Hip and knee disorders

Question 1

signs and symptoms of hip OA?

Answer 1

pain in the buttock referred to groin and thigh, stiffness (EMS <30 minutes), reduced ROM

signs:

• reduced ROM of hip joint, especially internal rotation
• crepitus
• may have antalgic gait or Trendelenberg gait

Question 2

what are the non-operative management options for hip OA?

Answer 2

• Weight loss advice (to reduce load travelling through hip)
• Use of walking stick in opposite hand to side of pain
• Analgesia (NSAIDs such as ibuprofen and naproxen)
• Physiotherapy to optimise range of movement

Question 3

what are the operative management options for hip OA?

how is the patient prepped for surgery?

Answer 3

hip arthroplasty (total hip replacement)

prepped with prophylactic antibiotics and thromboprophylaxis to reduce the risk of infection, deep vein thrombosis and pulmonary embolism

Question 4

what are the signs and symptoms of knee OA?

signs- look, feel, move

Answer 4

symptoms: pain especially when climbing stairs, stiffness, reduced ROM

signs:

• crepitus
• globally reduced ROM
• swelling due to synovial thickening/inflammation and effusion
• varus malalignment due to medial compartment OA
• Bony spurs/osteophytes may be felt, especially around the tibial plateau/joint line

Question 5

the conservative management of knee OA is the same as hip OA.

what is the surgical management of knee OA?

Answer 5

for early OA in young patients: tibial osteotomy (when a wedge of bone is removed from the lateral side of the tibia, helping to redistribute the load travelling across the knee joint, thereby diverting force away from the damaged medial compartment)

for OA that is localised to one compartment of the knee: unicompartmental joint replacement

otherwise: total knee replacement

Question 6

list common causes of hip avascular necrosis

Answer 6

• trauma - femoral neck/head fracture, hip dislocation
• steroids
• alcohol abuse
• chemotherapy
• viral infection (HIV, hepatitis)
• connective tissue disease (SLE, vasculitis)
• Haematological disease e.g. leukaemia, lymphoma, sickle cell
• Hyper-coagulable states e.g. pregnancy

Question 7

describe the pathological process causing hip AVN in traumatic and non-traumatic cases

Answer 7

traumatic: Direct injury to the vasculature supplying the femoral head, resulting in ischaemia

non-traumatic: thrombotic occlusion of the intra-osseous microcirculation causes retrograde arterial occlusion. this decreases the blood flow to the osteocytes in the femoral head and causes ischaemia

Question 8

what radiological imaging is used to detect AVN of the hip? which is best?

Answer 8

X-ray and MRI

MRI is best because it can detect changes much earlier within the bone. X-ray can detect advanced disease.

Question 9

what is a slipped upper femoral epiphysis? (SYFE)

Answer 9

SUFE is a fracture through the capital femoral physis, causing the epiphysis to ‘slip’ posteriorly and inferiorly.

physis = growth plate, epiphysis = end of a long bone

Question 10

what are the clinical features of a slipped upper femoral epiphysis?

Answer 10

symptoms:

• groin pain often referred to knee or thigh
• have a limp

signs:

• externally rotated and shortened leg on inspection
• tenderness around hip joint
• reduced ROM especially internal rotation

Question 11

who usually presents with a slipped upper femoral epiphysis?

what is the biggest risk factor?

Answer 11

a child aged 10-16 years, usually male and obese and after minor trauma

(Obesity is the single most significant risk factor due to increased forces travelling through the physis)

Question 12

Describe the x-ray appearances of SUFE

Answer 12

• Disruption to Shenton’s line
• Additional shadow behind the superior femoral neck (Steel sign)
• Apparent widening of the physis (growth plate) and a reciprocal decrease in the height of epiphysis
• Prominent lesser trochanter due to external rotation of hip joint
• Line drawn along the superior edge of the femoral neck (Klein’s Line) fails to intersect the lateral part of the superior femoral epiphysis

Question 13

what is developmental dysplasia of the hip and what does it lead to?

Answer 13

DDH is the abnormal development of the hip joint resulting in:

• dysplasia (shallow underdeveloped acetabulum)
• possible subluxation of the joint (partial displacement)
• potential hip dislocation (complete displacement)

Question 14

List the risk factors in DDH

Answer 14

• Family History in parent or first-degree sibling
• Breach position in utero or delivery
• Female
• being the first-born
• other MSK abnormalities e.g. foot deformity

Question 15

which children should be routinely ultrasound scanned for DDH?

Answer 15

• first-degree family history of hip problems in early life
• breech presentation at or after 36 weeks gestation
• multiple pregnancy

Question 16

what signs would you look for when examining a baby for DDH?

Answer 16

• postitve Barlow test: attempts to dislocate an articulated femoral head
• positive Ortolani test: attempts to relocate a dislocated femoral head
• asymmetry of hips (extra or deeper thigh creases)
• leg length discrepancy
• positive galleazi test
• restricted abduction of the hip in flexion

Question 17

when does a hip X-ray become the first line imaging for diagnosing DDH?

Answer 17

if the infant is > 4.5 months then x-ray is the first line investigation

Question 18

what is the management for DDH

Answer 18

most unstable hips will spontaneously stabilise by 3-6 weeks of age

Pavlik harness (dynamic flexion-abduction orthosis) in children younger than 4-5 months

older children may require surgery: Femoral or acetabular osteotomy, Closed or open reduction of hip joint under anaesthesia followed by period of immobilisation

Question 19

what are the complications of a hip arthroplasty?

Answer 19

perioperative:

• venous thromboembolism
• intraoperative fracture
• nerve injury
• surgical site infection

leg length discrepancy

Hip posterior dislocation

Question 20

describe the clinical features of a ruptured quadriceps tendon

Answer 20

symptoms:

• pain at the site of the rupture
• previous history of tendinopathy before rupture

signs:

• bruising and swelling around the area
• Unable to extend the knee against resistance

Question 21

risk factors for quadriceps and patella tendon rupture

Answer 21

• Previous tendon injury
• Existing tendinopathy
• Previous corticosteroid injection
• Steroid use
• Co-morbidities e.g. SLE, rheumatoid arthritis, chronic renal disease, diabetes
• Increasing age (for quadricep rupture)

Question 22

what is the treatment for patellar and quadriceps tendon rupture?

Answer 22

quadriceps: open repair followed by protection in extension cast or splint

patellar:

Non-operative (for partial tears with intact extensor mechanism) – immobilisation in full extension + progressive exercise programme

Operative (for complete rupture) – open repair of tendon

Question 23

what are the typical symptoms and signs of a patient presenting with an acute meniscal tear?

Answer 23

Due to a twisting knee injury

symptoms:

• pain worse on straightening the knee
• knee may ‘give way’
• displaced meniscal tears may cause knee locking
• tenderness along the joint line
• McMurrays test- compressing and twisting the knee joint produces pain

Question 24

what are the typical symptoms and signs of a patient presenting with an acute ligament injury of the Knee?

Answer 24

• sudden swelling
• pain
• feeling of a “pop” in the knee
• instability - feel like the knee will give way
• positive anterior draw test

Question 25

What are OA radiographic features

Answer 25

L- loss of joint space

O- osteophytes

S- subchondral cysts

S- sclerosis

Question 26

What two tests would you do to confirm a knee menisceal tear

Answer 26

McMurrays Test- compressing and twisting the knee produces pain

Thessaly’s test - weight bearing at 20 degrees of knee flexion, patient supported by doctor, positive if pain on twisting knee