TSA Technique
Goal
- head that translates 50% in all directions
- allows 30o ER with arm at side
- stable posteriorly
Pre-Op
- antibiotics
- consider specific Propionobacterium cover
- 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
A. Longitudinal Cut
- plantar proximal / dorsal distally
- ends up being parallel to sole
- leave strong plantar portion of head to prevent dorsiflexion
- mark centre of head
- distally to a point 2mm prox and 3mm above the centre of the head
B. Transverse cuts
- plantar proximal / dorsal distal
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
Trauma
RA
Rickets / osteomalacia
Horizontal joint line important
- < 10° tilt acceptable
> 10o joint line tilt / due to femoral valgus
- continues to overload lateral compartment
1. Incision and skin flaps
- previous incision may be L shaped
- may be good to use a vertical midline incision initially in HTO
- can usually incorporate incision
2. Removal of hardware
- may wish to consider staged procedure
- staples not usually a problem (can ignore)
Position
- GA, IV Abx
- supine on radiolucent table