MSK: joint injuries lectures in w9, 10 and 11 Flashcards
Classify fracture types
Greenstick: incomplete fracture of long bone, usually in children under 10, often mid-diaphysial, due to tension, rapid healing
Torus: also incomplete and more common than greenstick, force applied to concave side of bending bone causing compression fracture and a bulge to appear (also called buckle fracture). Rapid healing
Transverse: 2 fragments, broken piece of bone is at a right angle to the bone’s axis, horizontal fracture line
Oblique: 2 fragments, break has a curved/sloped pattern
Spiral: 2 fragments, rotating force causes a spiral-shaped fracture line around the bone
Comminuted: bone breaks into several pieces (3 or more), very unstable
Compression: vertebral fracture due to trauma or weakening (osteoporosis)
Stress: hairline crack
Buckled/impacted: ends of bone fracture driven into each other
Classify fractures according to location
Diaphyseal-Shaft
Metaphyseal-wide part between epiphysis and diaphysis
Epiphyseal-Salter Harris classification. May get growth arrest so bone may not heal or start to deform
Condylar
Articular-dramatically increases chance of osteoarthritis
Avulsion-fragment of bone tears away
Fracture dislocation-both fracture and dislocation occur
Signs and symptoms of a fracture
Pain Loss of function Swelling Deformity Bony tenderness Crepitus Abnormal movement
What is a pathological fracture?
A fracture that occurs through abnormal bone under physiological bone
The pathology can be local or systemic (bone not formed properly in one place, or disease affecting all the bones)
How to describe displacement of distal fragments in a fracture?
Angulation
Displacement
Axial
Rotation
Describe some factors which influence bone healing
Local: fracture configuration, soft tissue injury, type of bone (cancellous vs cortical), treatment (reduction/stability/infection)
Regional: blood supply, muscle cover
Systemic: age, comorbidity, bone pathology, head injury
Closed and open fractures?
Closed: overlying skin intact (used to be called simple fractures)
Open: break in overlying skin and fracture site communicates with the outside environment, high risk of infection (used to be called compound fractures). Classification related to size of wound, energy and contamination
What are the complications associated with poor wound healing?
Malunion: deformity, late arthritis
Non-Union: hypertrophic (bone moving all the time so doesn’t get a chance to heal), atrophic (bone quality too poor or not enough blood supply)
Infection
Describe some early fracture complications
Local: nerve and vascular injury, avascular necrosis, compartment syndrome, infection, surgical errors
Systemic: hypovolaemia, fat embolism, thromboembolism, acute respiratory distress, disseminated intravascular coagulation
Describe some late fracture complications
Local: delayed union (slow healing), non-union (doesn’t heal), malunion (heals in wrong position), myositis ossificans (starts to form bone then joint stiffens), re-fracture
Regional: osteoporosis, joint stiffness, chronic regional pain syndrome, abnormal biomechanics, osteoarthrosis
What is compartment syndrome?
Raised pressure within an enclosed fascial space leading to localised tissue ischaemia.
Pain on passive stretch which is excessive, progressive and not relieved by analgesia. Neurovascular changes are late
What are stress fractures caused by?
Repetitive, non-violent stresses, commonly in the spine, tibia, femur, pelvis and foot.
Risk factors: osteoporosis, sports and eating disorders
Osteoporotic fractures
Low bone mineral content, enhanced bone fragility and therefore increased fracture risk. Sensitive to oestrogen. Prevented by weight-bearing exercise pre-35 years, vitamin D and calcium. Diagnosed with DEXA scan
How might a fracture be stabilised?
Traction (not really any more as keeps in hospital longer)
Plaster of Paris
External fixation
Open reduction and internal fixation (ORIF)
Non-operative fracture treatment
Wool and crepe Sling/collar and cuff Crutches Plaster of paris or fibreglass cast (need to elevate limb, exercise joints not in plaster, return if have pain) Functional brace Traction: skin/skeletal
Operative fracture treatment
Protect soft tissues/avoid infection Open or closed reduction Implants Anatomical reduction (intra-articular) Inter-fragmentary compression Stable fixation Early joint/muscle rehabilitation
Clavicle fractures
Caused in sporting or falling injuries
Middle 1/3 usually fractured: junction between medial 2/3 and lateral 1/3
Sling for 3 weeks; slow to heal but most heal and remodel
Proximal humeral fractures
Usually due to falls in the elderly. Surgical neck commonly fractures into 2-4 parts
Minimally displaced treat with collar and cuff
Displaced: closed reduction + internal fixation, open reduction + internal fixation, hemiarthroplasty
Distal radius fractures in children
Buckle fractures: Salter Harris II
Minimally displaced: pop 3/52
Displaced: MUA + POP +/- wire
Distal radius fractures in adults
Often more likely because of osteoporosis
Colle’s fracture: fall onto outstretched hand, pronated forearm in dorsiflexion. Fracture of distal radius in dorsal metaphyseal region. Most fractures dorsally angulated and impacted. Distal fragment displaced posteriorly, producing dinner fork deformity
Smith’s: fractured distal radius with palmar angulation of distal fragment, usually transverse. ess common than Colle’s
Minimal displacement=POP for 4-5 weeks
Displaced: MUA +/- wire 5 weeks, plate, external fixation
Hip fractures
Intracapsular: femoral head and neck fractures. Usually due to a fall in an elderly person with osteoporosis. High risk of AVN as branches of medial circumflex artery usually torn. Minimally displaced can do internal fixation, displaced need closed reduction and internal fixation or hemiarthroplasty
Extra capsular: trochanteric, intertrochanteric, and subtrochanteric fractures. Falls in elderly/osteoporosis, low avascular necrosis risk. Undisplaced closed reduction and internal fixation, displaced need hip screw
Tibial shaft fractures
Falls/RTC/sport. Often the mid to distal area of the shaft, often open. Compartment syndrome can occur
Undisplaced: POP
Displaced: intramedullary nailing, external fixation
Ankle fractures
Falls/sport
Uni or bimalleolar, or in tib-fib syndesmosis
Stable: brace/POP for 3 weeks
Unstable: open reduction and internal fixation
Describe in general the effects of ageing on the MSK
Bone density reduces
Chondroid tissue has less water so stiffens (Articular cartilage, IV disc, menisci)
Fibrous tissue less water and stretch but don’t retain as much elasticity (tendons, ligaments, joint capsule)
Skeletal muscle harder to build up and loss (sarcopenia), loss of contractility, loss of neuronal innervation
Tend to get less fat
What accelerates bone loss?
Low reproductive hormone levels Poor Ca2+ and/or vitamin D status Inactivity Endocrine/GI pathologies Loss of bone mineral-->changes in trabecular structure
What is osteoporosis and give some risk factors
Low bone mass per unit volume, deterioration of micro-architecture, increased bone fragility and increased susceptibility to low trauma fractures. Bone resorption by osteoclasts (break down bone mineral and matrix) is higher than bone formation by osteoblasts (form matrix).
Type 1 postmenopausal related to loss of oestrogen; type 2 senile and age related in addition to Ca2+ deficiency
Risk factors: increasing age, low bone mass, Caucasian/Asian, previous fragility fracture, family history, low BMI, lifestyle (smoking, alcohol, diet), early menopause
Briefly outline how bisphosphanates are used in treatment of osteoporosis
Decrease bone turnover (affect osteoclasts), increase bone mineralisation, minimal effect on bone volume
Describe the consequences of hip fractures
High mortality
High morbidity: PE, PVT, MI, stroke, pressure sores, chest infections, UTIs, reduced mobility, confusion
What is osteoarthritis?
A disorder of synovial joints characterised by focal areas of damage to articular cartilage. There is remodelling of underlying bone and the formation of osteophytes: new bone at joint margins. Mild synovitis
80% of over 80 year olds have it, with it commonly being painful in the hip and knee. Characteristics include pain, stiffness, deformity, joint swelling.
Radiologically see decreased joint space, sclerosis, osteophytosis and bone cysts
Treated with weight loss, exercise, physiotherapy, analgesia, NSAIDs, joint injection. May need arthroscopy, osteotomies, arthrodesis or arthroplasty
Describe the complications of hip replacement surgery
Local: leg length disparity, dislocation, infection, loosening of joint, sciatic/femoral nerve/common peroneal nerve damage
Systemic: UTIs, chest infections, clinical DVT, non-fatal PE, fatal PE
What is rheumatoid arthritis?
A chronic, autoimmune inflammatory condition affecting multiple organs, but predominantly attacks synovial tissues and joints.
Onset: insidious or abrupt, usually arthritis symptoms in hands and wrists then in larger joints. Stiffness, swelling, rheumatoid nodules.
Radiography: soft tissue swelling, osteoporosis, joint space narrowing, marginal erosions
