DISORDERS OF THE HIP AND KNEE Flashcards
What is the term that has replaced the previous name of congenital dislocation of the hip?
Developmental dysplasia of the hip
What is the incidence of developmental dysplasia of the hip?
1.5 in 1000 births
What is developmental dysplasia of the hip?
Represents a spectrum of hip instability ranging from a dislocated hip to hips with various degrees of acetabular dysplasia.
What is acetabular dysplasia?
Where the femoral head stay in position but the acetabulum is shallow.
When does developmental dysplasia of the hip occur?
Previously thought to be entirely congenital, but it is now known to also occur after birth in previously normal hips.
What are the two types of developmental dysplasia of the hip?
Typical - affecting otherwise normal babies
Teratological - associated with neurological and genetic conditions.
What are the risk factors for developmental dysplasia of the hip?
Congenital muscular torticollis
Congenital foot abnormalities
Female sex
First baby - squeezed in more tightly
Breech delivery
Family history
Oligohydramnios
Neuromuscular disorders
Birth weight more than 5 kg
What are the warning signs of developmental dysplasia of the hip when it is not diagnosed at birth?
Delayed walking
A painless limp
A waddling gait - Trendelenburg gait
Apparent short femur - unequal knee height (Galeazzi sign)
Why are asymmetrical skin creases not a reliable sign of developmental dysplasia of the hip?
Because 30% of all babies will have these
How is developmental dysplasia of the hip usually diagnosed or screened for?
6 week check:
Barlow manoeuvre - used to screen for DDH
Ortolani manoeuvre - used to confirm Barlow findings to check that hip is actually dislocated
How do you perform the Barlow manoeuvre?
Flex knees and hips to 90˚
Line up legs in parallel to each other in line with shoulders
Apply backward pressure to each knee in turn.
A subluxable hip is suspected on the basis of palpable partial or complete displacement using your finger.
How do you perform Ortolani manoeuvre?
Flex knee and hips to 90˚
Line up legs in parallel to each other in line with shoulders
Abduct hip whilst applying anterior pressure on the thigh to relocated the hip.
A relocating hip will be felt with your finger on the joint.
What proportion of cases of developmental dysplasia of the hip will be missed by examination alone (Barlow and Ortolani manoeuvre)?
40%
What investigation should be done in addition to examination in babies at high risk of developmental dysplasia of the hip?
Ultrasound scanning is diagnostic.
X-rays are not useful until after 4-5 months of age when femoral head has ossified.
What is Allis sign?
This is when the femur is shortened. Sometimes associated with DDH.
How do we treat developmental dysplasia of the hip?
If less than 8 months:
This involves fixing the hip in abduction. This is usually done with a Pavlik or Von Rosen harness. Harness must be adjusted every two weeks for growth and should be kept on at all times.
If more than 8 months old:
Open reduction and derotation femoral osteotomy needs to be performed, followed by Spica case. Often accelerated degenerative changes might necessitate total hip replacement in early adult life.
What is Perthes’ disease?
An idiopathic disorder characterised by osteonecrosis of the femoral head. Caused by impaired blood supply to the femoral head, causing bone infarction.
What are the risk factors for developing Perthes’ disease?
Five times as common in males than females
Family history
What ages are children mostly affected by Perthes’ disease?
Between 2 - 12
What are the clinical features of Perthes’ disease?
Limp - insidious onset
Pain in hip, knee or thigh
What proportion of cases of Perthes’ disease are bilateral?
20%
What initial investigation would you do for someone in whom you suspected Perthes’ disease?
Hip X-rays
What would you see on hip x-ray of someone with Perthes’ disease?
Widening of joint space
Epiphyseal destruction - decreased femoral head size
Deformed acetabula
If hip x-ray was normal but a child continued to show signs of Perthes’ disease, what imaging might you send him or her for?
Technetium bone scan
OR
MRI
What is the system used to classify severity of Perthes’ disease? What are the different levels?
Catterall staging:
Stage 1 - clinical and histological features only
Stage 2 - Sclerosis with or without cystic changes and preservation of the articular surface
Stage 3 - Loss of structural integrity of the femoral head
Stage 4 - Loss of acetabular integrity
How do we manage Perthes’ disease?
Need to keep femoral head within acetabulum using cast or braces as well as activity restriction.
Analgesia
Revascularization and reossification occurs with resumption of growth - cycle takes 3-4 years
Surgery may be need if there is deformity
What is the prognosis following diagnosis of Perthes’ disease?
Usually good especially if under 6 years old.
In older children and those where more than half the epiphysis is involved, femoral deformity occurs in 40% resulting in early arthritis.
What are the complications of Perthes’ disease?
Permanent deformity
Earlier degenerative arthritis
What is the most common cause of hip pain in children?
Transient synovitis of the hip (irritable hip)
What age are children affected by transient synovitis of the hip?
2 - 12 years old
What is the aetiology of transient synovitis of the hip?
Largely unknown but associated with viral infection
What are the clinical features of transient synovitis of the hip?
Sudden onset of hip pain
No pain at rest
Limp
Refusal to bear weight on the affected side
Limited passive abduction and rotation on examination
Afebrile, otherwise well child
What is the main differential diagnosis to exclude when someone presents with the signs and symptoms of transient synovitis of the hip?
Septic arthritis
What investigations would you do in a child that presents with signs and symptoms of transient synovitis of the hip?
FBC - looking at WCC
CRP
ESR
Blood cultures
If there is doubt, the joint should be aspirated for culture followed by prompt administration of IV antibiotics
How do we treat confirmed transient synovitis of the hip?
Analgesia
Avoid strenuous activity
What is the prognosis for transient synovitis of the hip?
It will resolve within 2 weeks
What is slipped upper femoral epiphysis?
Displacement of the femoral head epiphysis in a medial postero-inferior direction.
What is the typical age of children affected by slipped upper femoral epiphysis?
10 -15 years old - occurs during the growth spurt
What are the risk factors for slipped upper femoral epiphysis?
Male
Obesity
Black
Associated with delayed skeletal maturation and endocrine disorders such as hypothyroidism, hypopituitarism and renal osteodystrophy
What are the clinical features of slipped upper femoral epiphysis?
Limp
Hip or referred knee/distal thigh pain
Can be acute following trauma but more often chronic
Waddling gait
Loss of internal rotation, as well as as reduced abduction and flexion.
What percentage of cases are found to have bilateral slipped upper femoral epiphysis?
20%
How do we diagnose slipped upper femoral epiphysis?
X-ray - The Southwick angle gives indication of disease severity
How do we manage slipped upper femoral epiphysis?
Unstable hips are an orthopaedic emergency
Femoral head needs to be pinned percutaneously or osteotomy
Non-surgical treatment is ineffective
What are the complications of slipped upper femoral epiphysis?
Avascular necrosis
Premature fusion of epiphysis
What is the other name for Osgood-Schlatter disease?
Tibial apophysitis
What is Osgood-Schlatter disease?
Osteochondritis of the patellar tendon insertion at the knee.
Who tends to be affected by Osgood-Schlatter disease?
Adolescent males who play sport particularly football or basketball
What are the clinical features of Osgood-Schlatter disease?
Knee pain after exercise
Localised tenderness
Swelling over the tibial tuberosity
Hamstring tightness
Bilateral in 25-50%
How do we treat Osgood-Schlatter disease of the knee?
Most resolve with rest. Knee immobiliser splint may be helpful
May need physiotherapy to strengthen quadriceps and stretch hamstring
Occasionally orthotics are required.
Who tends to be affected by chondromalacia patellae?
Adolescent females
What is chrondomalacia patellae?
Softening of the articular cartilage of the patella
What are the clinical features of chondromalacia patellae?
Pain when patella is tightly apposed eg when standing from prolonged sitting or walking up and down stairs
What features is chondromalacia patellae associated with?
Hypermobility
Flat feet
How do we manage someone with chondromalacia patellae?
Rest
Physiotherapy for quadricep muscle strengthening
What is the other name for osteochondritis dissecans?
Segmental avascular necrosis of the subchondral bone
Who is most likely to suffer from osteochondritis dissecans?
Very active adolescents
What causes the pain associated with osteochondritis dissecans?
Separation of the bone and cartilage from the medical condyle following avascular necrosis.
What are the clinical features of osteochondritis dissecans?
Pain after exercise
Knee locking or giving way
How do we manage osteochondritis dissecans?
Rest
Physiotherapy to strengthen quadriceps
Sometimes arthroscopic surgery is required`
What are the features of subluxation of the patella?
Medial knee pain
Knee may give way
