Duplicated ureter or Duplex Collecting System is a congenital condition in which the ureteric bud, the embryological origin of the ureter, splits (or arises twice), resulting in two ureters draining a single kidney. It is the most common renal abnormality, occurring in approximately 1% of the population. Pathophysiology
Ureteral development begins in the human fetus around the 4th week of embryonic development. A ureteric bud, arising from the mesonephric (or Wolffian) duct, gives rise to the ureter, as well as other parts of the collective system. In the case of a duplicated ureter, the ureteric bud either splits or arises twice. In most cases, the kidney is divided into two parts, an upper and lower lobe, with some overlap due to intermingling of collecting tubules. However, in some cases the division is so complete as to give rise to two separate parts, each with its own renal pelvis and ureter. Diagnosis
Prenatally diagnosed hydronephrosis (fluid-filled kidneys) suggest post-natal follow-up examination. The strongest neo-natal presentation is urinary tract infection. A hydronephrotic kidney may present as a palpable abdominal mass in the newborn, and may suggest an ectopic ureter or ureterocele. In older children, ureteral duplication may present as:
Urinary tract infection - most commonly due to vesicoureteral reflux (flow of urine from the bladder into the ureter, rather than vice versa). Urinary incontinence in females occurs in cases of ectopic ureter entering the vagina, urethra or vestibule. Classification
Ureteral duplication is either of:

Partial
I.e., the two ureters drain into the bladder via a single common ureter.
In the long term, physical therapy will be given to build strength in the muscles of the neck to increase stability and better protect the cervical spine. Collars, traction and surgery can be used to immobilize and stabilize the neck after a cervical fracture. Cervical collar
Minor fractures can be immobilized with a cervical collar without need for traction or surgery. A soft collar is fairly flexible and is the least limiting but can carry a high risk of further neck damage in patients with osteoporosis. It can be used for minor injuries or after healing has allowed the neck to become more stable. A range of manufactured rigid collars are also used, usually comprising a firm plastic bi-valved shell secured with Velcro straps and removable padded liners. The most frequently prescribed are the Aspen, Malibu, Miami J, and Philadelphia collars. All these can be used with additional chest and head extension pieces to increase stability. Rigid braces
Rigid braces that support the head and chest are also prescribed. Examples include the Sterno-Occipital Mandibular Immobilization Device (SOMI), Lerman Minerva and Yale types. Special patients, such as very young children or non-cooperative adults, are sometimes still immobilized in medical plaster of paris casts, such as the Minerva cast. Traction
Traction can be applied by free weights on a pulley or a halo type brace. The halo brace is the most rigid cervical brace, used when limiting motion to the minimum that is essential, especially with unstable cervical fractures.