77/78: Ped Hip, Knee, and Leg - Mahoney Flashcards Preview

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Flashcards in 77/78: Ped Hip, Knee, and Leg - Mahoney Deck (53)
1

what is the angle of inclination of femur?

  • angle in the frontal plane formed by the axis of the head and neck of the femur and shaft of the femur
  • Infant-150°
  • Adult-125°
  • The inclination angle allows abductors to function with a mechanical advantage as they counterbalance body weight in one-legged stance
    • w/o --> trendelenburg gait
  • Hip abductors should be as far laterally from the hip as possible to achieve muscle stability which is greatest when the child begins to stand

2

coxa vara vs. coxa valga

  • Coxa vara: a decrease in the angle of inclination so that the distal femur is directed towards the midline and the knees are closer together (genu valgum)
    • more common
    • caused by overgrowth of the femoral epiphysis which leads to limb shortening and limitation of passive hip abduction

  • Coxa valga: an increase in the angle of inclination so that the distal femur is directed away from the midline and the knees are farther apart (genu varum)
    • uncommon

3

an abnormal angle of inclination (not achieved the 125) will cause a child to stand with the pelvis tilting down on ...

contralateral side

4

what is alsberg's angle?

  • Alsberg’s angle: angle formed by a line through the epiphyseal plate of the neck of the femur and the long axis of the femur
  • Normal adult-41°
  • Increase is coxa valga, decrease is coxa vara

5

what is the normal angle of declination of femur?

  • Infant-30° (up to 60°) of internal rotation
  • Adult-8° to 12° of internal rotation
  • Therefore, angle decreases about 20° (up to 50°) by rotating externally, but still remains internally rotated by about 10° in the adult

 

6

what is the angle of declination?

Angle of Declination of Femur: angle in the transverse plane formed by the axis of the neck of the femur and the transcondylar axis of the knee with the apex of the angle lateral when looking from proximal to distal through the femur

7

why is normal fetal position described "buddha"

hips and knees flexed, hips externally rotated, legs and feet internally rotated

  • When the HIP is flexed in utero, it is also externally rotated
  • When the LOWER LIMB is flexed in utero, it is also internally rotated

8

version vs. torsion

  • both refer to how much twist is in the bone
  • Version: angular difference between the transverse axis of motion of each end of a long bone (does NOT mean soft tissue position) normal
    • Normal version is present when the angular difference is within 2 standard deviations of the mean
  • Torsion: present when the version is excessive (abnormal) or greater than 2 standard deviations outside of the mean
    • clinically = deformity or abnormality

9

femoral antetorsion

  • medial femoral or internal femoral torsion-abnormal increase in femoral anteversion
  • Retrotorsion: lateral femoral or external femoral torsion-abnormal increase in femoral retroversion

10

femoral vs. tibial version

  • Femoral version: angular difference between the transcondylar axis of the knee and the neck of the femur
  • Tibial version: angular difference between the transcondylar axis of the knee and the transmalleolar axis of the ankle

11

When looking at our diagram, the axis of the neck of femur makes a larger angle with the transcondylar axis of the knee =

  • answer = Femoral anteversion: the normal angle of femoral version made when the axis of the neck is directed forward or anterior from the femoral shaft
  • Femoral retroversion: the angle of femoral version made when the axis of the neck is directed backward or posterior from the femoral shaft

    • When looking at our diagram, the axis of the neck makes a smaller angle with the transcondylar axis of the knee

12

A femur which exhibits an internal rotation less than 2 standard deviations from normal is called

femoral anteversion

 

  • Femoral torsion: abnormal increase in femoral version
  • Antetorsion: medial or internal femoral torsion-abnormal increase in femoral anteversion
  • Retrotorsion: lateral or external femoral torsion-abnormal increase in femoral retroversion

13

  • At birth the femur is rotated internally to about 30°
  • At the same time, the soft tissue of the hip externally rotates the thigh to about 50°

how does this change as you age?

  • The angle of declination decreases from 30° internal to about 10° internal (or femur externally rotates 20°)
  • Subsequently, the soft tissue changes around the hip, internally rotate thigh from 50° external to 10° external (or internally rotates thigh 40°)
  • The 8 to 12° of femoral anteversion is balanced by the external rotation of about 10° caused by normal soft tissue contraction at the hip
  • The end result is that the knee is eventually pointed straight ahead in gait (by 4 years of age)

14

normal hip rotational development

  • Infants: 60-90° external; 0-30° internal (3:1 ratio)
  • Up to 1 year: 50-60° external; 30° internal (2:1 ratio)
  • 4 years to adult: 45° external; 45° internal (1:1 ratio)
  • When this does not occur, we will have either an externally rotated or internally rotated leg and foot

15

osseous antetorsion will cause an ... gait

osseous retrotorsion will cause an .... gait

*******

  • Antetorsion will cause an in-toe gait, retrotorsion an out-toe gait
  • An in-toe gait can also be caused by tightness of the internal rotators of the hip or a tight iliofemoral, pubofemoral, or ligamentum teres ligament
  • An out-toe gait can be caused by tightness of the external rotators of the hip or a tight ischiofemoral ligament

16

muscles that are external hip rotators

  gluteus maximus

  obdurators

  adductors

  gemelli

  sartorius

  quadratus femoris

  piriformis

17

muscles that are internal hip rotators

  gluteus medius

  gluteus minimus

18

How do we determine if the rotational deformity is due to femoral torsion or a soft tissue contracture (or laxity)?

  • Need to determine neutral femoral position of the hip with the hip extended and with the hip flexed
  • A difference between NFP readings with the HF and HE suggests that there is a soft tissue cause of the rotational deformity
  • The same reading for NFP with the HF and HE suggests it is solely femoral torsion

19

A 2 year old child presents with an out-toe gait.  You measure 60° of external hip rotation and 40° of internal hip rotation with the hip flexed and extended.  is this normal?

yes, it is femoral retroversion

if this was a 6 yo = femoral retrotorsion

20

describe the uterine position

  • This uterine position leads to:
    •  an increase in external rotation and flexion of the hip
    •  femoral anteversion caused by femoral head and neck rotating inward against the shaft-allows maximal rotation of hip in flexed position
  • The anteverted hip fits well into the acetabulum in utero while the hip is hyperflexed (walking on all fours is the true physiologic position of the hip), but as soon as the hip extension begins after birth, anterversion angle must be reduced or there will be an unstable, ANTERIOR dislocatable hip or an in-toe gait
  • Anteverted position increases leverage of the gluteus maximus which allows it to better maintain the body in an upright position
    • However, the upright position on an anteverted leg causes the anterio-superior portion of the femoral head to be exposed

21

the anteverted position of the femur is important because ...

1.It is the most stable position of the hip in utero

2.It allows the child to walk in-toed which is more stable

3.It increases the leverage of the gluteus maximus

4.It increases the leverage of gluteus medius and minimus

1 and 3

22

what 3 activities occur to mold the epiphysis of the femoral head to reduce anteversion?

1.        Upper end of femur yields under pressure to tight anterior capsule so that excessive anteversion slowly molded away

  • Torsion at birth is reduced when the erect posture is assumed by pressure on the tense anterior hip capsule
  • Major force
  • if anterior capsule stretched, the hip dislocates anteriorly. Less force is exerted on the femur, so there is less tendency for correction of anterversion

2.      Force also produced by contraction of internal rotator muscles and external rotators which gives rise to a shearing force acting in the AP direction on the femoral head which causes the femoral epiphysis to slip and reduce anteversion

3.     Pelvic movement of inward rotation on a loaded hip joint also applies a dynamic force in the AP direction on the femoral head

therefore .... walking is the decisive factor for reducing anteversion (as well as, the angle of inclination)

23

Leads to an intoe gait, anterior pelvic tilt (to cover the femoral head), lumbar lordosis, apparent genu valgum (due to internal positioning of the patella), genu recurvatum, and possible flatfoot to compensate for foot adduction (causes skewfoot)

femoral antetorsion

24

most common cause of intoeing after age 2/3

  • internal femoral torsion or antetorsion or tight internal hip rorators and/or tight iliofemoral, pubofemoral or ligamentum teres ligaments
  • The most common cause of outoeing at any age is external femoral torsion or retrotorsion or tightness of the external hip rotators and/or ischiofemoral ligament

25

how can you tell that the child might have a problem with the hip joint?

  • With the child sitting in a chair with legs in dependency, the patella and feet are pointed inward
  • if pointing out = retrotorsion or tight external rotators

26

A child exhibits an in-toe gait.  You find that the child has more internal rotation of the hip over external with the hip extended.  Possible causes of the in-toe gait include

1.Femoral retrotorsion

2.Femoral antetorsion

3.Tight gluteus minimus

4.Tight gluteus maximus

5.Tight pubocapsular ligament

6.Tight ischiofemoral ligament

2, 3, or 5

27

how often does developmental hip dysplasia occur?

1-2/1000 births

28

clinical s/s dislocatable hip

  • child may not move involved extremity
  • DHD is often unrecognizabel except by clinical exams
    • x-rays are standard for establishing diagnosis after 5 month (femoral head ossification)
  • assymetry of gluteal folds "broken anchor sign" --> short leg
  • limited abduction of affected hip
  • galleazzi's or allis' sign - with child supine and hip flexed and knee flexed, there is a lower level of the knee on the affected side
  • Ortaloni’s sign-more evident if hip is truly dislocated; presence of palpable click in and out as the hip is reduced by abduction and dislocated by adduction [ the hip is out ]

  • Barlow's test -used with dislocatable, unstable hip.Child is supine with hips and knees flexed. Finger placed over greater trochanter and thumb over lesser trochanter. Hips brought into midabduction and thumb pressure is applied posteriorly over the lesser trochanter. Dislocation of femoral head across the posterior lip of the acetabulum occurs; releasing thumb allows head to slip back into acetabulum

  • Telescoping sign-when extremity is pushed in piston type fashion with hip flexed and extended, abnormal mobility or telescoping is felt

  • Trendelenburg test is positive-due to dislocation of hip causing weak abductors, the unaffected side of the pelvis is not held level and drops down. Child older and walking

29

describe the dislocation of DHD

  • DHD includes the entities of true dislocation, as well as subluxation of the hip and refers to a syndrome where over 90% of the time, the head of the femur is positioned upward, lateralward, and POSTERIORLY from its usual position in the acetabulum
  • 10% of time, hip dislocates anteriorly as we had discussed with femoral anteversion
  • DHD is generally the result of abnormal development of the soft tissues surrounding the hip joint and eventually, if not corrected, changes in the shape of the acetabulum, itself

30

which factors are necessary to prevent an anterior dislocated hip?

1.Walking

2.Tight posterior hip capsule

3.Muscle contraction of the internal and external hip rotators

4.External pelvic rotation

1 and 3

31

4 most common criteria DHD

1. leg length discrepancy

2. limited hip abduction

3. ortolani/barlow test

4. first degree family hx

32

the most common  dislocated hip moves ...

superior, lateral, posterior

33

A dislocated hip exhibits ...

1.A short leg on the dislocated side

2.A long leg on the dislocated side

3.Lack of spontaneous movement of the dislocated side in a newborn

4.Limitation of abduction

5.Limitation of adduction

1, 3, and 4

34

what are the radiographic findings in DHD?

  • X-ray Dx made by studying measurement of the lateral, upward, and posterior displacement of the head of the femur
    • This alters all pelvic relationships to the proximal femur
    • right hip dislocated in picture
  • Hilgenreiner’s Line (HL): horizontal line connecting the two most medial and inferior points of acetabular cavities
    •  Normal: head of femur found below HL
    •  DHD: head of femur above HL
  • Perkin’s Line (PL): vertical line from most ossified lateral margin of rim of acetabulum-crosses HL perpendicularly, forming quadrants
    •  Normal: femoral head in lower-medial quadrant
    •  DHD: femoral head in upper-lateral quadrant
  • Acetabular index: angle formed by HL and a line connecting it from the most prominent medial and lateral points at rim of acetabulum
    •  Normal: 30°
    •  DHD: >30°
  • Shenton’s or Menard’s Line: arc drawn along medial border of femoral neck and superior portion of obturator foramen
    •  Normal: uninterrupted arc
    •  DHD: arc is broken

35

knee joint development in the frontal plane

36

frontal plane and sagittal plane deformities of knee

  • Frontal Plane
    • Genu varum (bowlegged) and genu valgum (knockneed) are usually normal developmental changes, but consider possibility of epiphyseal disease causing a non-uniform growth between the medial and lateral aspects of either the femoral or tibial epiphysis
  • Saggital Plane (genu recurvatum)
    • Hyperextension deformity of knee
    • Can be remarkable at birth due to intrauterine position, but improves with age
    • Posterior displacement of extended knee greater than 15° is pathological

37

Patella are __________  in newborn

Patella are externally rotated 30° in newborn (due to normal increase in external hip rotation over internal)

38

normal

with KE, tibia rotates

with KF, tibia rotates

  • With KE, tibia rotates laterally on femur
  • With KF, tibia rotates slightly medially

39

pseudolack of malleolar torsion

  • Small amount of transverse plane motion in the knee (excessive motion is called pseudolack of malleolar torsion)
  • false lack of external malleolar position
  • At birth, total range of motion is 15° with the greatest percentage internal
  • At 3, it is 5°
  • Anything greater than 15° is called pseudolack of malleolar torsion (the foot appears internally rotated due to an apparent lack of normal external malleolar position)

40

define tibial torsion

 “a change in the transverse relationship of the foot to the thigh”

  • May involve rotation of knee on the leg in relation to the thigh; twisting in the leg, itself; or rotation of ankle joint on the leg
  • We are measuring the distal tibiofibular axis created by the malleoli in relation to the axis of the knee
  • Impossible to measure any amount of actual torsion or twisting of the tibia

41

developmental changes in external malleolar position

  • At birth, there is generally between 0° and 5° of external malleolar position
  • At one year, it is 10°
  • It increases by one degree for each year of age until 12 or 13
  • Final result is 18-23° of external malleolar positioning
  • Actual amount in tibial torsion is 13-18°
  • Anything less than these values is called “internal tibial torsion”
  • It is the most common cause of in-toe gait before the age of 2 or 3
  • The term version is not used when discussing the rotational deformities below the knee 

42

most common cause of in-toe gait before the age of 2 or 3

internal tibial torsion

43

why is external tibiofibular torsion necessary?

  • External tibiofibular torsion is necessary to counteract two natural formations of the talus:
  • flexion and extension of the talus occurs in an axis 10° internally rotated to the transmalleolar axis
  • head and neck of talus is internally rotated compared to the transmalleolar axis
  • If external torsion did not occur, in-toe gait would occur

44

how do you measure tibial torsion?

  • Measure with child sitting in chair with KF and leg in dependency
  • Normally, patella points forward and feet are also pointing straight
  • With internal tibial torsion, patella points forward, but foot points inward (but there is no deformity of the foot, itself, ie no metatarsus adductus)
  • Measure with the knee extended, because with the knee flexed, there is some internal rotation of the knee and the amount of external tibial torsion will be smaller

45

steps in exam for in/out toeing child

***

  • 1. Place child in sitting position with knee flexed over ledge.
    • Patella straight with foot internally rotated-ITT and/or MA (metatarsus adductus)
    • Patella straight with foot externally rotated: ETT
    • Patella internally rotated and foot internally rotated-IFT and possibly ITT and/or MA
    • Patella externally rotated and foot externally rotated-EFT plus possibly ETT
  • 2. Evaluate patellar and foot position while walking
    • Results should mimic sitting position findings
  • 3. Evaluate hip range of motion with HE and HF to determine NFP
    • If rom remains the same with both maneuvers, rotational deformity is due to femoral torsion
    • If rom changes, rotational deformity is due to soft tissue contractures
  • 4. With child supine and HF, perform tests for DHD
  • 5. Test for medial and lateral hamstring tightness which could cause in-toe or out-toe gait respectively
  • 6. Measure amount of transverse plane motion at the knee with KE
    • If >15°, diagnosis of pseudolack of malleolar torsion
  • 7. Measure amount of knee extension beyond 180°
    • If an additional 15° of extension occurs, diagnosis of genu recurvatum occurs
  • 8. With child supine and KE, measure amount of malleolar position
    • less than 5° external, consider ITT
    • > 20° external, consider ETT
  • 9. Evaluate foot for metatarsus adductus

46

internal tibial torsion

47

internal femoral torsion

48

sitting in W position indicates ...

femoral antetorsion

49

most common cause of intoeing before the age of 2 or 3

most  common cause of intoeing after the age 2 or 3

most common cause of outtoeing before the age 2 or 3

most  common cause of outtoeing after the age 2 or 3

most common cause of intoeing before the age of 2 or 3 = internal tibial torsion

most  common cause of intoeing after the age 2 or 3 = femoral antetorsion

most common cause of outtoeing before the age 2 or 3 = femoral retrotorsion

most  common cause of outtoeing after the age 2 or 3 = femoral retrotorsion

50

normal knee position based on age

genu varum

genu valgum

straight

genu varum: 0-2

genu valgum: 4-6, 12-14

straight: 2-4, 6-12, and greater than 14

51

With a 10 year old child in the sitting position, the knees are pointed straight ahead, but the feet are externally rotated.  A possible cause of this position is:

external tibial torsion

52

The clinical sign of developmental hip dysplasia where there is an interruption of the normal posterior folds of the buttocks is called:

broken anchor sign

53

A 5 year old exhibits an intoe gait.  All of the following are possible etiologies:

1.Internal femoral torsion

2.Femoral anteversion

3.Pseudolack of malleolar torsion

4.Pronation

5.Internal tibial torsion

1, 3, 4, 5

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