Position
- GA, IV Abx
- supine on radiolucent table
- no nerve blocks (eidural / sciatic / femoral)
- knee roll / lateral support
- II available
Incision with knee at 90°
- midpoint tibial tuberosity & fibular head
- extend proximally to LFC
- incise deep fascia / ITB in line with incision
- reflect underlying T ant & EDL anteriorly
- expose proximal tibia anteriorly and posteriorly
Anterior Tibio-Fibula joint
- must release
- place osteotome in joint to gauge direction & remove sliver of head medial fibular head
- locate & cauterize the Lateral Inferior Genicular Artery
- protect the CPN by staying superior to neck
- must leave LCL and biceps attached
Two threaded guide wires at superior level osteotomy
- under II guidance
- 2cm distal to joint in AP and lateral
- parallel to posterior slope
Osteotomy Jigs
- attach to superior 2 guide wires
- guide saw blade to hit superior osteotomy at medial cortex
- variable angles involved
Soft tissue protection crucial
- homan retractor anteriorly under patella tendon
- dissect soft tissue subperiosteally off posterior tibial cortex
- Homan to protect posterior structures
Osteotomy
- superior and inferior
- attempt to leave medial cortex intact
- must divide anterior and posterior cortices in full
- try to remove wedge of bone intact
- medial aspect of wedge difficult to remove
Straighten knee & close osteotomy
- do so slowly
- allow stress relaxation to occur
Check correction
- diathermy lead
- from centre of femoral head to centre of ankle
- must pass through lateral plateau
- if insufficient must recut distally
Stabilise ostetomy
- ORIF with 2 x staples / plate
- suture ITB & deep Fascia over drain
Post op
- splint
- monitor overnight for compartment syndrome
- PWB 6/52