MSK Session2 And 3 Clinical Flashcards
Femoral shaft injuries are usually the result of
high velocity trauma
Risk of blood loss in closed femoral shaft fracture
Hypovolaemic shock
Treatment of femoral shaft fractures
Surgical fixation
Distal femoral fractures mechanisms
high energy sporting injury in kids and osteoporotic falls in elderly
Tibial fractures are
Fractures affecting articulating surface of tibia within knee joint, can be unicondylar or bicondylar
Tibial plateau fractures outcome
Articular cartilage always damaged, most patients will develop post traumatic osteoarthritis
Tibial plateau fractures are associated with
Meniscal tears and ACL injuries
Patellar fractures key points
Often palpable defect, if fracture splits patella, patient cannot perform straight leg raise as extensor mechanism disrupted
Most common direction for patella to dislocate
Laterally
What is the the unhappy triad /blown knee
Injury to anterior cruciate ligament, medial collateral ligament and medial meniscus, results from strong force applied to lateral aspect of knee
ACL tear key features
usually non contact, result of quick deceleration, hyperextension or rotational injury, sudden sensation of knee giving way (anterolateral rotatory instability), tibia can slide anteriorly under femur when ACL ruptures
PCl injury key features
Dashboard injury- knee flexed and large force applied to upper tibia, displacing it posteriorly, tibia can be displaced posteriorly
tests for ACL and PCL injuries
Anterior and posterior drawer tests, lachman’s test
Dislocation of knee joint key features
At least 3 of 4 ligaments have to be ruptured (MCL, LCL, ACL, and PCL), associated arterial injury is common as popliteal artery is immobile, endothelial damage can lead to thrombotic occlusion (Virchow’s triad)
What is knee effusion
Accumulation of fluid inside knee joint
2 types of knee effusion
Haemoarthrosis (blood in joint, usually ACL rupture), Lipo-haemarthrosis (blood and fat in joint, usually fracture as fat released from bone marrow)
What is bursitis
Inflammation of a bursa
Pre-patellar bursitis key features
Housemaids knee, knee pain and swelling, may be some erythema, superficial bursa with a thin synovial living between skin and patella
Infrapatellar bursitis key features
2 bursa- one between patella tendon and skin and another between patella tendon and bone. Occurs due to repeated micro trauma such as clergyman’s knee
Suprapatellar bursitis
Extension of synovial cavity of knee joint, a knee effusion presents with swelling in suprapatellar pouch. Usually a sign of pathology - OA, RA, Infection, Gout, microtrauma from running on weird surface
Semimembranosus bursitis
Indirect consequence of swelling within knee joint, located between deep fascia of popliteal fossa and posterior capsule of knee joint. Fluid can force its way through from knee joint. Swelling in popliteal fossa known as popliteal cyst or Baker’s cyst
Osgood-Schlatter’s disease
Inflammation of apophysis of patellar ligament into tibial tuberosity, teenagers who play sport, intense knee pain. Pain and swelling resolve when apophysis fuses when older.
OA symptoms
Knee pain, stiffness and swelling. Deformity (varus, valgus or fixed flexion)
OA signs
Loss of articular cartilage leads to friction, can be felt as crepitus, effusion may develop, muscle weakness (especially quadriceps)
Septic arthritis of knee aetiology
Invasion of joint by micro-organisms, often staph aureus, prosthetic joints particularly at risk, articular cartilage damaged, hydrolysis of collagen and proteoglycans
Septic arthritis symptoms and treatment
Fever, pain, reduced range of motion, aspiration of joint
Primary causes of OA
Age, sex, ethnicity, nutrition, genetics
Secondary causes of OA
Obesity, trauma, malalignment, infection, RA, metabolic/haematological/endocrine disorders
Pathology of OA
XS loading of joint and damage to articular cartilage, increased proteoglycans synthesis by chondrocytes, flaking and fibrillation of articular cartilage, erosion of cartilage down to subchondral bone
Altered joint biomechanics in OA leads to
Vascular invasion, cystic degeneration and osseous metaplasia of connective tissue
Radiological features of OA
Sclerosis (more white), no joint space, cysts noted, osteophytes
Management of OA
Activity modification, weight loss, walker, physio, NSAIDs, Corticosteroids, joint replacement
Hip fractures signs and symptoms
Reduced mobility, pain, shortened and rotated
NOF fracture definition
Fracture of proximal femur, up to 5cm below the lesser trochanter
Types of NOF
Intracapsular, extracapsular (intertrochanteric or subtrochanteric)
Problem with Intracapsular fracture
More likely to disrupt ascending cervical branches of MFCA (artery of ligamentum teres cannot sustain metabolic demand), risk of avascular necrosis. Increased risk if fracture displaced
NOF presentation
Shortened, abducted and externally rotated
Why does NOF cause hip to be shortened, abducted and externally rotated
Short lateral rotators (piriformis, obturator internus, superior and inferior gemellus and quadratus femoris) contract and laterally rotate. Iliopsoas also now acts as lateral rotator. Glut med and min abduct and rotate laterally. Rectus femoris, adductor magnus and hamstring muscles shorten the limb by pulling distal fragment of femur up
Dislocation of hip definition
Femur being fully displaced out of acetabulum
2 types of hip dislocation
Congenital, traumatic
90% of hip dislocations are
Posterior
Most common cause of knee dislocation
Impact of dashboard during road traffic collision
Posterior Hip dislocation presentation
Shortened, flexed, adducted and medially rotated. Sciatic nerve palsy present in 8-20% of cases
Why do shortening and internal rotation of the limb occur after posterior dislocation of the hip?
Femoral head pulled upwards by strong extensors (glut max and hamstrings) and adductors after being pushed backwards over acetabulum. Anterior fibres of glut med and min cause internal rotation by pulling on posteriorly displaced greater trochanter.
Anterior hip dislocation presentation
Externally rotated and abducted with slight flexion. Femoral nerve palsies can be present but are uncommon
Central hip dislocation presentation
Head of femur driven into pelvis though acetabulum. Always fractured. Femoral head is palpable on rectal examination. High risk of intra pelvic haemorrhage. Life threatening
