• Fractures

    by  • 20/06/2013 • Rheumatology

    General principles of fractures

    1. Fracture is a loss of continuity of the substance of the bone due to physical force. Covers severely comminuted, hairline crack (can cause a periosteal reaction 2 weeks later) and micro fracture.
    2. Dislocation is a complete loss of contact between articulating surfaces of a joint
    3. Subluxation of a joint has some contact but joint is no longer congruous.

     

    Types of fractures:

    1. Intracapsular

     

    1. Femoral head fracture - rare and usually associated with hip dislocation.

     

    More common in younger patients.

    1. Femoral neck fracture - Usually associated with osteoporosis/osteomalacia and common in the elderly (90% falls). Displacement of the head often leads to avascular necrosis. 4 types – stress fractures, impacted fractures, partially displaced, completely displaced.

     

    1. Extracapsular:

     

    1. Trocanteric fractures - caused by avulsion of the greater/lesser from the femur by muscle. Most common in children and athletes.

     

    1. Intertrochanteric fracture - See in the elderly and women with osteoporosis. Does not give displacement, just a fracture line.
    1. Subtrochanteric fracture - is associated with young adults and high energy trauma or the elderly with osteoporosis and falls. Can be stable or unstable.

     

    Cause of fractures:

    1. Main cause of fractures linked to falls in patients with osterporosis (= low bone mass and microarchitectural deterioration, causing enhanced bone fragility).
    2. N.B. Osteopenia – risk factor for osteoporosis

     

    Ix:

    1. Do a bone profile
      1. o Calcium, phosphorus, Alk. Phosphate levels
    2. X-ray
    3. DEXA scan – calcium content
    4. Myeloma screen – looks at serum and urine electrophoresis (rule out), analysis of Bence-Jones protein.
    5. Frax score – scores the risk of another fall in the next 10 years (% risk)

     

    Mx:

    Drugs

    1. PAIN RELIEF! (ibruprofencodeine)
    2. Alendronic acid – Bisphosphonate (stops bone resorption by osteoclasts)
    3. Calcium and Adcal D3 supplement, vitamin D, oestrogen, strontium – used in the elderly but causes dramatic increase in bone density so cannot monitor progress with DEXA.
    4. Digoxin – must have correct K+ levels
    5. Serro K – potassium supplement
    6. (Clexane, salbutamol, beclamethosone, atrovent, prednisolone, furosemide)
    7. HRT (now not recommended) as at risk of breast and uterine cancers.
    8. Selective oestrogen receptor modulators (SERMs) but has no effect outside the vertebrae

     

    1. Be cautious of polypharmacy and falls

     

    Anabolic agent:

    1. Teriparatide (PTH) builds up bone density, reserved for those of T score less than -4, injection given once a day.Contraindicated in Pagets disease

     

    Other bone formation stimulating agents: Calcitriol, androgens

    Surgical treatment of fractures:

     

    1. Reduction may be ‘closed’ or ‘open’ if cannot be done closed, or if reduction needs to be very accurate. E.g fracture if a joint (intra articular) then an open reduction is performed.
    2. Retention is holding the bone unloaded until it is healed
    3. Rehabilition via exercises to return limb function. Even in cast exercise the other joints of the limb.
    4. Stabilisation: Non operative by strapping, plaster cast.
    5. Traction (traditional method appropriate for certain groups such as paediatrics – involves realignment and retention.

     

    Internal fixation procedures

    Intracapsular fractures

    1. Total hip replacement - acetabular cup made from polyethylene/metal/ceramic. The cartilage is removed and cup fixed into plate using cement and screws. Femur is shaped to take prosthetic ball and stem, and cemented into shape. Used in patients with severe comminution of head +/or neck

     

    1. Hemiarthroplasy - semi replacement by removal of head of femur, do not take out the acetabulum, replacement just fits into the bone cup. Used in patients with femoral neck/head fractures who are older and are too unwell to have secondary operations

     

    1. Pinning/cannulated screws - multiple pins or screws are drilled across the fracture to hold the bone together. Can be carried out as a closed or open procedure, suitable for simple neck of femur fractures. Often in young patients with no osteoporosis, and used for simple fractures

     

    For extra capsular fractures:

    1. Inter medullary nail (aka Gamma nail) - nail placed in the midline of the shaft, sometimes fixed with screws. Used in intertrochanteric and subtrochanteric fractures

     

    1. Dynamic hip screws and plate - compression screw drilled into medulla of neck/head of femur. Screw slides into a sleeve attached to shaft of femur allowing for movement. Also allows for bone remodelling around. Carried out with a guide wire, no open operation. Used for intertrochanteric and subtrachanteric fractures. Plate may be removed later in younger patients.

    Bone density change of 5-8% can change the risk of falls by around 30%

    External fixation procedures:

    External Fixation: pins are inserted into each major fragment and connected to an external frame. Pin site care is paramount.

    Surgical complications:

    1. Operate on a fracture can make patient worse by effecting the haematoma and inflammatory processes, also introducing infection.
    2. Complications include soft tissue damage and recumency.

     

    Complications specific to fractures:

    Problems with union, joint stiffness, AVN, myosotis ossificans (the laying down of bone in muscle tissue), infection, nerve and visceral damage.

    1. Malunion: where a fracture had united with a poor position can be cosmetic or functional deformity. Shortening, angulation, rotation.
    2. Delayed union: union fails to occur within the expected time, X-ray shows bone reabsorption and poor quality callus.
    3. Non union: shows fracture failure to unite, can only be diagnosed 6 months after event.
      1. o Hypertrophic has inadequate stability but the bones are still viable. Still has good blood supply but fracture has too much movement. Can be stabilised.
      2. o Atrophic non-union is a failure of the biology, no evidence of cellular activity. Treatment is less reliable, but includes removal of bone back to

     

    Other causes of low bone mass:

    1. Osteomalacia
    2. Osteogenesis imperfect
    3. Hyperparathyroidsim

     

    1. Hyperthyroidism
    2. Cushings
    3. Muliple myeloma
    4. Rheumatoid arthritis
    5. Renal failure
    6. Idiopathic hypercalciurea

     

    Fractures glossary:

    1. Closed (simple) fracture = overlying skin is in tact
    2. Open (Compound) fracture = break in overlying skin or nearby viscera with potential contamination of bone ends
    3. Complete fracture: A fracture in which bone fragments separate completely
    4. Incomplete fracture: A fracture in which the bone fragments are still partially joined
    5. Linear fracture: A fracture that is parallel to the bone’s long axis.
    6. Transverse fracture: A fracture that is at a right angle to the bone’s long axis.
    7. Oblique fracture: A fracture that is diagonal to a bone’s long axis.
    8. Spiral fracture: A fracture where at least one part of the bone has been twisted.
    9. Impacted fracture: A fracture caused when bone fragments are driven into each other.
    10. Comminuted fracture = where there is more than two fragments of bone
    11. Complicated fracture = where other important structures are involved/damaged (=nerve, blood vessels)
    12. Greenstick fracture = one side of bone is fractured, the other side simply bends
    13. Pathological fracture = a bone broken secondary to bone disease (metastasis).
    14. Epiphyseal injuries at site of growth plate (=’Salter Harris fracture’) – fracture through the zone of provisional calcification. 
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