Photo by Susan NYCSteep stairs are a danger for the very young and very old, who must gingerly pick their way down stairs, to avoid a fall. Inevitably, despite all due care, some individuals will slip and injure themselves.
In this case, a 66 year old man fell going down steep stairs, and presented to his orthopedic surgeon with knee pain and loss of extensor strength.
A sagittal T2 fatsat image depicts a high grade partial tear of the quadriceps tendon. The distal edge (red arrow) of the tendon is well seen, as is the large hematoma (green arrow). The patella (pink arrow) is positioned more inferiorly than normal, and the patellar tendon (white arrow) is lax, suggesting that this is functionally a complete tear. The deep layer of the quadriceps tendon, composed of the vastus intermedius (yellow arrow), remains intact.
An axial image better depicts the size of the hematoma (green arrows) and again identifies the intact vastus intermedius component (yellow arrow) of the quadriceps tendon:
The quadriceps femoris (Latin for "four-headed muscle of the femur"), is a group of four muscles in the anterior thigh:
- rectus femoris
- vastus medialis
- vastus lateralis
- vastus intermedius
These four muscles originate from the pelvis and femur, and form the quadriceps tendon, which inserts on the superior aspect of the patella.
Photo by robswatski
On this frontal view, we can see the rectus femoris (white arrow), vastus medialis (yellow arrow), and vastus lateralis (green arrow). The vastus intermedius is deep to the rectus femoris, and is not seen.
The quadriceps tendon has 3 distinct layers:
- superficial layer, formed by the rectus femoris
- intermediate layer, formed by the vastus lateralis and vastus medialis
- deep layer, formed by the vastus intermedius [you can remember that the deep layer is the vastus intermedius by "intermediate is inside"]
The quadriceps tendon rarely ruptures in the young and healthy; rather, this is a disease of the old, with ruptures most common in the 6th & 7th decade of life. There is a strong male preponderance, with male victims outnumbering females 8:1. Quadriceps ruptures are associated with cortisone injections, diabetes, chronic renal failure, hyperthyroidism, and gout.
Most injuries are treated surgically, optimally within a few days of the injury.
Vic David MD