Advances & Techniques in Joint Replacement Surgery

Courtesy: Dr C Ranawat, Ashok Shyam TV, Ortho

Case 1: Young, Active Patient with Varus & Flexion Deformity

Patient Profile

• Age: 56 years

• Weight: 250 lbs

• Long-standing post-traumatic deformity

• 15° varus + 15° flexion contracture

• Previously active tennis player

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Key Considerations

• Young, high-demand patient.

• Long life expectancy ? risk of polyethylene wear.

• Need durable fixation.

• Must correct both varus and flexion deformity.

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Implant Selection Discussion

Common considerations:

• Posterior stabilized (PS) design.

• Rotating platform (mobile bearing) design.

• Monoblock tibial options.

• Long-term wear profile is critical.

Rationale for Mobile Bearing (Rotating Platform)

• Theoretical reduction in polyethylene wear.

• Improved contact mechanics.

• Useful in active patients (<60–65 years).

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Sports After TKA – Tennis

• Many patients resume sports despite counseling.

• High-impact activities generate:

  • 3–5× body weight during forceful movements.

• Real-world data:

  • Some patients return to singles tennis.

  • Doubles often recommended.

• Counseling ? compliance.

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Patellar Resurfacing Debate

Three approaches exist:

1. Always resurface.

2. Never resurface.

3. Selective resurfacing.

Decision often depends on:

• Surgeon philosophy.

• Patellofemoral symptoms.

• Cartilage status.

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Case 2: Valgus Knee (Type II Deformity)

Patient Profile

• 65-year-old female.

• Progressive disability.

• Significant valgus deformity.

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Why Do Valgus Knees Present Later?

Observation:

• Less pain compared to varus knees.

Reason:

• Lateral compartment remains more congruent.

• Less edge loading.

• Primary complaint is instability rather than pain.

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Soft Tissue Considerations

• Medial collateral ligament (MCL) elongated.

• Lateral structures tight.

• Type II deformity = ligament elongation.

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Bone Defects

• Lateral tibial plateau defect:

  • Often contained.

  • Typically posterior-central.

• Management:

  • Usually cement filling after drilling.

  • Rarely need wedges or grafts.

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Technical Strategy in Valgus Knee

Avoid Aggressive Initial Bone Cuts

• Reduce tibial and distal femoral resection.

• Compensate for medial ligament elongation.

• Maintain joint line.

• Avoid thick inserts.

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Peroneal Nerve Risk

Higher risk in:

• Fixed valgus deformity.

• Combined valgus + flexion contracture.

Important insight:

• Prophylactic nerve exploration does NOT reduce palsy risk.

• In some studies, exploration increased complications.

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Tibial Cut in Valgus Knee

• Often appears in slight varus (2–3°) on short films.

• Due to:

  • Tibial diaphyseal remodeling.

• Must maintain ankle-horizontal alignment.

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Lateral vs Medial Approach

Debate:

• Lateral approach:

  • Useful if extensive lateral release anticipated.

• Medial approach:

  • Most surgeons more familiar.

  • Can achieve same correction with proper technique.

Key principles to avoid formal lateral release:

• Correct tibial cut.

• Proper femoral rotation.

• Appropriate sizing.

• Component lateralization.

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Case 3: Severe Post-Traumatic Varus (34°)

Challenges

• Extra-articular deformity.

• Soft tissue contracture.

• Potential bone loss.

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Decision Point: Intra-articular vs Extra-articular Correction

Key determinant:

• Distance between mechanical axis and joint line.

• Ability to preserve medial collateral ligament sleeve.

• Maintain ?20 mm residual bone stock.

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Strategy Used

• Limited tibial and femoral resection.

• Complete medial release to free tibia.

• TC3 constrained implant.

• 12.5 mm insert used.

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Stem Use in Constrained Implants

Pros:

• Improved load transfer.

• Reduced micromotion.

Cons:

• Risk of cortical compromise in distorted anatomy.

Evidence mixed; decision individualized.

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Case 4: Old Open Fracture with Healed Infection + Tibial Bowing

Additional Challenges

• Prior infection (30–40 years ago).

• Tibial deformity.

• Patella baja.

• Ipsilateral hip disease.

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Infection Risk

• Previous osteomyelitis increases infection risk:

  • 2–3× higher than primary TKA.

• If remote, healed infection:

  • Risk present but acceptable with precautions.

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Osteotomy vs Intra-articular Correction

Decision based on:

• Degree and location of deformity.

• Ability to align tibial cut parallel to ankle joint.

• Stem trajectory feasibility.

In this case:

• Intra-articular correction sufficient.

• No tibial osteotomy performed.

• Alignment restored via careful tibial cut.

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Core Principles Highlighted Across Cases

1. Preserve Joint Line

2. Avoid Excessive Bone Resection

3. Respect Soft Tissue Sleeve

4. Anticipate Long-Term Wear in Young Patients

5. Constrained Implants Only When Necessary

6. Prior Infection Requires Extra Vigilance

7. Mechanical Alignment Must Consider Diaphyseal Remodeling

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Final Take-Home Messages

• Complex knees demand individualized planning.

• High-demand patients require durability-focused implant selection.

• Valgus knees require controlled releases—not aggressive bone cuts.

• Severe deformities can often be managed intra-articularly.

• Revision-level thinking is essential even in complex primaries.

• Always anticipate complications before they occur.