Articular Cartilage Lesions

Question 1

What is the function of the articular cartilage?

Answer 1

Provides low friction weight bearing surface

 Low coefficient of friction – 15X less than ice on ice

Question 2

What is important to remember about the vascularity and neural component of the cartilage?

Answer 2

Minimal ability to repair / regenerate and lacks inflammatory phase as it is avascular and aneural

Question 3

What about the underlying bone?

Answer 3

Abundance of nerve
endings
– Well vascularized

Question 4

What are two important anatomical features of articular cartilage?

Answer 4

 Chondrocytes
– Orchestrate matrix
balance

 Tidemark
– Junction of calcified articular cartilage with subchondral bone (critical part for healing or no healing)

Question 5

What are the 4 types of lesion classification?

Answer 5

type 1- softening
type 2- fibrilation
type 3- fissuring to bone
type 4- full thickness

Question 6

What is size classification for an articular cartilage damage?

Answer 6

small less then 2 cm
mod- 2-10 cm
large over 10 cm

Question 7

What are non surgical options for cartilage lesions?

Answer 7

Nsaids, glucosamine/chondrotin injections, hyaluronic acid injections can provide 6-12 months of pain relief

Question 8

Other then meds what is used for non surgical cartilage lesions?

Answer 8

bracing to unload joint, orthotic therapy, exercises to let muscles absorb more shock

Question 9

What is a common procedure to attempt and repair cartilage lesions?

Answer 9

Microfracture- stimulates marrow stem cells

Question 10

What is important to remember about micofracture procedure?

Answer 10

it replaces hyaline cartilage with fibrocartilage

Question 11

What is major difference between hyaline and fibrocartilage?

Answer 11

hyaline- organized collagen fiber formation

fibrocartilage- unorganized collagen which makes it not as strong and not as resistant to load

Question 12

What are advantages of a micro fracture procedure?

Answer 12

relatively simple procedure, high long term success rate, doesn’t burn any bridges for other procedures

Question 13

What are criteria for a likely successful micro fracture procedure?

Answer 13

small area, acute injury (3 months), weight bearing surface, young patient (under 40)

Question 14

What is key for micro fracture rehab?

Answer 14

is to create a healing environment without overloading healing tissue

Question 15

What is typical WB status following a MF procedure?

Answer 15

small- NWB-TDWB- 4-6 weeks

large- NWB-TDWB 6-8 weeks

Question 16

What are usual PT guidelines for rehab?

Answer 16

Weight shifts week 4
Squats week 6
Lunges & Step-ups week 8 Walking program week 10 Moderate sports week 12-16 High impact athletics week 18-26

Question 17

What is an OATS procedure?

Answer 17

osteochondral graft transfer, transferring healthy cartilage from minor load bearing surface to area of lesion so replacing hyaline with hyaline

Question 18

Why would an allograft be used in an OATS vs an autograft?

Answer 18

allograft- larger area, but slower bone incorporation and higher non union rates

Question 19

What is typical weight bearing status after an OATS procedure?

Answer 19

 Week 0-2 NWB brace locked @ 0°  Week 3-4 TDWB brace locked @ 0°  Week 5-6 PWB
 Week 6-8 FWB

too much load early on will disrupt healing

Question 20

What is typical rehab after an OATS procedure?

Answer 20

Weight shifts week 4
Squats week 6
Lunges & Step-ups week 8 Walking program week 10 Moderate sports week 12-16 High impact athletics week 18-26

Question 21

What is an ACI procedure?

Answer 21

autologous chondrocyte implantation, two stages

1. arthroplasty- determine area
2. open- execute procedure

Question 22

What is premise behind ACI?

Answer 22

harvest cells from healthy cartilage and then inject cultured cells into unhealthy cartilage

Question 23

What is most crucial part of ACI rehab?

Answer 23

PT education about procedure and why it is important to follow guidelines to protect healing

Question 24

What are goals during protection phase post ACI?

Answer 24

 Protect healing tissue from load and shear forces  Decrease pain and effusion
 Restore full passive knee extension
 Improve knee flexion
 Improve quadriceps control

Question 25

What is weight bearing status 0-6 weeks post ACI?

Answer 25

 NWB 1-2 weeks

 TTWB 2-3 weeks  PWB 4-5 weeks

Question 26

What are rehab goals in the transitional phase of post ACI?

Answer 26

 Gradually increase ROM

 Gradually improve quadriceps strength/endurance  Gradual increase in functional activities

Question 27

When should a brace be discharged post ACI?

Answer 27

week 6

Question 28

What is WB status in weeks 6-12 post ACI?

Answer 28

Progress to WBAT
 FWB at week 8-9
 D/C crutches at week 8-9

Question 29

What is ROM goals weeks 6-12 post ACI?

Answer 29

 Maintain full passive knee extension  Increase knee flexion to 125°-135°

Question 30

What are goals weeks 12-26 post ACI?

Answer 30

– Goals:
 Improve muscular strength and endurance Increase functional activities
– ROM:
 Patient should exhibit full ROM in flexion and extension

Question 31

What are goals weeks 26-52 post ACI?

Answer 31

Gradual return to full functional activities Begin sport-specific programs

Question 32

What is the future of articular cartilage repair?

Answer 32

use of hydrogels, similar water content to cartilage has low coefficient of friction and can withstand a lot of load

however having trouble integrating to bone