Knee Differentials

What is patellofemoral pain (PFP)?

Anterior knee pain associated with patellofemoral joint loading.

What activities commonly aggravate PFP?

Stairs, squatting, prolonged sitting, kneeling, and inclines.

What is a common movement impairment with PFP?

Dynamic knee valgus.

What hip weakness may contribute to PFP?

Hip abductor and extensor weakness.

What is ROM often like with PFP?

Within normal limits.

What foot alignment may contribute to PFP?

Excessive pronation or pes planus.

What finding suggests patellofemoral instability?

Patellar subluxation, dislocation, or apprehension.

In what direction do most patellar dislocations occur?

Laterally.

What is chondromalacia patella?

Softening of cartilage on the posterior patella.

How does patellofemoral OA differ from chondromalacia?

OA involves degenerative joint changes; chondromalacia describes cartilage softening.

What is a common mechanism of meniscal injury?

Twisting on a flexed, weight-bearing knee.

What symptoms suggest a meniscal tear?

Joint-line pain, catching, locking, and restricted motion.

Which meniscus is injured more frequently?

Medial meniscus.

What type of meniscal tear may mechanically block motion?

Bucket-handle tear.

What commonly causes a traumatic medial meniscal tear?

Axial rotation, sometimes combined with valgus force.

What finding helps distinguish a meniscal tear from PFP?

Joint-line tenderness with mechanical symptoms.

What tests are used to assess meniscal pathology?

McMurray, Thessaly, and Apley compression.

What is a common noncontact ACL injury mechanism?

Deceleration, cutting, pivoting, or hyperextension.

What symptoms suggest an ACL tear?

Instability, giving way, and possible rapid swelling.

What is the primary instability associated with ACL injury?

Excessive anterior tibial translation.

What other structures may be injured with an ACL tear?

Menisci, MCL, articular cartilage, or bone.

What mechanism commonly injures the PCL?

Posterior force on the tibia with the knee flexed.

What instability is associated with a PCL tear?

Excessive posterior tibial translation.

What force commonly injures the MCL?

Valgus force.

What force commonly injures the LCL?

Varus force.

What test primarily assesses the MCL?

Valgus stress test.

What test primarily assesses the LCL?

Varus stress test.

What does valgus laxity at 30° suggest?

MCL injury.

What may valgus laxity at 0° suggest?

Additional capsule or cruciate ligament involvement.

What finding helps distinguish ligament injury from meniscal injury?

Excessive ligamentous laxity on stress testing.

What is a common nontraumatic cause of knee pain?

Knee osteoarthritis.

What are common findings with knee OA?

Pain, swelling, loss of ROM, and possible deformity.

What are the three compartments affected by knee OA?

Medial tibiofemoral, lateral tibiofemoral, and patellofemoral.

What alignment changes may occur with knee OA?

Genu varum or genu valgum.

How can OA differ from an acute meniscal tear?

OA generally develops gradually; traumatic tears may follow twisting.

What surgical option may be considered for end-stage knee OA?

Total knee arthroplasty.

What commonly causes patellar or quadriceps tendinopathy?

Repetitive loading and overuse.

What examination findings help identify tendinopathy?

Local tenderness and pain with resisted loading.

What condition commonly causes lateral knee pain with repetitive flexion/extension?

Iliotibial band friction syndrome.

Where is ITB friction commonly described in the lecture?

Over the lateral femoral condyle.

What training factors may contribute to ITB syndrome?

Increased mileage, sloped surfaces, and repetitive activity.

What examination findings may be relevant for ITB syndrome?

Lateral tenderness, hip abductor strength, and ITB flexibility.

What is a common cause of prepatellar bursitis?

Direct trauma or repetitive kneeling.

Where is pes anserine bursitis pain located?

Medial knee, distal to the joint line.

What distinguishes plica syndrome from uncomplicated PFP?

Medial parapatellar tenderness or snapping with mechanical symptoms.

What is a plica?

A fold of synovial membrane.

What is Osgood-Schlatter disease?

A growth-related apophysitis at the tibial tuberosity.

What is Sinding-Larsen-Johansson syndrome?

Growth-related pain at the inferior patellar pole.

A teenage volleyball player has anterior knee pain with stairs and sitting, plus hip abductor weakness. Most likely diagnosis?

Patellofemoral pain.

A patient twists on a planted knee and develops joint-line pain, catching, and loss of motion. What pathology should you suspect?

Meniscal injury.