Measurement of Tibial Tuberosity-Trochlear Groove Distance in an Eastern Mediterranean Population: A Retrospective Single-Center Study

Author(s): Hala Ishak, Hasan Nahouli, Asdghig Der- Boghossian,Lamya A. Atweh, Nabil J. Khoury, Hasan Baydoun

Purpose: The Tibial Tuberosity–Trochlear Groove (TT-TG) distance is a key parameter used to assess patients with patellar dislocation. Different values are reported in different populations. Our purpose is to determine the TT-TG distance in an Eastern Mediterranean population and to identify an association with baseline characteristics.

Methods: The knee computed tomography of adult patients from Eastern Mediterranean origin was identified through our institutional database. Patients who had a previous history of patellar dislocations or other pathologies were excluded. A sports medicine orthopedic surgeon, a musculoskeletal radiologist, and a non-musculoskeletal radiologist read the scans. The TT-TG distance and knee size were measured twice by each reader and the average was obtained for the population. We extracted the baseline characteristics of the patients from the medical records and correlated them with the measured TT-TG distances and knee sizes. We also calculated the inter-observer and intra-observer reliabilities of the measurements.

Results: One hundred one knee scans in 86 patients were read. The mean TT-TG distance was 14.76 mm ± 3.91 mm with no statistically significant association with patient age, gender, sex, height, weight, BMI, or knee size. Knee size was 80.51 mm ± 6.70 mm with a statistically significant correlation with the patient’s gender, height, and weight. Our results showed excellent intra-observer and inter-observer reliability.

Conclusion: Mean TT-TG distance in the normal Eastern Mediterranean population is more similar to the Western population but on the higher side of the spectrum of previously reported populations.