Orthopaedics - Knee, Ankle + Foot Flashcards
Describe the mechanism of low energy fractures of the tibia
Invariable twisting, inversion or eversion injuries
Often occur following a fall from a standing height
Describe the mechanism of high energy tibial fractures
Direct blow to the tibia and fibula causing fracture comminution and soiling of the wound
What additional imaging is needed for tibial plateau fractures? Why?
CT scan - aids in operative planning
How are ankle fractures classified? Describe this briefly
Weber classification
A - Below syndesmosis
B - At level of syndesmosis
C - Above syndesmosis
What is a Pilon fracture?
Intra-articular fracture of the ankle joint
What classification is used for Pilon Fractures?
Ruedi and Allgower Classification
For which fractures is an above knee back slab indicated?
- Tibial plateau
- Diaphyseal
For what sort of fractures is a below knee back slab indicated?
- Pilon
- Ankle fracture
What classification is used for tibial and fibular fractures?
Schatzker
Define achilles tendonitis and describe its pathophysiology briefly
Inflammation of the calcaneal tendon – repetitive action of the tendon results in microtears –> localised inflammation –> thickening, fibrosis and loss of elasticity
What are the risk factors for achilles tendonitis?
- Unfit individual suddenly increasing exercise frequency
- Poor footwear
- Male
- Obesity
- Fluroquinolone use (rupture)
What are the clinical features of achilles tendonitis?
- Gradual onset of pain + stiffness
- Pain often worse with movement
- Can be relieved by mild exercise or heat
- Tenderness over tendon (worst 2-6cm above insertion)
What are the clinical features of achilles tendon rupture?
- Sudden onset severe pain in posterior calf
- Audible popping sound + feeling
- Loss of power in ankle plantar flexion
How is plantar flexion still maintained despite achilles tendon rupture?
Peroneal tendons also contribute to plantarflexion
What are the two most commonly used indicators of achilles tendon rupture?
- Simmond’s test
- Palpable ‘step’ in the tendon
What is Simmond’s test?
Assesses potential achilles tendon rupture :
- Patient kneels on a chair, affected ankle hanging off edge
- Squeeze affected calf
- -> plantar flexion absent if tendon is ruptured
What are the main DDx for achilles tendonitis?
- Ankle sprain
- Stress fractures of tibia or calcaneus
- Osteoarthritis
What investigation can be used if you are not sure of a diagnosis of achilles tendonitis?
USS of ankle
What is the management for achilles tendonitis?
Supportive - stop precipitating exercise, ice the area and use anti-inflammatories
What is the management for an acute achilles tendon rupture (<2wks)?
- Analgesia
- Immobilisation
- Ankle splinted in plaster in full equinus (max. pointed) for 2 weeks
- Move ankle to semi equinus for 4 weeks
- Move ankle to neutral for 4 weeks
What is the management for a delayed (>2wks) achilles tendon rupture?
Surgical fixation with end-to-end tendon repair
What is plantar fasciitis? Describe the physiology
Inflammation of the plantar fascia of the foot - microtears of the fascia
What are the risk factors for plantar fasciitis?
- Anatomical eg. excessive pronation or pes cavus (high arch)
- Weak plantarflexors
- Tight gastrocnemius or soleus
- Prolonged standing or excessive running
- Leg length discrepancy
- Obesity
- Unsupportive footwear
What are the main clinical features in a history of plantar fasciitis?
- Sharp pain across plantar aspect
- Pain most severe in heel + can radiate distally
- Worse after inactivity
What may be seen on examination of plantar fasciitis?
- Tender palpation of infracalcaneal region
- Palpation of medial calcaneal tubercle reproduces symptoms
- Overpronation
- High arches
- Leg length discrepancy
- Femoral anteversion
What are the main DDx to consider for plantar fasciitis?
- Achilies tendonitis
- Morton neuroma
- Calcaneal stress #
- Inflammatory arthropathy
What can be seen if an X ray is done in plantar fasciitis?
Plantar heel spur
What imaging modality can be used to visualise plantar fasciitis?
MRI scan - identify areas of thickening and any associated oedema
What is the main management for plantar fasciitis?
- Activity moderation
- Regular analgesics
- Change of footwear
- Physiotherapy
- Corticosteroid injections
- Plantar fasciotomy
What are the main functions of the menisci?
- Shock absorbers of the knee joint
- Increase articulating surface
What are the different types of meniscal tears?
- Vertical
- Longitudinal (Bucket-Handle) ***
- Transverse (Parrot-beak)
- Degenerative
What are the most common causes for meniscal tears?
- Trauma related injury
- Degenerative disease
What is the most common mechanism of injury in traumatic meniscal tears?
Twisted knee while flexed + weight bearing
What are the common clinical features on presentation of a meniscal tear?
- Tearing sensation in the knee
- Intense sudden-onset of pain
- Slow swelling of knee (~6-12hrs)
- May be locked in flexion/unable to extend
What may be seen on examination of a meniscal tear?
- Joint line tenderness
- Significant joint effusion
- Limited knee flexion
What specific tests can be used for assessment of a meniscal tear?
- McMurray’s test
- Apley’s grind test
What are the DDx to consider in an acutely swollen knee joint post trauma?
- Fracture
- Cruciate ligament tear
- Meniscal tear
- Colateral ligament tear
- Osteochondritis dissecans
What is the gold standard investigation for confirmation of a meniscal tear?
MRI
What is done in arthroscopic surgery for meniscal tears of different regions?
- Tear in outer 1/3 of meniscus - suture tear together
- Tear in inner 1/3 - trim tear
- Tear in middle 1/3 - either repair or trim
What is the main complication of a meniscal tear?
Increased risk of developing osteoarthritis later in life
What are the main risks associated with knee arthroscopy?
- DVT
- Damage to local structures eg. saphenous N+V, Peroneal nerve + popliteal vessels
Why does an ACL tear often result in significant functional impairment of the knee joint?
ACL is an important stabiliser + is primary restraint to limit anterior translation of tibia
How does an ACL injury often occur?
Twisting injury whilst weight bearing eg. landing from a jump
What are common clinical features of ACL tears?
- Rapid joint swelling
- Significant pain
- Instability (leg ‘gives way’)
Why is there joint swelling in an ACL tear?
Highly vascular ligament –> haemoarthrosis (within 15-30mins)
What is Lachman’s test?
Used to assess ACL tear
- Place knee in 30 degs flexion
- Pull tibia forward whilst stabilising femur
Which specific test on examination is best for assessing for an ACL tear?
Lachman’s test
What DDx should be considered in an ACL tear?
- Fracture
- Meniscal tear
- Collateral ligament tear
- Quadriceps/patellar ligament tear
Why should an X ray be done for a suspected ACL tear?
Exclude bony injuries, joint effusion or lipohaemoarthrosis
What is the gold standard investigation to diagnose an ACL tear?
MRI of knee
What conservative management is there for an ACL tear?
- Strength training of the quadriceps - stabilises the knee
- Canvas knee splint
What surgical management is there for ACL tears?
Tendon or artificial graft for the ACL
What is the main complication of ACL tears?
Post-traumatic osteoarthritis
How do PCL tears tend to occur?
- High energy trauma eg. RTA
- Low energy trauma with hyeprflexion of knee on plantarflexed foot
What are the main clinical features of a torn PCL?
- Immediate posterior knee pain
- Instability of joint
- Positive posterior drawer test
- Posterior sag
What is the gold standard diagnostic test for a PCL tear?
MRI scan
What is the conservative management for a PCL tear?
Knee brace and physio
What injury is an ACL tear most commonly associated with?
Meniscal tear (lateral meniscus more common)
Which is the most commonly injured ligament of the knee?
Medial collateral ligament
How is the MCL often injured?
When external rotational forces are applied to the lateral knee
What is the primary function of the MCL?
Valgus stabiliser
How are MCL injuries graded?
Grade 1 - mild, minimal torn fibres + no loss of MCL integrity
Grade 2 - Moderate, incomplete tear and increased laxity of MCL
Grade 3 - severe, complete tear and gross laxity of MCL
What are common clinical features of an MCL tear?
- Immediate medial joint line tenderness
- Swelling (after few hours)
- Increased laxity
- Hears a ‘pop’ at time of injury
How can a grade 2 MCL tear be differentiated from a grade 3?
Grade 2 = lax on 30 degs of flexion but solid in full extension
Grade 3 = lax in both positions
What is the gold standard investigation for a MCL tear?
MRI scan
What is the management for an MCL tear (based on grade)?
- Grade 1 –> RICE + strength training
- Grade 2 –> Analgesia + knee brace with strength training
Grade 3 –> Analgesia with knee brace + crutches
When is surgery considered for a MCL tear?
Grade 3 tear with associated distal avulsion
What are the timescales for full recovery of an MCL tear based on grade?
Grade 1 = 6wks
Grade 2 = 10wks
Grade 3 = 12wks
What are the main complications following an MCL tear?
- Instability in the joint
- Damage to saphenous nerve
What is iliotibial band syndrome? How is it thought to be caused?
Inflammation of the IT band - repetitive flexion/extension of knee causing impingement of band against lateral femoral condyle
What anatomical risk factors are there for IT band syndrome?
- Genu varum
- Excessive internal tibial torsion
- Foot pronation
- Hip abductor weakness
What are the main clinical features of IT band syndrome?
- Lateral knee pain
- Exacerbated by exercise
- Pain often worse running downhill
What special tests are there for IT band syndrome?
- Nobles test
- Renne test
Describe Nobles test briefly
- Patient supine
- Examiner places finger on lateral femoral condyle
- Knee slowly extended
+ve if pain felt at 30degs (ITB passing over lateral femoral condyle)
Describe Renne test briefly
- Examiner places pressure on lateral epicondyle
- Patient asked to squat
+ve if pain felt at 30 degs of flexion
What are the main DDx for ITB syndrome?
- Degenerative joint disease
- Fractures
- Ligamentous injury
How is ITB syndrome managed?
- Modification of activity
- Analgesia in periods of pain
- Local steroid injections
- Physiotherapy
When is surgery indicated in ITB syndrome? What is involved?
Still symptomatic or functionally limited after 6months
–> Release of ITB from attachments
What is the mechanism of injury in a tibial plateau fracture?
High energy trauma or axial loading - causes impaction of the femoral condyle onto the tibial plateau
Why is the lateral tibial plateau more commonly fractured?
Usually a varus-deforming force
What are commonly seen clinical features of a tibial plateau #?
- Sudden onset pain
- Unable to weight bear
- Knee swelling –> lipohaemoarthrosis
- Tenderness over medial or lateral aspects of proximal tibia
- Potential ligament instability
What is first line investigation for a tibial plateau #?
Anteroposterior and lateral X-ray
What is the investigation used for assessment of severity in a tibial plateau #?
CT scan
What classification is used for tibial plateau fractures?
Schatzker
Briefly outline the Schatzker classification
Used for tibial plateau #: 1 - Lateral split # 2 - Lateral split + depressed 3 - Lateral pure depression 4 - Medial plateau 5 - Bicondylar # 6 - Metaphyseal-diaphyseal disassociation
When is conservative management indicated in a tibial plateau fracture?
Uncomplicated - no evidence of ligamentous damage, tibial sublaxation or articular step <2mm
What conservative management is there for tibial plateau fractures?
- Hinged Knee brace
- Non/partial weight bearing for around 8-12wks
- Physiotherapy
- Suitable analgesia
What is considered a complicated tibial plateau fracture?
- Articular step >2mm
- Angular deformity >10 degs
- Metaphyseal-diaphyseal translation
- Ligamentous injury
- Associated tibial fractures
What is the typical surgical management for a tibial plateau fracture? What is the purpose of this
ORIF - aim is to restore joint surface congruence and ensure stability
Fill metaphysical gaps with bone graft or bone substitute
Why are tibial plateau fractures considered significant?
Disruption of the congruence of the articular surface - if left leads to rapid degenerative change
What is the main complication post tibial plateau fracture?
Post-traumatic arthritis
Where do talar fractures tend to most commonly occur?
Through the talar neck
What is the risk in talar fractures?
High risk of avascular necrosis - talus relies predominantly on extraosseous arterial supply which is highly susceptible to interruption
What are the clinical features of a talar fracture?
- Hx of high impact trauma
- Immediate pain and swelling around the ankle
- Clear deformity if dislocation
- Patient unable to dorsi/plantarflex ankle
How are type 1 and 2 talar fractures differentiated on imaging?
Take an x-ray in both dorsiflexion and plantarflexion
–> Plantarflexion will reduce any sublaxation
What classification is used for talar fractures? Outline this briefly
Hawkin's Classification 1 - Undisplaced 2 - Subtalar dislocation 3 - Subtalar and tibiotalar disolcation 4 - Subtalar, tibiotalar and talonavicular dislocation
How are type 1 talar fractures managed?
Conservatively in a plaster with non-weight bearing crutches for ~3months
–> assess for union + AVN in fracture clinic
How are type 2-4 talar fractures managed?
Closed reduction
Once reduced place a cast + order repeat radiographs
THEN definitive surgical fixation when next available
What are the main complications to be aware of in talar fractures?
- AVN
- Osteoarthritis
- Arthodesis
What is Hawkin’s sign?
Subchondral lucency of the talar dome - visible 6-8wks post injury –> indicates sufficient vascularity of talus and so low risk of AVN
What is the medical term for a bunion? What is this?
Hallux valgus – Deformity at the first metatarsophalangeal joint
Describe hallux valgus
- Medial deviation of the first metatarsal
- Lateral deviation +/- rotation of the hallux
- Associated joint sublaxation
Why do high heels/narrow fitting footwear cause increased risk of hallux valgus?
Keep the hallux in a values position (first metatarsal head drifts more medially)
What are the main risk factors for hallux valgus?
- Female
- CT disorders
- Hypermobility syndrome
- Anatomical variants (eg. long 1st metatarsal, malalignment of the 1st MTP joint, flat feet)
How does a hallux valgus typically present?
- Painful medial prominence
- Aggravated by walking, weight bearing or narrow toe shoes
What are the main DDx to consider in hallux valgus?
- Gout
- Septic arthritis
- Hallux rigidus
- Osteoarthritis
- Rheumatoid arthritis
What investigation is used for hallux valgus? What does it look at?
X ray
- Degree of lateral deviation
- Signs of joint sublaxation
What measurement is said to be diagnostic of hallux valgus?
Angle between first metatarsal and first proximal phalanx >15 degs
What is the conservative management for hallux valgus?
- Sufficient analgesia
- Adjustment of footwear
- Orthosis (if flat foot)
- Physiotherapy
What surgical procedures are there for problematic hallux valgus?
- Chevron procedure
- Scarf procedure
- Lapidus procedure
- Keller procedure
What surgical complications are there for hallux valgus?
- Wound infection
- Delayed healing
- Nerve injury
- Osteomyelitis
- Recurrence
What are the complications of hallux valgus?
- AVN
- Non-union
- Displacement
- Reduced ROM
