Coxofemoral Luxation Flashcards
Coxofemoral luxations are the most common form of traumatic luxation encountered in dogs and cats and in one study accounted for what % of all luxations?
90%
What causes 85% of coxofemoral luxations?
RTA
Other than RTA, what are the common causes of coxofemoral luxations? (3)
- Falls
- Severe hip dysplasia
- Spontaneous hip luxations
Why do luxations tend not to occur in young animals as frequently?
The force required to cause a luxation would normally cause a physeal fracture in a skeletally immature animal.
What age do coxofemoral luxations start happening normally?
1yr
Which direction are 90% of femoral head luxations?
Craniodorsal
How many canine coxofemoral luxations are bilateral?
5%
How many feline coxofemoral luxations are bilateral?
9%
What do chronic luxations present with?
Lameness - but do start weight bearing
What do acute luxations present with?
Non weight bearing lame
What is found on CE of the hip with coxofemoral luxations? (3)
- PAIN
- often with crepitus
- Manipulation may not be poss if severe pain
Craniodorsal luxation results in the limb being
rotated
A) Which direction?
B) positioned?
. The greater trochanter of the luxated limb is palpably more prominent dorsally. Examination reveals that the affected limb appears
C) Length? when comparing with the contralateral limb.
A) Externally
B) Adducted
C) Shorter
Ventral luxation results in the limb being
rotated:
A) Which direction?
B) Positioned?
. Examination reveals that the affected limb appears
A) Length? when comparing with the contralateral limb.
A) internally
B) Abducted
C) Longer
How to confirm coxofemoral luxation?
Radiographs are required to confirm the diagnosis, determine the direction of the luxation and evaluate for other abnormalities (fractures, hip dysplasia etc.). As always, orthogonal projections should be obtained.
Why must xrays be evaluated for OA when diagnosing a coxo femoral luxation?
May alter treatment plan
Treatment options for a coxofemoral luxation? (4)
Closed reduction
Open reduction
Surgical stabilisation
Salvage surgery such as FHNO and THR.
Following closed coxo femoral luxation reduction, what is the re-luxation rate?
50%
Ideally closed or open reduction of coxofemoral luxations should be attempted as soon as possible to minimise the damage to?
Articular cartilage
What can be placed if the animal allows following reduction?
Ehmer sling
What must be used when performing closed reduction of the coxo femoral?
GA
What can be placed following ventral luxation replacement of the coxo femoral?
Hobbles
What is the success rate with closed reduction withOUT hobbles?
80%
Unstable closed reduction and recurrent luxations are an indication for?
Open reduction and stabilisation
What techniques can be used for stabilisation? (4)
-IIlio femoral suture
- Transarticular pining
- Hip toggle
+/- capsulorraphy
It would be unusual to perform capsulorraphy without ?
an additional method of stabilisation.
Which method of stabilisation technique is superior?
There is little comparative data to show that any technique is superior to another, so the choice is often based on surgeon’s preference.
What are the disadvantages of transarticular pinning? (2)
Damage to the articular cartilage
The need for a second anaesthetic procedure to remove the pin.
A) What is the success rate of a hip toggle?
B) What are the disadvantages (2)
A) 90%
B) Challenging to perform
Increased risk of septic arthiritis (material left in joint esp if multifilament!!)
‘Salvage surgery with either ? (2) is necessary in cases with recurrent failed stabilisation, chronic luxations, cases with hip dysplasia, already well-established osteoarthritis or unreconstructible femoral head and neck fractures.
FHNE or hip replacement
What are the 2 ways a hip can be approached for capsulorrhaphy?
Craniolateral
Dorsal
What are the 2 landmarks identified for lateral approach to hip?
Greather trochanter
Proximal femur
What suture material is sed for a torn joint capsule?
- Size?
- Filament?
- Absorbale?
Large
Monofilament
non or absorbable
The sutures are preplaced in the torn joint capsule using what pattern? (2)
- Horizontal
- Cruciate
When are the torn joint capsule sutures tightened?
Hip internally rotated and abducted
Often alternative techniques are required for the closure of joint capsules - why?
Often to severley damaged
Which approach to the hip is used for an anchored prosthetic capsule?
Dorsal or craniolateral
Anchored prosthetic capsule:
If the joint capsule is damaged or avulsed from the acetabulum, what is placed and where to serve as anchor points for suture attachment?
2 bone screws or bone anchors
in the dorsal acetabular rim
Observing the hip from a lateral-to-medial direction, Where are screws placed for anchored prosthetic capsule with the LEFT hip?
10 and 1 o clock
Observing the hip from a lateral-to-medial direction, Where are screws placed for anchored prosthetic capsule with the RIGHT hip?
11 and 2 o clock
When placing screws for anchored prosthetics; where are they placed and in which direction to avoid damage to articular cartilage?
0.5-1cm from acetabular rim
Directed medially
Screw size for anchored prosthetics:
In medium/toy breed dogs?
2.7mm
Screw size for anchored prosthetics:
In large breed dogs?
3.5-4mm
Anchored prosthetics:
What is used with each screw to prevent suture material slipping?
Washer
What could be used in anchored prosthetics instead of screws/washer?
Bone anchors
Anchored prosthetic:
Where is the anchor point created and how (direction)?
on the femoral side by drilling a hole from cranial to caudal through the proximal portion of the femoral neck.
What type of material and patten is placed between the screw heads and the hole in the femoral neck to create additional support over the joint and to prevent re-luxation with achored prosthetics?
Large mono or multifilament
Figure of 8
What position should the limb be in when tightening sutures for anchored prosthetics? (3)
weight-bearing position with slight abduction and internal rotation.
What suture materials are commonly used for anchored prosthetics?
Nylon
Woven multifilament
Which approach is used for open technique?
Craniolateral or dorsal
Toggle Rod Stabilisation:
A) A hole is drilled through the?
B) What drill guide is used to aid?
A) Femoral head and neck from the region of the 3rd trochanter to the fovea capitis
B) C shaped
Toggle Rod Stabilisation:
Where is the second hold drilled? Size?
The centre of the acetabular fossa (penetrating the medial acetabular wall) large enough to accommodate the toggle rod.
Toggle Rod Stabilisation:
One or two strands of suture material are inserted through the hole in the centre of the ?. The suture may be attached to the toggle rod by inserting a loop of suture through the hole in its centre and then placing the ends of the suture in place.
toggle rod
Toggle road stabilisation:
The toggle rod is inserted through the hole drilled in the A) . The toggle rod is positioned against the B) by pulling alternately on the suture ends. The free ends of the sutures are then passed through the bone tunnel in the femoral head and neck, exiting near the C)
A) acetabular fossa
B) medial acetabular wall
C) 3rd trochanter.
Toggle rod stabilisation:
Passage is facilitated by the use of a A) or a commercially available instrument designed for this purpose. The sutures are secured to the lateral aspect of the femur by tying them to a sterile polypropylene button or a second toggle rod.
A) fine-gauged wire loop
B) lateral
Alternatively, the suture can be secured by drilling another hole through the A) passing one end of the suture through the hole, and tying the two ends together. The suture is tied while the hip is held in a reduced position, taking care not to B) the suture.
A) lateral femoral cortex,
B) overtighten
Toggle Red stabilisation:
An appropriately tight suture should not allow A) of the hip but should allow a B).
A) subluxation
B) good range of motion for hip flexion and extension
Toggle rod stabilisation may be augmented by what if a midsubstance tear of the capsule occurs, ?
Capsulorrhaphy
Toggle rod stabilisation may be augmented by what if the capsule is avulsed from the acetabluar rim of femoral neck?
Prosthetic capsule
If a dorsal approach was used for a toggle rod stabilisation, what happens to the greater trochanter?
It is is transposed or reattached to its original position using pin and tension band wire fixation.
What approach is used for an Extraarticular Iliofemoral Suture?
Craniolateral
What else is performed after Extraarticular Iliofemoral Suture reduction?
capsulorrhaphy
Extraarticular Iliofemoral Suture:
Using a drill bit or a A) pin, a hole is drilled from B) (direction)? in the ilium just cranial to the acetabulum dorsal to the origin of the C) .
A) Steinmann
B) lateral to medial
C) rectus femoris
Where is the second hold made with Extraarticular Iliofemoral Suture?
A second hole is drilled from caudal to cranial through the femur just distal to the insertion of the gluteal muscles at the base of the greater trochanter.
Extraarticular Iliofemoral Suture
One or more strands of large, monofilament suture material is passed in which direction through the hole in the ilium.
from lateral to medial
Extraarticular Iliofemoral Suture
Following the placement of suture in the ilium, A curved haemostat is placed under the ventral edge of the ilial body to grasp the suture and bring it to the ?? side of the ilium.
Lateral
Extraarticular Iliofemoral Suture
Once suture is at the lateral side of the ilium what are the two direction this is now passed in using a haeostat or straight needle?
The suture is then passed from cranial to caudal through the hole in the femur, and from caudal to cranial beneath the insertion of the gluteal muscles
When is the suture tied with Extraarticular Iliofemoral Suture?
Joint internally rotate and abducted; suture tied.
What is An alternative method of placing the suture, which avoids the need to drill holes in the ilium and femur, which has been described?
The suture is anchored cranially in the tendon of origin of the psoas minor muscle and caudally to the tendon of insertion of the middle gluteal muscle.
Possible complications following coxo femoral reduction? (6)
Re-luxation
Implant failure
Pin migration
Infection
Septic arthritis
Osteoarthritis
How many cases acqurie OA after luxation?
55-62%
If reduction and stability is achieved soon after injury, the prognosis after femoral head luxations can be considered to be
Fair to good
What % remained severly lame after reduction?
20%
Normal range of motion occured in what % after reduction?
90%
In which of the following circumstances is closed reduction of a coxofemoral luxation most likely to be successful:
Persistant re-luxations
In joints with concomitant injuries
In acute luxations
In chronic luxations
Acute luxation
