Exposure Aaron G Rosenberg MD Professor of Orthopedic Surgery Rush Medical College Chicago, Illinois Exposure - Incision Single incision can be used or modified Multiple longitudinal incisions favor the more lateral Transverse or oblique? create crossing at widest angle to minimize wound complications EXPOSURE Extend old incision proximally Expose virgin quadriceps tendon Dissect into virgin territory proximally Find a healthy fascial layer Keep skin and fat together Blood supply is sub-dermal
Things to worry about! Diabetes Steroids Smokers Vascularity Plastic Surgery & Flaps may help Be prepared for complications Preoperative Sham (delayed) Incision Skin Expansion Postoperative Gastroc Flap Free Flap Myo-cutaneous Rotation Flap Principles of Exposure 1) Take your time 2) Keep your eye on the patellar tendon 3) Protect the patellar tendon 4) Remove intra-articular scar 5) Free supra-patellar pouch 6) Sublux patella 7) Attack the gutters medially and laterally PROTECT THE PATELLAR TENDON
4 Leashes Quad Medial Retinaculum Patella Lateral Retinaculum Patellar Tendon Patellar Eversion Requires 180 o Rotation About the Long Axis Patella Medial Tendon Lateral Tubercle Clear medial gutter Attempt patellar eversion Externally rotate the tibia
Scar Lateral to the Tendon Inferolateral patellar tendon scar must be debrided as needed
Principles of Exposure Patellar subluxation is usually adequate eversion not needed Place pin in tendon if in doubt Obtain more release if needed Snip V/Y Tubercle Osteotomy The Quad Snip Takes tension off quadriceps tendon proximal leash Requires no modification of postop therapy Can be made more extensile Extending the Snip V/Y Turndown Much more exposure Allows quadriceps lengthening Requires rehab modification 10% patellar osteonecrosis
Turndown?? Even without lengthening Quads can be weak Lags are frequent Lengthening makes this worse Reserve for combined quad + flexion contracture Quad Lengthening?
Tibial Tubercle Osteotomy Widest exposure Good for repeat debridement Heals reliably Allows extensor lengthening Exposes IM canal Stress riser may lead to fracture Requires rehab modification Primum non nocere Don t Disrupt The Extensor Obtain Excellent Exposure Access the fixation interface accurately Disrupt interface without damaging surrounding structures Use minimum force Maximize Remaining Bone Stock
THANK YOU
COMPONENT REMOVAL IN REVISION TKA Douglas A. Dennis, M.D Adjunct Professor, Dept. of Biomedical Engineering University of Tennessee Adjunct Professor of Bioengineering University of Denver Clinical Director, Rocky Mountain Musculoskeletal Research Laboratory Denver, Colorado DISCLOSURE Consultant / Royalties: Depuy Laboratory Research Support Depuy Porter Adventist Hospital TKA COMPONENT REMOVAL: GOALS Preservation of Bone Stock For Upcoming Revision TKA Avoid Fracture Page 1
BONE STOCK PRESERVATION Tedious Prosthesis Removal Complete Interface Disruption Early Revision If Osteolysis»Xrays Underestimate Bone Loss TKA COMPONENT REMOVAL: KEY Initially Divide The Prosthesis-Cement Interface Then Remove Cement Under Direct Vision CEMENT REMOVAL: KEYS Divide & Conquer Divide Into Small Sections Before Removal Beware Of Thick Cement Thin With A High Speed Burr Then Section & Remove Page 2
TKA REMOVAL TOOLS Thin Osteotomes Power Saw Section Polyethylene Gigli Saw Cementless Components Posterior Femur Disimpaction Punches TKA REMOVAL TOOLS High Speed Burrs Section Metal IM Cement Ultrasound Diaphyseal Cement Component Extractors Universal Prosthesis Specific FEMORAL / METAL BACKED TIBIAL COMPONENTS Thin Osteotomes / Mini-Oscillating Saw Page 3
POLYETHYLENE TIBIAL COMPONENT REMOVAL Section Stem With Oscillating Saw Removal Of Stem Under Direct Vision POLYETHYLENE PATELLAR COMPONENT REMOVAL Thin Osteotomes / Oscillating Saw Section Peg-Patellar Component Junction METAL BACKED PATELLAR COMPONENT REMOVAL Dennis, J. Arthroplasty, 1993 Page 4
METAL BACKED PATELLAR COMPONENT REMOVAL TKA REMOVAL TKA REMOVAL: SUMMARY GOALS: Preservation Of Bone Stock Avoidance Of Fracture KEYS: PATIENCE!!! Complete Division Of Fixation Interface Divide Cement-Implant Interface First Remove Cement Under Direct Vision Page 5
THANK YOU Page 6
8/6/2012 Bone Preservation and Reconstruction in Revision TKA Preserve Ligaments and Bone Stabilize Implants (Augments, Reinforced Components, Porous Stem) Bone Graft Defects Bone and Ligament Damage Bone Loss and Ligament Damage In Extension 1
8/6/2012 Bone Loss and Ligament Balance in Flexion Preserve Bone Shell and Soft Tissue Attachments Preserve Soft Tissue Attachments Tibial Tubercle Osteotomy for Exposure 2
8/6/2012 Align with Medullary Canal: Minimal Bone Resection Preserve Soft Tissue Attachments: Reconstruct Bone Alignment in Flexion 3
8/6/2012 Size Femoral Comp and Choose Augments Stabilize First in Flexion Extend Knee Missouri Bone & Joint 4
8/6/2012 Distal Repositioning for Hyperextension Missouri Bone & Joint Raise Joint for Flexion Contracture Missouri Bone & Joint Conforming Polyethylene 5
8/6/2012 Anterior Cortex Distal and Posterior Seating Stable in Flex and Ext Revision TKA Severe Bone Loss Severe Bone Loss Intact Capsular Sleeve 6
8/6/2012 Major Bone Loss Clean Bone Surfaces Ream Femur and Tibia 7
8/6/2012 Suction Medullary Canals Save Medullary Contents Minimal Bone Cut 8
8/6/2012 Size Femoral: Mark Epi Axis Align with Epi Axis Position on Anterior Cortex Seat Distal and Posterior Debride Bone 9
8/6/2012 Position Joint Surface Stabilize in Flexion First Then Extend Knee Stem and Rim Fixation 10
8/6/2012 Bone Healing 3 Months Missouri Bone & Joint Bone Healing Leg Length and Joint Line 11
8/6/2012 Posterior Offset Good ROM Quadriceps Deficiency Major Condylar Bone Loss 12
8/6/2012 Major Condylar Bone Loss Ligament Balance: Flexion Ligament Balance: Extension 13
8/6/2012 Lateral Femoral Augmentation Medial Femoral Gap Ligament Balance: Flexion 14
8/6/2012 Ligament Balance: Extension Cement Lateral Augment Fit Medial Augment 15
8/6/2012 Reinforced Implant Porous Stem Porous Augments Lateral Contact: Medial Gap Apply Porous Spacer 16
8/6/2012 Bone Contact Distal and Posterior Cement Interval Final Implant 17
8/6/2012 Final Implant Anterior Cortex Distal Seating Posterior Seating Porous Coated Stem Patella: Trim and Balance One Month Post-Op 18
8/6/2012 One Month Post-Op One Month Post-Op One Month Post-Op 19
8/6/2012 Bone and Ligament Reconstruction in Revision TKA 89 Knees 7-12yrs 1 Loosening 2 Recent Stem Fractures Bone Preservation and Reconstruction in Revision TKA Preserve Ligaments and Bone Stabilize Implants: (Augments, Reinforced Components, Porous Stem) Bone Graft Defects 20
Re-establishing the Joint Line in Revision TKR The Treatment of Bone Loss In Revision TKR Disclosure In accordance with ACCME guidelines the author acknowledges there is a financial relationship with Industry Royalties: Aesculap Consulting Aesculap Blue Belt Technologies Innomed Stryker Zimmer FDA status: All Devices Cleared Goals for Rx of Bone Defects in Total Knee Replacement Femur: Establish correct joint line distally and posteriorly Provide stable support for implant Posterior joint line Distal joint line 1
Goals for Rx of Segmental Bone Defects in Total Knee Replacement Tibia Provide stable support for implant Stabilize knee with correct polyethylene All Tibial Cavitary Defects, Of Any Size, Can Be Treated With Impacted Cancellous Graft Bone grafts, not metal augments, are the treatment of choice in all CAVITARY defects Small Tibial Segmental Defects Can Be Treated With Bone Grafts Cavitary Small segmental <25% peripheral rim <10mm deep Does Not Support Implant! <25% 2
Drawbacks of Bone Grafts for Rx of Femoral Bone Defects Preparation of desired graft shape is imprecise (free-hand): Joint Line establishment difficult Allografts of correct size/shape may be difficult to obtain Large allografts are expensive Attachment of graft to host bone is technically demanding and dependent upon host bone quality (less reliable in osteoporotic bone) Drawbacks of Bone Grafts for Rx of Femoral Bone Defects Graft union to host bone is unpredictable Large allografts may weaken with time resulting in loss of implant support (esp. if deformity/instability) Incorporation of large allografts is incomplete/unpredictable Advantages of Metal Augments for Rx of Femoral Bone Loss Preparation of bone for augment is done using instruments which increases accuracy and reproducibility of procedure Precise posterior augment cut Resection for posterior augment 3
Advantages of Metal Augments for Rx of Femoral Bone Loss Placed on firm, viable host bone, assuring stable fixation Advantages of Metal Augments for Rx of Femoral Bone Loss It is important to have available femoral stems of appropriate size and offset when using metal augments: Provides Implant: 1) Stability 2) Orientation Goals for Rx of Bone Defects in Total Knee Replacement Femur: Establish correct joint line distally and posteriorly Provide stable support for implant Posterior joint line Distal joint line 4
Outline of Surgical Technique 1) Measure distal Jt. Line 2) Insert IM Rod 3) Resect Distal Femur 4) Size Femur 5) Resect Posterior Femur 6) Prepare Tibia Goals for Rx of Bone Defects in Total Knee Replacement Femur: Establish correct joint line distally and posteriorly Provide stable support for implant 5
Goals for Rx of Segmental Bone Defects in Total Knee Replacement Tibia Provide stable support for implant Stabilize knee with correct polyethylene Tibial Segmental Defect Trabecular Metal tibial augment- 1 yr. post-op Thank You 6