PURPOSE

The aim of the study was to explore if the patellar tendon angles (PTAs) is an intrinsic risk factor for anterior cruciate ligament (ACL) rupture. We hypothesised that the PTAs will be increased in ACL rupture patients compared to matched controls.

METHODS

We performed a retrospective radiographic cohort study. A cohort of ACL-injured patients between 2019 and 2022 was utilised. The control population, from the same time period, was a consecutive series of 100 patients without ligament or meniscal injuries which were prospectively added to our institutional registry. Posterior tibial slope (PTS), static anterior tibial translation (SATT), patellar tendon to tibial plateau angle (PT-TPA), patellar tendon-tibial shaft angle (PT-TSA) were measured.

RESULTS

A total of 100 patients were included in the control cohort and 110 in the ACL cohort. The PT-TPA was significantly less in the ACL cohort compared to the control cohort, mean and SD of 15.33 (±5.74) versus 13.91 (±5.68), respectively ( = 0.01). PT-TSA was also less in the ACL cohort, mean and SD of 116.15 (±5.89) versus 114.27 (±4.81), however, this failed to reach statistical significance ( = 0.08). The PT-TPA was not correlated with PTS ( = 0.65) and the PT-TSA was inversely correlated with PTS; Pearson correlation coefficient of -0.28 ( < 0.01). The PT-TSA had a greater correlation -0.4 ( < 0.01) with SATT than PTS 0.37 ( < 0.01).

CONCLUSION

PTAs are not elevated in ACL-injured subjects. While anteriorisation of the tibial tubercle is utilised in dogs to decrease the anterior thrust resulting from the anteriorly directed vector of the quadriceps, this treatment in the humans is not warranted and methods to reduce the PTAs should focus on prehabilitation and rehabilitation.

LEVEL OF EVIDENCE

Level III.