Lateral Retinacular Release Case Study
I. Pathology of the injury/surgery
Introduction and Anatomy:
Lateral release surgery is used to treat patella femoral
syndrome and other tracking problems with the patella. Patella femoral syndrome is a
very complex condition, often with several different contributing factors. Basically, it
centers around the patellafemoral joint and the way it tracks within the femoral groove.
To understand this, a look at the anatomy of the patellafemoral joint is necessary.
The patellafemoral joint is a major source of pain and dysfunction at the knee
joint. While appearing to act simply as a plane joint, it actually undergoes an intricate
combination of flexion, slide, tilt and rotation during motion of the knee.
functions of the patella are to increase the efficiency of the quadriceps muscles (vastus
medialis, vastus intermedius, vastus lateralis, and rectus femoris) and to provide anterior
bony protection to the femur. The quadriceps muscles are the large muscles on the front
of your upper leg, and connect to the patella, and then the patellar tendon
connects them to the lower leg. In a sense, the patella is an extensor
Anatomical conditions affecting the extensor mechanism and tending
to pull the patella to the outer side include a twisted femur (femoral torsion) or
a tibial tubercle which is too far over to the outer side. A measure of the likely
stress on the patella is the 'Q-angle' 'quads' angle (see image). The average
angle is 15.8˚ ± 4.5˚. Clinically, above 15˚ is usually considered to be
excessive for men, and 17˚ in females. The bigger this angle, the greater the
force trying to pull the patella to the outer side, and the restraints and the
trochlear groove are not always sufficient to keep the patella where it should
be. The Q-angle is affected by the width of the pelvis, hip rotation, femoral
anteversion and the position of the tibial tubercle.
One tissue that plays a role in keeping the patella in place located on
the lateral side of the knee is the lateral retinaculum. The pulling of the lateral
retinaculum is usually countered on the medial side by the medial
patellofemoral ligament and strong quadriceps muscles, especially the vastus
medialis oblique. The medial restraints are usually less tight than the lateral
side, so if the vastus medialis oblique muscle becomes weak, there may be a
tendency for the patella to be pulled to the lateral side
As a result of this pull, two common movements of the patella occurs.
The first is called a lateral patellar tilt. This means that instead of sitting
directly in the femoral groove, you patella is tilted laterally or towards the
outside of your knee. With lateral tilt, the patella is not able to sit in the
groove normally and so you end up with pain every time you bend your knee.
Another type of movement is called a lateral riding patella, which means that