THR complications Flashcards Preview

Reconstruction FRCS > THR complications > Flashcards

Flashcards in THR complications Deck (17):

Name the complications post THR?

  • Nerve palsies
  • LLD
  • iliopsoas impingement
  • Heterotrophic ossification
  • Blood transfusion


Describe the epidemiology of sciatic nerve palsy post THR?

  • Uncommon
  • potentially devastating complx
  • Peroneal division of sciatic n most commonly affected 80%
    • sciatic n travels closest to acetabulum at level of ischium
    • must aviod posterior acetabular retraction when hip flexed position
    • less commonly affected- femoral/obturator/Superior gluteal


What are the causes of  sciatic nerve palsy post THR?

  • Compression most common due to 
    • haematoma
    • retraction
    • tight bandages
  • Direct trauma
  • heat from Polymethylmethacralate polymerisation
  • unknown 40%


What are the risk factors for  motor nerve palsy post THR?

  • DDH
  • Revision surgery
  • Female
  • LLD
  • Post traumatic arthritis
  • surgeon self rated proceedure as difficult


What is the prognosis of sciatic nerve palsy post THR?

  • only 35-40% recover full strength after complete palsy


What is the presentation of pt with  sciatic nerve palsy post THR?

  • Numbness
  • Parathesia
  • weakness


What investigations are helpful in a pt with suspected sciatic nerve palsy post THR?

  • CT
    • identify a haematoma
  • USS
    • identify haematoma
  • EMGs
    • confirm level of injury and guide discussion w pt regarding prognosis


What is the tx of patient with  sciatic nerve palsy post THR?

  • Immediate post op
    1. Place hip in extension and knee flexion
      • for immediate post op palsy
      • decreases tension along sciatic nerve
    2. Immediate excavation of haematoma in op room
  • Persistent foot drop
    • AFO orthosis
      • first line


What is the problem with LLD post op?

  • Most common cause of litergation following THR
  • Operative leg lengthening most common
  • functional but transient limb length differences are common
    • weak abductors may provide the sensation of a long leg in the absence of true LLD
    • usually resolves within 3-6 months


How would you measure LLD?

  • On patient
    • true LL
      • ASIS( up from inguinal lig) -> Medial malleolar 
    • Aparant - Xipsternum to Medial malleolus
  • Imaging
    • draw line along bottom of obturator rings
    • then meadsure a distance from this line to top of lesser trochanter. LLD is usually between these measurements.
  • NB increasing neck length will increase limb length, increasing femoral offset will not increase leg length


How is LLD post THR tx?

  • Shoe- lift
    • adequate most cases
    • wait 6 months until tx to allow adequate relaxation of muscles


What is the cause of post THR of iliopsoas impingment?

  • Retained cement
  • malpositioned acetabular component
  • LLD
  • Excessive length of screws


What is the presentation of a pt with iliopsaos impingement?

  • groin pain
  • injection of corticosteriod into ilipsoas sheath helpful in dx


What is the tx for iliopsoas impingement?

  • Non operative -rarely used
  • Operative
    • Iliopsoas tenotomy or resection
      • in cases of normal post op xrays
    • Acetabular component revision
      • in cases of excessive anterior cup overhand


What is the risk factors for developing heterophic ossification post THR?

  • Prolonged surgical time
  • excessive soft tissue handling during proceedure
  • Hypertrophic osteoarthritis
  • male gender


What is the tx for heterophic ossification?

  • Surgical excision
    •  for severe loss of motion
    • once HO is visible on xrays only surgical excision with eradicate
    • must wait 6 months after inital proceedure to allow for maturation and formation of a capsule
    • perioperative prophylaxis with perioperative radiation or nsaids


How is HO prevented?

  • Oral Indomethacin
  • Radiation therapy
    • 600-800Gy administered ideally within 24-48hrs following proceedure