Disorders of the Hip

Question 1

Types of Hip Arthritis

Answer 1

1ary OA –> due to wear on the hip joint
2nary OA –> Developmental diseases, AVN, sickle cell, inflammatory arthritis, infections, traumatic, protrusio, neurological dysfunction

Question 2

Protrusio

Answer 2

A defect of the acetabulum where the femoral head lies too deep in the pelvis - may be primary or secondary
Can occur unilaterally or bilaterally depending on the cause

Question 3

Treatment of bony hip dysfunction

Answer 3

Arthrodesis
Osteotomy
Athroplasty

Question 4

Arthrodesis

Answer 4

Artificially fusing the hip joint - accelerates wear in the surrounding joints (back, contralateral hip and ipsilateral knee)
Was common as pain removing operations but now rarer

Question 5

Osteotomy

Answer 5

An operation to remove bone to improve the life of the hip –> ideally should be done before the onset of osteoarthritis

Question 6

Athroplasty

Answer 6

Can be totally or partially or non-cemeted - more reliable but with a limited lifespan. Hybrid THR have a cemented femoral part and a uncemented acetabular part

Question 7

Coxa vara

Answer 7

A deformity of the hip where the angle between the head and the shaft becomes less than 120 degrees - Coxa valga is when the angle is greater than 135 degrees

Question 8

Bearing surfaces in Hip replacements

Answer 8

Traditionally metal on polyethylene - in young people can use ceramic on ceramic, metal on metal/cross-linked poly, or oxynium

Question 9

Resurfacing

Answer 9

THRs have a definite shelf-life so resurfacing is a bone preserving alternative which buys time for the young patient –> stable and with less wear. But there is a risk of femoral neck # and possibly SEs from metal ions

Question 10

Complications of hip replacements

Answer 10

Infection Loosening it
Dislocation DVT/PE
Limb length inequality Neurovascular injuries

Question 11

Minimally invasive Hip replacement surgery

Answer 11

Pros –> claims to have short recovery time

Cons –> higher complication rate (infection, malposition, femoral #), life span unclear

Question 12

Pethre’s Disease

Answer 12

AVN of femoral head in children leading to collapse, deformity, progressive hip and groin pain, stiffness and reduced RoM, M>F (5:1). Has also been associated with small stature, hyperactivity and other congenital abnormalities. onset 4-8yrs. 10% bilateral. Can present as knee pain

Question 13

SUFE (Slipped upper femoral epiphysis) or SCFE

Answer 13

Most common hip disorder in adolescence - presenting with groin pain, distal thigh pain and difficulty walking - 1/5 is bilateral - young black males - gradual onset pain with reduced RoM (internal rotation) - onset later in boys normally (10-16yrs)
Mostly stable (can walk) but 10% unstable (cant walk). bilateral in 20%. Caused by obesity & endocrine dysfunction

Question 14

CDH (Congential dysplasia of the hip)

Answer 14

1-3% of newborns - 80% girls - 17x risk if breech and 7x if breech CS. Can present at any age (0-2yrs usually) or at screening - may present with reduced RoM or dislocation
Can be bilateral or unilateral - may also have leg length disparities or asymmetric gluteal folds

Question 15

Hip pain can be referred from?

Answer 15

Spine
Intra-abdominal or hernia
Genitalia

Question 16

Soft tissue diseases of the Hip

Answer 16

Trochanteric bursitis
Ischial bursitis
Adductor tendinitis
Meralgia paraesthetica

Question 17

Meralgia paraesthetica

Answer 17

Entrapment of the lateral femoral nerve – purely sensory causing burning or numbness down the upper lateral aspect of the thigh (L2/3)
More common in men, linked to pressure on the lateral thigh or increased abdominal pressure (pregnancy, obesity, ascites) - reproduced by deep pressure below ASIS or leg extension

Question 18

Trochanteric bursitis

Answer 18

Pain and tenderness over the bursa at the upper, lateral aspect of the thigh – particularly on walking or lying on that side
Causes: trauma, idiopathic, 2nary to gluteal tendon disease (middle aged women), unequal leg length

Question 19

Adductor tendinitis

Answer 19

Groin pain/tenderness from inflammation of the adductor tendon/insertion - due to trauma or overuse - running and particularly turning at high speed. Pain may be reproduced by squeezing the legs together or abducting the leg. Treat with physiotherapy or rest (should self limit)

Question 20

Ischial bursitis

Answer 20

Pain/tenderness in the lower buttock when sitting, standing or walking up stairs
Caused by prolonged sitting or impact on the bursa
Treat with physiotherapy or rest (should self limit)

Question 21

After having a hip replacement

Answer 21

Physiotherapy and home exercises - walking sticks/crutches are usually used for 6wks
Should be one LMWH for the first six weeks

Question 22

To minimise the risk of Hip displacement

Answer 22

avoid flexing the hip greater than 90 degrees
Avoid low chairs
Dont cross their legs
Sleep on their backs for the first six weeks

Question 23

Transient idiopathic osteoporosis

Answer 23

A rare condition causing groin pain with reduced RoM in women in the 3rd trimester. Will be unable to weight bare and ESR may be elevated.

Question 24

Referred lumbar spine pain

Answer 24

femoral nerve compression may cause referred pain in the hip. Femoral stretch test will be positive.

Question 25

Management of DDH

Answer 25

Most will spontaneously stabilise by 3-6wks. Before 4-5months a Pavlik harness (flexion-abduction orthosis) can be used. After this surgery is needed.