Articular Cartilage Lesions Flashcards
What is the function of the articular cartilage?
Provides low friction weight bearing surface
Low coefficient of friction – 15X less than ice on ice
What is important to remember about the vascularity and neural component of the cartilage?
Minimal ability to repair / regenerate and lacks inflammatory phase as it is avascular and aneural
What about the underlying bone?
Abundance of nerve
endings
– Well vascularized
What are two important anatomical features of articular cartilage?
Chondrocytes
– Orchestrate matrix
balance
Tidemark
– Junction of calcified articular cartilage with subchondral bone (critical part for healing or no healing)
What are the 4 types of lesion classification?
type 1- softening
type 2- fibrilation
type 3- fissuring to bone
type 4- full thickness
What is size classification for an articular cartilage damage?
small less then 2 cm
mod- 2-10 cm
large over 10 cm
What are non surgical options for cartilage lesions?
Nsaids, glucosamine/chondrotin injections, hyaluronic acid injections can provide 6-12 months of pain relief
Other then meds what is used for non surgical cartilage lesions?
bracing to unload joint, orthotic therapy, exercises to let muscles absorb more shock
What is a common procedure to attempt and repair cartilage lesions?
Microfracture- stimulates marrow stem cells
What is important to remember about micofracture procedure?
it replaces hyaline cartilage with fibrocartilage
What is major difference between hyaline and fibrocartilage?
hyaline- organized collagen fiber formation
fibrocartilage- unorganized collagen which makes it not as strong and not as resistant to load
What are advantages of a micro fracture procedure?
relatively simple procedure, high long term success rate, doesn’t burn any bridges for other procedures
What are criteria for a likely successful micro fracture procedure?
small area, acute injury (3 months), weight bearing surface, young patient (under 40)
What is key for micro fracture rehab?
is to create a healing environment without overloading healing tissue
What is typical WB status following a MF procedure?
small- NWB-TDWB- 4-6 weeks
large- NWB-TDWB 6-8 weeks
What are usual PT guidelines for rehab?
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
What is an OATS procedure?
osteochondral graft transfer, transferring healthy cartilage from minor load bearing surface to area of lesion so replacing hyaline with hyaline
Why would an allograft be used in an OATS vs an autograft?
allograft- larger area, but slower bone incorporation and higher non union rates
What is typical weight bearing status after an OATS procedure?
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
What is typical rehab after an OATS procedure?
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
What is an ACI procedure?
autologous chondrocyte implantation, two stages
- arthroplasty- determine area
- open- execute procedure
What is premise behind ACI?
harvest cells from healthy cartilage and then inject cultured cells into unhealthy cartilage
What is most crucial part of ACI rehab?
PT education about procedure and why it is important to follow guidelines to protect healing
What are goals during protection phase post ACI?
Protect healing tissue from load and shear forces Decrease pain and effusion
Restore full passive knee extension
Improve knee flexion
Improve quadriceps control
What is weight bearing status 0-6 weeks post ACI?
NWB 1-2 weeks
TTWB 2-3 weeks PWB 4-5 weeks
What are rehab goals in the transitional phase of post ACI?
Gradually increase ROM
Gradually improve quadriceps strength/endurance Gradual increase in functional activities
When should a brace be discharged post ACI?
week 6
What is WB status in weeks 6-12 post ACI?
Progress to WBAT
FWB at week 8-9
D/C crutches at week 8-9
What is ROM goals weeks 6-12 post ACI?
Maintain full passive knee extension Increase knee flexion to 125°-135°
What are goals weeks 12-26 post ACI?
– Goals:
Improve muscular strength and endurance Increase functional activities
– ROM:
Patient should exhibit full ROM in flexion and extension
What are goals weeks 26-52 post ACI?
Gradual return to full functional activities Begin sport-specific programs
What is the future of articular cartilage repair?
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
