Hip Joint

Question 1

Percentage of innominate bones that make up acetabulum

Answer 1

Ilium and Ischium: 75%

Pubis: 25%

Question 2

Which way is the femur’s convexity?

Answer 2

Anterior

• -> Compression force posteriorly
• -> Tensile force anteriorly
• -> Increased weight bearing tolerance

Question 3

Femoral Head

Answer 3

Projects medially and slightly anteriorly

2/3 of a nearly perfect sphere

Question 4

Femoral Neck

Answer 4

• Common site of fx

- Displaces the shaft of the femur away from the joint –> reduces chance of bony impingement

Question 5

Intertrochanteric line

Answer 5

1. Anterior

2. Attachment of ligaments

Question 6

Intertrochanteric crest

Answer 6

1. Posterior

2. Joins neck and shaft of femur

Question 7

Acetabular labrum

Answer 7

Increases stability of hip joint - deepens socket

• Fibrocartilage
• Semi-circular
• Thicker medially, superiorly, posteriorly
• Helps reduce friction between bony surfaces

Question 8

Femoral Neck Angle of Inclination

Answer 8

Angle between longitudinal axis of femoral neck to that of femoral shaft, in frontal plane

Newborn: 140-150
Adults: 125

Coxa Vara: 105
Coxa valga: 140

Question 9

Femoral Torsion

Answer 9

Relative twist between proximal and distal femur

• Anteversion is normal
• Measure using Craig’s test

Abnormal torsion common with CP

Question 10

Femoral Anteversion

Answer 10

Normal, > 6 years old: 12-15
Newborn: 30-40 degrees

Excessive anteversion –> Toeing in gait
- Pt will sit comfortable in “w” (hockey goalie) position

Question 11

Femoral Retroversion

Answer 11

Less common than anteversion

–> toe out gait (in order to improve congruency of joint surfaces)

Question 12

Congenital Hip Dysplasia

Answer 12

Can either be:

1. Dysplastic
2. Dislocated

Treatment: Pavlik harness (ABD, ER, Flex)

Question 13

Legg-Calve Perthes Disease

Answer 13

Avascular necrosis of femoral head, resulting in flattened femoral head

• Boys 4-8 years old
• Insidious onset of intermittent anterior groin pain, may radiate to thigh and knee
• Antalgic gait
• Limited IR
• -> DJD

*Important to catch early

Treatment: Abduction orthosis

• Keeps femoral head in acetabulum, increasing blood flow
• May be worn up to 2 years
• Take off for short periods during day

Question 14

Slipped Capital Femoral Epiphysis

Answer 14

Displacement of epiphyseal plate

• Males> Females
• Sudden onset, not necessarily associated with trauma
• Antalgic gait, leg ER
• Limited IR
• Pain can be felt in knee

Management: Stabilization

Often –> LLD

Question 15

Acetabular Labrum Tears

Answer 15

• Not necessarily assoc. with trauma
• Young mean age: 38 years
  Presentation:
• Constant deep ache in groin with periodic sharp pain (can radiate to knee)
• Mechanical pain (locking, giving way)
• Frequently present in conjunction with OA

Greater chance of being missed in younger populations

No great special tests
Gold standard for diagnosis: MRArthrograph

Question 16

Hip OA or DJD

Answer 16

• Often result of previous trauma or wear and tear
• Pain, stiffness, loss of ROM, limp, or need for assistive device

Treatment: Pain management, muscle balance exercises (strength), THA
- Often tight flexors and adductors, weak extensors and abductors

Question 17

Imaging signs of hip OA

Answer 17

1. Decreased joint space
2. Osteophytes (often around rim of acetabulum)
3. Sclerosis (whitening of bone)

Question 18

How long does THA last?

Answer 18

15-20 years

Question 19

Most common THA approach:

Answer 19

Posterolateral

Lateral approach: Detach glut med, more limp afterward
Anterior approach: B/w TFL and IT band

Question 20

Femoral Fracture

Answer 20

• 20% die within a year, related to fx
• 80% over 65 are female
• Risk doubles each decade after 50 (osteoporosis + fall risk)

Question 21

Femoral neck fracture sign

Answer 21

Injured limb is externally rotated with a shorten limb length on that side

Question 22

Hip Joint Capsule

Answer 22

Attachments: Intertrochanteric line and lateral 1/3 of posterior neck

• Very strong and thick
• Forms a cylindrical sleeve
• Encloses neck
• -> Can hold everything together if there is a femoral neck fx without displacement

Question 23

Open/ close pack position of hip

Answer 23

Open: Flex, ABD, ER
Closed: Ext, ABD, IR

Most congruent: 90 flex, mid range ABD and ER

Question 24

Hip joint ligaments

Answer 24

Iliofemoral
Pubfemoral
Ischiofemoral

All 3 wind around femoral head
Limit extension as a whole
Allow for flexion

Question 25

Iliofemoral ligament

Answer 25

- AIIS to intertrochanteric line - Anterior lateral capsule - Strongest - AKA Y ligament - Limits extension and ER - Passive role in stance

Question 26

Pubofemoral ligament

Answer 26

- Medial inferior capsule surface - From superior ramus of pubic to neck of femur - Limits extension and abduction

Question 27

Ischiofemoral ligament

Answer 27

- Posterior capsule - Posterior acetabulum to femoral neck - Limits extension and IR

Question 28

Ligamentum Teres

Answer 28

Small intracapsular ligament (from acetabulum to fovea of femur) Key component to femoral head integrity - Arterial supply and innervation - Checks lat and sup subluxation - Possesses mechanoreceptors

Question 29

Bursas in hip

Answer 29

Ilipectineal, trochanteric (multiple), ischial

Question 30

Blood supply to hip joint

Answer 30

Branches of medial and lateral circumflex arteries | Ligamentum teres

Question 31

Nerve supply to hip joint

Answer 31

Branches from obturator and gluteal nn. Nerve to quadratus femoris Representation L2-S1

Question 32

Normal ROM for hip motions

Answer 32

``` Flexion: 120 Extension: 20 - more likely to lose than flex Adduction: 25 Abduction: 45 IR: 35 ER: 45 ```

Question 33

Which types of muscles tend to get tight?

Answer 33

Two-Joint muscles

Question 34

Iliopsoas attachments

Answer 34

Iliac fossa, Anterior T12-L5 --> Lesser trochanter Action: - Hip flexion - Ant pelvic tilt - Lumbar extension

Question 35

Adductor group attachments

Answer 35

Inferior pubic rami --> Adductor tubercle Control hip and pelvic motion during WB

Question 36

Gluteus Maximus

Answer 36

- Large, single joint, quadrilateral shaped, thick, superficial - Posterior sacrum and ilium --> Posterior femur (distal to greater trochanter) - Fibers attach to IT band and thoracolumbar fascia - Weak glut max often compensate with hamstring

Question 37

Glut Med

Answer 37

- Ilium to greater trochanter - Critical in unilateral stance (control and stabilize pelvis) - OKC hip abduction (ext and ER) - CKC stabilize neutral pelvis "Money muscle" of hip

Question 38

TFL

Answer 38

- External lip of iliac crest --> IT tract --> Lateral tibial condyle - Flex, IR, ABD (pelvic stabilizer) Often recruited when pt has weak glut med

Question 39

Piriformis syndrome

Answer 39

- Compression of sciatic nerve due to shortening and/or hypertonicity of piriformis - Radicular pain - Frequently associated with decrease in function of pelvic stabilizers - Sacral torsion can be present

Question 40

Biomechanics of walking : Sagittal plane

Answer 40

- Hip flex/ext: Often lacking ext, may flex knee early to compensate, or affect trunk position (look at arm swing) - Lumbar and knee actions

Question 41

Biomechanics of walking: Frontal plane

Answer 41

- Hip abd/ add Greatest deviation noted in single limb support Look to see pelvic obliquity change Trendelenburg gait

Question 42

Biomechanics of walking: Transverse plane

Answer 42

- IR/ER Initial contact: ER of femur Loading phase: progression into IR (eccentric ERors) Terminal stance: Motion back toward ER Problem: Fails to move into IR or moves into ER too quickly

Question 43

PROM exam for OA:

Answer 43

- Ext often restricted | - Capsular pattern of limitation has been proposed (IR, flex, ABD, ext) - and refuted.

Question 44

Why do a lateral glide of hip?

Answer 44

Tight Adductors

Question 45

Why use direct hip traction vs. pulling at ankle?

Answer 45

Knee pathology