PCL CONTROVERSY IN TKR

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MIS TKA today
Prof. P Aglietti Director of the First
Orthopaedic Clinic University of Florence, Italy
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Promises, promises

• Less trauma
• Less pain
• Less blood loss
• Faster rehabilitation
• Better cosmesis

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Mini-Subvastus vsTraditional Medial ParaPatellar

• Prospective, matched case-control study
• Implants LPS (stemmed tibial component)
• Analgesia femoral nerve block PCEA

Mini-Subvastus 60
TKA Traditional Medial ParaPatellar 60 TKA
Boerger-Aglietti, CORR 2005
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Mini-Subvastus

• L-shaped capsular incision

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• Limited blunt dissection over the septum

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• Tibia first (in situ)
• Patella not everted

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Distal cut from medial
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Exposure of both condyles
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• Complete preservation of VMO insertion

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Results in favor of Mini-SV
Less blood loss Less pain day 1 Earlier SLR 90
reached sooner (statistically significant)
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Disadvantages of Mini-SV

• More tourniquet time
• More complications (one each)
• PT rupture
• Lateral condyle fracture
• Varus tibial component
• Initial experience

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Limitations of MIS
Inflammatory arthritis Restricted flexion (less
than 80) Patella infera (IS-R lt 0.6) Morbid
obesity (BMI gt 35.0) Risk of ischemic skin
complications Very severe deformities (more than
20) Large muscular males
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Hypothesis
Could we obtain the same MIS advantages with a
shorter but more conventional approach, with less
complications and more precision ?
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Limited ParaPatellar

• Quad incision 5 cm above patella
• No patellar eversion

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• Femur first distal cut from anterior
• (with downsized instrument)

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• Femoral component sizing/rotation

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• Femoral a/p cuts
• (downsized cutting block)

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• Tibial cut with tibia subluxed forward
• (EM cutting jig)

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• Complete tibial exposure
• for a variety of tibial implants

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Fluted
High flex mobile RP
Mini-keel
TM
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Limited ParaPatellar vsMini-Subvastus approach
Prospective matched case-control study Same
implant (LPS) and multimodal pain management
Limited ParaPatellar 30 TKA Mini-subvastus
30 TKA
Sensi-Aglietti, submitted to KSSTA 2007
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Demographics
LPP 30 Mini-SV 30
Age (yrs) 71 (61-87) 70 (59-80)
Female/male ratio 2.7 1.7
Previous HTO 10 13
BMI 28.9 (24-32) 28.8 (27-34)
Varus/valgus ratio 4.0 5.0
Preop flexion 105 (85-125) 110 (75-130)
Extension loss 1.8 (0-5) 2 (0-10)
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Complications
LPP 30 Mini-SV 30
DVT (distal) 3 4
Minimal PT detachment 0 1
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Clinical results
Subjective
Postoperative Pain LPP 30 Mini-SV 30 Significance
6h (VAS) 3.0 2.7 n.s.
day 1 (VAS) 3.8 3.4 p0.04
day 2 (VAS) 2.8 2.7 n.s.
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Clinical results
Objective
Average LPP 30 Mini-SV 30 Significance
Tourniquet time 61 83 plt0.001
Total blood loss 807 ml 832 ml n.s.
Active SLR 1.7 day 1.4 day p0.03
90 flexion 2.3 day 1.9 day n.s.
Flexion 10 days 95 101 p0.03
Flexion 30 days 106 110 p0.04
Flexion 90 days 115 119 n.s.
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Radiographic results
LPP 30 Mini-SV 30 Significance
Mech. axis outliers gt0?2 0 0 n.s.
Tibial varus position gt2 0 0 n.s.
Tibial medialization (3 mm) 0 3 n.s.
Post slope spread 2-5 1-5 n.s.
Retained cement fragment 0 2 n.s.
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• Mini-SV radiographic imperfections

Tibial medialization
Retained cement
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1. Conclusion

• The Mini-Subvastus had easier recovery but more
  complications and more tourniquet time than the
  Traditional Parapatellar approach.

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2. Conclusion

• Less invasive TKA is not for everybody it has
  many limitations or contraindications.

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3. Conclusion

• The Limited ParaPatellar was only slightly
  inferior to the Mini-Subvastus in the first weeks
  after surgery, but with less tourniquet time and
  improved radiographic results.

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4. Conclusion

• Outcome of TKA is multifactorial
• Less invasive surgical technique
• Preop patient education with clear expectations
• Postoperative pain control
• Rehabilitation

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5. Conclusion

• Less invasive technique
• Reduced QT incision
• No patella eversion
• No tibial subluxation ?

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6. Conclusion

• The less invasive concept is here to stay.
• It has stimulated new technical solutions, with
  small smart instruments and new surgical skills.

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Risks and benefits Comfort zone for the surgeon
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The importance of being MIS

• Minimally IS
• Medium IS
• Maximally IS