This document discusses approaches to the knee joint and describes the operation of total knee arthroplasty (TKA) in detail. It outlines various approaches to the knee including medial para-patellar, subvastus anteromedial, and anterolateral approaches. It then describes the operative technique of TKA, including preoperative planning, bone cuts of the femur and tibia using cutting guides, and the importance of soft tissue balancing and implant fixation for achieving good results.

1. DISCUSS APPROACHES TO
THE KNEE &
DESCRIBE IN DETAIL THE
OPERATION OF TKA
Dr. Arojuraye S. A
(Senior Registrar)
National Orthopaedic Hospital,
Dala – Kano
5th January, 2018

2. Outline
 Approaches to the Knee
 Indications
 Positioning
 Landmarks
 Incision
 Dissection
 Dangers
 Closure
 Total Knee Arthroplasty
 Indications
 Preoperative Evaluation
 Operative Techniques
 Postoperative Care
 Complications
 Outcomes
 Conclusion

3. Introduction
 The knee is an unconstrained hinge joint
 Often described as subcutaneous
 Its anteromedial & anterolateral coverings consist:
 Largely of fibrous tissue
 Patellar retinaculum
 Joint capsule
 Incisions through these coverings is safe

4. Introduction…
 TKA is currently one of the most successful
Orthopedic surgical procedures
 Long-term outcomes ranging from 90% to 98%
 The success undoubtedly demands compliance with:
 Restoration of a correct leg axis
 Correct components positioning
 Proper ligament balancing
 Correct exposure

5. Approaches to the Knee Joint
(Arthroscopy has largely replaced open procedures)
 Anteromedial
 Para patellar
 Subvastus
 Anterolateral
 Posterolateral
 Postero medial
 Medial
 Transverse
 Lateral
 Posterior
 Extensile approaches
 Mc Cannell
 Fernandez

6. Medial Para-patellar Approach
(Von Langenbeck)
Indications
 Total knee arthroplasty
 Synovectomy
 Medial meniscectomy
 Ligament reconstruction
 Patellectomy
 Drainage of the knee
 ORIF of distal femur

7. Medial Para-patellar Approach
 Positioning
 Supine
 Sand bag
 Landmarks
 Patella
 Patellar ligament
 Tibial tubercle

8. Medial Para-patellar Approach
 Incision
 Longitudinal straight
 7 - 10cm above the patella
 Tibial tubercle
Many patients who require an
open operation on the knee as
young adults ultimately come
to require TKA and the utility
of the anterior midline incision
should be remembered!

9. Medial Para-patellar Approach
Superficial Dissection
 Medial skin flap exposes
 Quadriceps tendon
 Medial border of the patella
 Patellar tendon
 Capsulotomy
 This is done leaving a cuff of
tissue medial to the patella to
facilitate closure

10. Medial Para-patellar Approach
Deep dissection
 Patella is
dislocated
laterally
 Rotated 1800
 Knee flex (900)

11. Medial Para-patellar Approach
Deep dissection…
 In difficult patella eversion
 Superior extension
 Quadriceps snip
 Tubercle osteotomy
Avulsion of the patellar tendon is
difficult to repair and can be a
devastating complication

12. Medial Para-patellar Approach
Dangers
 Patellar tendon avulsion
 Medial collateral
ligament
 Infra-patellar branch of
saphenous nerve

13. Subvastus Anteromedial Approach
(Southern)
 1st described in 1929 (Erkes)
 Indications
 TKA
 Medial unicompartmental knee arthroplasty
Because it preserves the entire extensor mechanism's attachment
on the patella, the subvastus approach has an anatomic edge on
other arthrotomies of the knee joint

14. Subvastus Anteromedial Approach
Position
 Supine
 Knee flexed to 900
Skin Incision
 8cm above the Patella
 2cm distal to the tibial
tubercle (medial)

15. Subvastus Anteromedial Approach
Superficial dissection
 Superficial fascia:
incised slightly medial
to the patella
 Vastus medialis fascia:
bluntly dissected down
to it insertion.

16. Subvastus Anteromedial Approach
Deep Dissection:
 Inferior edge of vastus
medialis and adductors
are identified
 Intermuscular septum is
bluntly dissected 10cm
proximal to the adductor
tubercle

17. Subvastus Anteromedial Approach
Deep Dissection…
 Vastus medialis is lifted
anteriorly
 ‘L’ shaped arthrotomy
 Beginning medially
through the vastus
insertion
 along the medial edge of
the patella

18. Subvastus Anteromedial Approach
Deep Dissection…
 Medial edge of the
patella tendon is
partially released
 Patella is everted
laterally with the knee
extended

19. Subvastus Anteromedial Approach
Closure
 Tension and tie the
capsular sutures with
the knee in 90 degrees
of flexion to avoid
overtightening the
medial capsule.

20. Subvastus Anteromedial Approach
Advantages
 Good exposure
 Less blood loss
 Preserves patella blood
 Less postop pain
 Faster recovery
Draw backs
 Subvastus haematoma
 Stretching of VM
 Difficult extension
 Obesity
 Patella baja

21. Anterolateral Approach
(Kocher’s)
Indications
 TKA in valgus deformity
 Iliotibial band lengthening
 Excision of fibular head
 To decompress peroneal nerve
 Access to lateral femoral condyle
 Access to lateral tibial condyle
 Lateral meniscectomy

22. Anterolateral Approach
Incision:
 7.5cm above the patella
 Insertion of the V. lateralis into
the Q tendon
 Along the lateral border of
 Q. tendon
 Patella
 Patellar tendon
 2.5cm distal to the tibial tuberosity

23. Anterolateral Approach
Superficial dissection:
 Follows skin incision

24. Anterolateral Approach
Deep dissection
 Gentle sharp dissection
through the joint capsule
 Patella is retracted
medially to expose the
articular surface

25. Anterolateral Approach
Disadvantages
 It is difficult to displace the patella medially
 It require longer incision
 Require patellar tendon must be freed

26. Operative Detail
Total Knee Arthroplasty (TKA)

27. Total Knee Arthroplasty
Orthopaedic elective surgical procedure where the
articular surfaces of the knee ( the femoral condyles &
tibial plateau) are replaced
 Successful orthopaedic procedures
 Longevity
 Ability to relieve pain
 Attention to technique is of utmost importance in
achieving good results

28. Total Knee Arthroplasty
Indications
 Severe knee pain
 Degenerative osteoarthritis
 Post-traumatic osteoarthritis
 Rheumatoid arthritis
 Post infective (e.g TB)
 Severe deformity

29. Total Knee Arthroplasty
Contraindications
 Infections (Active / Recent)
 Critical arterial damage
 Non-functioning extensor mechanism
 Severe neurological disorders (relative)
 Well functioning arthrodesis
 Age (Very young & Very old patients)

30. TKA (Preoperative Planning)
 History
 Pain / deformity
 Comorbidities
 Examination
 Alignment
 Deformity / Instability
 Range of motion
 Extensor mechanism function
 Distal neurovascular status

31. TKA (Preoperative Planning)
 Plain radiographs
 Recent weight bearing
 AP, Lateral & Skyline
 Long leg alignment view
 Other investigations
 FBC, ESR, CRP
 Urinalysis
 FBS
 CXR, ECG
 Clotting profile

32. TKA (Preoperative Planning)
 Informed consent
 Surgery
 Anaesthesia
 Complications

33. TKA (Preoperative Planning)
 Templating
 Surgical plan
 Correct technique
 Deformities
 Implant selection

34. TKA (Operative Techniques)
 Anaesthesia
 General
 Regional
 Prophylactic antibiotics
 Positioning
 Supine
 Thigh support
 Foot Bolster

35. TKA (Operative Techniques)
 Pneumatic tourniquet
 The limb is prepared
 Water-proof drape
 Mark with sterile pen
 Opsite

36. TKA (Operative Techniques)
 Landmarks
 Patella
 Patellar ligament
 Tibial tubercle
 Incision
 Longitudinal straight
 5 – 10cm ↑ the patella
 Tibial tubercle

37. TKA (Operative Techniques)
 Arthrotomy
 Dissection
 Retropatella fat
 Menisci
 ACL
 PCL
 Osteophytes

38. TKA (Operative Techniques)

39. TKA (Operative Techniques)
 10 goals of surgery
 Pain relief
 Restoration of function
 Longevity of the prosthesis
 Immediate technical aims
 Anatomical alignment
 Good range of motion
 Good stability
 Ligamentous balancing
 Good patella tracking

40. TKA (Operative Techniques)
 Good results
 Accurate bone cuts
 Equal flexion / extension gaps
 Correct soft tissue balancing
 Adequate fixation of implants
 ↓↓ risk of adverse intraoperative events
The surgeon must appreciate that TKA is as much a soft
tissue operation as a bony procedure.

41. TKA (Operative Techniques)

42. TKA (Operative Techniques)
Bone Cut
 Femoral Cut
 Tibia cut
Whether the femoral or tibial cut is made first depends on the
surgeon’s preference & type of prosthesis used

43. TKA (Operative Techniques)
Femoral Cut
 Knee is flexed & patella everted
 Medullary entry
 1cm anterior to insertion of PCL
 Big drill bit
 Insertion of intramedullary rod
 Distal femoral cutting jig
 Cut set @ 5 – 90 valgus
 Match contralateral limb

44. TKA (Operative Techniques)
NOHD-Kano

45. TKA (Operative Techniques)

46. TKA (Operative Techniques)
Femoral Cut…
 The distal cutting jig
 Secured with 2 or 3pins
It is imperative that the medial & lateral soft tissues are retracted
& protected with either Hohmann or Trethowan retractors.

47. TKA (Operative Techniques)
Femoral Cut…
 Distal femur is then sized
 Stylus of the sizer seated on the cortex
 Overlying synovium removed
 Marker holes are made through the jig
 Order of cut
 Anterior
 Posterior
 Anterior Chamfer
 Posterior Chamfer
 Box cut (post & cam mechanism)

48. TKA (Operative Techniques)
NOHD - Kano

49. TKA (Operative Techniques)
NOHD - Kano

50. TKA (Operative Techniques)
Femoral Cut…
 Cutting block is placed
 Firm on the cut surface
 Slight external rotation (30)
 Pegs sitting on the marker holes
 Secured with obliquely placed pins
 Cutting guide “angel wing”
 Avoid notching

51. TKA (Operative Techniques)
Femoral Cut…
 Difficulty sitting sizer / cutting block
 Remove osteophytes
 Adequate meniscal resection
 Bone cuts complete
 Sufficient soft tissues retraction

52. TKA (Operative Techniques)
Tibial cut
 900 to the axis of the tibia (coronal plane)
 AP slope of 3° (sagittal plane)

53. TKA (Operative Techniques)
Tibia cut…
 In varus knee:
 Resect 10 mm from the normal lateral compartment
 2 mm from the abnormal medial compartment
 In valgus knee:
 Resection can be more difficult to estimate
 Should extend to the level of the tip of the fibula head

54. TKA (Operative Techniques)
Tibia cut…
 Confirm correct height (using Stylus)
 Cutting block is fixed with pins
 Intramedullary rod removed

55. TKA (Operative Techniques)
Tibia cut…
 If extramedullary referencing is used:
 Rod in line with tibial crest
 Distal tip lie just medial to the centre of the ankle
 The tibia is
 Externally rotated &
 Subluxed anteriorly
(To expose entire articular surface)

56. TKA (Operative Techniques)
Tibia cut…

57. TKA (Operative Techniques)
Tibia cut…
 After complete tibial resection:
 Meniscal remnants are removed
 Tibial component is sized
 Trial components
The tibial component should lie in slight internal rotation on
the tibia, with the midpoint of the tibial baseplate being in line
with the medial third of the patella tendon to optimize
patellofemoral tracking

58. TKA (Operative Techniques)
Flexion / extension gaps
The femoral & tibial cuts should
be such that the rectangular
spaces created are the same in
both full extension & 90° of
flexion

59. TKA (Operative Techniques)
Common problems
 Tight in extension, flexion satisfactory
Solution:
 Release posterior capsule off femur
 Resect the PCL
 Increase distal femoral resection
(Beware of raising the joint)

60. TKA (Operative Techniques)
Common problems…
 Tight in flexion, extension satisfactory
Solution:
 Increase the anteroposterior tibial slope
 Downsize the femoral component
(Beware of notching the femur)
 Tight in flexion and extension
Solution:
 Increase tibial resection
(Beware of losing too much tibial surface area)

61. TKA (Operative Techniques)
Common problems…
 Loose in flexion and extension
Solution:
 Increase thickness of insert
(Beware gross ligamentous instability)

62. TKA (Operative Techniques)
Soft tissue balancing
 Scenarios
 Varus deformity
 Valgus deformity
 Fixed flexion deformity
Achieving anatomical alignment & equal flexion / extension gaps
is a combination of accurate bone cuts and correct soft tissue
balancing!

63. TKA (Operative Techniques)
Soft tissue releases in deformity correction

64. TKA (Operative Techniques)
Implantation of prosthesis
 Knee replacement systems
 Cemented
 Uncemented
 Hybrid design
 The polyethylene insert
 Modular
 Monoblock

65. TKA (Operative Techniques)
Implantation of prosthesis…
 Following satisfactory trial
 Selected implants are checked & opened
 Knee is flexed & patella everted
 Knee is washed out thoroughly & dried
 Expose bone trabeculae
 If sclerotic bone surface
 Small drill for multiple key holes
To maximize the mechanical fixation of the bone cement

66. TKA (Operative Techniques)
Implantation of prosthesis…
 All surgical team change their outer gloves
 Cement mixing for components
 Simultaneously
 Separately
Whether the femur or tibial prosthesis implanted first is the
surgeon’s preference

67. TKA (Operative Techniques)
Implantation of prosthesis…
 Tibia component
 Cement applied on to the cut surface
 Tibial component positioned
 Firmly seated with soft impactor & hammer
 Excess cement is removed
 Trial insert is applied to tibial baseplate
 Femur is lifted up

68. TKA (Operative Techniques)
Implantation of prosthesis…
 Femur component
 Cement is placed onto the prosthesis
 Prosthesis is then positioned
 Avoid flexion of the component
 Gentle firm impaction
 Remove excess cement
 Knee is extended & axial compression applied
Hyperextension leads to uneven cement pressurization and may
cause posterior ‘lift-off’ of the tibial baseplate

69. TKA (Operative Techniques)
Implantation of prosthesis…
 Tibia insert
 Trial insert is removed
 Baseplate inspected
 Definitive insert is impacted
 Knee is extended

70. TKA (Operative Techniques)
Closure
 Cement set
 Wash out (pulsed lavage)
 Tourniquet removal
 Before closure
 After closure
 Suction drain (lateral gutter)

71. TKA (Operative Techniques)
Closure…
 Repair:
 Water tight
 Good ROM
 Normal patella tracking
Closure of the knee in flexion ensures that the correct tension
is achieved

72. TKA (Operative Techniques)
Closure…
 Deep layer
 Heavy suture (e.g Vicryl 1)
 Continuous suture (quadriceps)
 Interrupted suture (parapatella retinaculum)
 Continuous suture (medial capsule to patella tendon)
 Interrupted sutures (subcutaneous fat)
 Skin
 Surgical staples
 Continuous absorbable subcuticular
 Interrupted fine nonabsorbable suture

73. TKA (Post-operative Care)
 Analgesia
 Antibiotics
 8hrs & 16hrs
 DVT prophylaxis
 Mechanical
 Chemical
 Observation
 Respiratory
 Cardiovascular
 Neurovascular

74. TKA (Post-operative Care)
 Removal of tubes
 Drains
 Epidural catheter
 Urinary catheter
 Intravenous cannula
 Hb concentration
 24 – 48 hrs

75. TKA (Post-operative Care)
 Full weight bearing
 Active ROM
 As soon as possible
 Wound inspection
 Radiograph
 B4 discharge
 Skin clips removal: 10 – 14 days

76. TKA (Post-operative Care)
 SOPD:
 6 weeks
 Follow up:
 Serial radiographs
 Ideally for life

77. Complications
 Early
 Anaesthetic
 Bleeding & haematoma
 DVT/PE
 Infection
 Transfusion reaction
 Neurovascular injury
 Late
 Implants failure
 Periprosthetic fracture

78. Conclusion
 TKA is currently one of the most successful
Orthopedic surgical procedures
 (good long-term outcomes: 90% to 98%)
 The success of the procedure demands
 Restoration of a correct leg axis
 Correct positioning of the components
 Proper ligament balancing
 Correct exposure of the joint

79. References William MM. Arthroplasty of the knee. In: Frederick MA, Canale ST, Beaty JH.
Campbell's Operative Orthopaedics, 13th ed, Elsevier 2017; Chap 7: 396 – 463.
 Lee D, Timothy WR. Primary Total Knee Arthroplasty. In: The Stanmore Guide,
Operative Orthopaedics; Hodder Arnold 2010; (11): 172 – 182.
 Mark WP. Knee. In: Morrey BF, Morrey MC. Master Techniques in Orthopaedic
Surgery: Relevant Surgical Exposures 1st ed. Lippincott Williams & Wilkins 2008;
9: 192 – 215.
 Stanley H, Piet D, Richard B. The Knee. In: Surgical exposures in Orthopaedics:
The anatomic approach, 4th ed. Lippincott Williams & Wilkins 2009; 10: 510 - 584
 Morten GT, Henrik H, Kristian SO, Thue Q, Anders T. Indications for knee
arthroplasty have remained consistent over time. Dan Med J 2012; 59 (8): A4492
 Marco S, Cristina S, Francesco C, Giuseppe P, Massimiliano S. Surgical
approaches in total knee arthroplasty. Joints 2013;1(2):34 – 44

80. many thanks