What is the threshold for TT-TG distance that is considered abnormal?

The threshold for TT-TG distance that is considered abnormal is generally recognized at 20mm. The TT-TG distance refers to the distance from the tibial tuberosity to the trochlear groove, which is crucial in assessing patellar stability and potential issues such as patellar dislocation or instability.

A TT-TG distance greater than 20mm indicates a significant lateral displacement of the patellar tendon and can correlate with a higher risk for patellar dislocation. Clinicians and researchers have established this cutoff based on studies showing that distances exceeding this value are associated with poorer surgical outcomes in cases of patellar stabilization surgery.

Understanding this measurement helps guide treatment decisions and predicts the need for possible surgical interventions to restore knee stability and function.