Sports injuries Flashcards
What are the menisci of the knee?
- two semicircular fibrocartilage structures that lie between the femoral and tibial articular surfaces
- they act as shock absorbers and are prone to injuries caused by the large forces crossing the knee
Basic anatomy of the knee diagram…
Knee anatomy cross-section…
Which meniscus (lateral or medial) is more commonly injured and why?
- the medial meniscus is more commonly injured because it is fixed, in comparison to the more mobile lateral meniscus
What are the 2 types of meniscal tears?
- Traumatic: injury usually occurs after landing or twisting witht he knee flexed (can be associated with ACL tear)
- Degenerative tears: occur in older population through abnormal cartilage (may occur with very little injury)
Bucket-handle meniscal tear…
Why is it clinically important to establish how peripheral (close to outer boundary) a meniscal tear is?
- very peripheral tears occur through vascular tissue and usually repair well
- meniscal tears further away from the blood supply (ie. further into the knee) cannot heal
Meniscal cyst diagram…
- meniscal cyst results from synovial fluid being pumped into the meniscal tear
- (a valve effect means the fluid in the cyst cannot drain back into the knee)
What injury usually causes a meniscal tear, and what are the clinical features of a meniscal tear?
- Type of injury: during a tackle, twisting or changing direction
- Symptoms: locked knee, effusion, joint line tenderness
How is diagnosis of meniscal tears made?
- usually just on history and examination (special tests for meniscal tears are not very reliable)
- MRI: confirms diagnosis but knee arthroscopy is most accurate way to confirm diagnosis
What is the management for meniscal tears?
- Conservative: RICE, physio
- Surgical: arthroscopy (meniscal repair if able to, partial meniscectomy removes damaged portion only and reduces risk of OA in future)
What is the role of the ACL and what is the mechanism of injury of an ACL tear?
- ACL prevents anterior translation of the tibia (also restrains rotation)
- Mechanism of injury: twisting or valgus strain pattern (common in football and skiing)
- note: associated injuries to the MCL and meniscus are common
Mechanism of injury in anterior cruciate ligament (ACL) rupture…
- knee is usually extended or slightly flexed with the foot fixed
What is the unhappy triad?
- ACL injury
- MCL injury
- meniscal injury
What are the symptoms of an ACL rupture/tear?
- Struggle to weight-bear
- Instability of knee (‘giving way’) but no pain
- struggle to change direction at speed
- effusion sometimes
What is the difference between onset of injury between meniscal tears and ACL tears, and why?
- ACL tears: swelling usually occurs within minutes to hours
- Meniscal tears: swelling usually occurs over 24 hours
- (this is because the ACL is more vascular than the menisci)
How is diagnosis of an ACL tear made and how is diagnosis confirmed?
- Anterior drawer test (Lachman test is +ve)
- diagnosis made clinically and confirmed with arthroscopy and MRI
What is the management for an ACL tear?
- Conservative: RICE and physio
- Surgical: ACL reconstruction by arthroscopy if knee is unstable (tendon graft)
What is the role of the PCL?
- PCL is the primary restraint to posterior movement of the tibia on the femur
What is the aetiology of a PCL tear?
- PCL injuries require a lot of force (usually from RTAs, dashboard injury)
- PCL can also rupture when knee is forcibly hyperextended
- Check neurovascular status of leg and foot as potential knee dislocation which is bad!)
Mechanism of injury in posterior cruciate ligament (PCL) injuries…
What are the clinical features of a PCL injury?
- unable to weight-bear
- positive posterior sag and positive posterior drawer test
- look for associated ligamentous injuries
What investigation should be done for suspected PCL injury?
- MRI
What is the management for PCL injuries?
- Conservative: rehabilitation
- Surgical: reconstruction
Which collateral ligament injury is more common (medial or lateral)?
- Medial (MCL) are more common, commonly associated with ACL injuries too
Mechanism of injury in collateral ligament tears…
What are the clinical features of collateral ligament injuries?
- pain and possible instability
- MCL: tenderness over attachment of MCL and opening up of joint on valgus stress is present
- LCL: easily palpable as a cord-like structure, area is tender, opening up of joint on varus stress is present
What is the management for collateral ligament tears?
- Conservative: physio and bracing for 6 weeks if bad
- Surgical: only if chronic unstable injuries
Anatomical features that prevent lateral dislocation of the patella…
What are the 2 types of patella dislocation and what is the aetiology?
- Habitual: usually young women with ligamentous laxity and a hypoplastic trochlea
- Traumatic: usually during sports with knee slightly flexed with side impact
What are the clinical features of a patella dislocation?
- very painful, tenderness over medial side of knee and an effusion
- patella usually spontaneously reduces if knee has been extended (if not then will be laterally displaced)
What is the patellar apprehension test?
- forced lateral displacement of the patella produces anxiety and resistance in patients with a history of lateral patellar instability
What is the management for a patella dislocation?
- Conservative: reduction, mobilisation encouraged, physio
- Surgical: osteochondral fractures should be repaired or removed arthroscopically, recurrent dislocations may require surgical realignment, repair of medial patellofemoral ligament is carried out where physio has failed
What is the aetiology of shoulder dislocations?
- The shoulder joint has very little stability
- The joint has sacrificed stability for movement
What is the pathology of a shoulder dislocation?
- Dislocation can be anterior (95%) or posterior (5%)
- Anterior dislocation: occurs when arm is forced back in a ball-throwing position of external rotation and abduction
- Posterior dislocation: occur with high-energy trauma, epileptic seizures, and electrocutions
What is a Bankart lesion?
- Glenoid labrum tear = Bankart lesion
- (predisposing to further dislocations)
What is a Hill-Sachs lesion?
- Recurrent dislocations cause a Hill-Sachs lesion due to impaction of the glenoid on the posterior part of the humeral head
What are the clinical features of a shoulder dislocation?
- patient usually sports player (rugby)
- lots of pain, shoulder usually being held by other arm
- Examination findings: loss of normal contour, palpable glenoid, complete loss of movement
- (posterior: arm held in fixed internal rotation)
Abnormal shoulder contour in anterior dislocation of the humerus…
What investigations should be done for suspected shoulder dislocations?
- Confirm anterior dislocation with x-ray (always performed to exclude fracture)
- Posterior dislcoation often missed (AP x-ray appears normal), should be suspcected if arm in fixed internal rotation
Posterior dislocation of shoulder: AP X-ray showing light bulb sign…
Posterior dislocation of shoulder: CT scan (axial view)…
- there is posterior subluxation of the head with impaction of the head from the glenoid rim
What is the management for a shoulder dislocation?
- Conservative: reduction with adequate analgesia, then joint is rested in collar and cuff, then physio
- (check axillary nerve is functioning before and after any intervention)
- Surgical: posterior dislocation may require open reduction with general anaesthesia
Elderly people when they dislocate their shoulder don’t usually get a Bankart lesion, what happens instead?
- rotator cuff usually tears instead
What is the aetiology of an ankle sprain?
- commonly found on the sports field
- mechanism of injury is inversion or eversion with damage to the lateral ligament and medial ligament respectively
What is the pathology of a lateral ligament sprain and what is the pathology of a medial ligament sprain?
- Lateral ligament sprain: varus tilt of talus, anterior talofibular and calcaneofibular ligaments are torn
- Medial ligament sprain: valgus tilt of talus, deltoid ligament complex is torn
Lateral ligament sprain/rupture diagram…
What are the clinical features of an ankle sprain?
- pain, ‘feels something go’, swelling occurs immediately
- tenderness over the medial or lateral aspect of the ankle
When would an x-ray be done in suspected ankle sprain?
- x-ray only done if there is bony tenderness (malleoli) and inability to bear weight (Ottawa ankle rules)
What is the management for an ankle sprain?
- Conservative: analgesia, RICE, physio
A patient comes in after an injury at the gym whilst bicep curling, on his upper arm their is a ‘pop eye’ sign, what is the diagnosis?
- proximal biceps tendon rupture
