Ch 63 - Fractures of the Tibia and Fibula Flashcards
What major muscles attach to the tibia and what is their function?
- Quadriceps femoris (stifle extension)
- Biceps femoris (stifle flexor)
- Caudal part of sartorius (stifle flexor)
- Cranial tibial muscle (tarsal flexor)
List the 4 epiphyses of the tibia
- Proximal epiphysis
- Tuberosity epiphysis
- Distal epilphysis
- Medial malleolar epiphysis
What is an apophysis?
A traction epiphysis such as the tibial tuberosity
How much of the longitudinal length of the tibia is from the proximal and distal epiphyses respectively?
- Proximal 40%
- Distal 60%
At what age does the tuberosity epiphysis fuse with the proximal epiphysis?
At what age does the tuberosity physis normally close?
- Fuses to proximal epiphysis 5-9m in large dogs
- Physis closes over 12m in large dogs
At what age does the medial malleolar epiphysis fuse to the distal epiphysis?
Very early, approx 4-5m in large breeds.
What part of the tibial plateau is articular?
The caudal 1/2
What muscles attach to the tibial tuberosity?
- Quadriceps femoral
- Parts of biceps femoris and sartorius
What are the main vessels which supply blood to the tibia and fibula?
Tibia
- Cranial tibial artery
Fibula
- Cranial tibial artery (head)
- Peroneal artery (fibula)
What vessels and nerves surround the tibia
- Medial saphenous artery and vein and saphenous nerve obliquely cross the medial tibia
- Tibial and popliteal artery along lateral and caudal aspect
- Peroneal and cutaneous nerves along lateral and caudal aspects
What can result in a tibial tuberosity avulsion?
Contraction of the quadriceps while the stifle is flexed and the foot is firmly on the ground
What is Osgood Schlatter disease?
Considered to be a form of osteochondrosis but has been suggested that it should be classified as a minimally displace tibial tuberosity fracture
What leg position can aid in reduction of a tibial tuberosity fracture? What are the repair options?
Hip flexed and stifle extended
Repair options:
- 2 K-wires in a caudoproximal direction (very young small dogs with minimal displacement)
- Pin and tension band (preferred)
- Reattachment of patella tendon to bone tunnel if not enough bone to reattach
What are the repair options for a proximal physeal fracture?
Pinning!
- At least 2 cross pins
- Third pin through tuberosity recommened for better stability
What are the repair options for proximal metaphyseal fractures?
- IM pin, cross pins, plate, lag screws
- If fibular head had detacted from tibia, should be reattached with screws
- If comminuted, plate must be placed on side of comminution to act as buttress plate
What is the ideal pin insertion point for normograde tibial IM pinning?
What is the recommended size?
- Approx 1/3 - 1/2 distance from cranial tibial tuberosity to medial condyle of tibia
- 50% width of isthmus (smaller that usually recommended as needs to bend with s-shaped bone)
- 30-40% if using with a plate
What unique consideration needs to be realised when placing cerclage around the distal tibia?
The tibia and fibula are closely associated from mid-diaphysis distally usually requiring the cerclage wire to be placed around both bones
What is the reported rate of non-union in tibial fracture repairs?
4.1%
What are the repair options for distial tibial physeal fractures?
- Cross-pinning from medial and lateral malleoli
- IM pinning or single transarticular pin (talus to tibial medullary cavity) with rigid external coaptation. Less desirable, ONLY if not enough bone for cross pinning
What are the repair options of malleolar fractures?
- Pins alone
- Pin and tension band
- Screw
List the main forms of congenital/developmental tibial deformities and the breeds most commonly associated with them
- Pes Varus - Dachshunds
- Pes Valgus - Shelties, Large breeds
- Significant increase in TPA - Westies
