THR complications Flashcards
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
-
Place hip in extension and knee flexion
- for immediate post op palsy
- decreases tension along sciatic nerve
- Immediate excavation of haematoma in op room
-
Place hip in extension and knee flexion
- Persistent foot drop
-
AFO orthosis
- first line
-
AFO orthosis
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
- true LL
-
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
-
Iliopsoas tenotomy or resection
What is the risk factors for developing heterophic ossification post THR?
- Prolonged surgical time
- excessive soft tissue handling during proceedure
- Hypertrophic osteoarthritis
- male gender
