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Tkr by dr. saumya agarwal
Total knee replacement (TKR) involves replacing the weight-bearing surfaces of the knee joint to relieve pain and correct deformities. The document discusses the anatomy of the knee joint, common conditions requiring TKR such as osteoarthritis and rheumatoid arthritis, the evolution of TKR implant designs, surgical approaches, the procedure, goals of alignment and balancing, and potential complications. Computer-assisted technology can provide real-time feedback on bony cuts and alignment during surgery. While TKR successfully relieves pain in most patients, some may still experience complications such as stiffness, infection, or loosening of implants.
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Tkr by dr. saumya agarwal
- 1. TOTAL KNEE REPLACEMENT Presenter: Dr. Saumya Agarwal Junior resident Dept of Orthopaedics J.N .Medical College and Dr. Prabhakar Kore Hospital and MRC, Belgaum
- 2. INDEX • Anatomy ofthe knee joint • Common conditions leading to TKR • Evolution of TKR • Total knee replacement
- 3. • Approaches • Procedure •Complications • Computer assisted technology • Questions
- 4. Anatomy Of TheKnee Joint • Three bones and three compartment
- 5. Knee Stabilizers • Medial •Lateral • Anterior • Posterior • Rotatory
- 8. Osteokinematics Gross movements ofbones at joints Flexion / extension Abduction / adduction Internal rotation / external rotation Arthrokinematics Small amplitude motions of bones at joint surface Roll Glide (or slide) Spin
- 9. INTRODUCTION Arthroplasty is thesurgical reconstruction of a joint which aims to relieve pain , correct deformities and retain movements of a joint. Total Knee Arthroplasty(TKA) is the surgical procedure to replace the weight-bearing surfaces of the knee joint.
- 10. Common Conditions ThatLead To TKR • OSTEOARTHRITIS Primary (idiopathic) Secondary Post traumatic arthritis • RHEUMATOID ARTHRITIS
- 11. Evolution of TKR •Fergussen(1860) resection arthroplasty • Verneuil performed first interposition arthroplasty • 1940s- first artificial implants were tried when molds were fitted in the femoral condyle • 1950s- combined femoral and tibial articular surface replacement appeared as simple hinges
- 12. Evolution …. • FrankGunston(1971), developed a metal on plastic knee replacement • John Insall(1973), designed what has become the prototype for current total knee replacements. This was a prosthesis made of three components which would resurface all 3 surfaces of knee - the femur, tibia and patella
- 13. Classification of ImplantsDesign • Unconstrained – Cruciate retaining – Cruciate substituting – Mobile bearing knees • Constrained (Hinged) • Unicondylar Prosthesis • Total Condylar Prosthesis
- 14. Prosthetic Design Femoral rollback –Posterior translation femur with flexion – Controlled by PCL – Improves Quad function and knee flexion
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- 16. Cruciate retaining Intact PCL Varus< 10 Valgus < 15 • Advantage 1. Avoid post cam impingement/ dislocation 2. More closely resembles knee kinematics 3. Bone preserving 4. Improved proprioception • Disadvantage 1. Tight PCL – Increased poly wear 2. Rupture PCL – flexion instability
- 17. Cruciate stabilized • Camand post mechanism • Insert more congruent / dished Advantages Easier to balance knee More range of motion Disadvantages Cam jump Post wear Patellar clunk syndrome Additional cut from distal femur ABSOLUTE INDICATION •Previous patellectomy •Inflammatory arthritis •Deficient PCL
- 18. Cruciate sacrifice /retain - Evidence PS increased ROM – No functional improvement No difference in ROM between PS and CR PCL does not work in CR knees Increased wear Ps knee – cam & post Cochrane review – No difference in function whether cruciate retained or sacrificed
- 19. Mobile Bearing Design •Poly Rotates over tibial base plate • Reduced poly wear • Bearing spin out
- 20. Fixed Bearing ormobile bearing - Evidence • No advantage of mobile bearing over fixed bearing • Increased wear in undersurface of mobile bearing
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- 22. Constraint – Ability ofprosthesis to provide varus – valgus and flexion –extension stability in presence of ligamentous laxity / bone loss
- 23. Constrained Hinged design •Linked femoral and tibial components • Tibial bearing rotates around yoke Aseptic loosening Large amount bone resection INDICATION Global ligamentous deficiency Hyperextension instability
- 24. Hi Flex Design •Cultural / pt expectation • Cut more posterior condyle Preop flexion - most significant - Gatha etal 2008 No difference in ROM - Mehin JBJS 2010 No difference in ROM Sumino Int Ortho 2010
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- 26. Advantages of UnicondylarTKR • Shorter rehabilitation time • Greater average post-op range of movement • Preservation of proprioception function of cruciate ligaments
- 27. CONTRA-INDICATIONS a) Inflammatory conditions b)Damage to articular cartilage c) Flexion contracture of 5° or more d) Preoperative arc of motion less than 90° e) Angular deformity of more than 15° f) ACL deficiency
- 28. Total Knee ReplacementToday • Large variety is available • Majority of TKR today are condylar replacements which consist of the following – Cobalt-chrome alloy femoral component – Cobalt-chrome alloy or titanium tibial tray – UHMWPE tibial bearing component – UHMWPE patella component
- 29. Who Is ACandidate For TKR • Quality of life severely affected • Daily pain • Restriction of ordinary activities • Evidence of significant radiographic changes of the knee
- 30. INDICATIONS • Severe arthritis •Young pts with systemic arthritis with multiple joint involvement • Osteonecrosis with subchondral collapse of a femoral condyle • Severe pain from chondrocalcinosis and pseudogout in elderly • Severe patello femoral arthritis rarely
- 31. CONTRA-INDICATIONS • Recent/current kneesepsis • Remote source of ongoing infection • Extensor mechanism discontinuity • Recurvatum deformity secondary to muscle weakness • Presence of painless, well functioning knee arthrodesis
- 32. What Is TheTime For Replacement • Old age with more sedentary life style • Young patients who have limited function • Progressive deformity • Other treatment modalities have failed
- 33. TKR should bedone before things get out of hand and the patient experiences a severe decrease in ROM, deformity, contracture, joint instability or muscle atrophy
- 34. Evaluation Of PatientBefore Surgery • A Complete Medical History • Thorough Physical Examination • Laboratory Work-up • Anesthesia Assessment 34
- 35. Recommended Preoperative Radiographsin Knee Replacement Surgery 1. Standing full-length anteroposterior radiograph from hip to ankle 2. Lateral knee x ray 3. Merchant’s view
- 36. Radiographs • Standing Ap& Lateral • Sunrise – Merchant view • Hip to ankle x- rays – Bony deformity – Short stature ( < 150 cm) – Very tall ( > 190 cm)
- 37. Radiographs • Femoral andtibial cut • Position of femoral canal entry • Bone defects • Joint subluxation • Ligament stretch out – Varus Thrust • Ligament release • Constraint needed
- 38. Goal of TKR •Pain relief • Restoration of normal limb alignment • Restoration of a functional range of motion
- 39. Successful Results Dependsupon: • Precise surgical technique • Sound implant design • Appropriate material • Patient compliance with rehabilitation
- 40. Technical Goals OfKnee Replacement Surgery 1. The restoration of mechanical alignment 2. Preservation (or restoration) of the joint line 3. Balanced Ligaments 4. Maintaining or restoring a normal Q angle
- 41. Mechanical Alignment TKA aimsat restoring the mechanical axis of the lower limb by: Sequential soft tissue releases Correction of bone defects by grafts or prosthetic augments
- 42. Ligament Balancing a. CoronalPlane – For varus deformities – For valgus deformities b. Sagittal Plane – Flexion contractures – Extension contractures
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- 53. Medial parapatellar approach •Most common • Surgeon are familiar
- 54. Lateral parapatellar approach •Valgus knee • Allows access to lateral side • Technically demanding • Medial patellar eversion difficult
- 55. Midvastus approach • SparesVMO insertion Advantages Accelerated rehab. Improved patellar tracking Disadvantages Less extensile Difficult in obese & flex contracture
- 56. Subvastus approach • Vastusmedialis lifted off Lateral intermuscular septum Advantages Intact quad Preserved vascularity of patella Disadvantage Least extensile Denervation of VMO possible
- 57. Femoral Cut • Valguscut angle • AAF – MAF • Between 5 – 7 deg • Intramedullary guide
- 58. Tibial Cut • Anglebetween AAT – MAT • Tibial cut angle- Zero • Tibial deformity – cut perpendicular to MAT • Intra or extramedullary guide
- 59. Joint line preservation •Inserting prosthesis same size as removed bone and cartilage Elevate joint line - mid flexion instability Abnormal patellofemoral tracking Equivalent to Patella Baja Lowering joint line - Lack of full extension
- 60. Knee Balancing • Balancein Coronal and saggital plane • Concave side – ligaments contracted – release • Convex side – ligaments stretched – Fill gap
- 61. Varus Knees HenriK Schroeder– Boesch – Ligament balancing in TKR
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- 64. Grade 2b release •Grade 2b release Posterior part tight in extension Anterior part tight in flexion
- 65. Grade 3 release •Grade 2a + 2b
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- 67. Valgus deformity • Osteophytes •Lateral capsule • Iliotibial band - Tight in extension • Popliteus – Tight in flexion • LCL
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- 70. Flexion contracture • Osteophytes •Posterior capsule • Gastrocnemius ( Medial and lateral head) • Inreased distal femoral cut
- 71. Saggital plane balancing •Mc Pherson’s rule Symmetric gap – address tibia Asymmetric gap – address femur
- 72. Tight in Extension Tightin flexion Symmetric gap Cut more tibia Loose in Extension Loose in Flexion Symmetric gap •Thicker poly •Tibial Metal augmentation
- 73. Extension good Loose inflexion Asymmetric gap 1. Increase size femoral component 2. Translate femoral component posterior 3. Use thicker poly and readdress as tight extension gap
- 74. Extension Tight Flexion Good AsymmetricGap 1. Cut more distal femur 2. Release posterior capsule
- 75. Extension Good Flexion Tight Asymmetricgap 1. Decrease femoral component size 2. Recess PCL 3. Check slope of tibia
- 76. Extension Loose Flexion Good Asymmetricgap 1. Distal femoral augmentation 2. Decrease femoral component size and thicker poly
- 77. Patellofemoral Alignment • Mostcommon complication • Maintain Q angle • Proper component rotation • Maintain normal patellofemoral tension
- 78. • Maintain Qangle Avoid 1. Int rotn fem component 2. Medial rotn fem component 3. Int rotn tibia 4. Patella prosthesis lateral rotn
- 79. Femoral component rotation •Ap Axis ( whiteside line) • Transepicondylar axis • Post condylar axis • Tibial alignment axis • Gap balance
- 80. Tibial component • Introtn tibia – increased Q angle
- 81. Patellar component • Centreor medialized • Avoid lateralizing • Increases Q angle and cause patella maltracking
- 82. Patella Baja • Patellarcomponent superior • Lower joint line • Transfer tibial tubercle cephalad • Patellectomy
- 83. Patella resurfacing vsnon resurfacing • Resurfacing – Component loosening – Clunk – Fracture – AVN • Non resurfacing – Anterior knee pain – May require second resurfacing
- 84. Patellar resurfacing Vsnon resurfacing - Evidence • Metal backed patella higher complications • Patellar replacement does not gurantee painless Patellofemoral joint • No significant benefit of patellar replacement
- 85. Complication • Femoral notch Sawcuts into anterior femoral cortex Increases chance of periprosthetic fracture Femoral stem extension
- 86. Complication Peroneal Nerve palsy( .3 to 2 %) Pre op Flexion and Valgus Tourniquete time > 120 min. Epidural anaesthesia post op Aberrant retractor placement EMG & NCV at 3 months Nerve decompression at 3 months
- 87. Complication • Vascular complication( <.17% - .2%) • Risk factor – Sharp dissection – Posterior retractor placement – Pre existing vascular disease – Immediate vascular repair
- 88. Complication • Extensor mechanismrupture ( .17% - 2.5% ) – Direct repair with suture - < 30 % avulsion – Primary repair and augment with graft – Allograft repair
- 89. Complication • Stiffness – Flexioncontracture 10 – 15 % deg – Flexion < 90 deg • Treatment – Manipulation under Anaesthesia – Arthroscopic lysis of adhesion – Revision TKR
- 90. Complication • Hypersensitivity Rare (nickel) • Patch testing • Lymphocyte transformation test • Revise to non allergic metal prosthesis
- 91. Summary • Choose correctpt • Plan properly • Adequate exposure • Follow principles to align and balance knee • Meticulous closure Hope for the best because 20 % of pt. with well performed TKR are not happy !!
- 92. Post Operative Rehabilitation –Rapid post-operative mobilization • Range of motion exercises started • CPM • Passive extension by placing pillow under foot • Flexion- by dangling the legs over the side of bed • Muscle strengthening exercises • Weight bearing is allowed on first post op day
- 93. Prosthesis Survival Different studiesshows different results • Ranawat et al (Clin Orthop Relat Res ) 95% at 15 years 91% at 21 years • Gill and Joshi (Am J Knee Surg) 96% at 15 years 82% at 23 years • Font-Rodriguez (Clin Orthop Relat Res ) 98% at 14 years
- 94. COMPUTER-ASSISTED ALIGNMENT TECHNIQUE • Thetechnique involves the attachment of active or passive trackers on femur and tibia, which are then tracked by a computer-assisted camera. • Computer gives real-time feedback about alignment of bony cuts in all three anatomic planes, which allows surgeon to make changes and to measure the accuracy of the bony cuts.
- 95. • Computer navigationsystems also can aid in determining the proper implant size as well as alignment. Soft tissue balancing and measurement of flexion and extension gaps during the procedure are other significant advantages to computer- assisted TKA. • Objective measurement of the gaps ensures proper soft tissue balancing and gaps that will provide a stable joint throughout a range of motion. • Another advantage of computer navigation is avoidance of violation of the femoral intramedullary canal, which may reduce blood loss and cardiac- related complications because fewer emboli are placed into the venous system than with placement of an intramedullary alignment rod.
- 96. Questions in exams?? Long Question? 1) Describe in detail about the kinematics of knee and enumerate the indications, procedure and complications of TKR Short Questions? 1) Approaches for TKR 2) Hi flexion type implant in TKR 3) Computer assisted technology for TKR 4) Complications post TKR
Editor's Notes
- #3 In today’s talk we will discuss brief anatomy of the knee joint, and then about the common knee problems that may lead to tka surgery. I will talk about brief history of TKR. then we will discuss how tkr is performed. At the end I will show u few cases of TKR done in our unit during the last one year. But first, lets review the anatomy of the knee joint
- #5 The bony anatomy of the knee joint includes the distal femur, the proximal tibia and the patella. The knee joint is a tricompartmental joint and consists of a patellofemoral articulation and medial and lateral femorotibial articulations.
- #6 The knee joint has no inherent stability rather it is provided by the surrounding ligaments and muscles.The ligaments about the knee include the collateral ligaments and the cruciate ligaments.the medial and lateral cpllateral ligaments prevent valgus and varus stresses, respectively. The anterior and posterior cruciate ligaments prevent anterior and posterior tibial traslation on the femur and secondary restraint to rotation. Fibrocartilagenous medial and lateral meniscus provides stability and shock absorption , especially with axial loading.
- #7 Knee motion during normal gait is more complex than simple flexion and extension. It occurs in abduction adduction, internal and external rotation and obviously the flexion and extension
- #11 The most common conditions that can lead to TKR are osteoarthritis which may be primary and secodary and the rheumatoid arthritis. Arthritic conditions can be classified as non inflammatory and inflammatory types. The classic type of non-inflammatory diseases are primary osteoarthritis and pot traumatic arthritis. The classic type of inflammatory arthritis is rheumatoid arthritis. The other types include gout, arthritis of psoriasis, ankylosing spondylitis etc.
- #12 1860- fergussen reported performing a resection arthroplasty of the knee for arthritis Few years later- verneuil performed first interposition arthroplasty using join capsule. Other substances were subsequently tried including muscle, fascia an fat. 1940-but these designs had problems with loosening and persistent pain. 1950s-These implants failed to account for the complexities of knee motion and consequently had high failure rates from aseptic loosening. They were also associated with unacceptably high rates of postoperative infection.
- #13 In 1971, Gunston importantly recognized that the knee does not rotate on a single axis like a hinge, but rather the femoral condyles roll and glide on the tibia with multiple instant centers of rotation. His polycentric knee replacement had early success with its improved kinematics over hinged implants but was unsuccessful because of inadequate fixation of the prosthesis to bone. In 1973 total condylar prosthesis was designed by Insall at the hospital for special surgery and this desighn is basically the model used today
- #14 There are 2 broad categories of implants design used for TKR
- #16 Un-constrained> most common type, used for un complicated knee problems, artificial components inserted into the knee are not linked to each other, have no stability built into the system, relyes on the person’s own ligaments and muscles.
- #22 Constrained> rarely used as a first choice, knee joint linked with a hinge, used when knee is highly unstable, useful in severly damaged knees, it is not expected to last as long as other types.
- #26 Unicondylar> replaces only half of the knee joint when damage is limited to one side of the knee,
- #29 1-Cobalt-chrome alloy femoral component replacing femoral condyles and the patella trochlea. Cobalt-chrome alloy or titanium tibial tray affixed to the upper tibia. UHMWPE tibial bearing component fixed into the tibial tray. UHMWPE patella component
- #30 When the quality of life is such that they are willing to undertake the risks of major surgery. Any arthritic disorder of the knee that is nonresponsive to the usual nonoperative treatment, when the patient’s pain is such that he or she can no longer accomplish his or her required activities of daily living. Before surgery is considered, conservative treatment measures should be exhausted. Destruction of knee> Significant arthritis involving all three compartments of the knee but occasionally may be indicated with only unicompartmental or bicompartmental involvement
- #33 Old age> b/c tkr has a finite expected survival that is adversely affected by activity level, it generaly is indicated in olger patients with more sedentary life styles. It is preferable that pts undergoing TKA have a remaining life expectancy of b/w 20 and 30 years so that the need for repeat arthroplasty for a failed TKA will be minimal . Young pts> tka may be indicated in a young age group but the pt must understand the limitations of the procedure, be willing to modify his or her life style to prolong the life of the prosthesis and be willing to risk the loer success rate in a revision arthroplasty. Deformity> deformity can become the principle indication for arthroplasty in pts with moderate arthritis and variable levels of pain when the progression of deformity begins to threaten the expected outcome of an anticipated arthroplasty. Intervening before this degree of deformity is present allows the use of a prosthesis that has a more favorable expected survival.
- #35 Remember that TKR surgery is elective it is not an emergency so the patient’s condition should be optimized before embarking on surgery. A detailed medical history should be obtained to prevent potential complications that can be life threatening or limb threatening. b/c most pts undergoing TKR are elderly, comorbid diseases must be considered. Examination> end stage arthritis may be associated with flexion contractures, varus or valgus angulations. All of these mal alignments must be taken into consideration when planning for TKR. Rule out and evaluate for potential serious vascular disease in the lower extremity. assessment of the skin is also important in TKR
- #42 The mechanical axis of the lower limb is an imaginary line through which the weight of the body passes. It runs from the center of the hip to the center of the ankle through the middle of the knee. This is altered in the presence of deformity and must be reconstituted at surgery, which protects the prosthesis from eccentric loading and early failure
- #93 Post operative physical therapy and rehabilitation greatly influence the outcome of TKR. ROM exercises are performed post operatively with or with out the assistance of CPM. CPM assist in obtaining knee flexion more quickly and thus decreasing the hospital stay.
- #94 Various studies shows varying results but most of them have 95% survival rate at 15 years