# When scoliosis surgery in a child unexpectedly resolves hydronephrosis: A case report and review of the literature

## TL;DR

A child's kidney swelling unexpectedly improved after scoliosis surgery, suggesting a rare dual benefit of the procedure.

## Contribution

This is the first reported case of hydronephrosis resolving after scoliosis correction.

## Key findings

- A 12-year-old girl with scoliosis and hydronephrosis showed complete resolution of kidney swelling after spinal surgery.
- The correction of spinal alignment may have improved urinary drainage by adjusting the angle between the renal pelvis and ureter.
- This case suggests scoliosis surgery can have a dual therapeutic effect on both spinal and urinary issues.

## Abstract

Hydronephrosis, defined as dilation of the renal pelvis and calyces, may occur with scoliosis or after corrective surgery. However, spontaneous resolution of pre-existing hydronephrosis following scoliosis correction has not been previously reported. We present a 12-year-old girl with a ZMYM2 mutation, severe thoracolumbar scoliosis (Cobb 103°), and bilateral hydronephrosis. After posterior spinal fusion (T4–L3), hydronephrosis resolved completely. Just as the spinal angle, likely the angle between the renal pelvis and ureter was similarly adjusted, facilitating improved urinary drainage. This rare case highlights a possible dual therapeutic effect of scoliosis correction on spinal alignment and urinary drainage in selected cases.