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Optimizing the Patellofemoral Joint in TKR. Dr Sarbjit Singh, MD. TKA Complications. Patellofemoral Problems Most Common Complication After TKR Historically Up To 24% Now 0.5% to 5% Most Common Cause For Revision Up To 50% 90% of Early Historical Implants
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Optimizing thePatellofemoralJoint in TKR Dr Sarbjit Singh, MD
TKA Complications Patellofemoral Problems Most Common Complication After TKR Historically Up To 24% Now 0.5% to 5% Most Common Cause For Revision Up To 50% 90% of Early Historical Implants Rand, JBJS – A, 1994 Boyd, et al,. JBJS – A, 1993
Patellar Complications Subluxation Dislocation Fracture Loosening Poly Wear Metal Wear
Patellar Complications Tendon Rupture Osteonecrosis Weakness Stiffness Soft Tissue Impingement Anterior Knee Pain Patella Baja
Patello-Femoral Complications AreNOT Reduced By Not Resurfacing The Patella With Resurfacing Of The PF Joint Have: • Less Pain • Better Function • Fewer Revisions Relative To The PF Joint Boyd. Et al: JBJS 1993 Schroeder-Boerech et al, Arch Orthop Trauma Surg 1998 Daly et al. AAOS 2000 Newman, et al: The Knee 2000 Schroeder-Boersh et al, Arch Orthop Trauma Surg 1998 Waters et al. JBJS – A 2003
Optimizing PF Function In TKRSurgical Technique Extremely Rotate Femoral Component And Tibial Component Do NOT Internally Rotate Femoral Component Or Tibial Component Internal Rotation Of Components Most Common Error Leading to Revision Surgery Eckhoff et al: J Arthroplasty 1996 Feinstein et al: CORR 1996
Externally Rotate The Femoral Component Enhances Patellar Tracking Properly Locates the PF Sulcus • Trans-Epicondylar Axis • Whiteside’s Line • Tibial Cut Surface • 3º to 5º External Rotation Relative To Posterior Femoral Condyles • Except In Valgus Knee
Externally Rotate The Femoral Component Should Remove More Bone From Medial Femoral Condyle Than Lateral Femoral Condyle Especially In A Valgus Knee
Externally Rotate The Femoral Component The “Grand Piano” Sign
Lateralize The Femoral Component Improves Patellar Tracking Avoid Medial Positioning the Femoral Component: Creates Lateral Tracking Of Patella Harwin, Techniques in Knee Surgery 2003
Externally Rotate The Tibial Component Right Knee Improves Patellar Tracking Decreases the Q Angle Starts With How Orient The Tibial Cutting Jig
Externally Rotate The Tibial Component Beware The Tendency Of The Patellar Tendon To Push The Handle Into Internal Rotation Harwin, Techniques in Knee Surgery 2003
Extremely Rotate The Tibial Component Center Of The Tibial Component Should Be Rotated To Medial Third Or Center Of Tibial Tubercle
Externally Rotate The Tibial Component There Should Be Some Exposed Bone At The Postero – Medial Corner Of The Tibia
Lateralize The Tibial Component Improves Patellar Tracking Avoid Medial Positioning the Tibial Component: Increases the Q Angle Irritates the MCL Harwin, Techniques in Knee Surgery 2003
Keep The Tibial Component Posterior Decreases Patellar Forces By Effectively Shifting Tibial Tubercle Anterior
Do Not Oversize The Femoral Component Stuffs the PF Joint Stuffs the Flexion Gap Can Cause Pain and Stiffness Daluga et al: J Arthroplasty 1991
Try Not Raise The Joint Line Causes Patella Baja Increased PF Contract Pressure Decreased ROM Alters Kinematics Especially With PCL Retention Daluga et al: J Arthroplasty 1991
Avoid Increasing the Q Angle Increased Tibio – Femoral Valgus Increases The Q Angle And Leads to Increased Lateral Forces On The Patella Alignment: 7º Valgus Or Less Mechanical Axis = 0º Harwin, Techniques In Knee Surgery 2003
Measure Before And After Patellar Cut Measure Patellar Thickness Before Cut Leave at Least 12 to 15 mm of Residual Bone Take More From Medial Side Leave Symmetrical Residual Bone Goldberg et al: CORR 1988
Measure Before And After Patellar Cut Do Not Increase Thickness Of Residual Patella and Component Compared To Initial Patellar Thickness Irrigate When Making Patellar Cut So Don’t Burn Bone
Medialize Component On Patella Position Component At The Medial Edge Of Patella Consider Prosthesis With Medial Offset Oval Design Component Provides Better Coverage Of Patellar Bone Harwin, Techniques in Knee Surgery 2003
Choose A Smaller, RatherThan A Larger Component Larger Implants Exacerbate Maltracking Avoid Overhanging Poly Trim Uncovered Lateral Bone Clean Excess Cement Before It Sets
Balance the Soft Tissues Follow the Rule of NO Thumb No Direct Pressure on Patella Needed To Make Track Correctly While Testing OK To Take Slack Out of Quad With a Tenaculum Or Single Suture To Check Check Entire Arc of Motion Ewald Techniques Orthop 1991
Balance the Soft Tissues Follow the Rule of NO Thumb No Direct Pressure on Patella Needed To Make Track Correctly While Testing Test After The Tourniquet Is Down Assess for Lateral Retenacular Release If You Think About It, Just Do It Marson et al, J Arthroplasty 1999 Laskin, CORR 2001
If Necessary, Re-Align The Extensor Mechanism Recheck alignment, Cuts and position Proximal Realignment Tibial tubercle transfer
Optimizing PF Function In TKR Summary Externally Rotate Components Medialize Patellar Component Balance Soft Tissues If Think About Lateral Retinacular Release, Just Do It