MSK: joint injuries lectures in w9, 10 and 11

Question 1

Classify fracture types

Answer 1

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

Question 2

Classify fractures according to location

Answer 2

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

Question 3

Signs and symptoms of a fracture

Answer 3

Pain
Loss of function
Swelling
Deformity
Bony tenderness
Crepitus
Abnormal movement

Question 4

What is a pathological fracture?

Answer 4

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)

Question 5

How to describe displacement of distal fragments in a fracture?

Answer 5

Angulation
Displacement
Axial
Rotation

Question 6

Describe some factors which influence bone healing

Answer 6

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

Question 7

Closed and open fractures?

Answer 7

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

Question 8

What are the complications associated with poor wound healing?

Answer 8

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

Question 9

Describe some early fracture complications

Answer 9

Local: nerve and vascular injury, avascular necrosis, compartment syndrome, infection, surgical errors
Systemic: hypovolaemia, fat embolism, thromboembolism, acute respiratory distress, disseminated intravascular coagulation

Question 10

Describe some late fracture complications

Answer 10

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

Question 11

What is compartment syndrome?

Answer 11

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

Question 12

What are stress fractures caused by?

Answer 12

Repetitive, non-violent stresses, commonly in the spine, tibia, femur, pelvis and foot.
Risk factors: osteoporosis, sports and eating disorders

Question 13

Osteoporotic fractures

Answer 13

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

Question 14

How might a fracture be stabilised?

Answer 14

Traction (not really any more as keeps in hospital longer)
Plaster of Paris
External fixation
Open reduction and internal fixation (ORIF)

Question 15

Non-operative fracture treatment

Answer 15

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

Question 16

Operative fracture treatment

Answer 16

Protect soft tissues/avoid infection 
Open or closed reduction
Implants
Anatomical reduction (intra-articular)
Inter-fragmentary compression
Stable fixation
Early joint/muscle rehabilitation

Question 17

Clavicle fractures

Answer 17

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

Question 18

Proximal humeral fractures

Answer 18

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

Question 19

Distal radius fractures in children

Answer 19

Buckle fractures: Salter Harris II
Minimally displaced: pop 3/52
Displaced: MUA + POP +/- wire

Question 20

Distal radius fractures in adults

Answer 20

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

Question 21

Hip fractures

Answer 21

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

Question 22

Tibial shaft fractures

Answer 22

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

Question 23

Ankle fractures

Answer 23

Falls/sport
Uni or bimalleolar, or in tib-fib syndesmosis
Stable: brace/POP for 3 weeks
Unstable: open reduction and internal fixation

Question 24

Describe in general the effects of ageing on the MSK

Answer 24

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

Question 25

What accelerates bone loss?

Answer 25

Low reproductive hormone levels
Poor Ca2+ and/or vitamin D status
Inactivity
Endocrine/GI pathologies
Loss of bone mineral-->changes in trabecular structure

Question 26

What is osteoporosis and give some risk factors

Answer 26

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

Question 27

Briefly outline how bisphosphanates are used in treatment of osteoporosis

Answer 27

Decrease bone turnover (affect osteoclasts), increase bone mineralisation, minimal effect on bone volume

Question 28

Describe the consequences of hip fractures

Answer 28

High mortality

High morbidity: PE, PVT, MI, stroke, pressure sores, chest infections, UTIs, reduced mobility, confusion

Question 29

What is osteoarthritis?

Answer 29

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

Question 30

Describe the complications of hip replacement surgery

Answer 30

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

Question 31

What is rheumatoid arthritis?

Answer 31

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