Platelet rich plasma
2 main components
1. Platelets
- contain PDGF, TGF, VEGF
2. Growth factors
- ILGF
- FGF
Formed from the separation of whole blood into plasma and RBC
- separation usually achieved with centrifugation
Platelet concentration
Types
1. Supracondylar
2. Unicondylar
3. Intracondylar
Supracondylar / Extra-condylar
1. Provide representative sample
- to determine whether benign or malignant
- to determine cell line
- to grade lesion
2. Not compromise definitive treatment
Last step in evaluation / after staging
Don't perform definitive procedure immediately after biopsy unless
- pre-operative & Xray information characteristic
Option 1
- lateral and medial aspect femoral trochlea
Option 2
- intercondylar notch
Option 3
- allograft
- can take larger grafts without donor site risk
- head that translates 50% in all directions
- allows 30o ER with arm at side
- stable posteriorly
- antibiotics
- consider specific Propionobacterium cover
Best results
- long posterior musculocutaneous flap
- well cushioned mobile muscle mass
- full thickness skin
- very anterior scar
Contraindication
- non-ambulator
- get FFD
- better with through knee amputation
Advantages over AKA
1. Good Healing
First generation (late 70s early 80s)
Results
Attempt to reduce outliers in all 3 planes of the knee
- improve alignment
- theoretically improve survival and outcomes
Image based
Pre-op CT
- uncommon
- resource heavy
Meniscectomy
- resect 30%
- increases contact pressures 3.5 x
- shock absorbing capacity reduced to 20% normal
Results of partial & total meniscectomy are very poor in children
- meniscectomy in children is a last resort
- repair amenable tears
- treat others non-operatively
- only real indication for meniscectomy is locked knee not amenable to repair
Young patient
- previous total or near total meniscectomy
- developing joint line pain
- early chondral changes
- normal anatomic alignment
- stable or reconstructable knee
> Grade 2 Chondral changes
Farr et al Am J Sports Med 2007
- combined mensical transplantation with ACI