MVSC CLINCIAL CLUB 24TH MARCH 2010

							MVSC CLINCIAL CLUB JUNE 2010

Case One

44kg Red Cloud Kelpie with 2 year history of plantigrade talocrural joint with flexed
digits when weight bearing. Onset of stance unknown.

1.1    What is the diagnosis

Chronic common calcaneal tendon avulsion

1.2    What are the components of the Achillies tendon

Superficial digital flexor tendon
Gastrocnemius
Gracilis
Semitendinosis
Biceps femoris

1.3     A. What are the treatment options. B. What is the essential feature of all treatment
options. C. What is the essential difference in management compared to an acute
laceration?

A. Fix tibiocrural joint in extension using either
1. Calcaneal tibial screw
2. Transarticular external skeletal fixature
+/- tendon resection and primary repair

B. Removing weight bearing from tendon by having tibiocrural joint in extension

C. Acute laceration – anatomical reduction of tendon and urgent tendon repair before
onset of muscle contraction. Improved prognosis compared to chronic avulsions.

1.4     List tendon suture patterns and for bonus points the most appropriate suture for
specific tendons.

Three loop pulley – round tendons (modified through bone tunnel)
Krackow – flat tendons
Kessler / locking loop – round tendons

1.5    What are the most significant factors that influence tendon healing?

Gap (<1mm)
Immobilisation
Cause
Location
Case Two
Road traffic accident injury sustained 24 hours previously.

2.1      What are the radiographic features of this fracture?

Segmental
Highly comminuted
Limited bone stock proximally and distally

2.2     How does the fracture configuration affect decision making with regards to
fracture fixation choices?

Fracture can not be anatomically reduced hence fixation will have buttress properties
rather than neutralization / compression. Consequently increased stiffness required –
plate rod, tied in I/M pin and Ex Fix or buttress plate.

2.3     What advantage does the 2.0mm screw have over the 2.7mm screw when utilized
in stabilization of cat long bone fractures?

2.0mm screws have a finer pitch hence more threads per unit length compared to 2.7mm
screws. Consequently improved torque loading. Additionally 2.7mm screw often too
large for bone stock.

2.4      What are the theoretical advantages of the plate rod system?

Axial and rotation resisted by plate, bending by I/M pin. Theoretical advantage is that the
combination results in an increased area of inertia (of combination) and hence improved
resistance to bending beyond summation of each individual component. The assumption
is that the plate/rod act as a single unit and are connected rather than independent units.

2.5      A. Has any bone healing occurred between the two series of post operative
radiographs? B. What are your recommendations for fracture management following the
last series of radiographs?

      A. Yes, rounded fracture ends and reduced width of fracture gap.

      B.
      a. Repeat radiographs in a further 8 weeks?
      b. Bone graft proximal fracture line?
      c. Encourage limb use (delayed healing due to excessive stress protection?)
Case Three

2 yr old Bulldog with medial patella luxation. Luxation is a grade II with pain on direct
palpation of patella .

3.1    How does the grading system assist decision making? i.e. for what grades is
surgical management indicated?

Grade 1 without clinical signs is not treated
Grade 2 mild or intermittent lameness then surgery if deteriorates
Grade 3 surgery unless mild intermittent lameness
Grade 4 early surgical intervention to prevent severe bony deformation and disability –
prognosis guarded.

3.2   What is the advantage of a trochlear block recession procedure over a trochlear
wedge recession? ***

TBR increases proximal patellar depth, increases patellar articular contact with the
recessed proximal trochlea, recesses a larger percentage of trochlear surface area, and
results in a greater resistance to patellar luxation in an extended position as compared
with TWR

3.3    What are the indications for a distal femoral osteotomy in the management of
medial patella luxation?

Distal femoral varus in conjunction with medial patella luxation.

3.4    What implant has facilitated performing distal femoral osteotomies for
management of patella luxations and why does the implant assist in performing this
procedure? ***

Supracondylar femur plates (St Lucia Surgical Services). The osteotomy is at the point of
greatest curvature which is at the distal aspect of the femur. The plate improves contour
to the distal femur and increases the number of screws that can be placed in the distal
femur.

3.5     Does this dog require a distal femoral osteotomy? What is the recommendation
for obtaining radiographs of the femur when considering this technique?

No – the apparent distal femoral varus is due to poor positioning of the femur (not a true
craniocaudal projection.
The radiographs is obtained by placing the dog in dorsal recumbency with the limb draw
forward. A caudocranial projection of the femur is then taken with the femur parallel t
the table.
Case Four
3yr old Italian Greyhound which jumped of a balcony yesterday

4.1    What are the radiographic features of these fractures?

Distal transverse fracture of radius and ulna

4.2    What are the concerns with regards to fracture repair?

Limited distal bone stock
Bilateral fractures
Italian greyhound is a recognized breed for non union of these fractures.

4.3    What are the options for fracture repair and what system has been used?

Ring fixator
Hybrid ring fixator
Standard external skeletal fixator – type 1b most likely
T plate?
Medial (or lateral) and cranial plate combined

4.4     What does the ring fixator rely upon to maintain stability in the fixation (i.e. how
do the fine wires resist loading)? What size wires should be used?

Tension in the wire resists axial compression
<10kg – 1.0mm
10 – 20kg – 1.2mm
>20kg – 1.5mm

4.5    Why has the complication occurred? What guideline could have reduced the
chance of this complication?

External fixator pin is too large
Ex fix pin 20 – 30% diameter of bone
Case Five
6 month old cross breed found acutely lame

5.1    Describe the radiographic features of the fracture?

Distal femur Salter Harris type 1

5.2    What fixation techniques are listed in the literature and which are considered
appropriate?

Cross pins – appropriate
Intramedullary pin – not appropriate
Lag screws – not appropriate
Rush pins – questionable

5.3    What is the common error made when repairing these fractures?

Under reduction of fracture
Excessively caudal placement of pins


5.4    What is a recommendation to assist reduction of these fractures?

The use of pointed reduction forceps from the intercondylar notch to the cranial aspect of
the distal femur