Abstract
When trochlear dysplasia is present, it is difficult to measure the tibial tuberosity
to trochlear groove (TT–TG) distance. A new measurement to assess tuberosity position
was recently described by Seitlinger et al, which avoids the difficulty of identifying
the TG as it references the posterior cruciate ligament (PCL). To evaluate the reproducibility
of the Seitlinger et al findings, 42 knees in 41 patients with a documented history
of recurrent patellar instability and 84 knees in patients with no history of patellar
instability or patellofemoral symptoms were evaluated with magnetic resonance imaging.
The TT–PCL distance was increased in the instability group (mean, 21.6 mm) compared
with the control group (mean, 19.0 mm). The TT–PCL distance is an independent risk
factor for patients with recurrent patellar instability. Its role in surgical planning
remains to be determined.
Keywords
TT–TG - TT–PCL - patellar instability - patellar dislocation - tibial tuberosity/tubercle
medialization
