Tkr by dr. saumya agarwal

TOTAL KNEE REPLACEMENT

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 of the knee joint Common conditions leading to TKR Evolution of TKR Total knee replacement

3. Approaches Procedure Complications Computer assisted technology Questions

4. Anatomy Of The Knee Joint Three bones and three compartment

5. Knee Stabilizers Medial Lateral Anterior Posterior Rotatory

6. Osteokinematics Gross movements of bones at joints Flexion / extension Abduction / adduction Internal rotation / external rotation Arthrokinematics Small amplitude motions of bones at joint surface Roll Glide (or slide) Spin

7. INTRODUCTION Arthroplasty is the surgical 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.

8. Common Conditions That Lead To TKR OSTEOARTHRITIS Primary (idiopathic) Secondary Post traumatic arthritis RHEUMATOID ARTHRITIS

9. 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

10. Evolution …. Frank Gunston (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

11. Classification of Implants Design Unconstrained Cruciate retaining Cruciate substituting Mobile bearing knees Constrained (Hinged) Unicondylar Prosthesis Total Condylar Prosthesis

12. Prosthetic Design Femoral rollback Posterior translation femur with flexion Controlled by PCL Improves Quad function and knee flexion

13. Unconstrained TKR

14. Cruciate retaining Intact PCL Varus < 10 Valgus < 15 Advantage Avoid post cam impingement/ dislocation More closely resembles knee kinematics Bone preserving Improved proprioception Disadvantage Tight PCL – Increased poly wear Rupture PCL – flexion instability

15. Cruciate stabilized Cam and 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

16. 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

17. Mobile Bearing Design Poly Rotates over tibial base plate Reduced poly wear Bearing spin out

18. Fixed Bearing or mobile bearing - Evidence No advantage of mobile bearing over fixed bearing Increased wear in undersurface of mobile bearing

19. Constrained TKR

20. Constraint Ability of prosthesis to provide varus – valgus and flexion –extension stability in presence of ligamentous laxity / bone loss

21. 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

22. 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

23. Uni condylar TKR

24. Advantages of Unicondylar TKR Shorter rehabilitation time Greater average post-op range of movement Preservation of proprioception function of cruciate ligaments

25. CONTRA-INDICATIONS 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

26. Total Knee Replacement Today 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

27. Who Is A Candidate For TKR Quality of life severely affected Daily pain Restriction of ordinary activities Evidence of significant radiographic changes of the knee

28. 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

29. CONTRA-INDICATIONS Recent/current knee sepsis Remote source of ongoing infection Extensor mechanism discontinuity Recurvatum deformity secondary to muscle weakness Presence of painless, well functioning knee arthrodesis

30. What Is The Time For Replacement Old age with more sedentary life style Young patients who have limited function Progressive deformity Other treatment modalities have failed

31. TKR should be done before things get out of hand and the patient experiences a severe decrease in ROM, deformity, contracture, joint instability or muscle atrophy

32. Evaluation Of Patient Before Surgery A Complete Medical History Thorough Physical Examination Laboratory Work-up Anesthesia Assessment 34

33. Recommended Preoperative Radiographs in Knee Replacement Surgery Standing full-length anteroposterior radiograph from hip to ankle Lateral knee x ray 3. Merchant’s view

34. Radiographs Standing Ap & Lateral Sunrise – Merchant view Hip to ankle x- rays Bony deformity Short stature ( < 150 cm) Very tall ( > 190 cm)

35. Radiographs Femoral and tibial cut Position of femoral canal entry Bone defects Joint subluxation Ligament stretch out – Varus Thrust Ligament release Constraint needed

36. Goal of TKR Pain relief Restoration of normal limb alignment Restoration of a functional range of motion

37. Successful Results Depends upon: Precise surgical technique Sound implant design Appropriate material Patient compliance with rehabilitation

38. Technical Goals Of Knee Replacement Surgery The restoration of mechanical alignment Preservation (or restoration) of the joint line 3. Balanced Ligaments 4. Maintaining or restoring a normal Q angle

39. Mechanical Alignment TKA aims at restoring the mechanical axis of the lower limb by : Sequential soft tissue releases Correction of bone defects by grafts or prosthetic augments

40. Ligament Balancing a. Coronal Plane For varus deformities For valgus deformities b. Sagittal Plane Flexion contractures Extension contractures

41. Surgical Procedure

42. Procedure

43. Procedure

44. Procedure

45. Procedure

46. Procedure

47. Procedure

48. Procedure

49. VIDEO

50. APPROACHES

51. Medial parapatellar approach Most common Surgeon are familiar

52. Lateral parapatellar approach Valgus knee Allows access to lateral side Technically demanding Medial patellar eversion difficult

53. Midvastus approach Spares VMO insertion Advantages Accelerated rehab. Improved patellar tracking Disadvantages Less extensile Difficult in obese & flex contracture

54. Subvastus approach Vastus medialis lifted off Lateral intermuscular septum Advantages Intact quad Preserved vascularity of patella Disadvantage Least extensile Denervation of VMO possible

55. Femoral Cut Valgus cut angle AAF – MAF Between 5 – 7 deg Intramedullary guide

56. Tibial Cut Angle between AAT – MAT Tibial cut angle- Zero Tibial deformity – cut perpendicular to MAT Intra or extramedullary guide

57. Joint line preservation Inserting prosthesis same size as removed bone and cartilage Elevate joint line - mid flexion instability Abnormal patellofemoral tracking Equivalent to P atella Baja Lowering joint line - Lack of full extension

58. Knee Balancing Balance in Coronal and saggital plane Concave side – ligaments contracted – release Convex side – ligaments stretched – Fill gap

59. Varus Knees HenriK Schroeder – Boesch – Ligament balancing in TKR

60. Grade 1 release

61. Grade 2a release Grade 2A

62. Grade 2b release Grade 2b release Posterior part tight in extension Anterior part tight in flexion

63. Grade 3 release Grade 2a + 2b

64. Grade 4 release

65. Valgus deformity Osteophytes Lateral capsule Iliotibial band - Tight in extension Popliteus – Tight in flexion LCL

66. Pie crusting

67. Flexion contracture Osteophytes Posterior capsule Gastrocnemius ( Medial and lateral head) Inreased distal femoral cut

68. Saggital plane balancing Mc Pherson’s rule Symmetric gap – address tibia Asymmetric gap – address femur

69. Tight in Extension Tight in flexion Symmetric gap Cut more tibia Loose in Extension Loose in Flexion Symmetric gap Thicker poly Tibial Metal augmentation

70. Extension good Loose in flexion Asymmetric gap Increase size femoral component Translate femoral component posterior Use thicker poly and readdress as tight extension gap

71. Extension Tight Flexion Good Asymmetric Gap Cut more distal femur Release posterior capsule

72. Extension Good Flexion Tight Asymmetric gap Decrease femoral component size Recess PCL Check slope of tibia

73. Extension Loose Flexion Good Asymmetric gap Distal femoral augmentation Decrease femoral component size and thicker poly

74. Patellofemoral Alignment Most common complication Maintain Q angle Proper component rotation Maintain normal patellofemoral tension

75. Maintain Q angle Avoid Int rotn fem component Medial rotn fem component Int rotn tibia Patella prosthesis lateral rotn

76. Femoral component rotation Ap Axis ( whiteside line) Transepicondylar axis Post condylar axis Tibial alignment axis Gap balance

77. Tibial component Int rotn tibia – increased Q angle

78. Patellar component Centre or medialized Avoid lateralizing Increases Q angle and cause patella maltracking

79. Patella Baja Patellar component superior Lower joint line Transfer tibial tubercle cephalad Patellectomy

80. Patella resurfacing vs non resurfacing Resurfacing Component loosening Clunk Fracture AVN Non resurfacing Anterior knee pain May require second resurfacing

81. Patellar resurfacing Vs non resurfacing - Evidence Metal backed patella higher complications Patellar replacement does not gurantee painless Patellofemoral joint No significant benefit of patellar replacement

82. Complication Femoral notch Saw cuts into anterior femoral cortex Increases chance of periprosthetic fracture Femoral stem extension

83. 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

84. Complication Vascular complication ( <.17% - .2%) Risk factor Sharp dissection Posterior retractor placement Pre existing vascular disease Immediate vascular repair

85. Complication Extensor mechanism rupture ( .17% - 2.5% ) Direct repair with suture - < 30 % avulsion Primary repair and augment with graft Allograft repair

86. Complication Stiffness Flexion contracture 10 – 15 % deg Flexion < 90 deg Treatment Manipulation under Anaesthesia Arthroscopic lysis of adhesion Revision TKR

87. Complication Hypersensitivity Rare ( nickel) Patch testing Lymphocyte transformation test Revise to non allergic metal prosthesis

88. Summary Choose correct pt 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 !!

89. 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

90. Prosthesis Survival Different studies shows 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

91. COMPUTER-ASSISTED ALIGNMENT TECHNIQUE   The technique 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.

92. Computer navigation systems 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.

93. 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