Orthopaedics - Arthritis Flashcards
•Link between osteoarthritis & exercise
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
Wolff’s Law?
In growing bones, the shapes of bones can be easily influences by COMPRESSIVE FORCES
Hueter-Volkmann’s Law?
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
When can Hueter-Volkmann’s Law be applied?
Can be applied when addressing/correcting malformations in children
Varus vs. Valgus alignment?
KNEE!
Varus = bowlegged Valus = knock-kneed
Within whom is varus, valus, neutral alignment more common in?
Varus alignment
• more common in SPORT PLAYERS
Valus alignment
• more common in MODELS/SLIM WOMEN
Neutral alignment
• more common in DESK JOB PEOPLE
What is Varus Knee associated with?
Higher osteoarthritis
What effect does miss-alignments have?
Put abnormal pressure on one side of the PROXIMAL TIBIA
• i.e. varus alignment puts abnormal pressure on the medial aspect on the knee
How can Varus Alignment be treated?
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
Give examples of Wolff’s Law in action
Surfers knobs/knuckles
• kneeling on board can lead to bone growth
Astronauts
• dis-use atrophy
Tennis players
• get dominant forearm appositional bone growth
DDH?
Developmental Dysplasia of the Hip
Explain DDH and its features
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
2 types of hip impingmenets?
CAM impingement
&
PINCER impingement
Explain CAM impingement
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!)
Explain PINCER impingement
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!!)
What is the treatment for CAM & PINCER Hips
Hip arthroscopies can shave off:
• the bumps OR inappropriate appositional bone growth
Explain what helps prevent injury to the knee joint
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
What happens if the ACL is ruptured?
The risk of meniscal injuries goes UP
• because the menisci resist the femur sliding backwards
How can injury to the menisci be treated?
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).
However, what can be an issue if the menisci is removed?
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.
ACL function?
ACL function:
– prevent anterior displacement of tibia to femur
– hyperextension of the knee (same thing).
PCL function?
PCL function:
– prevent posterior displacement of tibia to femur
Menisci function?
Menisci function:
– resist compressive forces
– prevent over rotation of the tibia to femur
