Testicular volume and Tanner stage: determinant factors for testicular torsion

To assess testicular volumes and sexual maturation in patients with testicular torsion.

A retrospective analysis of consecutively treated patients with testicular torsion between 2016 and 2018. Age, pubic hair staging (Tanner), and by ultrasonography, volume of the unaffected testis (in cubic centimeters) were evaluated either immediately before surgery or at the first postoperative visit. Patients with previous testicular disease, such as cryptorchidism, or with no records of testicular volume were excluded. The analysis included descriptive statistics and Bayesian regression.

We treated 149 patients during the study period, and 141 (94.6%, median age 17.3 years) met the inclusion criteria. Median testicular volume was 13.0cm3 (interquartile range of 10.5-15.2), with similar right and left volumes (12.9cm3versus 13.3cm3; p=0.94). Sixty-five (46.1%) patients were Tanner stage IV, 17 (12.1%) stage III, and 59 (41.8%) stage V.

In this study, we were able to estimate volumes of testicular torsion, which aggregated around late puberty values (13.0cm3 for the whole dataset, 12.2cm3 for patients <25 years), suggesting that testicular hypermobility, due to congenital anatomical abnormalities, remains quiescent until the organ reaches a critical volume, after which torsion becomes possible. These findings provide a tentative explanation for the disease's age distribution.