Conditions Of The Hip

Question 1

What is at risk when administrating IM injections in the gluteal region? 1️⃣

Answer 1

Injury to the sciatic nerve

Question 2

When is the dorsogluteal site used? 1️⃣

Answer 2

In children 3-7

Question 3

When is the ventrogluteal site used? 1️⃣

Answer 3

Children >7 and adults

Site is further from neurovascular structures but requires better patient compliance

Question 4

How is the ventrogluteal site located? 1️⃣

Answer 4

• place palm over greater trochanter
• point thumb towards inguinal region
• point index finger toward anterior superior Iliad crest
• spread index and middle fingers to make a V
• inject between the proximal interphalangeal joints of the fingers, into the gluteus medius

Question 5

What does a superior gluteal nerve lesion lead to? 2️⃣

Answer 5

Superior gluteal nerve supplies hip abductors therefore lesion leads to weakness in thigh abduction at the hip

Question 6

How can the superior gluteal nerve be injured? 2️⃣

Answer 6

• complication of hip surgery
• injections into buttock
• # of greater trochanter (insertion site of gluteus medius)
• hip joint dislocation

Question 7

What prevents hip tilting when standing on one leg? 2️⃣

Answer 7

Standing erect with one foot lifted off ground:

• gluteus medius and minimus is supporting limb usually contract
• prevents tilting of pelvis towards unsupported side

Question 8

Describe a postitive Trendelenburg sign 2️⃣

Answer 8

Person with superior gluteal nerve palsy asked to stand on injured lower limb:

-pelvis on unsupported side descends

Question 9

When does a hamstring injury tend to occur (‘pulled hamstrings’) 3️⃣

Answer 9

During sudden muscular exertion that results in stretching of the posterior thigh muscles :

• jumping
• sprinting
• lunging

Relatively common in athletes and footballers esp in absence of a proper warm up

Question 10

What occurs in a hamstring injury? 3️⃣

Answer 10

• sudden tension in hamstrings results in either a muscle sprain, partial tear or a complete tear of the origin of the hamstrings from the ischial tuberosity
• sometimes accompanied by avulsion of a fragment of bone

Question 11

What is the pathological definition of osteoarthritis? 4️⃣

Answer 11

A degenerative disorder arising from the breakdown of articulate hyaline cartilage

Question 12

What is the clinical definition of osteoarthritis? 4️⃣

Answer 12

A clinical syndrome comprising joint pain accompanied by functional limitation and reduced QoL

Question 13

What joints are most commonly affected by OA? 4️⃣

Answer 13

• hips
• knees
• cervical spine
• lumbar spine
• small joints of the hands

Question 14

Describe the features of OA 4️⃣

Answer 14

• chronic disease of musculoskeletal system
• without systemic involvement
• non-inflammatory
• in comparison to some other inflammatory arthropathies, ankylosis (bone fusion across a joint) is very rarely seen

Question 15

Difference between primary and secondary OA 4️⃣

Answer 15

Primary OA: unknown cause

Secondary OA: known precipitation cause

Question 16

What are some risk factors for primary OA? 4️⃣

Answer 16

• age
• female sex
• ethnicity (increased in African-Americans, American Indians and Hispanics)
• Genetics (OA) runs in family
• Nutrition (consumption of antioxidant-rich diet may provide some protection)

Question 17

Give examples of specific causes of secondary OA 4️⃣

Answer 17

• obesity
• trauma
• malalignment
• infection e.g septic arthritis and tuberculosis
• inflammatory arthritis e.g RA
• metabolic disorders affecting joints e.g gout
• haematological disorders e.g haemophilia with haemarthrosis
• endocrine abnormalities e.g diabetes with neurovascular impairment leading to chronic malalignment of articular surfaces

Question 18

State some symptoms of OA 4️⃣

Answer 18

• deep aching joint pain, exacerbated by use
• reduced range of motion and crepitus
• stiffness during rest i.e morning stiffness

Question 19

What do precipitating risk factors of OA cause? 4️⃣

Answer 19

Lead to excessive or uneven loading of the joint

Leads to damage to the hyaline cartilage covering articular surface

Question 20

Describe what happens to hyaline cartilage in OA 4️⃣

Answer 20

• initially becomes swollen due to increased proteoglycan synthesis by chondrocytes with increased numbers of chondrocytes differentiating from chondroprogenitor cells
• this stage reflects an attempt to repair the cartilage damage and can continue for several years

Question 21

Describe what happens to the hyaline cartilage as the disease progresses 4️⃣

Answer 21

• proteoglycan content falls
• causes cartilage to soften and lose elasticity
• microscopically, flaking and fibrillation develop along the normally smooth articular surface
• over time, the cartilage becomes eroded down to the subchondral bone, resulting in loss of joint space

Question 22

What does the surface changes in hyaline cartilage cause? (Eburnation)4️⃣

Answer 22

• alters the distribution of biomechanical forces and trigger further active changes in the tissues
• subchondral bone responds with vascular invasion and increased cellularity, becoming thickened and denser at areas of pressure

= eburnation - manifests as subchondral sclerosis on x rays

Question 23

What else happens to the traumatised subchondral bone in OA? 4️⃣

Answer 23

May undergo cystic degeneration to form subchondral bone cysts

Attributable to either issues necrosis secondary to chronic impaction or to the intrusion of synovial fluid

Question 24

How do the osteophytes form? 4️⃣

Answer 24

At areas along the articular margin, osseous metaplasia of connective tissue occurs, leading to irregular outgrowth of new bone

Question 25

State 4 cardinal signs of OA in x rays 4️⃣

Answer 25

• reduced joint space
• osteophytes
• bone cysts
• subchondral sclerosis

Question 26

Who is OA of the hip most common in? 5️⃣

Answer 26

Males over 40 years old

Question 27

Describe the symptoms of hip OA 5️⃣

Answer 27

• joint stiffness
• pain in hip, gluteal and groin regions radiating to the knee via obturator nerve
• mechanical pain
• crepitus
• reduced mobility

Question 28

What does treatment of hip OA involve? 5️⃣

Answer 28

• weight reduction if patient overweight or obese
• activity modification
• walking stick or walking frame
• muscles strengthening exercises
• orthotic footwear to rebalance misaligned load through the joint
• Analgesia and anti-inflammatories
• nutritional supplements
• steroid injections into joint to reduce swelling and alleviate stiffness and pain
• hyaluronic acid injections into joint (viscosupplementation) may increase lubrication and possible promote cartilage repair

Question 29

What is the only cure for hip OA? 5️⃣

Answer 29

Total Hip Replacement: replaces damaged surfaces with implants and helps to relieve pain and restore mobility

Question 30

Define fractured neck of femur (#NOF) 6️⃣

Answer 30

Fracture of the proximal femur, up to 5cm below the lesser trochanter

Question 31

How are #NOFs classified? 6️⃣

Answer 31

• intracapsular
• extracapsular - further divided into intertrochanteric and subtrochanteric

Classification is important as the site of the fracture has implication for the blood supply and therefore viability of the femoral neck

Question 32

What implications to blood supply are intracapsular fractures likely to cause? 6️⃣

Answer 32

• disrupt ascending cervical (retinacular) branches of the MFCA
• due to inability of the Artery of the Ligamentum Teres to sustain the metabolic demand of the femoral head, there is a high risk of avascular necrosis of the bone.
• Risk increased if fracture displaced

*with extracapsular fractures, retina your arterial supply to the femoral head to likely to remain intact

Question 33

Who are #NOFs common in and when can they occur?6️⃣

Answer 33

-intracapsular fractures: elderly esp post-menopausal women with osteoporotic bone.
Usually after a minor fall

-extracapsular fractures: young and middle aged population
Usually result of significant traumatic force

Question 34

How is a displaced #NOF treated in an older person? 6️⃣

Answer 34

Due to high risk of a vascular necrosis, treated by surgical replacement of the femoral head or a total hip replacement.

Question 35

What are the symptoms of a #NOF? 6️⃣

Answer 35

• reduced mobility/ sudden inability to bear weight on the limb
• pain which may be felt in the hip, groin and/or knee

Question 36

Upon physical examination, how does a displaced #NOF present? 6️⃣

Answer 36

affected leg usually:

• shortened
• abducted
• externally rotated

There us exacerbation of pain on palpating if the greater trochanter and pain is exacerbated by rotation of hip

Question 37

Why is the hip shortened, abducted and externally rotated in a displaced #NOF? 6️⃣

Answer 37

• the #NOF allows shaft of femur to move independently of the hip joint
• the axis of rotation of femur that normally passes obliquely through the head and down the neck of the femur, shifts to pass through the greater trochanter and vertically down the long axis of the femoral shaft
• the short lateral rotators of the hip (piriformis, obturator internus, superior and inferior gemelli and quadratus femoris) contract and externally rotate the femoral shaft. Iliopsoas also now acts as a lateral rotator of the femur as it pulls the lesser trochanter anteriorly about the new axis of rotation so the femoral shaft rotated externally
• the string abductors that attach to the greater trochanter abduct the femur dusts, to the fracture sire. They also rotate the greater trochanter laterally about the new longitudinal axis
• shortening occurs because the strong muscles of the thigh pull the distal fragment of the femur upwards. This includes the rectus femoris, adductor Magnus and hamstrings

Question 38

Define dislocation of the hip 7️⃣

Answer 38

The head of femur being fully displaced out of the cup shaped acetabulum of the pelvis

Question 39

Describe congenital dislocations 7️⃣

Answer 39

• developmental dysplasia of the hip

- not always congenital, can develop after birth

Question 40

Describe traumatic hip dislocation 7️⃣

Answer 40

• acute traumatic hip dislocation
• affected hip extremely painful and patient resists attempt to move the limb
• 90% posterior
• most common cause is knee impacting dashboard during road traffic collisions
• affected limb shortened and held in position of flexion, addiction and internal rotation
• sciatic nerve palsy in 8-20% cases

Question 41

Why do shortening and internal rotation of the limb occur after the posterior dislocation of the hip? 7️⃣

Answer 41

• femoral head pushed backwards over posterior margin of acetabulum and comes to lie on lateral surface of the ilium. Head of femur pulled upwards by strong extensors (gluteus maximums and hamstrings) and hip adductors, causing limb shortening
• anterior fibres of gluteus medius and minimus pull on the posteriorly displaced greater trochanter, causing internal rotation.

Question 42

Describe anterior hip dislocation 7️⃣

Answer 42

• limb held in position of external rotation and abduction with slight flexion
• femoral nerve pulses can be present but uncommon

Question 43

Describe central hip dislocation 7️⃣

Answer 43

• femoral head driven into pelvis through acetabulum
• always a fracture-dislocation
• femoral head palpable on rectal examination
• High risk of intrapelvic haemorrhage due to disruption of the pelvic venous plexuses- life-threatening