Patellar Dislocation & Recurrent Instability: Precision Diagnosis, Anatomic Analysis, and Long-Term Joint Preservation

When the kneecap slips out of place — whether once or repeatedly — it’s more than a painful event. Patellar instability is a structural and biomechanical condition that can cause cartilage damage, recurrent injuries, and long-term joint degeneration if not evaluated with precision.

At SIGMA Orthopedics & Sports Medicine, our approach is different: We identify why the kneecap dislocates, assess every anatomic factor, and design a customized plan that restores stability while protecting your knee for life.

What Is Patellar Instability?

Patellar instability occurs when the kneecap slides out of the groove where it normally tracks. This may happen once during a traumatic injury—or become recurrent due to underlying anatomic issues such as trochlear dysplasia, patella alta, MPFL insufficiency, or rotational malalignment.

Common Symptoms:

  • Repeated “slipping” or dislocation events
  • Pain along the inner or outer knee
  • Swelling, bruising, and difficulty weight-bearing
  • Feeling that the knee “gives out”
  • Persistent apprehension with pivoting or running
  • Damage to cartilage after each episode

The SIGMA Precision Diagnostic Protocol

Why the SIGMA Approach Is Different

Traditional evaluations often miss the root cause of instability. The SIGMA Protocol uses a Six-Sigma, aviation-inspired diagnostic pathway that eliminates variance and identifies the exact biomechanical contributors that must be corrected.   

Structural Anatomy Analysis

High-definition imaging and AP/Lateral/Merchant views to assess:

  • Trochlear morphology
  • Patella height (Caton-Deschamps Index)
  • TT-TG/TT-PCL distances
  • Rotational alignment of the femur/tibia
  • MPFL integrity  

High-Definition MRI Evaluation

MRI assessed through a patellar-specific lens:

  • MPFL rupture pattern
  • Osteochondral injuries
  • Lateral femoral condyle bruising
  • Chondral defects requiring preservation
  • Tibial tubercle alignment metrics  

Dynamic Examination

  • Real-time assessment of tracking, tilt, glide
  • Apprehension testing
  • Jump/landing analysis when indicated

Six Sigma Surgical Planning (When Needed)

If surgery is indicated, the SIGMA pathway identifies exactly which procedures (MPFL, tibial tubercle osteotomy, trochleoplasty, derotation osteotomy) will eliminate instability—not just “patch it.” 

When to Seek Treatment

Seek evaluation if you experience:

  • A first-time traumatic dislocation
  • Recurrent subluxation or instability episodes
  • Clicking, catching, or swelling after sports
  • Loss of confidence or fear of movement
  • MRI evidence of cartilage damage
  • Persistent pain with stairs, pivoting, or deep knee flexion
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Treatment Options at SIGMA

Our Goal: Stabilize the Patella, Protect the Cartilage, and Restore High-Level Performance

1. Non-Surgical Management (When Appropriate)

Best for isolated, first-time traumatic events without major anatomic risk factors.

Includes:

  • SIGMA PT Protocol for patellar tracking
  • Strengthening of VMO, hip abductors, external rotators
  • Motion recovery and swelling control
  • Bracing for early sport re-entry
  • Return-to-sport testing

2. MPFL Repair or Reconstruction

Indicated when the ligament that stabilizes the kneecap is stretched, torn, or chronically insufficient.

SIGMA Reconstruction Advantages:

  • Personalized graft sizing
  • Anatomic femoral insertion mapping (fluoro-verified)
  • Allograft or autograft options
  • Six Sigma reproducibility to reduce recurrence
  • Outpatient recovery pathway with early motion

3. Anatomic Realignment Procedures

Used when structural abnormalities drive recurrent instability.

These may include:

  • Tibial Tubercle Osteotomy (TTO) for TT-TG elevation
  • Trochleoplasty for trochlear dysplasia
  • Derotation Osteotomy for femoral anteversion abnormalities
  • Cartilage restoration when fractures or defects occur

Every surgical plan is fully customized based on SIGMA metrics—not a one-size-fits-all operation.

Joint Preservation: Protecting the Cartilage

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Recurrent instability injures cartilage every time the patella dislocates or subluxes.

SIGMA’s preservation strategy includes:

  • Microfracture alternatives (A2M, PRP, orthobiologics)
  • Arthroscopic chondroplasty
  • Osteochondral grafting (OATS/allograft)
  • Patellar preservation mapping during surgery

Goal: prevent early arthritis and safeguard long-term knee performance.

The SIGMA Recovery Pathway

High-reliability rehabilitation designed for predictable, measurable outcomes.

Includes:

  • Week-by-week PT milestones
  • Motion and strength targets
  • Return-to-sport clearance testing
  • App-based healing roadmap (100-Day SIGMA Plan)
  • Cartilage-protection protocols
  • Individualized orthobiologic adjuncts

Each patient receives a precision recovery plan backed by Six Sigma metrics. 

Man jogging outdoors during his grade 1 meniscus tear recovery.
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Why Patients Choose SIGMA

  • Harvard-trained orthopedic sports surgeon
  • Aviation-grade safety and reproducibility
  • Precision anatomic assessment
  • Cartilage-preserving surgical techniques
  • Faster, predictable return to sport
  • Concierge-level patient support
  • Proven outcomes with high satisfaction rates

Call to Action: Take the Next Step

If your kneecap continues to feel unstable, slips out of place, or impacts your confidence with sports, the SIGMA approach can help you regain stability and protect your knee for the long-term.