Lower limb (2) pathologies Flashcards
Describe a fracture of the femoral shaft (different fragments, causes)
High-velocity trauma in healthy young, low-velocity trauma in osteoporotic bones & patients with bone lesions
Proximal fragment is often abducted due to pull of gluteus medius and minimus and flexed due to iliopsoas
Distal fragment is adducted into a varus deformity due to adductor muscles and extended due to pull of gastrocnemius
Tense, swollen thigh & treated with surgical fixation
Describe distal femoral fractures
High-energy sporting injury in young, fall in elderly
Popliteal artery may be involved if significant displacement (neurovascular structures should be carefully assessed throughout)
Describe tibial plateau fractures
High-energy injuries (axial loading with varus or valgus angulation of the knee)
Articular cartilage is always damaged
Most patients will develop post-traumatic osteoarthritis in the affected joint
Describe patellar fractures
Caused by direct impact injury or eccentric contraction of quadriceps muscle
Patient will be unable to perform a straight leg raise
Displaced = surgery fixation & reduction, undisplaced = protected while healing takes place eg. crutches, splinting therefore surgery not required
Describe patella dislocation
Patella is completely displaced out of its normal alignment
Most common to dislocate laterally, common cause trauma
Predisposing factors: weakness of quads, previous dislocations, generalised ligamentous laxity
Describe meniscal injuries
Most common knee injury -> occur during a sudden twisting motion of a weight-bearing knee in a high degree of flexion
Intermittent pain localised to joint line, knee clicking
Swelling is a delayed symptom
Acute treated with surgery, chronic treated with conservative management
Describe collateral ligament injuries
Common sporting injury (acute varus or valgus angulation of the knee)
Valgus strain = medial collateral ligament, varus strain = lateral collateral ligament
MCL more commonly injured, but a torn LCL causes more instability
Describe an anterior cruciate ligament injury
Result of quick deceleration, hyperextension or rotational injury = non-contact injury
Feel popping sensation with immediate swelling & knee gives way (anterolateral rotatory instability)
Surgical reconstruction
Lachman’s test used to detect ACL injuries
Describe a posterior cruciate ligament injury
‘dashboard injury’ = knee is flexed and a large force is applied to the upper tibia (can be torn in football)
Dial test used to detect PCL injuries
What is the unhappy triad?
Injury to the:
1) Anterior cruciate ligament
2) Medial collateral ligament
3) Medial meniscus
Describe dislocations of the knee joint
Uncommon injury & high-energy trauma
Three of MCL, LCL, ACL and PCL must be ruptured
Associated artery injury is common (popliteal)
Describe prepatellar bursitis (‘housemaids knee’)
Knee pain, swelling
Difficult to walk and can’t kneel on affected side (repetitive trauma to the bursa)
Describe superficial infrapatellar bursitis (‘clergyman’s knee’)
Occurs due to repeated microtrauma caused by activities involving kneeling
Describe suprapatellar bursitis (knee effusion)
Usually a sign of significant pathology in the knee joint
Causes of a knee effusion: osteoarthritis, infection, gout
Describe semimembranosus bursitis (popliteal cyst)
Indirect consequence of swelling within the knee joint
Effusion -> fluid can force its way through the narrow communication into the semimembranosus bursa
Describe Osgood-Schlatter’s disease
Inflammation of the apophysis of the patellar ligament into the tibial tuberosity
Occurs in teenagers in who play sport & causes localised pain and swelling
Resolves with rest and ice
Describe septic arthritis
Invasion of the joint space by microbes
Most common pathogen = staph aureus
Prosthetic joints are particularly at risk
Major consequence = damage to the articular cartilage due to bacterial invasion
Aspiration of joint should be carried out immediately
Describe osteoarthritis of the knee
Knee pain, stiffness and swelling
Deformity is common eg. varus/valgus deformity
Increased friction can be felt as crepitus (grating sound on movement of the joint)
Surgery ultimately required
