Abstract
Purpose: Axial alignment with restoration of mechanical axis is a major determinant of outcome in Total Knee Replacement.
Two perceived weaknesses of Intramedullary Referencing of Tibia are crucial:
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difficulties in understanding where centre of medullary canal projects on the plateau to plan entry hole
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in bowing of tibia, technical axis differs from anatomical axis, resulting in varus placement of tibial tray.
We evolved two technical pointers for optimal Tibial Intramedullary Referencing.
We undertook a retrospective study to analyse feasibility of our technique of Tibial Intramedullary Referencing.
Methods and Results: The study included 206 consecutive Total Knee Replacements between 2000 and 2008. Two – significant tibia vara and maluited tibial fracture- were excluded. Two techniques were used to avoid poor selection of entry hole and eccentric rod placement
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Entry Drill Hole is made to a depth of 2–3 cm only and intramedullary rod is passed to find its own way into canal. This avoids tilted position of rod forced by a deeper drill hole and minimises tilted or wrongly sloped position of tibial tray.
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Identification of Entry Point is facilitated by clearing soft tissue at tibial attachment of ACL over intercondylar eminence and confirmed by placing distal phalanx of surgeon’s thumb over bare area of anterior tibial plateau.
Entry point is usually at the tip of thumb.
We encountered no problems by our technique in Tibial Intramedullary Referencing in 204 Total Knee Replacements.
Conclusion: The two technical pointers help to overcome perceived drawbacks of Intramedullary Tibial Referencing.
Correspondence should be addressed to BOSA at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE, England.
