Knee Anatomy, Conditions, and Treatments

Knee Anatomy and Common Conditions

Leg Length Discrepancy

• Anatomical (True): Leg length difference from structural changes in the femur or lower leg.
• Functional (Apparent): Legs are equal in length but appear or feel shorter due to muscle imbalance, hip issues, etc.

Q-Angle

• Measured from the ASIS to the patella center, then from the tibial tubercle to the patella center.
• Normal: 10 degrees for males, 15 degrees for females.
• Greater angles may cause patellar tracking issues.

A-Angle

• Patellar orientation to the tibial tubercle.
• Angle >35 degrees may relate to anterior knee pain.

Tibial Torsion

• Rotation of the tibia on the femur.
• Medial: Feet point inward.
• Lateral: Feet point outward excessively.

Patellar Tendon Issues

Patellar Tendinopathy

• Also known as Jumper's or Kicker's knee.
• Inflammation and degeneration of the patellar or quad tendon.
• Precursor to Osgood-Schlatter disease.

Apophysitis

• Osgood-Schlatter's: At the tibial tubercle, forms a bony callus.
• Larsen-Johansson's: At the inferior pole of the patella.

Other Common Knee Conditions

IT Band Friction Syndrome

• Runner's or cyclist's knee; IT band rubs over the condyle.
• Pain and swelling over the lateral femoral condyle and Gerdy's tubercle.

Pes Anserine Tendinopathy

• Common in runners; pain at the pes anserine insertion on the tibia.
• Associated with genu valgum and running on lateral slopes.

Patellofemoral Pain Syndrome

• Anterior knee pain, with or without degeneration.
• Pain with stairs; treated with quad and hip strengthening.

Chondromalacia Patella

• Softening and deterioration of the patellar articular cartilage.

Osteochondritis Dissecans

• Separation of articular cartilage from bone; "loose bodies."
• Mostly in the medial femoral condyle.

Bursitis

• Prepatellar: From direct trauma or kneeling.
• Infrapatellar: From direct trauma or patellar tendon overuse.
• Suprapatellar: From direct trauma or quad tendon overuse.