# Congenital Scoliosis > Congenital scoliosis for NEET-PG Orthopaedics: hemivertebra, failure of segmentation versus formation, renal and cardiac associations and surgical planning. - Canonical URL: https://prepelephant.com/topics/neet-pg/orthopaedics/congenital-scoliosis - Exam / course: NEET-PG · Subject: Orthopaedics - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-14 - Last updated: 2026-10-14 - Reference basis: Apley's System of Orthopaedics and Fractures; Tachdjian's Pediatric Orthopaedics - How to cite: "Congenital Scoliosis", PrepElephant, https://prepelephant.com/topics/neet-pg/orthopaedics/congenital-scoliosis ## Direct answer Congenital scoliosis is a lateral spinal curvature caused by a vertebral malformation present from birth, classified as failure of formation, failure of segmentation or a mixed type. Unlike idiopathic scoliosis, the curve is structural and tends to progress, and it is often associated with renal, cardiac and spinal cord anomalies. The workup therefore includes screening of the kidneys and heart, plus MRI of the whole spine. ## What you must remember - **Failure of formation:** a hemivertebra or wedge vertebra, from loss of one half of the vertebral body; progression depends on the type and location. - **Failure of segmentation:** a unilateral unsegmented bar, the worst progressor of all, or a block vertebra, which is bilateral and rarely progresses. - **Mixed type:** both mechanisms in one spine, with a unilateral bar on one side and a hemivertebra on the other often forming the worst-prognosis pattern. - **Renal anomalies:** horseshoe, pelvic and absent kidneys are commonly associated; renal ultrasound is standard screening. - **Cardiac anomalies:** septal defects are the commonly associated lesions; echocardiography completes the screen. - **Cord anomalies:** diastematomyelia, tethered cord and syrinx are detected on MRI and must be excluded before surgery. - **Bracing:** largely ineffective, because the curve is structural and rigid rather than flexible. - **Surgery:** early in-situ fusion, hemiepiphysiodesis or hemivertebra excision for progressive curves, with growing rods in very young children with severe progression. ## A workup built around the vertebral defect A 3-year-old is found to have a thoracic curve on clinic examination. The workup first defines the malformation, then screens the organs most often involved before any surgical choice is made. 1. **Define the malformation:** standing and supine radiographs identify whether the defect is a hemivertebra, a unilateral bar or a block vertebra. 2. **Measure the curve:** the Cobb angle on serial films, taken at regular intervals, shows the rate of progression and whether intervention is needed. 3. **Screen for associated anomalies:** renal ultrasound and echocardiography look for the commonly associated kidney and heart defects. 4. **Image the cord:** MRI of the whole spine excludes diastematomyelia, tethered cord and syrinx before any osteotomy or fusion. 5. **Choose by growth:** observation suits a non-progressing curve, while a progressing curve in a young child is treated early by hemivertebra excision, hemiepiphysiodesis or in-situ fusion rather than by waiting for growth to finish. 6. **Do not rely on bracing:** a brace is rarely effective for a structural curve, so it should not delay definitive planning when progression is documented. ## Where the exam tries to catch you Examiners test whether you recognise the structural nature of the curve and screen for associated anomalies. - **Trap:** treating congenital scoliosis with a brace as for adolescent idiopathic scoliosis. **Correct:** the curve is structural and rigid, so bracing rarely controls it and surgical planning should follow progression. - **Trap:** assuming a unilateral hemivertebra always progresses slowly. **Correct:** the defect type and location matter, and a unilateral unsegmented bar progresses fastest, especially with a contralateral hemivertebra. - **Trap:** skipping renal and cardiac screening. **Correct:** kidney and heart anomalies are common associations, and missing them endangers the child during surgery. ## Frequently asked questions ### What are the three types of congenital scoliosis? Congenital scoliosis is classified as failure of formation, failure of segmentation or mixed. Failure of formation produces hemivertebrae or wedge vertebrae, failure of segmentation produces unilateral unsegmented bars or block vertebrae, and mixed types combine both mechanisms. ### Why does failure of segmentation matter in congenital scoliosis? A unilateral unsegmented bar, a failure of segmentation, is the fastest-progressing lesion in congenital scoliosis, whereas a block vertebra rarely progresses. A unilateral bar in a growing child therefore warrants close surveillance and early surgical planning. ### Which associated anomalies should be screened for in congenital scoliosis? Renal anomalies such as horseshoe, pelvic or absent kidneys, and cardiac septal defects, are commonly associated with congenital scoliosis. Renal ultrasound and echocardiography are standard screening, and MRI checks the spinal cord for diastematomyelia or tethered cord. ### Why is bracing usually ineffective for congenital scoliosis? Bracing is usually ineffective for congenital scoliosis because the curve is structural, caused by a fixed vertebral malformation rather than a flexible curvature. A brace cannot correct the defect or reliably control it, so surgical planning is the usual route once progression is documented. ### What surgical options are used for progressive congenital scoliosis in children? Early in-situ fusion, hemiepiphysiodesis or hemivertebra excision, and growing rods in very young children with severe progression, are the usual options for progressive congenital scoliosis. The choice depends on the defect, the growth remaining and the age of the child.