterior/ posterior
b) ANGULATION:
X= Varus/ Valgus
Y= Internal/ external rotation
Z= Dorsal/ volar
What is the difference between varus and valgus angulation?
Varus= outward
Valgus= inward
What is the difference between dorsal and volar angulation?
Dorsal= angled upward
Volar= angled downward
Why do fractures differ in children?
ELASTICITY:
Children’s bone can bend – more elastic than adult
- Increased density of haversian canals
What are the types of fractures seen in children?
- Plastic deformity
– bends before breaks - Buckle fracture
- One side of a bone bends, raising a little buckle, without breaking the other side of the bone. - Greenstick
– One cortex fractures but does not break the other side
What are the 3 general principles for managing fractures?
- REDUCE:
- closed
- open - HOLD:
- no metal
- metal - REHABILITATE:
- move
- physiotherapy
- use
Describe how a fracture can be reduced
CLOSED:
- manipulated
- traction (on the skin or skeletal- pins in bone)
OPEN: (here nerve vessels can get tangled in the fracture)
- Mini-incision
- full exposure
Describe how a fracture is held in place
CLOSED:
- plaster
- Traction (skin or skeletal)
FIXATION
How is a fracture held with fixation?
Fixation=
INTERNAL:
- intramedullary (pins or nails)
- Extramedullary (plate/ screws or pins)
EXTERNAL:
- Monoplanar
- Multiplanar
How is a fracture rehabilitated?
- Use (pain relief and retrain)
- Move
- Strengthen
- Weight bear
What general complications can follow a fracture?
General (early or late):
- Fat embolus (hours)
- DVT (days-weeks)
- PE
- Infection/sepsis
- Prolonged immobility (UTI, chest infections, sores)
What are some urgent complications that follow a fracture?
- Local visceral injury
- Vascular injury
- Nerve injury
- Compartment Syndrome
- Haemarthrosis
- infection
- Gas gangrene
What are some less urgent complications following a fracture?
- Fracture blisters
- Plaster sores
- Pressure sores
- Nerve entrapment
- Myositis ossificans
- Ligament injury
- Tendon lesions
- Joint stiffness
- Algodystrophy
What are some complications of fracture that is left untreated for long/ treated late?
- delayed union
- malunion
- non-union
- avascular necrosis
- muscle contracture
- joint instability
- osteoarthritis
What is fractured NoF?
“Fractrured Neck of Femur”
What are the causes of FNoF?
“Fractrured Neck of Femur”
- Osteoporosis (older)
- Trauma (younger)
- Combination
What kind of things do you ask about during a history for suspected FNoF?
“Fractrured Neck of Femur”
- Age
- Comorbidity: respiratory/cardiovascular/diabetes/cancer
- Preinjury:
mobility/ independent/shopping/walking/sports
- Social hx: relatives, stairs, etoh
What are the types of NoF you can have?
“Fractrured Neck of Femur”
Can be categorized by location of fracture:
1. Subcapital (intracapsular)
2. Transcervical (intracapsular)
first 2 can affect blood supply to femoral head= necrosis
3. Intertrochanteric (extracapsular)
4. subtrochanteric
5. part intertrochanteric
Do you fix or replace a fractured NoF?
“fractured neck of femur”
depends on location/displacement and age:
1. Extracapsular: minimal risk to blood supply and AVN: fix with plate and screws (Dynamic hip screw)
2. Intracapsular: if undisplaced: less risk to blood supply: fix with screws
3. If displaced: 25-30% risk AVN: replace in older patients; fix if young
Describe the management for a fractured NoF
“fractured neck of femur”
is it:
1. Extracapsular
(Internal fixation (plate and screws or nail))
2. Intracapsular
- displaced
Less than 55yrs: reduce and fixation with screws OR >65 yrs replace (Fit and mobile: total hip replacement or Less fit: hemiarthroplasty)
- undisplaced
Fixation with screws
How do we classify joints?
- Fibrous (sutures, syndemosis, interosseous membrane)
- Cartilaginous (synchondroses- spine, symphyses- pubic)
- synovial (plane, hinge, condyloid, pivot, saddle, ball & socket)
How are synovial joints stabilised?
- muscles/ tendons
- ligaments
- bone surface congruity
What are the components of a synovial joint?
- Articular cartilage: a thin layer of cartilage at the end of the bone in the joint
- Type II collagen
- Protecoglycan (aggrecan) - Join cavity containing synovial fluid: “synovial fluid”=
- hyaluronic acid- rich viscous fluid - Synovium: a specialized connective soft-tissue membrane that lines the inner surface of synovial joint capsules:
- 1-3 cell deep lining containing macrophage-like phagocytic cells (type A synoviocyte) and fibroblast-like cells that produce hyaluronic acid (type B synoviocyte)
- Type I collagen
What is cartilage?
- Cartilage is composed of:
1) specialized cells (chondrocytes)
2) extracellular matrix: water, collagen and proteoglycans
(mainly aggrecan) - Cartilage is avascular – it has no blood supply
What is aggrecan?
Aggrecan is:
-a proteoglycan that possesses many chondroitin sulfate and keratin sulfate chains
-characterized by its ability to interact with hyaluronan (HA) to form large proteoglycan aggregates
What is arthritis?
disease of the joints
- There are many different types of arthritis, but there are 2 major divisions:
1. Osteoarthritis (degenerative arthritis)
2. Inflammatory arthritis (main type is rheumatoid arthritis)
What are the radiographic changes seen in RA vs ostoarthritis?
RA:
- Joint space narrowing
- No subchondral sclerosis
- No osetophytes
- osteopenia
- bony erosions
osetoarthritis:
- Joint space narrowing (indicates articular cartilage loss- can occur in both)
- Subchondral sclerosis
- Osetophytes (a.k.a Heberden’s nodes if at distal inter- phalangeal joints, and Bouchard’s nodes if at the proximal inter-phalangeal joints)
- No osteopenia
- No bony erosions
What is osetoarthritis?
According to WHO:
OA: is a long-term chronic disease characterized by the deterioration of cartilage in joints which results in bones rubbing together and creating stiffness, pain, and impaired movement.
- Degenerative disease of chondral cartilage
- Inflammation occurs late in disease cf. rheumatoid
- Essentially cartilage wears away, bones rub togetther to cause damage and fluid comes out forming cysts
- Inflammatory mediators include proteinases, e.g., matrix metalloproteinases (MMPs) and aggrecanases, and inflammatory cytokines, including interleukin (IL)-1β and tumor necrosis factor α (TNFα), which enhance the synthesis of proteinases and other catabolic factors to degrade the articular cartilage membrane
What are the main risk factors for osteoarthritis?
- age
- excess weight and obesity
- mechanical constraints (intense sport, some professions)
- Heredity
- Female gender, menopause
- Osteonecrosis
- Leg bone malalignement
- Estrogen deficiency
- Metabolic syndrome
- Advanced hip osetoarthritis
What are the clinical features of osteoarthritis?
- Pain (exertional/rest/night)
- Disability: walking distance/stairs/giving way
- Deformity
Previous history:
- trauma/infection
- Treatments given (physio/injections/operations)
- Other joints affected
How do you assess suspected osteoarthritis?
Look (deformity: varus? valgus? scars?)
Feel (fluid in the knee)
Move (test flexion and extension)
Special tests (anterior drawer suggesting ACL injury, Lachmanns again for ACL injury
What is meant by “weight bearing view” on image?
- when the patient is standing vs sitting for the scan
How is Osteoarthritis managed?
- Conservative:
- Analgesics
- Physiotherapy
- Walking aids
- Avoidance of exacerbating activity
- Injections (steroid/viscosupplementation) - Operative: (last resort)
- Replace (knee/hip) “total knee replacement”
- Realign (knee/big toe)
- Excise (toe)
- Fuse (big toe) “ankle fusion”
- Synovectomy (Rheumatoid)
- Denervate (wrist)
What type of bone infection can you have?
- Bone: osteomyelitis:
Refer to pathology lectures
Acute or chronic
Primary or secondary
Pain/swelling/discharge
Systemic signs:
Fevers, sweats wt loss - Joint: septic arthritis:
Pain
Joint swelling/stiffness
Fevers, sweats, wt loss
What causes septic arthritis?
Bacterial infection of a joint (usually caused by spread from the blood)
- Common organisms:
Staphylococcus aureus, Streptococci, Gonococcus
What are the risk factors for septic arthritis?
immunosuppressed, pre-existing joint damage, intravenous drug use (IVDU)
What is septic arthritis?
Serious type of joint infection:
- Septic arthritis is a medical emergency
-> Untreated, septic arthritis can rapidly destroy a joint
- Usually only 1 joint is affected* (monoarthritis)
- gonococcal septic arthritis is an exception:
-It often affects multiple joints (polyarthritis)
-It is less likely to cause joint destruction
What are the symptoms of septic arthritis?
Consider septic arthritis in any patient with an acute painful, red, hot, swelling of a joint, especially if there is fever
How do you diagnose septic arthritis?
Diagnosis is by joint aspiration (aspiration of pus from the joint- should wear gloves). Send sample for urgent Gram stain and culture
How is septic arthritis treated?
- Surgery: joint washout and drainage (repeated if required)
- Iv antibiotics (days/weeks)
- Immobilise joint in acute phase
- Physiotherapy once over acute phase
What tools are used to investigate septic arthritis?
- Radiology:
Plain films
MRI scans: bony architecture/collections
CT if MRI not available
Bone scans: multifocal disease
Labelled White cell scans - Bloods:
CRP: acute marker
ESR slower response
WCC
TB culture/PCR
How is osetomyelitis treated?
“infection in a bone”
- Antibiotics: iv weeks
- Surgical drainage: especially collections/sequestrum
- Chronic: antibiotic suppression/dressings
- Possibly amputation
What shoulder conditions are common from the ages 15-45 yrs ?
Dislocation
fractures
What shoulder conditions are common from the ages 45-60 yrs?
Impingement
Dislocation
ACJ OA
Rotator cuff tears
fractures
What shoulder conditions are common from the ages > 60 yrs?
Glenohumeral OA
Impingement
Cuff tears
Fracture
What hip conditions are common from the ages 15-45 yrs?
Developmental dysplasia
Leg length discrepancy
Impingement
What hip conditions are common from the ages 45-60 yrs?
OA
Avascular necrosis
impingement
What hip conditions are common from the ages > 60 yrs?
OA
Post Total hip replacement
What knee conditions are seen from the ages 15-45 yrs?
Patellofemoral maltracking
ACL/PCL
Meniscal tears
fractures
What knee conditions are seen from the ages 45-60 yrs?
OA
Patellofemoral maltracking
ACL/PCL
Meniscal tears
Fractures
What knee conditions are seen from the ages > 60 yrs?
OA
