Approach to the Adult with Knee
Pain
MARCH 2014
Objectives
 Broadly categorize knee pain
 Identify most common differential diagnosis of knee
pain
Knee Pain
Traumatic
Non –Traumatic
Intrinsic
Intraarticular
Structural
Inflammatory
Extrinsic
Periarticular
Anatomy
http://www.aafp.org/afp/2003/0901/p907.html
http://www.knee-pain-explained.com/KneeBursa.html
Clinical Question
 57 yo M with PMH of Hypertension, Diabetes presents with
right knee pain started 3 months ago. He noticed his knee
slowly became more red and swollen. He works in an office
and sits most of the day. He does not recall any trauma. He
likes to walk with his wife in the evenings and occasionally
does gardening on the weekends. He denies any fevers, rash or
pain in other joints. On physical exam there is no click, there is
full range of motion however painful and with tenderness to
palpation on the medial aspect of knee. What condition does
he most likely have?




Iliotibial band syndrome
Prepatellar Bursitis
Meniscal tear
Patellofemoral pain syndrome
Step 1: Intrinsic vs Extrinsic
 Knee motion rarely aggravates referred pain
 If examination of knee is normal. Test hip and ankle
to identify referred pain
Step 2: Periarticular versus Intraarticular
 Intra-articular - structural defect or an
inflammatory process


patient experiences discomfort within the knee
often a chronic effusion is present and tenderness is diffuse
Peri-articular – patient’s can localize the pain to a
specific area around the knee
•

Specific examination maneuvers (direct palpation, valgus or
varus stress) elicit a focal pain at the involved structure
Varus and Valgus Stress Tests
Periarticular Pain by Location
Location
Most common diagnoses
MCL and Pes Anserine Bursitis
Anterior
Medial
patellofemoral pain syndrome, prepatellar bursitis
Lateral
lateral collateral ligament injury, iliotibial band syndrome
Posterior
Popliteal (Baker’s Cyst) , joint effusion
Intraarticular Knee Pain:
Step 3: Inflammatory vs Structural
 Structural – pain is usually provoked by activity and is
absent at rest


Meniscal tear, ACL tear
Inflammatory process -pain with activity AND at rest
o
Often presents with joint effusion and fluid analysis is needed by
aspiration of the effusion
Common Causes of Intra-articular Knee Pain
Structural
Inflammatory
Meniscal Injury
Septic arthritis
ACL injury
Gout
PCL injury
Reactive arthritis
Knee Dislocation
Fractures
Osteonecrosis
Osteoarthritis
Knee Pain
Traumatic
Non –Traumatic
Intrinsic
Intraarticular
Structural
Pain with activity
Inflammatory
Pain with rest and
activity
Extrinsic
Periarticular
Focal pain, Ddx
based on location
Referred from other
joints like hip, ankle,
back
Summary
 Use the step wise algorithm in your approach to
creating a differential diagnosis
 Localization of the pain can help narrow the
differential
References
 Up to Date: General evaluation of the adult with
knee pain
 MKSAP 16 Rheumatology
 MKSAP 16 General Internal Medicine
 MedStudy 15th Edition Core curriculum Book 3
Rheumatology