**[Differential Diagnosis -- Knee Pain]{.underline}**

**Submitted by:**

**LT Matthew Armentano**

**matthew.armentano@ihs.gov**

**[Differential Diagnosis of Knee Pain by Age Group]{.underline}**

  ----------------------- ----------------------- -----------------------
  **Children and                                  **Older adults**
  adolescents**                                   

  Patellar subluxation    Patellofemoral pain     Osteoarthritis
                          syndrome                
                          (chondromalacia         
                          patellae)               

  Tibial apophysitis      Medial plica syndrome   Crystal-induced
  (Osgood-Schlatter                               inflammatory
  lesion)                                         arthropathy: gout,
                                                  pseudogout

  Jumper's knee (patellar Pes anserine bursitis   Popliteal cyst (Baker's
  tendonitis)                                     cyst)

  Referred pain: slipped  Trauma: ligamentous     Metastatic Cancer
  capital femoral         sprains (anterior       
  epiphysis, hip fracture cruciate, medial        
                          collateral, lateral     
                          collateral), meniscal   
                          tear, Fractures, muscle 
                          strains                 

  Osteochondritis         Inflammatory            
  dissecans               arthropathy: rheumatoid 
                          arthritis, Reiter's     
                          syndrome, Pigmented     
                          Villanodular Synovitis  

  Juvenile Rheumatoid     Tendonitis (quadriceps, 
  Arthritis               Patellar tendon, etc)   

  Trauma: ligamentous     Septic arthritis        
  sprains (anterior                               
  cruciate, medial                                
  collateral, lateral                             
  collateral), meniscal                           
  tear, Fractures to                              
  include Epiphyseal                              
  Fracture , muscle                               
  strains                                         

                          Stress Fracture/Stress  
                          Reaction                

                          Referred Pain:          
                          Neurogenic, Hip and leg 
                          pathology               
  ----------------------- ----------------------- -----------------------

# Common Knee pain by Anatomic Site

**Anterior knee pain**

> Patellar subluxation or dislocation
>
> Tibial apophysitis (Osgood-Schlatter lesion)
>
> Jumper\'s knee (patellar tendonitis)
>
> Patellofemoral pain syndrome (chondromalacia patellae)

**Medial knee pain**

> Medial collateral ligament sprain
>
> Medial meniscal tear
>
> Pes anserine bursitis
>
> Medial plica syndrome

**Lateral knee pain**

> Lateral collateral ligament sprain
>
> Lateral meniscal tear
>
> Iliotibial band tendonitis

**Posterior knee pain**

> Popliteal cyst (Baker\'s cyst)
>
> Posterior cruciate ligament injury

Differential Diagnosis

Page two

**[Mechanism of Injury:]{.underline}**

**Trauma -** Fracture of Femur, Tibia, Fibula, Patella

-   Ligamentous Sprain (ACL, MCL, LCL, PCL)

-   Mensical Tear

-   Patellar subluxation/dislocation

-   Muscle Strain

-   Osteochodral fracture

**Atraumatic -** Osteoarthrits

-   Rheumatoid or other inflammatory Arthritis (Pigmented villonodular
    arthritis, gout, reiters syndrome)

-   Septic Arthrits

-   Popliteal cyst

-   Stress Fractures/reactions (tibial plateau & shaft, femur, patella)

-   Tendonitis

-   Patellofemoral Syndrome

-   Medial plica syndrome

-   Referred pain (hip OA, Lumbar radicular sx)

-   Metastatic cancer

**[References:]{.underline}**

**Diagnosis and management of the osteonecrotic triad of the knee**. PM
Soucacos, et al. *Ortho Cl N Am*, 35 (2004) 371-381*.*

### Evaluation of Patients Presenting with Knee Pain: Part II. Differential Diagnosis. WL Calmbach and M. Hutchens, *American Family Physician*, Volume 68 • Number 5 • September 1, 2003 

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