Orthopaedics - knee & leg

Question 1

Knee OA risk factors

Answer 1

Genetic factors
Increasing age, female, obesity & low bone density
Local factors – previous joint injury, occupational/recreational stresses on the joint, reduced surrounding muscle strength, joint laxity/malalignment

Question 2

Knee OA clinical features

Answer 2

Pain – felt around the knee, can radiate to the thigh & hip, exacerbated by exercise, relieved by rest
Often have bilateral disease, associated joint stiffness which can result in reduced function
Examination – reduced range of movement, evidence of muscle wasting, crepitus

Question 3

Knee OA investigations

Answer 3

Plain film radiograph – AP and lateral views (skyline view can be useful to assess for any patellar involvement)
Blood tests – infective causes
MRI – ligamentous injury

Question 4

Knee OA initial management

Answer 4

Lifestyle modifications – weight loss, regular exercise, smoking cessation
Adequate pain control – ensure ongoing mobility and quality of life
Physiotherapy

Question 5

Knee OA surgical management

Answer 5

Total knee replacement is standard treatment for advanced OA – majority will function for at least 10 years
10% of patients only requires a partial knee replacement – used for disease localised to a single compartment (faster recovery times)

Question 6

Patellofemoral OA

Answer 6

OA affecting the articular cartilage along the trochlear groove and on the underside of the patella
Risk factors – patella dysplasia, previous patella fracture

Question 7

Patellofemoral OA clinical features & management

Answer 7

Anterior knee pain, specifically worse with activities that put pressure on the patella eg. climbing a flight of stairs
Joint stiffness and swelling
Skyline view on plain film radiographs
Conservative management first, then patellofemoral replacement may be required (other parts involved = total knee replacement)

Question 8

ACL tear clinical features

Answer 8

History of twisting the knee whilst weight-bearing
Majority occur without contact and patient is unable to weight bear
Rapid joint swelling (ligament is highly vascular -> haemarthrosis) & significant pain
Specific tests – Lachman test (more sensitive) and anterior draw test

Question 9

ACL tear investigations

Answer 9

Plain film radiograph (AP and lateral) – exclude bony injuries
- Segond fracture (bony avulsion of the lateral proximal tibia) is pathognomic of ACL injury
MRI scan is gold-standard

Question 10

ACL tear management

Answer 10

Immediate management – RICE (rest, ice, compression & elevation)
Conservative – rehab, cricket pad knee splint can be applied for comfort
Surgical reconstruction of ACL involves the use of a tendon/artificial graft – not performed acutely but after PT for a period of months
Acute surgical repair of the ACL – re-suturing the ends of the torn ligament together

Question 11

ACL tear complications

Answer 11

Post-traumatic OA

Question 12

PCL tear

Answer 12

Typically occur in high-energy trauma, such as a direct blow to the proximal tibia during a RTA
Result in immediate posterior knee pain, instability of the joint and a positive posterior draw test
MRI scan is gold standard
Can often be treated conservatively with a knee brace and physiotherapy (may require surgery id doesn’t get better)

Question 13

Iliotibial band syndrome

Answer 13

Inflammation of the band (branch of longitudinal fibres that form the shared aponeurosis of tensor fascia latae & gluteus maximus)
Most common cause of lateral knee pain

Question 14

Iliotibial band syndrome risk factors

Answer 14

Regular exercise – repetitive flexion and extension (runners, weightlifters, cyclists)
Anatomical risk factors – genu varum, excessive internal tibial torsion, foot pronation and hip abductor weakness

Question 15

Iliotibial band syndrome clinical features

Answer 15

Lateral knee pain, exacerbated by exercise
Assess for any previous trauma or features of OA
Examination may often be unremarkable, only with pain localising to lateral aspect of the knee
Special tests – Nobles and Renne

Question 16

Iliotibial band syndrome management

Answer 16

Advise to modify their activity & use of simple analgesics during periods of acute pain
Longer-term management – local steroid injections, PT
Surgical – only if patients remain symptomatic/functionally limited after 6 months
- Release of the iliotibial band from its attachments from the patella

Question 17

MCL tear clinical features

Answer 17

Typically occurs after trauma to the lateral aspect of the knee
Isolated medial collateral ligaments tears – usually direct below in a valgus stress direction
Non-contact MCL injuries occur less commonly & often arise from a valgus stress with external rotation force
Patient may report hearing a ‘pop’ with immediate medial joint line pain, delayed swelling
Increased laxity when testing the MCL

Question 18

MCL tear investigations

Answer 18

Plain film radiograph – exclude any fracture
MRI – gold standard

Question 19

MCL tear management

Answer 19

Dependent on the grade of injury:
1) Grade I – RICE with analgesia as the mainstay, strength training as tolerated, aim to return to full exercise within around 6 weeks
2) Grade II – analgesia with a knee brace and weight-bearing/strength training as tolerated, should aim to return to full exercise within around 10 weeks
3) Grade III – analgesia with a knee brace and crutches, patients should aim to be able to return to full exercise within around 12 weeks

Question 20

MCL tear complications

Answer 20

Instability in the joint
Damage to the saphenous nerve

Question 21

Meniscal tear clinical features

Answer 21

Tearing sensation in their knee, associated with an intense sudden-onset pain, knee swells slowly
Knee may be locked in flexion
Examination – joint line tenderness, significant joint effusion, limited knee flexion
- Specific tests: McMurray’s & Apley’s grind test

Question 22

Meniscal tears investigations

Answer 22

Plain film radiographs – exclude a fracture
MRI – gold standard investigation to confirm a meniscal tear

Question 23

Meniscal tears management

Answer 23

Immediate management – RICE
Larger tears/remaining symptomatic: arthroscopic surgery is indicated

Question 24

Meniscal tears complications

Answer 24

Secondary OA
Knee arthroscopy – risk of DVT, damage to local structures

Question 25

Patella fractures clinical features

Answer 25

Anterior knee pain, following a mechanism of injury eg. hard blow to the patella/strong contraction of the quadriceps
Pain will be made worse with movement and the patient will be unable to straight leg raise
Examination – affected knee will be significantly swollen and bruised
Visible & palpable patellar defect is present between the bone fragments

Question 26

Patella fractures investigations

Answer 26

Plain film radiographs – AP, lateral and skyline
CT – indicated in comminuted fractures & in cases not overtly apparent on plain films but clinically suggestive

Question 27

Patella fractures conservative management

Answer 27

Used in cases of non-displaced or minimally displaced patella fractures
Brace/cylinder cast, ensuring early weight bearing in extension with initial minimal displacement and articular step-off

Question 28

Patella fractures surgical management

Answer 28

Indicated in cases of significant displacement or compromise to the extensor mechanism
ORIF with tension band wiring
Simple vertical/transverse fractures occurring in healthy cancellous bone – screw fixation without the use of wires

Question 29

Patella fractures complications

Answer 29

Loss of range of motion
Secondary OA

Question 30

Tibial plateau fractures

Answer 30

High-energy trauma from the impaction of the femoral condyle onto the tibial plateau
Typically a varus-deforming force, meaning that the lateral tibial plateau is more frequently fractures that the medial side

Question 31

Tibial plateau fractures clinical features

Answer 31

History of trauma
Sudden onset of pain in affected knee, being unable to weight bear & swelling of the knee
Examination – significant swelling will be evident, tenderness over the medial/lateral aspects of the proximal tibia, with potential ligament instability
Check for peripheral neurovascular status

Question 32

Tibial plateau fractures investigations

Answer 32

Plain film radiographs – AP and lateral, also be a lipohaemarthrosis present
CT – almost all cases apart from undisplaced fractures, help both in assessment of severity & surgical planning

Question 33

Tibial plateau fractures conservative management

Answer 33

Trialled in uncomplicated tibial plateau fracture
Hinged knee brace
Non or partial weight bearing for around 8-12 weeks, alongside ongoing PT and suitable analgesia

Question 34

Tibial plateau fractures operative management

Answer 34

Typically warranted in complicated tibial plateau fractures
ORIF – aim is to restore the joint surface congruence and joint stability
Post-op – hinged knee brace is fitted with early passive range of movement but limited/non-weight bearing for around 8-12 weeks is required
External fixation with delayed definitive surgery – indicated in cases of significant soft tissue injury

Question 35

Tibial shaft fracture clinical features

Answer 35

History of trauma
Severe pain (high risk for compartment syndrome) in lower leg and inability to weight bear
Examination – clear deformity, significant swelling and bruising
Careful inspection of the skin
Full neurovascular examination should be performed

Question 36

Tibial shaft fracture investigations

Answer 36

Urgent bloods, including coagulation and group & save, should be sent
Full length AP and lateral plain film radiographs of the tibia and fibula should be requested
CT imaging – potential intra-articular extension/fracture of posterior malleolus

Question 37

Tibial shaft fracture conservative management

Answer 37

Realigned ASAP
Above knee backslab should be applied to control rotation, limb elevated immediately & closely monitored
Post-manipulation plain radiographs & neurovascular status re-assessed
Sarmiento cast can be considered in closed stable tibial fractures

Question 38

Tibial shaft fracture surgical management

Answer 38

Intramedullary nailing
Proximal/distal fractures – ORIF
Associated fractures of the fibular can usually be left alone as they heal very well once tibial fracture has been stabilised

Question 39

Tibial shaft fracture complications

Answer 39

Compartment syndrome
Ischaemic limb
Open fractures
Malunion
Non-union