Total Knee Arthroplasty (replacement)

27/01/2010

A surgical procedure that replaces worn joint facets of the knee (proximal ends of the  tibia, fibula and distal femur) with a joint of man-made materials.

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The Gamma Nail

26/01/2010

The Gamma nail was designed to treat unstable intertrochanteric and subtrochanteric fractures.

 The device was developed after cadaver studies and has been used clinically since 1985.

 The Gamma nail transmits weight closer to the calcar than does the dynamic hip screw and it has greater mechanical strength.

A semi-closed operative technique is used, with an average duration of operation of 35 minutes and little blood loss. Distal locking screws can be used to maintain rotational stability.

Wheeless, Clifford R. Weeless’ Textbook of Orthopedics.


Basilar Skull Fracture

16/01/2010

a fracture of the base of the skull, typically involving the temporal, occipital, sphenoid and ethmoid bones of the skull.

Such fractures can cause tears in the cerebral meninges, with resultant leakage of the cerebrospinal (CSF) and hematoma formation.

Manifestations:

  • otorrhea – leakage of CSF from the auditory canal
  • rhinorrhea – leakage of CSF from the nasal passages
  • hematoma presentation surrounding the orbits and ears as blood is flushed to the surface of the facial tissues.
  • Battle’s sign is bruising over the mastoid sinus (just behind the auricle) and is a delayed physical finding associated with basilar skull fractures.
  • Hemotympanum (blood behind the ear drum) and “raccoon eyes” (periorbital bruising) are other delayed findings consistent with basilar skull fractures.”

Patients are prone to meningitis due to CSF leakage and meningeal trauma increasing the microbial portal of entry and menigeal integrity.


Hip Joint Replacement

22/12/2009

 

Indications for Orthopedic Surgical interventions

  1. unstabilized fracture
  2. deformity
  3. joint disease
  4. necrotic or infarcted tissue
  5. tumors

 

Indications for Joint Replacement

 

  1. severe joint pain
  2. severe disability
  3. osteoarthritis
  4. rheumatoid arthritis
  5. trauma
  6. congenital deformity
  7. femoral neck fractures where blood supply has been disrupted

 

Joint Implant Types

 

  1. Metal and high-density polyethylene components
  • implants are usually cemented in place with polymethacrylate (PMMA)
  • PMMA is a bone binding agent that has similar properties to bone
  • Loosening of prosthesis is the main reason for prosthesis failure

bone ingrowth on right:

 2. Press-fit ingrowth prosthesis

  • porous-coated and cementless
  • bone grows into the implant

 

Pre-operative considerations: organ functioning

  1. Cardiovascular
  2. Respiratory
  3. Renal
  4. Hepatic

 

Risk factors for DVT and Pulmonary embolism

  1. age
  2. obesity
  3. preoperative leg edema
  4. DVT Hx
  5. Varicose Veins

 

Post-operative complications

 

  1. hip prosthesis dislocation
  2. excessive wound drainage
  3. thromboembolism
  4. infection
  5. heel pressure ulcers
  6. heterotrophic ossification = bone growth in the periprosthetic space
  7. avascular osseous necrosis
  8. loosening of the prosthesis

 

Martin, Glenn and Porth, Carol, Mattson. 2009. Pathophysiology Concepts of Altered Health States. 8th ed. Lippincott Williams and Wilkins. Philadelphia


Pedicle Screw

19/12/2009

Used to stabilize the vertebra after laminectomy or during spinal fusion.


Hemiarthroplasty

12/10/2009

a surgical procedure which replaces one half of the joint with an artificial surface and leaves the other part in its natural (pre-operative) state. This class of procedure is most commonly performed on the hip after a subcapital (just below the head) fracture the neck of the femur. The procedure is performed by removing the head of the femur and replacing it with a metal or composite prosthesis. The most commonly used prosthesis designs are the Austin Moore prosthesis and the Thompson Prosthesis.

 

Orthropod. 2002. Hemiarthroplasty of the Hip. Retrieved October 12, 2009 from http://www.eorthopod.com/public/patient_education/6500/hemiarthroplasty_of_the_hip.html


Osteogenesis Imperfecta or Brittle Bone Disease, or “Lobstein syndrome”

22/09/2009

 

Osteogenesis Imperfecta, OA or Brittle Bone disease

 

    Etiology

 

  • Osteogenesis Imperfecta is subdivided into 6 clinical types

  • genetic mutation collagen compromising bone formation and development

  • autosomal dominant pattern of inheritance

  • mutation in Type 1 collagen gene, however, type 4 has no detectable mutation

  • Causes bone fragility and low bone mass

  • results in moderate to severe increase in fragility of long bones and vertebral bodies

  • Elevated collagen type I N-telopeptide levels in urine (indicative of increased osseous hyperplasia due to fracture healing)

                   Clinical Presentation

                          Presentation/Fractures Pathologic Minimal Trauma

                         Note: May be suspect child abuse (prior to diagnosis)

 

                     Type 1

  • symptoms are mild

  • normal of near normal height

  • blue sclera (visible sign in the eye, indicative of collagen dysfunction)

                            Type 2

  • typically lethal in the perinatal period

                           Type 3

  • progressive deforming osteogenesis imperfecta

  • the most severe form in children surviving the neonatal period

  • characteristic phenotype

  • extreme short stature

  • severe spinal, thoracic and extremity deformities

  • blue sclera

                           Type 4

  • patients presenting with moderate to severe symptoms of osteogenesis imperfecta yet who do not fit into the above descriptions

                          Type 5

  • present with moderate to severe symptoms of osteogenesis imperfecta

  • have no detectable genetic mutation

                         Type 6

  • present with moderate to severe symptoms

  • have mineralization defect and present with accumulation of osteoid

  • note: osteoid is the organic matrix of protein and polysaccharides, secreted by osteoblasts, that becomes bone after it mineralizes

                             Tx

  • Symptoms and Pain management

  • Continued care for chronic condition

 

                            Sources:

  1. Bishop, Nicholas, J, Fassier, Francois, Glorieux, Delphine, F, Glorieux, Franis, H, Lalic, Ljiljana, Plotkin, Horacio, Rauch, Frank, Roughley, Peter, Travers, Rose and Ward, Leanne. 2000Type V Osteogenesis Imperfecta: A new form of brittle bone disease. Journal of Bone and Mineral Research. 15:1650-1658.

  2. Bishop, Nicholas, J, Fassier, Francois, Glorieux, Delphine, F, Glorieux, Franis, H, Lalic, Ljiljana, Plotkin, Horacio, Rauch, Frank, Roughley, Peter, Travers, Rose and Ward, Leanne. 2000Type V Osteogenesis Imperfecta: A new form of brittle bone disease. Journal of Bone and Mineral Research. 15:1650-1658.