1. MSK Ortho 2 Flashcards
2 most commonly affected joints in OA:
1) Knee
2) Hip
Local risk factors for hip OA:
Local Hx of trauma
Anatomical abnormalities
Muscle weakness
Joint laxity
High impact sports
Genetic?
Clinical features of OA of the hip:
Pain in the groin area, or lateral hip / deep buttock
Antalgic gait
Trendelenburg gait
Fixed flexion deformity
Painful passive movement and reduced ROM
DDx for OA of the hip:
Sciatica
NOF#
Trochanteric bursitis
Gluteus medius tendinopathy
Management of hip OA:
Conservative efforts as in all OA cases; pain control, lifestyle measures, physio.
Definitive = arthroplasty or hemiarthroplasty. Posterior approach is most common (risk of sciatic nerve injury and dislocation), followed by anterolateral (risk of damage to gluteal nerve).
Designed to last 15-20 years.
AVN of the hip usually starts asymptomatic and then progresses to pain in the affected joint. List 4 causes of AVN of the hip:
Long term steroid use
Alcohol excess
Trauma
Chemotherapy
Pathophysiology of AVN of the hip:
The medial circumflex artery (branch of profunda femoris) is responsible for the majority of blood supply to the hip joint. Damage can result in avascular necrosis as there is little input from any other arteries e.g. the lateral circumflex.
Investigations and findings for AVN of the hip:
Plain x-ray; may show nothing initially. Osteopenia and microfractures, then progression to collapse of the articular surface and the crescent sign.
MRI is scan of choice.
What causes the ‘crescent sign’ on x-ray, and where is it most often seen?
A sign of osteonecrosis.
Trabeculae failure, leading to subchondral fracture.
It is most often seen in the femoral and humeral heads.
What does SUFE stand for, and who usually presents with it?
Slipped Upper Femoral Epiphysis
Children, 10-15 year old males, more common in obesity.
Describe the innervation of the hip.
Sciatic, femoral and obturator nerves.
The same innervation as the knee, which is why pain can be referred between these two joints.
What is the classic treatment for DDH, and how does it help?
Pavlik harness
Holds the femoral head in the acetabular fossa and promotes proper development of the hip joint.
Common clinical features of DDH in younger children (3):
Limited hip abduction
Limb length discrepancy (affected = shorter)
Asymmetrical gluteal or thigh skin folds
What is the problem in SUFE, and what is the timing of presentation?
Postero-inferior displacement of the femoral head epiphysis.
Can present following trauma, or chronic, persistent symptoms.
Clinical features of SUFE:
Hip, groin, medial thigh or knee pain
Loss of internal rotation of the leg in flexion
Bilateral in 20%
Which investigations are diagnostic for SUFE?
AP and lateral ‘frog leg’ x-ray views.
Shows widening of the physis at the proximal affected femur.
Management of SUFE:
Internal fixation - cannulated screw inserted into the centre of the epiphysis.
DDH is a spectrum of disorders that includes mild dysplasia, subluxation and dislocation of the hip. What are some risk factors for this condition?
Female
First born
Positive FHx
Breach position
Oligohydramnios - low levels of amniotic fluid lead to increased intrauterine pressure
Incorrect swaddling techniques
Clinical signs of DDH in an older child / teenager:
Gait abnormalities - waddling / limping
Osteoarthritis
Hip pain
The diagnosis of DDH is based on clinical examination and imaging. List 3 imaging modalities and describe the instances in which they would be performed.
US = <4-6 weeks
Plain x-ray (AP + lateral frog leg) = >4-6 weeks
CT/MRI if surgical planning / other imaging is inconclusive.
What 3 factors inform the treatment of DDH?
Patient’s age
Severity
Underlying risk factors
List 3 types of treatment for DDH:
Pavlik harness
Closed reduction
Open reduction
+ regular monitoring, clinical examination and imaging for all
Which children with DDH are treated with a Pavlik harness?
<6 months with reducible dislocations or mild/mod dysplasia
Which children with DDH are treated via closed reduction and spica casting?
6 months to 2 years, or if Pavlik fails.
Closed reduction is done under GA, and then a spica cast is applied.
When is open reduction considered for the treatment of DDH?
Children older than 2 or if closed reduction hasn’t worked.
+/- pelvic or femoral osteotomies
Describe the Salter-Harris fracture classification system:
I-V
‘SALTR’ mnemonic
I; fracture passes all the way through growth plate, not involving bone. ‘Slipped’
II; passes through most of the growth plate and up into the metaphysis. 75%, most common. ‘Above’
III; fracture plane passes along some of the growth plate and then down into the epiphysis. ‘Lower’
IV; through metaphysis, growth plate and epiphysis. ‘Together/transverse’
V; crush type injury, no displacement of growth plate but injury by compression. Worst prognosis. ‘Rammed’
https://radiopaedia.org/articles/salter-harris-classification?lang=gb
What are the 2 structures that are at risk of damage in a supracondylar distal humerus fracture?
Brachial artery
Anterior intraosseous nerve
4 types of clubfoot:
‘CAVE’
Cavus
Adductus
Varus
Equinuus
What is the official name for clubfoot?
Talipes equinovarus
Around 50% of cases are bilateral
What are some associated conditions of talipes equinovarus?
Spina bifida
Cerebral palsy
Edward’s syndrome (trisomy 18)
Oligohydramnios
Arthrogryposis
What is the mainstay of treatment of clubfoot and what is the relapse rate?
Serial casting using the Ponseti method
+ night-time braces until the child is 4 years old
The relapse rate is 15%
What does the Ponseti method consist of and what is it used for?
Correction of clubfoot
Manipulation and progressive casting, starting soon after birth. Usually corrects the deformity in 6-10 weeks.
An Achilles tenotomy is required in 85% of cases but can be done with local anaesthetic.