Background
Indications
RA
OA
AVN
Contra-indications
Infection
Charcot
Paralysis of deltoid
Torn rotator cuff
Insufficient glenoid bone stock
RA
OA
AVN
Infection
Charcot
Paralysis of deltoid
Torn rotator cuff
Insufficient glenoid bone stock
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
Patient > 70
Gjertsen et al JBJS Am 2010
- 4335 patients > 70 with displaced subcapital fractures
- minimum 1 year follow up
- 1 year mortality same in each group / 25%
- 22% reoperation in ORIF v 3% in hemiarthroplasty
- more pain / higher dissatisfaction / lower quality life in ORIF group
Hemiarthroplasty
- unipolar monoblock
- unipolar modular
1. Significant functional impairment
2. PIPJ contracture
- originally thought to intervene early
- Macfarlane showed residual FFD always about 30o
- may need to release check rein ligaments / accessory collateral ligaments
3. MCPJ contracture >30o
4. Trigger fingers
- must do limited fasciectomy
First generation (late 70s early 80s)
Results
1. Reduce implant loosening
- offset load sharing to diaphysis
- 30% if > 70 mm
2. Restore optimal alignment
1. Using augments or bone grafting
2. Increased constraint
- VVS / hinge
Aseptic loosening
Infection
Instability
Wear & breakage components
Fracture
Stiffness
Pain
Restoration of anatomical alignment
Restoration of joint line
Restoration of bone stock
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
Need the least amount of constraint necessary to obtain sufficient stability
Advantages
- increase stability
Disadvantage
- increase stress at implant host interface
1. Unconstrained
A. Posterior cruciate retaining