Arthritis

Question 1

what effect does exercise have on arthritis?

Answer 1

• arthritis is not worsened by sports, but improved

- exercise just increases the risks of breaks that contribute to arthritis

Question 2

what does the Hueter-Volkmann’s Law describe?

Answer 2

increased compression at the growth plate slows down longitudinal growth,

increasing tension at the growth plate speeds up longitudinal growth (stretching a yute)

Question 3

what sort of (mis)alignment/deformity is seen in sports players?

Answer 3

varus alignment
(outward bowing)

Question 4

what sort of (mis)alignment/deformity is seen in models/slim women?

Answer 4

valgus alignment

inwards

Question 5

what sort of alignment is seen in those with sedentary jobs?

Answer 5

neutral alignment

Question 6

what is the risk associated with varus knees?

Answer 6

higher risk of osteoarthritis

Question 7

where is the load placed on, leading to the varus deformity?

Answer 7

abnormal pressure on the medial knee joint

[push knees outwards from the inside]

Question 8

where is the load placed on leading to the valgus deformity?

Answer 8

abnormal pressure on the lateral knee joint

[push knees inwards from the outside]

Question 9

what change occurs in arthritis? when can it be diagnosed?

Answer 9

the cartilage gap decreased

diagnosed when Pt presents with pain rather than a biochemical test

Question 10

what effect does sport have on the intercondylar-intermalleolar distance?

Answer 10

it increases the distance –> varus alignment

Question 11

what is done surgically to realign varus/valgus alignment?

Answer 11

Osteotomy

• correct a mis-alignment in a younger person and thus can reduce incidence of arthritis later in life
• a bone is cut to shorten or lengthen it or to change its alignment.

Question 12

what does Wolff’s Law describe?

Answer 12

bones respond to stresses that are put on it

Higher stresses than normal will lead to more bone been laid to support itself

Question 13

give example of situations where Wolff’s Law applies

Answer 13

o Surfers knobs/knuckles
– kneeling on board can lead to bone growth.
o Dis-use atrophy in astronauts.
o Tennis players get dominant forearm appositional bone growth.

Question 14

what is Developmental Dysplasia of the Hip (DDH)?

Answer 14

In-utero malformation of the hip socket where the femoral head is not in location for the socket to form around it (the femur head being there should stimulate development of the socket)
This means the femur head is dislocated –> abnormal hip joint in the newborn

they are more likely to develop osteoarthritis when they are older

Question 15

what are the anatomical features of a developmentally dysplastic hip?

Answer 15

o Ileum has a steeper slope (socket not formed normally)

o Femur is at a higher insertion point.

Question 16

what effect does the femur being at a higher insertion point have on the pelvis?

Answer 16

The higher position can break down the acetabular labrum when the hip is flexed over time and stimulate osteophyte formation.

Question 17

Name two impingements of the hip joint

Answer 17

Cam and Pincer

occur in young people

Question 18

what is a CAM impingement?describe the deformity

Answer 18

thickening of bone at the femoral neck where is meets the acetabulum (near labrum)
- “pistol grip” deformity

Question 19

what effect does the CAM impingement have?

Answer 19

growth may hit the acetabular labrum and will ultimately affect deep flexion of the hip

this leads to labral tears and cartilage delamination

Question 20

what is a pincer impingement? describe the deformity

Answer 20

socket may be too deep so increased flexion of the hip may lead to increased growth of the acetabular labrum causing a pincer growth protruding over the femoral head

Question 21

what effect does the pincer impingement have?

Answer 21

the normal neck impacts the larger labrum leading to damage and increased ossification

Question 22

how can the cam and pincer impingement be repaired?

Answer 22

Hip arthroscopies

- shave off the bumps or inappropriate appositional bone growth.

Question 23

what is the role of the ACL?

Answer 23

prevents anterior displacement of the femur.

or hyperextension of the knee

Question 24

what is a synovial joint?

Answer 24

a joint containing:

• synovial fluid
• articular cartilage
• synovial membrane
• all surrounded by an articular capsule.

Question 25

what risk goes up with an ACL rupture?

Answer 25

the risk of meniscal injuries goes up as the menisci resist the femur sliding backward (act as shock absorbers)

Question 26

what are the layers of articular cartilage? describe the fibres inside each layer

Answer 26

1) superficial gliding zone
- horizontal fibres
2) middle transitional zone
- fibres are more random and oblique
3) deep radial zone
- fibres are vertical
4) tidemark

subcondral bone
cancellous bone

Question 27

what is done when a meniscus cannot be re-woven back together?
what is the impact on the blood supply?

Answer 27

the blood supply cannot be re-initiated

so a partial medial meniscectomy can remove a ruptured meniscus

Question 28

what is the significance of the meniscus in pressure distribution of the knee?

Answer 28

the menisci act to distribute compressive forces so without one, all the forces are targeted at one focal point on the tibia

little meniscus left over accelerates arthritis

ultimate outcome will be a total/partial knee replacement.

Question 29

what is the function of the PCL?

Answer 29

prevent posterior displacement of tibia to femur

Question 30

what is the role of the menisci?

Answer 30

resist compressive forces, prevent over rotation of the tibia to femur.