PRIMARY TOTAL KNEE ARTHROPLASTY IN PATIENTS WITH A FIXED VALGUS DEFORMITY - PowerPoint PPT Presentation

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PRIMARY TOTAL KNEE ARTHROPLASTY IN PATIENTS WITH A FIXED VALGUS DEFORMITY

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PRIMARY TOTAL KNEE ARTHROPLASTY IN PATIENTS WITH A FIXED VALGUS DEFORMITY Presented by Spencer Schuenman, D.O. – PowerPoint PPT presentation

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Title: PRIMARY TOTAL KNEE ARTHROPLASTY IN PATIENTS WITH A FIXED VALGUS DEFORMITY


1
PRIMARY TOTAL KNEE ARTHROPLASTY IN PATIENTS WITH
A FIXED VALGUS DEFORMITY
  • Presented by
  • Spencer Schuenman, D.O.

2
INTRODUCTION
  • There is an abundance of literature demonstrating
    excellent results regarding TKA.
  • Most of these are primarily for varus
    extremities.
  • Reports detailing the results achieved in knees
    with a valgus alignment are relatively rare.
  • The valgus is approached differently than a varus
    knee and poses a challenge to the implant surgeon

3
VALGUS KNEE
  • Typical findings in a valgus knee
  • Hypoplastic lateral femoral condyle
  • External rotation deformities of the tibia
  • Internal rotation of the femur
  • Tight IT Band
  • Posterolateral joint contractures

4
CLASSIFICATION
  • Type I Valgus deformity secondary to bone loss
    in the lateral compartment and soft tissue
    contracture with medial soft tissues intact.
  • Type II The above with obvious attenuation of
    the medial capsular ligament complex.
  • Type III Severe valgus deformity with valgus
    malpositioning of the proximal tibia after
    overcorrected proximal tibial osteotomy.

5
PRINCIPLES OF VALGUS KNEE REPLACEMENT
  • All the basic principles of knee replacement
    surgery apply the reconstruction of valgus knees.
  • Restore mechanical axis
  • Reestablish the tibiofemoral joint line
  • Resurface the articular surfaces
  • Balance collateral ligaments
  • Create a painless, stable, mobile knee

6
PRINCIPLES OF VALGUS KNEE REPLACEMENT
  • Technical considerations
  • Surgical exposure
  • Bone cuts of the distal femur and proximal tibia
  • Medial and lateral ligament balancing
  • Balancing the tibiofemoral joint
  • Preserving peroneal nerve function
  • Implant selection

7
PRINCIPLES OF VALGUS KNEE REPLACEMENT
  • Ligament balancing in paramount
  • Relies on the principle of first aligning the
    components correctly and positioning the femoral
    joint surfaces equidistant from the epicondylar
    axes throughout the arc of flexion

8
OPERATIVE PLAN
  • Preoperative plan - Treatment options
  • Surgical approach - Lateral Vs Medial
    Parapatellar
  • Bone resection - Dealing with bone deficiencies
  • Ligament releases Balancing the knee in flexion
    and extension

9
TREATMENT OPTIONS
  • Type II Valgus Knees
  • Constrained knee with a lateral soft tissue
    release
  • Nonconstrained knee with lateral soft tissue
    release and insertion of a thick polyethylene
    insert
  • Nonconstrained knee with lateral soft tissue
    release and medial soft tissue advancement

10
TREATMENT OPTIONS
  • Constrained knee with a lateral soft tissue
    release
  • Medial collateral ligament tension is not
    restored
  • Associated with loosening, anterior patellar
    pain, instability, and high infection rates
  • Reserved for elderly, low active patients

11
TREATMENT OPTIONS
  • Nonconstrained knee with lateral soft tissue
    release and insertion of a thick polyethylene
    insert
  • Restore sufficient medial collateral ligament
    tension in extension
  • This can elevate the tibiofemoral joint line
  • May limit flexion because of flexion/extension
    gap imbalance
  • May place stretch on the peroneal nerve

12
TREATMENT OPTIONS
  • Nonconstrained knee with lateral soft tissue
    release and medial soft tissue advancement
  • Indicated in younger, more active patients
  • Balances flexion and extension gaps
  • May require postoperative bracing

13
SURGICAL APPROACH
  • Medial parapatellar approach
  • Can be used for knees with mild valgus
    deformities (lt15-20 deg.)
  • Lateral parapatellar approach
  • Usually required for severe (gt20 deg) deformities
  • Some recommend the lateral approach for all
    valgus knees (Keblish CORR 271, 1991)

14
LATERAL APPROACH
  • Keblish studied 79 cases of valgus knees using
    the lateral approach.
  • Reported 94.3 good/excellent results using LCS
    knee.
  • Valgus deformity ranged from 12 to 45 deg (mean,
    22)
  • Mean total point score improved from 49
    preoperatively to 87 post op.

15
LATERAL APPROACH
  • Advantages
  • Surgical technique is direct, anatomic, more
    physiologic, and maintains soft tissue integrity
  • The lateral release is performed as part of the
    approach.
  • Patellofemoral tracking and alignment stability
    are optimized and medial blood supply is
    preserved
  • Approach of choice for valgus knees.

16
MEDIAL APPROACH
  • Can be used for most Valgus knees.
  • Must remember to avoid doing a medial release
    with valgus knees
  • Require a note for GOD! (Personal communication,
    P. Drouillard, DO)

17
BONE RESECTION
  • Distal femoral cut is made with an intramedullary
    guide
  • In many cases, no bone is resected from the
    lateral condyle secondary to it being hypoplastic
  • Tibial bone resection can also done with an
    intramedullary guide
  • Again, a very conservative cut is made,
    referencing off the intact medial plateau.

18
BONE RESECTION
  • After bony resections have been made, flexion and
    extension gaps are checked, along with medial and
    lateral ligament balancing.

19
BONE RESECTION
  • Tight in both flexion and extension Resect
    tibia
  • Loose in both flexion and extension Larger poly
  • Good in flexion, tight in ext Resect distal
    femur
  • Good in flexion, loose in ext Augment distal
    femur

20
SOFT TISSUE RELEASES
  • Ranawat studied ligament balancing performed
    before any bone cuts are made
  • First, the lateral retinaculum is released and
    the iliotibial band is cut transversely
  • Moderate deformities - release the LCL and
    popliteus from the femur with cautery
  • Severe deformities - posterior capsule, lateral
    intermuscular septum and lateral head of
    gastrocnemius are released in succession as
    necessary.

21
SOFT TISSUE RELEASES
  • Looked at 108 knees over an average of 14.1 years
  • Although he had a 91 survival rate at 13.2
    years, he found a 24 instability rate using
    this technique.
  • It is now recommended that the distal femoral and
    proximal tibial bone cuts are made before any
    soft tissue releases.
  • Preliminary data shows 6 instability at 7 years

22
WHITESIDE TECHNIQUE
  • Ligament releases
  • Trial components are inserted and releases are
    done sequentially while testing stability in
    flexion and extension
  • After balancing is done, local cancellous graft
    to fill the femoral and tibial defects is
    performed.

23
ANATOMY
  • Lateral structures of the knee in extension
  • LCL
  • Lateral posterior capsule
  • Popliteus tendon
  • IT Band

24
ANATOMY
  • Lateral structures with knee in flexion
  • LCL
  • Popliteus tendon

25
LIGAMENT RELEASES
  • 5 will require no releases
  • Tight lateral in flexion and extension (82)
  • Release popliteus tendon and LCL
  • Tight lateral in extension (12)
  • Release ITB and posterior capsule
  • Tight lateral in flexion (1)
  • Release popliteus tendon
  • Recommend beginning testing in flexion

26
SOFT TISSUE RELEASES
  • Flexion contractures are corrected by release of
    the capsule off the posterior femoral condyles

27
MEDIAL COLLATERAL LIGAMENT ADVANCEMENT
  • If there is still some laxity medially after all
    releases have been performed, a medial collateral
    ligament advancement may be done.

28
MEDIAL COLLATERAL LIGAMENT ADVANCEMENT
  • The proximal portion of the medial collateral
    ligament is elevated with a bone plug
  • The metaphyseal bone is then recessed with a bone
    tamp

29
MEDIAL COLLATERAL LIGAMENT ADVANCEMENT
  • A Krackow ligament suture is placed, then the
    ligament is recessed and advanced and is tied
    over a bony bridge or button on the lateral cortex

30
COMPLICATIONS
  • Patellar dislocation 2 - 4
  • Vascular compromise
  • Peroneal nerve palsy 3 - 4
  • Ligamentous instability

31
CONCLUSIONS
  • Total knee arthroplasty in patients with valgus
    knees can be stressful for the joint replacement
    surgeon

32
CONCLUSIONS
  • Dont let the sequence of ligament releases drive
    you to drink!

33
CONCLUSIONS
  • Follow a good pre-operative plan and follow your
    operative steps and you will forget your worries
    and enjoy other activities!
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