algorithm to correct varus knee in a tkr
TRANSCRIPT
The VARUS KNEEDr Vaibhav Bagaria
Sir HN Reliance Foundation HospMumbai India
Surgical AnatomyPes Anserinus
Superficial MCL
Deep MCL
Joint Capsule
Semi Membranous
Posterior Oblique ligament
MCL
Goal - Symmetrical Gaps
What is a Varus Knee
Maquet’s Line- Load Bearing Axis, Passes from centre of femoral head to Centre of Talus.
Ideally through the centre of Knee
Medial to Centre in case of Varus deformity
Maquet's Line
Maquet’s Line- Load Bearing Axis, Passes from centre of femoral head to Centre of Talus
Classification
Case1
Case 2
Case 3
Case 4
Case 5
Medial Exposure Using Scalpel -Subperisoteal elevation of the medial sleeve
Includes Joint Capsule and deep MCL
Continue with perisoteal elevator to elevate till Meta-physeal flare of tibia.
RanSall Manouveur: flexion- ER @ tibia
Medial Sleeve Creation
Step 1: Osteophytes
Remove all osteophytes from Femur & Tibia as they can tent the medial soft tissue sleeve and consequently shorten the MCL.
Remember to check the Posterior femoral condyle and Posteromedial tibia -> as they tighten extension gap.
Osteophyte Removal
Step 2: PCLMake sure PCL is resected before balancing
PCL is 2ry medial stabiliser so care should be taken not to release the entire sleeve of the tibia because it may cause medial instability
In CR PCL is left intact
PCL Release
Cuts and Balancing
Step 3: Semi Membranosus
If the tightness remains medially, the semimembranosus and posteromedial capsule can be released off the proximal tibia.
Semi Membranosus release
Step 4 - Posterior Oblique Lig
If the gap is tight only medially in the extension during varus valgus stress -> posterior Oblique Ligament can be subperiosteally released.
Is best done in a figure of 4 position
Step 5: Superficial MCL
Assess the flexion extension gap using Lamina Spreader/ Trial Component/ Spacer block - Varus Valgus.
If tight in both - release sub-periosteally SMCL off proximal tibia but not completely of distal tibia
Superficial MCL Release
Pie Crusting
AF PE ( Atrial fibrillation - Pulmonary Embolism)
Structures Responsible
step 6 Pes Release
Step 7: Shift and ResectInitial conservative tibial resection
Based on lateral side: 10mm
Angle perpendicular to long axis with 3 - 5 slope
Measure for size of tray
Downsize and lateralise
Shift & Resect
Shift & Resect
Shift & Resect
Lateralizing the component
Residual LCL laxity
IT band can usually dynamically restore the stability in most cases.
1st options: increase medial release/ medial cut and use thicker Poly
2nd: LCL advancement
AlgorithmCreate a Medial Subperiosteal Sleeve with DMCL
Remove the osteophytes
Take the cuts -remember ER may need to be increased
Check the Gaps
Release Semimembranosus, POL
SMCL ant or Post
Shift and Resect