Painful and Stiff Knee

Courtesy: Dr T Vail, Ashok Shyam TV, Ortho

 

Overview

• TKA is successful in ~95% of patients.

• The remaining 2–5%:

  • Experience pain, stiffness, or dissatisfaction.

  • Often consume a disproportionate amount of clinical time.

• Typical scenario:

  • Radiographs appear normal.

  • Patient reports the knee “just doesn’t feel right.”

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Clinical Presentation

Patients may report:

• Stiffness

• Swelling

• Limited flexion

• Sensation of instability

• Mechanical symptoms (crepitus, clunk)

On examination:

• Effusion

• Reduced range of motion

• Patellar clunk

• Arthrofibrosis

• Possible instability

Pain and stiffness:

• Reported in 5–10% of patients.

• Contribute significantly to patient dissatisfaction.

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Incidence of Stiffness

• Reported rates vary:

  • 8–12% in some series.

• Revision data:

  • ~17% of early revisions

  • ~12% of late revisions

  • Associated with stiffness-related issues.

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Functional Range of Motion Requirements

• 40–55° – Level walking

• ~85° – Stair climbing

• 90° – Rising from low chairs

• 110° – Kneeling

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Key Concept: Stiffness is a Final Common Pathway

Stiffness may result from:

• Chronic pain syndrome

• Infection

• Component malposition

• Oversizing

• Instability

• Improper rehabilitation

• Excessive scar formation (arthrofibrosis)

• Patient-specific biologic factors

It may occur:

• Early (infection, technical error, patient factors)

• Late (loosening, wear-related synovitis, instability)

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Common Clinical Scenarios

1. Early Pain with Stiffness

• Negative infection workup.

• Cementless implant not osseointegrated ? Loosening.

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2. Chronic Effusion and Stiffness

• Well-fixed components.

• Underlying infection identified.

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3. Late Instability with Loss of Flexion

• Polyethylene wear.

• Progressive instability leading to stiffness.

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4. Wear-Related Synovitis

• Well-fixed components.

• Chronic inflammation and effusion.

• Gradual loss of motion.

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Technical Factors Contributing to Stiffness

Component Issues

• Oversizing femoral component.

• Tibial overhang.

• Patellofemoral overstuffing.

• Malalignment.

• Improper flexion–extension gap balance.

Mobile Bearing Implants

• Cement or bone impingement may restrict motion.

• Must ensure unconstrained articulation.

Posterior Compartment Issues

• Retained posterior osteophytes.

• Posterior capsule tightness.

• Inadequate posterior release.

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Patient-Related Factors

• Large limb girth limiting motion.

• Post-traumatic scarring.

• Skin adherence to deeper structures.

• History of stiffness in contralateral knee:

  • Higher risk.

  • More frequent need for manipulation.

  • Requires aggressive early management.

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Early Management Principles

• Look for progressive improvement, not just a target number.

• Manipulation under anesthesia (MUA):

  • Best performed within 6–8 weeks.

  • Indicated if motion plateaus early.

Rehabilitation

• Early mobilization.

• Routine CPM:

  • Does not improve long-term outcomes.

  • May reduce hospital stay.

  • Useful in:

    • Unmotivated patients

    • Revision settings

    • Slow progress cases

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Kinematic Considerations

• Restore proper femoral offset.

• Avoid paradoxical anterior femoral translation.

• Posterior cruciate ligament (PCL) insufficiency:

  • Can cause posterior impingement.

  • Leads to stiffness sensation.

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Late Management

Indications for Revision

• Component malalignment.

• Oversizing.

• Loosening.

• Instability.

• Wear-related synovitis.

Surgical Options

• Revision to posterior-stabilized (PS) knee.

• Open scar excision.

• Complete capsulectomy (medial/lateral gutters, patellofemoral joint).

Arthroscopy:

• Rarely helpful.

• May assist in selected PCL imbalance cases.

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Outcomes of Revision for Stiffness

• Motion improvement possible.

• Example outcomes:

  • Pre-op ROM ~42°

  • Post-op ROM ~85°

• Improvement in both flexion and extension.

• Functional gains achieved, but rarely “normal.”

Better prognosis when:

• Correctable radiographic abnormality present.

• Clear mechanical cause identified.

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Key Take-Home Messages

• A stiff TKA with normal radiographs requires systematic evaluation.

• Stiffness is often secondary to another underlying issue.

• Early intervention improves outcomes.

• Revision can improve function but rarely restores normal motion.

• Identifying and correcting mechanical causes improves prognosis.