Disorders Of The Knee Flashcards
What is a femoral shaft fracture and what are the positions of the bones after the break.
Result of high velocity trauma.its a complete fracture of the femur. The proximal fragment is abducted due to pull of glutes on the greater trochanter and flexed due to action of iliopsoas on the lesser trochanter.the distal segment in adducted due to adductor mucous and extended. Patient has swollen tense thigh and closed blood loss which may cause hypovolaemia. May cause complications with neurovascular structure around break. Fixed with surgery
What is a distal femoral fracture
High energy sporting injury causin significant displacement of fracture fragments.popliteal artery may become involved and need to examine neurovascular status of limb. Look at X-ray pic
What happens during a tibial plateau fracture
Usually done via varus or valgus angulation (loaded in awkward medial or lateral load) of knee. They affect articulating surfaces of tibia, can be unicondylar or bicondylar (affecting 1 or 2 condyles). Articulate cartilage is damaged ad patients will develop post-traumatic osteoarthritis in that joint. Can also be associated with meniscal tears and cruciate ligament injuries.
What happens during patellar rapture
On examination there is a palpable patella and hamarthrosis (blood in joint)
What happens if the fracture entirely spilts in 2 (extensor mechanism disruption)
The patient will be unable to perform a straight leg raise.
How to treat a displaced and an undisplaced patellar fracture
Displaced- requires reduction and surgical fixation
Undisplaced- protected during healing through splint and using crutches
What is a patella bipartite and what can this be mistaken for
When the patellar is in 2 parts from birth (8% of population). Due to failure of secondary ossification centre fails to join to main body of patella. Can be mistaken for patellar fracture
What happens during patella dislocation
Completely displaced out its normal alignment. Partial displacement is subluxation. Usually causing by twisting during slight flexion
Factors that predispose patellar dislocation
Generalised ligamentous laxity
Weakness of quadriceps muscles especially VMO (hold patella in place)
Shallower trochlear grove with a floater lateral lip
Long patellar ligaments
Previous dislocations
Treatment of patellar dislocation
Extend the knee and then manually reducing the patella. Imobilisation is used whilst this happens. Then use physiotherapist to strengthen
When do meniscal injuries occur
Occur during sudden twisting motion of a weight bearing knee in a high degree flexion.
Symptoms of meniscal tear
Pain, feeling of locking knee, swelling (but delayed because the menisci are avascular), increased synovial fluid (chronic effusion), synovitis (inflammation of synovial membrane), patient has joint tenderness. Locking occurs due to loose meniscal fragments trapped articulated surfaces
