Testicular torsion or more specifically, torsion of the spermatic cord, is where contraction of the cremaster causes rotation of the testes and adnexa, resulting in outflow obstruction. Where there is a high insertion of the tunica vaginalis, the testicle is more mobile within the tunical cavity (described as a bell clapper deformity) and on clinical examination, can be felt as a horizontal lie.
As venous and lymphatic drainage stops, engorgement results with eventual arterial flow obstruction.
The speed and extent of damage results from the degree of torsion
a. Incomplete (<360o ) b. One turn ( 360o) c. 2 turns
With 2 or more turns, the time to necrosis shortens due to loss of arterial flow.
The peak incidence occurs in the 12- 18 year old group, typically with acute onset scrotal and/or testicular pain. Risk factors include horizontal lie, long spermatic cord and history of cryptorchidism. The other peak is in the first year of life.
There can be some delay in presenting, and an older paper gives a median time to presentation of 20 hours reported in under 18s (1) and of 4 hours in over 18s with associated orchidectomy rates of 44% and 8% respectively.