Pathologic Knee Fracture Anatomy
To better understand pathologic knee fracture, it helps to understand the anatomy of the knee joint.
Four bones come together at the knee joint:
- Thin bone on the side of the lower leg
The tibia supports all of the body's weight below the knee joint. The tibia and femur form the major portion of the knee joint, and the patella protects the front of the knee.
Bones of the knee:
The main tendons in knee include:
- Quadriceps tendon: attaches the quadriceps muscle to the kneecap
- Patellar tendon: attaches the patella to the tibia
- Popliteus tendon: extends from the outer bottom surface of the femur and travels diagonally behind the knee to attach to the inner upper surface of the tibia.
- Hamstring tendons: attach the hamstring muscles to the tibia
- Calf tendons: attach the calf muscles to the femur
Strong fibrous bands, called ligaments, support the knee. Injuries to the knee ligaments are common.
The knee ligaments include:
- Lateral collateral ligament: stabilizes the knee from stress applied to the sides of the knee
- Medial collateral ligament: stabilizes the knee from stress applied to the sides of the knee
- Posterior cruciate ligament: stabilizes the knee from stress applied to the front or back of the knee
- Anterior cruciate ligament: stabilizes the knee from stress applied to the front or back of the knee
Cartilage is a very smooth, firm layer of tissue that lines all of the joints in the body. Two discs of cartilage, called the medial meniscus, and lateral meniscus, line the inside of the knee. Torn cartilage refers to an injury to a meniscus.
- Boutin RD, Fritz RC. MRI of snow skiing and snowboarding injuries. Semin Musculoskelet Radiol. 2005 Dec;9(4):360-78. 
- Drabicki RR, Greer WJ, DeMeo PJ. Stress fractures around the knee. Clin Sports Med. 2006 Jan;25(1):105-15, ix. 
- Forster MC, Komarsamy B, Davison JN. Distal femoral fractures: a review of fixation methods. Injury. 2006 Feb;37(2):97-108. 
- Hoch AZ, Pepper M, Akuthota V. Stress fractures and knee injuries in runners. Phys Med Rehabil Clin N Am. 2005 Aug;16(3):749-77. 
- Khan Z, Faruqui Z, Ogyunbiyi O, Rosset G, Iqbal J. Ultrasound assessment of internal derangement of the knee. Acta Orthop Belg. 2006 Jan;72(1):72-6. 
- Woo SL, Abramowitch SD, Kilger R, Liang R. Biomechanics of knee ligaments: injury, healing, and repair. J Biomech. 2006;39(1):1-20.