Tibial tuberosity
What is a TT-TG?
Tibial tuberosity-trochlear groove
(TT-TG) distance is a measure of lateralization of the tibial tuberosity in relation to femoral trochlea.
How do you measure TTTG?
Patellar translation can be measured using the tibial-tuberosity to trochlear groove distance (TT-TG distance)
by calculating the transverse length between the trochlear groove on the femoral and tibial tuberosity on axial images
. The measurements are used to quantify patellar instability.
What is an abnormal TT-TG distance?
For years, a TT-TG of 15 mm was considered the threshold limit. Today, a TT-TG
greater than 20 mm
is considered pathological and therefore to warrant correction.
What is TTT knee surgery?
A tibial tubercle or tuberosity transfer (TTT) is
a surgical procedure to realign the tracking of the kneecap (patella)
. It involves removing a small piece of bone on the front of the shin bone and reattaching it with anchors or screws to a different position.
What causes increased Q angle?
Increase in Q angle is associated with:
Femoral anteversion
.
External tibial torsion
.
Laterally displaced tibial tubercle
.
Is patella a ratio?
IS ratio is measured with the knee flexed 30 degrees, to provide the right tension on the patellar tendon for right measurement. It is commonly measured by knee X-ray, Lateral view or MRI, sagittal plane. The
normal range is between 0.8 and 1.2
, with patella baja <0.8 and patella alta >1.2.
What is a Trochleoplasty?
• Trochleoplasty is
a surgical procedure that creates a groove in the trochlea to
.
prevent recurrent patella dislocations
, and the associated pain and disability. • The procedure will be performed under a general anaesthetic.
Is patella alta painful?
Both dislocation and subluxation are extremely painful
and both result in damage to the hyaline cartilage under the patella and to the groove in which the patella runs (the trochlear groove of the femur) which after a time causes osteoarthritis of the patellofemoral joint with severe pain and weakness of the muscles.
How is Trochlear depth measured?
The trochlear depth is calculated by measuring
the mean of the maximum anteroposterior (AP) distance of the medial and lateral femoral condyles minus the distance between the deepest point of the trochlear groove and the line paralleling the posterior femoral condyles surfaces
(Fig. 1).
What is the normal TT TG distance?
Several studies suggest that a normal TT-TG distance is
10 mm or less
[5, 7, 8]. A TT-TG distance greater than 15 mm in patients with patellofemoral insta- bility may predict limited benefit from phys- ical therapy [7].
What is the femoral trochlea?
The trochlea of femur (femoral trochlea) is
the cranial cartilaginous part of distal femur, for articulation with the patella fo form the femoral patellar joint
. It consists of a groove bounded by the medial and a lateral ridges.
How do you measure patella alta?
To determine to height of the patella. We measure the length of inferior articular surface and the anterior lip of the tibial plateau. A normal value of the patella is a ratio between 0,6 – 1,3.
When the ratio is higher than 1,3, there is patella alta
.
How long does TTT surgery take?
The incision required to perform the operation is approximately 3 inches in length and the entire surgery lasts
about an hour
.
What is a osteotomy procedure?
Osteotomy literally means “
cutting of the bone
.” In a knee osteotomy, either the tibia (shinbone) or femur (thighbone) is cut and then reshaped to relieve pressure on the knee joint.
What is a lateral release knee surgery?
Lateral release surgery of the knee is
an arthroscopic surgery that is performed through three small incisions in the knee
. Your doctor will cut through a tight group of tendons in the kneecap to allow the kneecap to move correctly into the proper groove, restoring normal alignment.
