Lec 8

Question 1

True or false

inferior tilt of acetabulum= 35 in male & 38 in female

Answer 1

False

inferior tilt of acetabulum= 38 in male & 35 in female

Question 2

Angle of inclination of the femur

Answer 2

تتولد كبيره وتصغر مع الكبر

Normal angle ( 120-125 )

Question 3

Angle of torsion of the femur

Answer 3

Normal ( 15-30 )
> 30: antiversion , teo in gait

Mechanical Effects of Anteversion

1. Increased range of internal
   rotation
2. Decreased range of external
   rotation
3. Frog sitting is the position of
   comfort
4. Excessive in-toeing

Nb. The opposite is true for hip retroversion

<30: retroversion , teo out gait

Question 4

ROM

Answer 4

normal gait on level ground requires at least 30 flex., 10 hyperexten., 5 abd. & add., 5 med. and lat. rotation

Question 5

Bilateral stance

Answer 5

Weight of head, arms & trunk
(HAT)= 2/3 body weight.

 Each hip joint receives 1/3
body weight.

 E.g. if someone weighted 120
kg., there will be a compressive force of 40 kg.
on each hip joint.

Question 6

How to reduce muscle force in
unilateral stance ?

Answer 6

1- reduce body weight

2- Compensatory lateral lean of the trunk

3- Use of a cane ipsilaterally

4- Use of cane contralaterally

5- Carrying a load ipsilaterally
 → shifting LOG towards the painful hip→ reduction of weight bearing torque → decrease hip abductors activity→ reduces JRF

20% of body weight carried ipsilaterally = same abductors activity needed under no- load condition

Question 7

Common deformities of the hip

Answer 7

Coxa vara

 Definition:
Neck-shaft angle < 120

 Causes:
1. Congenital
2. Slipped upper femoral epiphysis
3. Fractures
4. Bone softening disease e.g.
rickets

1. Lengthening the moment arm of abductor muscles → improve their mechanical advantage → contract less
   vigorously to stabilze the pelvis → reduce JRF

Nb. This +ve effect of coxa vara is utilized in osteotomies of the femur for treatment of OA,

2. JRF is displaced medially

Question 8

Treatment for Coxa vara

Answer 8

 Angle > 110:
1. Lift in the shoe
2. Stretching hip adductors
3. Stretching lateral rotators

Angle < 110
 Sub trochanteric or intertrochanteric osteotomy with screw and plate.

 If a screw & plate are used:
1. Hip spica (6-8 weeks)
2. Active ROM exercises
3. Active side-lying hip abduction
4. Standing hip hiking
(Trendelenburg’s) exercises
5. Gait training:
 Full ROM → three point gait is allowed
-ve Trendelenburg’
s sign → full WB is allowed

If bifurcated blade plate is used
1. Active ROM exercises
2. Strengthening exercises
3. Partial WB 4-5 days after surgery
 This procedure heals in approximately 8 weeks.

Question 9

Common deformities of the hip

Coxa valga

Answer 9

Coxa valga
 Definition
neck-shaft angle is greater than 130

 Causes:
1. Trauma
2. Congenital
3. Dislocation
4. Spastic paralysis

Mechanical effects of coxa valga

1. Shortens the lever arm of abductor muscles → decrease their mechanical advantage → have to contract more
   vigorously to stabilize the pelvis → increase JRF
2. Lateral displacement of JRF → decrease in the weight bearing area
3. 1+2 → increase stress → degenerative changes in the articular cartilage

Question 10

Signs & symptoms and Treatment of coxa valga

Answer 10

Signs & symptoms
1. Painless limp
2. Longer leg on the involved side
3. Adductor tightness
4. Weakness of abductors
5. Upward pelvic obliquity
6. Altered pelvic mechanics → back pain or sacroiliac joint dysfunction.

Treatment
1. Stretching adductors
2. Strengthening abductors
3. Balance exercises
4. Free exercises to improve posture
5. General leg exercises
6. Treat LBP & sacroiliac dysfunction
7. Severe cases are treated with osteotomy to correct leg-length differences and to restore normal mechanics