Week 6 - G - Regional Adult Trauma (6) - Knee&Patellar dislocations, Tibial fractures Flashcards
True knee dislocations are uncommon but can occur in high energy injuries or with severe hyperextension and/or rotational forces with a sporting injury. What ligament is torn in a knee dislocation?
Usually multiple ligaments are torn in a knee dislocation
What is a true knee dislocation?
It is where the bones of the tibia and fibula are moved in relevance to the femur
Obvious knee dislocations should be reduced urgently What should be checked urgently in a knee dislocation?
Check the neurovascular status
Patellar dislocations are relatively common. Is it more common to have a medial or lateral patellar dislocation?
It is more common to have a lateral patellar dislocation - virtually all are lateral
How do patellar dislocations tend to occur?
Tend to occur due to a direct blow to the kneecap or when the quadriceps tendon is contracted and the knee rotates
What is the groove between the condyles of the femur where the patella sits?
Sits in the trochlear groove
Patellar dislocations and subluxations are more common in adolescents, What are some predisposing risk factors to patellar dislocations and sublaxations?
Being female
Generalised ligamentous laxity
Muscular imbalnce
Valgus alignement of the knees
Shallow trochlear groove and
rotational malalignment
What is the main sign of patella femoral dysfunction?
There is knee pin with the leg being unable to flex
What percentage of patients will experience a further patellar dislocation after their first patellar discloation? What percentage of these patients will go on to have multiple recurrent dislocations?
Around 10% of all first time patellar dislocation patients will experience a further dislocation and
50% of those will have multiple recurrent dislocations
There 5% of patients will have multiple recurrent dislocations after their first patellar dislocation
What is the proximal part of the tibia known as?
The tibial plateua
Which bone of the leg does not take part in the knee joint?
The fibula
Tibial plateau fractures can be either high energy injuries in the younger patient or low energy in osteoporotic bone. What type of fracture is a tibial plateua fracutre?
It is an intraarticular fracture
What is the usual treatment of a tibial plateau fracture?
Intraarticular fracture usually treated using open reduction and internal fixation (ORIF) with plates and screws
Despite efforts to restore the articular surface, results of surgery are often disappointing and patients often require what as treatment?
Often require total knee replacement as treatment
What are the five types of fracture patterns?
Transverse fractures - occur due to bending
Oblique fractures - occur due to shearing (direct blow, decelerating)
Spiral fractures - due to torsional force
Comminuted - 3 or more segments -very unstable
Segmental - bone is fractured in 2 segments - v unstable
Tibial shaft fractures usually occur with indirect force and either * bending or * rotational energy , * compressive force from deceleration or, * a combination of these forces or from high energy injuries What pattern of fracture does each cause?
Bending - transverse fracture
Rotation energy - spiral fracture
Compressive force from deceleration - oblique fracture
Combination of these force or from high enrgy injuries - comminuted fracture
Up to 50% displacement and 5° of angulation in any plane for a tibial fracture requires what treatment?
Up to 50% displacement and 5degrees angulation is conservative treatment in an above knee cast
Why are open fractures not uncommon in tibial shaft fractures?
The tibial shaft is subcutaneous - very close to the skin
How are open tibial fractures treated?
Internal or external fixation provided a thorough debridement has been performed
Any internal rotation of the distal fragment is poorly tolerated in a tibial fracture What is the main method of treating a tibial shaft fracture if greater than 50% displacement or 5degrees angulation?
Internal fixation using an intramedullary nail
The intramedullary nail is inserted behind the patellar tendon and therefore what do 25% of patients complain of which is important to discuss?
25% of patinets suffer significant anterior knee pain (remember this pain aka patellofemoral pain typically occurs in young active females - mainstay of treatment is physiotherapy)
External fixation is favoured by some for tibial shaft fractures however what are some cons?
Pin site infection or loosening may occur
As tibial fractures are a main cause of compartment syndrome in the leg What is the treatment? How many compartments are in the leg?
Fasciotomy (4 compartments in the lower leg)
Just like distal femur fractures, distal tibial fractures can be extra or intra articular What is the treatment for extra-articular fractures in an acceptable position?
This would be conservative treatment
What is an intra-articular distal tibia fracture also known as?
Pilon fracture
What is the gernal treatment of pilon fractures?
If swelling present - then external fixation until swelling goes down and then ORIF
If the cause of the distal tibia fracture is post-traumatic OA, what is the treatment?
Usually arthrodesis
An intrarticular tibial fracture is known as a pilon fracture as pilon is french for pestle (mortar and pestle) The talus (pestle) drives into the distal tibia (mortar), how does this occur usually?
Usually high energy fractures due to a fall from a height or deceleration
Which bones form the ankle joint?
The tibia, fibula and the talus form the joint
