Ruptured Quadriceps Anatomy
To better understand quadriceps muscle rupture, it helps to understand the anatomy of the thigh and leg.
The thigh and leg (below the knee) contain four bones:
- Articulates with hip joint above and knee joint below
- The femur and tibia form the major portion of the knee joint,
- Thick bone in the front of the lower leg or shin
- The tibia supports all of the body's weight below the knee joint.
The quadriceps femoris muscles are a large powerful group of muscles located in the front of the thigh. Contraction of the quadriceps muscles flexes the hip and extends (straightens) the leg at the knee joint.
Four individual muscles make up the quadriceps femoris:
These four muscles attach to the pelvis and upper femur, and then come together to form the quadriceps tendon. This tendon attaches, or inserts, on the kneecap (patella). The patellar tendon then attaches the patella to the upper tibia at the tibial tuberosity.
Leg anatomy examples:
- Dobbs RE, Hanssen AD, Lewallen DG, Pagnano MW. Quadriceps tendon rupture after total knee arthroplasty. Prevalence, complications, and outcomes. J Bone Joint Surg Am. 2005 Jan;87(1):37-45. 
- Goelitz BW, Lomasney LM, Demos TC. Radiologic case study. Quadriceps tendon rupture. Orthopedics. 2004 Aug;27(8):790, 872-5. 
- Hansen L, Larsen S, Laulund T. Traumatic bilateral quadriceps tendon rupture. J Orthop Sci. 2001;6(2):187-8. 
- Shah MK. Outcomes in bilateral and simultaneous quadriceps tendon rupture. Orthopedics. 2003 Aug;26(8):797-8.