22. Bone, joint and Tendon Reconstruction

Question 1

What is osteoarthritis caused by?

Answer 1

Degeneration of articular cartilage and underlying subchondral bone

Question 2

What impacts does OA have?

Answer 2

Huge financial burden on society - bloody old people

• 95% surgical volume
• 1-2% GDP

OA is greatest mobility disability of all medical conditions

Question 3

What is the main treatment for OA?

Answer 3

Joint reconstruction / replacement, (Athroplasty)

Question 4

How long does it take an Athroplasty to restore a joint back to full strength?

Answer 4

Months or years!

Question 5

What are some side effects of Knee Arthroplasty?

Answer 5

Blood clots (15%)
Blood clots in lung
Urinary infections 
Leg length difference
Pain + stiffness
Loosening of prosthesis
Knee infection
Nerve injuries

Question 6

What are some side effects of hip Arthroplasty?

Answer 6

DVT + pulmonary embolism
Dislocation
Leg length inequality
Persistent chronic pain
Loosening of prosthesis
Fracture
Metal sensitivity 
Nerve injuries

Question 7

What are the post operative effects of Knee athroplasty?

Answer 7

90% = increased ROM 0-110 degrees

25% loosening of prosthesis @ 10 yrs

Question 8

How can dislocation be prevented after hip replacement?

Answer 8

Dont cross legs
Sleep with pillows between legs
Do not bend over 90 degrees

Question 9

What is the average lifespan of a prosthesis?

Answer 9

12-15 yrs

Question 10

What is a bone or bone substitue Graft/Implant?

Answer 10

Surgical procedure replacing missing bone with material from patients own body or an artificial substitute

Question 11

What is a bone graft/implant used to treat?

Answer 11

Complex fractures

Large defects

Question 12

What are the 4 types of bone substitutes?

Answer 12

1) Autologous + allogenic bone grafting
2) Calcium based chemical bone
3) Ceramic and polymer based
4) Steel based

Question 13

What requirements should a bone graft satisfy in order to promote osteoregeneration?

Answer 13

1) Osteogenecity - MSCs, osteoprogenitors etc
2) Osteoinductivity - growth factors (BMP)
3) Osteoconductivity - Carrier scaffold for new bone

Question 14

What is the current gold standard bone grafting treatment?

Answer 14

Autologous bone grafts

Stimulates regeneration at non-union site

Question 15

What are some limitations associated with autologous bone grafts?

Answer 15

Availability
Donor site morbidity
Donor site pain
Risk of infection
Variable fusion success rates

Question 16

What is surgical fusion?

Answer 16

Surgical technique used to join two or more vertebrae
- Reduce pain due to movement of vertebrae

Uses bone graft to augment surgery

Question 17

How long does it take surgical fusion to heal?

Answer 17

3 months

Question 18

What bone is commonly used in autologous graft of bone?

Answer 18

Iliac crest

Provides stem cells

Question 19

What two types of bone can be used in autologous bone Grafts?

Answer 19

Cortical

Cancellous

Question 20

What are the characteristics of cortical bone in relation to autologous bone grafts?

Answer 20

Low osteogenic potential
Barrier to vascular ingrowth and remodeling
Cortical bone loses strength during incorporation
Super strong

Question 21

What are the characteristics of cancellous bone in relation to autologous bone grafts?

Answer 21

Lacks compresive strength

Has greater conductivity, accelerates fusion mass

Question 22

What is the most common type of autologous bone graft used?

Answer 22

Cancellous bone

Question 23

Where is bone sourced in allograft bone grafts?

Answer 23

Cadaveric bone
Available in desired configuration
Avoids morbidity of donor site complications

Question 24

What are the disadvantages of allograft bone grafts?

Answer 24

Delayed vascular penetration
Slow bone formation + fusion
Accelerated bone resorption
Delayed graft incorporation
Increased infection rate
Lack of histocompatibility

Question 25

What is distraction osteogenesis?

Answer 25

Surgery using healing property of bone for reconstruction of skeletal deformities and lengthening of long bones

Question 26

What is the process of distraction osteogenesis?

Answer 26

Fracture created Ends of bone moved apart (distraction phase) New bone forms in gap Expands volume of surrounding tissues

Question 27

What are the applications of distraction osteogenesis?

Answer 27

``` Congenital and developmental deformities Post traumatic injuries - growth plate fractures - Bone defects Infections + diseases After tumours Short stature and cosmetic lengthening ```

Question 28

What are two types of bone lengthening surgeries?

Answer 28

Ilzarov Surgery = brutal | Fitbone surgery = involves nail which extends

Question 29

What does the Anterior Crucial Ligament (ACL) do?

Answer 29

Prevents anterior translation and medial rotation of tibia in relation to femur

Question 30

What does ACL rupture result in?

Answer 30

Impaired stability of knee Risk meniscal injury Increased risk of early regenerative disorders Increased risk of cartilage damage

Question 31

Can torn ACLs heal?

Answer 31

Not with conservative management

Question 32

What is the primary treatment for ACL rupture?

Answer 32

Autologous tendonous tissue is most popular method for reconstruction

Question 33

What are some common sources for ACL autograft?

Answer 33

Patellar tendon = za best Hamstring tendons Iliotibal band Quadriceps tendon

Question 34

What is the current gold standard for ACL reconstruction autografts?

Answer 34

Patellar tendon | 168% greater strength than native ACL

Question 35

What are the advantages of patellar tendon bone autograft?

Answer 35

High tensile strength Permits bone-to-bone union at insertion sites Does not sacrifice another significant stabilizer tendon of the knee

Question 36

What are some disadvantages of patellar - ACL reconstruction?

Answer 36

``` Donor-site morbidity Increased scar formation Increased risk of patellar tendonitis/rupture Risk of patellar fracture during harvest Post-op patellar tendon shortening ```

Question 37

What are the two types of tendon in the hamistring tendon, and what is the strength of them in ACL reconstruction?

Answer 37

Gracilis tendon alone = 49% of native ACL | Semitendinous = 70% of native ACL

Question 38

What are the advantages of hamistring tendon ACL replacement?

Answer 38

Low incidence of donor-site complications such as pain Faster, easier and significantly smaller wound

Question 39

What are the disadvantages associated with ACL reconstruction?

Answer 39

Longer period required for tendon-to-bone fixation Initial tensile strength of graft may not be sufficient to achieve post-op stability Inferior strength to original tendon Weakening of quads

Question 40

What are some cadaveric sources of allograft ACL reconstruction?

Answer 40

Patellar tendon Anterior tibialis tendon Achilles tendon Fascia lata

Question 41

What are the advantages of allograft tendon reconstruction?

Answer 41

``` No-donor site morbidity Cosmetically better outcome No size limitation Shorter operation time Decreased incidence of post op morbidity e.g. stiffness due to scar formation ```

Question 42

What are the disadvantages of allograft tendon reconstruction?

Answer 42

``` Disease transmission Host immune rejection Delayed incorporation Alteration of mechanical properties secondary to sterilization Cost ```