Orthopaedics - Arthritis

Question 1

•Link between osteoarthritis & exercise

Answer 1

Arthritis does NOT come about OR become worse by exercise

Exercise only increases chance of breaks etc. that may contribute to arthritis
• exercise is the BEST treatment for arthritis

Question 2

Wolff’s Law?

Answer 2

In growing bones, the shapes of bones can be easily influences by COMPRESSIVE FORCES

Question 3

Hueter-Volkmann’s Law?

Answer 3

Increased COMPRESSION at the growth plate SLOWS DOWN longitudinal growth

Increasing TENSION at the growth plate SPEEDS UP longitudinal growth

i.e. stretching a child (as they have growth plates that are unfused), can increase longitudinal growth

Question 4

When can Hueter-Volkmann’s Law be applied?

Answer 4

Can be applied when addressing/correcting malformations in children

Question 5

Varus vs. Valgus alignment?

Answer 5

KNEE!

Varus = bowlegged
Valus = knock-kneed

Question 6

Within whom is varus, valus, neutral alignment more common in?

Answer 6

Varus alignment
• more common in SPORT PLAYERS

Valus alignment
• more common in MODELS/SLIM WOMEN

Neutral alignment
• more common in DESK JOB PEOPLE

Question 7

What is Varus Knee associated with?

Answer 7

Higher osteoarthritis

Question 8

What effect does miss-alignments have?

Answer 8

Put abnormal pressure on one side of the PROXIMAL TIBIA

• i.e. varus alignment puts abnormal pressure on the medial aspect on the knee

Question 9

How can Varus Alignment be treated?

Answer 9

Osteotomy
• re-alignment surgery for malformations
• can use 3D-printed models as guides

Can correct a miss-alignment in a younger person and thus REDUCE INCIDENCE of ARTHRITIS in later life

Question 10

Give examples of Wolff’s Law in action

Answer 10

Surfers knobs/knuckles
• kneeling on board can lead to bone growth

Astronauts
• dis-use atrophy

Tennis players
• get dominant forearm appositional bone growth

Question 11

DDH?

Answer 11

Developmental Dysplasia of the Hip

Question 12

Explain DDH and its features

Answer 12

In-utero malformation of an unknown cause
 This is much more likely to develop osteoarthritis in older age

 Features:
o Ileum has a steeper slope.
o Femur is at a higher insertion point.

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

Question 13

2 types of hip impingmenets?

Answer 13

CAM impingement

&

PINCER impingement

Question 14

Explain CAM impingement

Answer 14

The neck of the femur may grow in response to activity
• forming a bump on the femur neck

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

(onenote picture!)

Question 15

Explain PINCER impingement

Answer 15

o The socket may be too deep and again sport activity (increased flexion of the hip) may lead to increased growth of the acetabular labrum causing a pincer impingement.

(onenote picture!!)

Question 16

What is the treatment for CAM & PINCER Hips

Answer 16

Hip arthroscopies can shave off:

• the bumps OR inappropriate appositional bone growth

Question 17

Explain what helps prevent injury to the knee joint

Answer 17

 ACL prevents anterior displacement of the femur.
• Cruciate ligaments generally stop the knee displacing too far forward/backward.

 Synovial joints include – a joint containing synovial fluid, articular cartilage, synovial membrane all surrounded by an articular capsule

ACL = anterior cruciate ligament

Question 18

What happens if the ACL is ruptured?

Answer 18

The risk of meniscal injuries goes UP

• because the menisci resist the femur sliding backwards

Question 19

How can injury to the menisci be treated?

Answer 19

A partial medial meniscectomy:
• can remove a ruptured meniscus (if the meniscus cannot be re-woven back together, AKA, the blood supply cannot be re-initiated).

Question 20

However, what can be an issue if the menisci is removed?

Answer 20

 However, the menisci act to DISTRIBUTE COMPRESSIVE FORCES so without one, all the forces are targeted at one focal point on the tibia which can ACCELERATE arthritis.
o The ultimate outcome will be a total/partial knee replacement.

Question 21

ACL function?

Answer 21

 ACL function:
– prevent anterior displacement of tibia to femur
– hyperextension of the knee (same thing).

Question 22

PCL function?

Answer 22

 PCL function:

– prevent posterior displacement of tibia to femur

Question 23

Menisci function?

Answer 23

 Menisci function:
– resist compressive forces
– prevent over rotation of the tibia to femur