Task Sheet - OA hip

Question 1

What sources of the hip joint can cause pain?

Answer 1

• Capsule
• Subchondral bone
• Acetabular fat pad
• Transverse acetabular ligament
• Ligamentum Teres
• Synovial membrane

Question 2

How does Hilton’s law apply to referred pain from the hip?

Answer 2

• The hip joint is supplied by branches nerves of the muscles which pass over it
• Peripheral nerves converge at the same dorsal horn in the spinal cord
• As the pain signals enter the CNS, there can be a misinterpretation of the pain
• Patient feels the pain over the anterior thigh rather than the hip joint itself

Question 3

Why do patients with OA have aching and stiffness in the morning?

Answer 3

Overnight - immobile for 8 hours - no sweep and squeeze mechanism so increase in synovial fluid viscosity - causing stiffness

Lack of sweep and squeeze means accumulation of inflammatory mediators in the synovial joint overnight - causing ache

Question 4

Why do patients with OA have aching at night?

Answer 4

If they have had an active day - there is WB through damaged cartilage - irritating the subchondral bone

Joint held in FFD can also mean increased strain on surrounding ligaments, capsule and musculature - causing pain

Question 5

Why do OA hip patients get pain when ascending stairs?

Answer 5

Loaded hip flexion position - puts a lot of force through the degraded cartilige

Compression of the anterior capsule and reduction of anterior joint space causing pain - particularly if osteophyte formation

Question 6

Why do OA hip patients get pain when crossing their legs?

Answer 6

Combined flexion and adduction compresses the medial joint capsule - with potential for impingement - especially if osteophytes present

Question 7

What causes reduced range of extension in hip OA?

Answer 7

Fibrosis of the ligaments and anterior joint capsule as they are being held in loose pack position

Increased viscosity of the synovial fluid due to decreased movement

Weakness in medial rotators - TFL, gluteus medius, gluteus minimus

Shortening of hip flexors - lengthening of hip extensors

Question 8

Why might there be tenderness over the greater trochanter?

Answer 8

Tendinopathy of the gluteals due to change in standing and walking postures - puts increased pressure and abnormal loading through the muscles - resulting in tendinopathy

Inflammation of the subtrochanteric bursa

Question 9

What signs and symptoms might someone with hip OA have?

Answer 9

Pain
Weakness
FFD
Reduced aROM and pRPM
Poor mobility - antalgic gait
Altered leg length

Question 10

What are the signs of OA on an X-ray?

Answer 10

white sclerosis - as the bone tries to strengthen due to increased load (due to loss of shock absorbing properties of the cartilage)

Flattening of the femoral head

Shortening of the femoral neck - leg length discrepencies

Question 11

What are the attachments of the iliofemoral ligament?

Answer 11

O: Lower AIIS and acetabular rim

I: intertrochanteric crest of femur

Question 12

Function of the iliofemoral ligament?

Answer 12

Limits extension and lateral rotation

Lower band - limits abduction

Upper band - limits adduction

Question 13

What are the attachments of the pubofemoral ligaments?

Answer 13

O: iliopubic eminence and superior pubic ramus

I: lower intertrochanteric crest

Question 14

What is the function of the pubofemoral ligament?

Answer 14

Limits extension, LR and abduction

Question 15

What are the attachments of the ischiofemoral ligament?

Answer 15

O: body of ischium and below the acetabulum

I: Neck of femur and root of greater trochanter

Question 16

What is the function of the ischiofemoral ligament?

Answer 16

Limits extension, medial rotation and adduction