Anthropometric differences in the tibial tuberosity to trochlear groove measurement in an African population



tibial tuberosity trochlear groove distance, measurement, anatomical variation, ethnic differences


Background: The tibial tuberosity to trochlear groove (TTTG) is a well-described radiographic measurement around the knee, which is of clinical significance in the assessment of patients with patellar instability. The TTTG is clinically relevant when considering the type of surgical procedures that may be required. The purpose of this retrospective observational study was to measure the TTTG measurement in the black African population and to compare it to the quoted norms in the literature.

Methods: A random sample was obtained of 100 consecutive CT scans of lower limbs for vascular pathologies from black African patients. The TTTG was measured by a single observer on the Siemens® syngo.plaza software.

Results: CT scans of 162 knees from 88 patients met the inclusion criteria. The median age was 34 years (range 19–85 years; interquartile range [IQR] 24–50). The majority of cases were male (75%; n=121). The mean TTTG was 20.3 mm (standard deviation [SD] 16.1; range 1–29.2 mm). The mean TTTG in males was 20.7 mm (95% confidence interval [CI] 19.9–21.5 mm) and 19.1 mm (95% CI 17.6–20.5 mm) in females (p=0.06). There was no correlation found between age and TTTG (p=0.12).

Conclusion: According to our study, barring some limitations, it appears that there may be a noteworthy difference in the TTTG measurement in the black African population. Larger comparative studies would be required to confirm these findings and to determine the clinical relevance.

Level of evidence: Level 4

Author Biographies

M Rankin, University of KwaZulu-Natal

MBChB(UKZN), FC Orth (SA); Registrar, Department of Orthopaedics, School of Clinical Medicine, University of KwaZulu-Natal

M A H Mohideen, Westville Life Hospital

BSc(UKZN), MBChB(Medunsa), FC Orth(SA); Orthopaedic Consultant, Westville Life Hospital