Courtesy: Ashok Shyam, Ortho TV

Introduction

• Knee preservation procedures require careful integration of:

  • Clinical examination

  • Radiological analysis

  • Alignment evaluation

  • Patient-specific functional demands

• Important surgical strategies discussed include:

  • Osteotomy for malalignment

  • Osteochondral reconstruction for cartilage defects

  • Revision anterior cruciate ligament reconstruction

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Case One

Varus Knee with Medial Compartment Pain

Patient Profile

• Forty-two-year-old female

• Body mass index approximately twenty-seven

• Occupation: beautician

• Primary complaint: left knee pain for one year

• Symptoms recently worsened over the previous month

• No significant traumatic injury

• Night pain present

• No complaints of instability

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Clinical Examination

Gait Assessment

• No obvious varus thrust during walking

• Ligaments appeared clinically stable during gait analysis

Alignment

• Visible varus deformity present during standing examination

Ligament Stability

• Varus and valgus stress testing performed in:

  • Full extension

  • Ten to twenty degrees of knee flexion

Key Observation

• The varus deformity could be partially corrected manually during flexion.

This suggests that:

• Some component of the deformity may be intra-articular, often due to medial joint space narrowing and meniscal extrusion.

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Rotational Assessment

The patient was also evaluated in the prone position to assess:

• Hip rotational profile

• Tibial torsion

• Femoral rotational alignment

Findings included:

• Approximately forty degrees of hip internal and external rotation

• Foot progression angle around thirty degrees

• No abnormal tibial or femoral torsion

This confirmed that the primary deformity was likely in the coronal plane rather than rotational.

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Radiographic Evaluation

Standard Radiographs

Radiographic evaluation included:

• Patellar skyline view

• Lateral knee radiograph

• Long-leg alignment radiograph

Key observations:

• Patella appeared well centered

• No major degenerative changes visible on lateral radiograph

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Mechanical Axis Assessment

The mechanical axis line was drawn connecting:

• Center of the femoral head

• Center of the ankle joint

This line determines the location of the load-bearing axis.

Interpretation

• The mechanical axis passed medial to the knee center

• This confirmed varus alignment.

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Deformity Analysis

To determine the origin of deformity, two key angles were measured:

Mechanical Lateral Distal Femoral Angle

• Measured between:

  • Femoral mechanical axis

  • Distal femoral joint line

Medial Proximal Tibial Angle

• Measured between:

  • Tibial mechanical axis

  • Proximal tibial joint line

Normal Reference Value

• Approximately eighty-seven degrees for each angle.

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Findings

Measured angles revealed:

• Femoral angle around ninety-three degrees

• Tibial angle around eighty-one degrees

Interpretation:

• Both femur and tibia contributed to the varus deformity.

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Surgical Planning

Because deformity existed in both bones, a double-level osteotomy was planned.

Planned Corrections

• Closing wedge distal femoral osteotomy

• Opening wedge proximal tibial osteotomy

The goal was to shift the mechanical axis to approximately fifty-two to fifty-three percent of the tibial plateau width.

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Importance of Joint Line Orientation

Correcting only one bone in a double-level deformity may lead to:

• Excessive joint line obliquity

• Abnormal joint biomechanics

Maintaining physiological joint line orientation is critical for:

• Joint stability

• Long-term cartilage health

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Leg Length Considerations

Opening wedge osteotomy can increase limb length due to:

• Straightening of the limb

• Opening of the osteotomy gap

Closing wedge osteotomy may shorten the limb slightly.

Balancing both procedures can help maintain appropriate leg length.

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Indications for Double-Level Osteotomy

A useful rule:

• When the mechanical axis does not intersect the tibial plateau, a double-level osteotomy should be considered.

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Role of Arthroscopy During Osteotomy

Routine arthroscopy before osteotomy remains debated.

Possible indications include:

• Mechanical symptoms

• Loose bodies

• Symptomatic cartilage flaps

Many surgeons now perform selective arthroscopy rather than routine arthroscopy.

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Case Two

Osteochondral Defect of the Lateral Femoral Condyle

Patient Profile

• Twenty-six-year-old professional wrestler

• Persistent knee pain following previous cartilage surgery

Previous Treatment

• Arthroscopy with microfracture procedure

Current Symptoms

• Pain during walking and squatting

• Recurrent swelling

• Occasional locking

• Inability to return to sport

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Clinical Examination

Key Findings

• Mild quadriceps muscle wasting

• Pain during deep knee flexion

• Sharp tenderness over the lateral femoral condyle

Functional Testing

• Pain reproduced during mini squat around twenty to thirty degrees of flexion.

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Imaging Findings

Magnetic resonance imaging demonstrated:

• Failed microfracture repair

• Large osteochondral defect of the lateral femoral condyle

• Subchondral cyst formation

Estimated lesion size:

• Approximately twenty by twelve millimetres

This confirmed involvement of the osteochondral unit rather than cartilage alone.

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Surgical Strategy

Because the subchondral bone was involved, treatment required osteochondral reconstruction.

Preferred Option

• Osteochondral autograft transfer procedure

Multiple graft plugs may be required due to lesion size.

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Additional Biological Augmentation

Remaining defect areas may be filled with:

• Cartilage matrix scaffold

• Collagen membrane

• Fibrin glue

These techniques aim to enhance biological repair.

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Case Three

Failed Anterior Cruciate Ligament Reconstruction

Patient Profile

• Twenty-four-year-old male

• Recreational badminton player

Injury History

• Initial anterior cruciate ligament reconstruction

• Reinjury three months before presentation

Current Symptoms

• Persistent instability

• Difficulty with pivoting movements

• Lack of confidence during activities

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Clinical Examination

Range of Motion

• Mild loss of extension due to locked medial meniscus tear

Stability Tests

Positive findings included:

• Grade three Lachman test

• Positive anterior drawer test

• Positive pivot shift test

Posterolateral Corner Testing

Testing demonstrated mild laxity but not significant instability.

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Imaging Evaluation

Radiographic Alignment

• Coronal alignment appeared normal

Magnetic Resonance Imaging

Findings included:

• Absent anterior cruciate ligament graft

• Bucket-handle tear of the medial meniscus

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Importance of Posterior Tibial Slope

Posterior tibial slope influences anterior tibial translation.

Increased slope can significantly increase:

• Stress on anterior cruciate ligament grafts

This increases the risk of graft failure.

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Computed Tomography Analysis

Computed tomography was performed to assess:

• Tunnel size

• Tunnel position

• Implant placement

Findings included:

• Tibial tunnel approximately twelve millimetres in diameter

• Femoral tunnel approximately fourteen millimetres

Tunnel positions were considered acceptable for revision surgery.

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Revision Surgery Planning

Key surgical decisions included:

Graft Choice

Autograft was preferred for revision reconstruction.

Tunnel Management

• Single-stage revision considered feasible

• Tunnel enlargement did not mandate staged reconstruction

Additional Procedures

Planned procedures included:

• Anterior closing wedge osteotomy to reduce tibial slope

• Lateral extra-articular tenodesis for rotational stability

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Meniscus Management

The patient also had a bucket-handle medial meniscus tear.

Intraoperative decision-making would determine whether to:

• Repair the meniscus

• Perform partial meniscectomy

Loss of medial meniscus function may increase instability risk.

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Key Lessons from These Cases

• Accurate deformity analysis is essential before performing osteotomy.

• Double-level osteotomy helps maintain normal joint line orientation.

• Failed cartilage procedures require treatment of the entire osteochondral unit.

• Posterior tibial slope plays an important role in anterior cruciate ligament stability.

• Revision anterior cruciate ligament reconstruction often benefits from additional stabilizing procedures.