Adolescent Idiopathic Scoliosis – Current S2k AWMF Guideline

Abstract

The adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity of unknown etiology and onset between 10 and 18 years of life. The current AWMF S2k guideline was elaborated with participation of the specialty associations in Germany aiming at improving and unifying the standard of care in AIS patients. The purpose of this review is to present a compact synopsis of the results of the expert consensus.

Keywords

adolescent - idiopathic - scoliosis

1. Definition and Aetiopathogenesis

Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity with onset between 10 and 18 years and no clear cause. The observed prevalence ranges from 0.47 to 5.2%. The ratio of girls to boys is between 1.5: 1 and 3: 1. In particular, in scoliosis with a higher Cobb angle, the prevalence in girls is significantly higher than in boys: The ratio of girls to boys increases from 1.4: 1 for curvatures from 10° to 20° to 7.2: 1 for curvatures above 40°.

The aetiopathogenesis of AIS is not yet fully understood but appears to be multifactorial involving the interplay between predisposition and environmental factors. Female sex, endocrinologic factors, increased length growth of the anterior column, and genetic factors seem to play an important role.

2. Clinical Examination

The following parameters should be collected during the clinical examination: Shoulder posture, pelvic tilt, frontal trunk overhang, waist triangles, rib hump, and lumbar prominence (measured with a scoliometer) using the forward-bend test (Adams test); neurological examination; height; weight; menarche details; pain. An X-ray should be performed to confirm the diagnosis if a rib hump or lumbar prominence of 5° or more is present.

3. Diagnostic Imaging

3.1. Plain X-ray

As part of the initial radiographic assessment, a full-spine standing X-ray in 2 planes should be performed. Separate images of the thoracic and lumbar spine are not appropriate. A leg length discrepancy should be corrected using a heel lift. Given the increased risk of radiation-induced tumours (particularly breast cancer), radiation protection measures should be strictly observed. Measures to reduce the cumulative radiation dose are mandatory.

The method of choice for quantifying the extent of scoliosis is the Cobb angle on radiographs, whereby the measurement error is 3°.

3.2. Cross-sectional imaging – MRI, CT

With regard to cross-sectional imaging, a full-spine MRI is essential prior to corrective surgery for AIS. In non-surgically treated patients, it is indicated only if pain or unclear neurological symptoms are present, or if congenital abnormalities need to be excluded.

Preoperative CT is not part of the routine diagnostic work-up for AIS.

3.3. Skeletal age assessment

Skeletal age should be assessed when a relevant clinical decision depends on it, such as indication for brace treatment, duration of brace use, weaning from the brace, surgical technique, or timing of surgery.

Conventional radiological methods for assessing skeletal age, such as the Risser sign (iliac apophysis) and Greulich and Pyle (left hand radiography), are now rarely used due to their imprecise assessment of the growth spurt and high inter- and intra-observer variability. The Tanner and Whitehouse method is more accurate, but is considerably more time-consuming; however, this can be facilitated through commercially available computer programs integrated into imaging review systems.

Owing to its accuracy and ease of use, Sander’s simplified skeletal maturity scale has been widely adopted in recent years. It allows the pubertal growth spurt to be more precisely classified into 8 stages, shows better correlation with the scoliosis growth patterns, and enables rapid clinical assessment.

Patient- and curvature-specific factors are considered when determining the approach to radiological follow-up for monitoring diagnosed AIS, during brace treatment, or postoperatively. Comprehensive recommendations are provided in the extended version of the guideline.

3.4. Rasterstereography

Rasterstereography has very limited reliability due to its inaccuracy. Rasterstereography does not replace radiographic monitoring, but can reduce the total number of X-rays during follow-up of AIS patients, as it can be used to monitor progression of mild and moderate scoliosis and detect changes in or progression of the curvature.

4. Classification

The Lenke classification has become established as a gold standard and is particularly important for planning the operative therapy. The classification defines structural and non-structural curves, and categorises AIS into six curve types (main thoracic, double thoracic, double major, triple major, thoracolumbar/lumbar without structural thoracic curve, thoracolumbar/lumbar with structural thoracic curve). A lumbar modifier describes the distance of the lumbar spine to the midline. Thoracic sagittal profiles are classified as hypokyphotic, normokyphotic or hyperkyphotic. The purpose of the Lenke classification is to establish curve type criteria that can inform recommendations for operative management. In principle, structural curvatures are to be corrected surgically, whereas spontaneous correction can be expected in the case of non-structural curvatures.

5. Natural course of untreated scoliosis

During growth, the likelihood of progression of untreated AIS mainly depends on the remaining growth potential and the Cobb angle. After growth is complete, a thoracic curvature greater than 50° may increase annually by about 1°. The clinical situation, including subjective well-being, can remain well-compensated for a long time in AIS patients despite progressive curvature.

Relatively late AIS surgery in later adulthood tends to be more difficult and invasive than adolescent surgery, and a longer fusion distance may be necessary to achieve the same degree of correction as surgery at an earlier age.

In terms of quality of life, a markedly increased risk of back pain and pulmonary symptoms was observed in untreated patients with curvatures above 50°.

6. Treatment

The most important factors in devising the treatment strategy are the degree of curvature and skeletal maturity.

Patients with AIS who have remaining growth potential and main curve Cobb angles < 25° in the thoracic spine or < 20° in the thoracolumbar or lumbar spine should be monitored with follow-up and can be managed with regular physiotherapeutic interventions.

In AIS patients with remaining growth potential and main curve Cobb angles > 25° in the thoracic spine or > 20° in the thoracolumbar or lumbar spine, bracing in combination with physiotherapy should be considered.

For AIS patients with remaining growth potential or who have reached skeletal maturity with main curve Cobb angles > 50° in the thoracic spine or > 40° in the thoracolumbar or lumbar spine, surgical correction of the scoliosis should be considered. For curvatures between 40° and 50° Cobb angle in the thoracic spine, surgery may be considered.

From 40° Cobb angle, individualised consultation in a surgical scoliosis centre should be provided.

6.1 Non-operative therapy

The following therapeutic goals were defined for non-operative therapy:

• Stop curvature progression at puberty and, if possible, even correct curvature

• Prevent and treat pulmonary problems

• Prevent and treat back pain

• Improve appearance by optimising trunk posture

There is very limited solid scientific literature on the empirical evidence of physiotherapy, manual therapy, and inpatient rehabilitation for AIS that demonstrate the role of physiotherapy as a “stand-alone treatment”. In most physical therapy efficacy studies, the methodology is of poor quality with inconsistent data collection and insufficient reporting of patient compliance, criteria for patient recruitment, etc. In some studies, the data on the change in curvature angles were evaluated as statistically significant; however, the absolute differences were within the 3° methodological error range of Cobb angle measurement, so the validity of these studies is weak and not clinically significant. There are no high-quality studies investigating whether manual therapy or osteopathy have a relevant effect on AIS, particularly on spinal curvature. Reduction of the Cobb angle via manual therapy has been reported only in small case series which tend to be of low scientific quality; therefore, manual therapy currently lacks sufficient evidence to warrant recommendation.

6.1.1. Physiotherapy

The following recommendations were made with regard to physiotherapy:

• When indicated, physiotherapy may be scoliosis-specific

• Patients should be advised that physiotherapy alone does not generally lead to a relevant (> 5°), permanent improvement of the Cobb angle.

• Manual therapy or osteopathic treatment in patients with AIS cannot be recommended to improve the Cobb angle, but it can have positive effects (e.g. on pain) as an adjunctive therapy.

• After skeletal maturity, AIS patients should receive physiotherapy if daily-life relevant factors such as pain, mobility limitations, muscle imbalances, or respiratory issues make it necessary.

• After surgery for AIS, physiotherapy can be considered (e.g. for non-instrumented secondary curves or to manage pain and muscle imbalances and to optimise mobility and respiration, etc.).

Although the evidence supporting physiotherapy in conjunction with bracing is limited, the guideline authors, drawing on their clinical experience, advise the use of concomitant physiotherapy.

6.1.2 Brace therapy

The following recommendations were made for brace therapy:

• AIS patients with remaining growth potential and Cobb angles of the main curvature from 25° in the thoracic spine or 20° in the thoracolumbar or lumbar spine should be treated with a brace.

• Considering the indication criteria, bracing should be advocated as the preferred non-surgical treatment for AIS and has been shown to be markedly more effective than mere progression monitoring.

• The success of the brace therapy correlates with how long the brace is worn. The aim should be to wear the brace full time (18 to 23 hours of “full-time” treatment).

• For the treatment of AIS, rigid orthoses based on the principles of active 3-dimensional 3-point correction are to be used (e.g. Boston, Chêneau, TLSO etc.).

• The radiologically determined primary correction in the brace should be at least 40% of the initial curvature.

• Brace therapy should be discontinued only after radiologically confirmed skeletal maturity corresponding to Sanders stage 7b.

There are no scientific studies on the contraindications to brace therapy. From the point of view of the authors of the guidelines, concomitant pulmonary diseases and skin problems do not in principle constitute absolute contraindications for brace therapy; however, the procedure must be guided by the requirements of the individual case. Bracing should not be used in cases of high thoracic structural curvature in the thoracic spine with an apex above thoracic vertebra 7 (T7). Thoracic hypokyphosis is not an absolute contraindication for brace therapy; however, if hypokyphosis worsens during bracing, discontinuation of brace treatment may be considered.

Psycho-social and emotional factors are not absolute contraindications for brace therapy, but should be taken into account when assessing the indication for treatment and discussed with the affected person.

If a patient rejects the brace treatment, psychological support should be provided.

6.2 Surgical interventions

For surgical treatment of AIS, the gold standard is instrumented corrective spinal fusion. This involves the placement of implants into the vertebrae within the affected curvature, which are then used to apply corrective manoeuvres to achieve the desired spinal alignment of the AIS.

Fixation is typically achieved using pedicle screws, or hooks and rods attached to dorsal structures, with pedicle screws constituting the standard in posterior scoliosis correction and demonstrating superiority over hook systems.

From the anterior side, vertebral body screws can be inserted directly into the vertebrae via a thoracotomy, lumbotomy, or thoracophrenolumbotomy. Both anterior and posterior surgical procedures can achieve comparably good results in terms of correction, function and patient satisfaction.

Posterior correction has the advantage over anterior corrective spinal fusion in AIS in that all curvatures can be addressed posteriorly.

The limitation of anterior surgery lies in the type of curvature. Only single-curve deformities (Lenke type 1 and 5) can be corrected from the anterior approach. The uppermost vertebra to be reached is usually T5. Another limitation is pulmonary function. Anterior thoracic approaches should be avoided in patients with markedly reduced pulmonary function, given the elevated intraoperative and postoperative risk of worsening respiratory performance.

In dorsally instrumented spondylodesis, instrumentation is often extended to the caudal neutral vertebra or to the stable vertebra. In the case of anterior correction, instrumentation up to the “caudal end vertebra” of a curvature is usually sufficient. The latter results in posterior corrective spinal fusion often being instrumented slightly further caudally than anterior corrective spinal fusion. However, there is no consensus on whether, when incorporating bending or traction radiographs, shorter instrumentation might also be feasible with the posterior approach. In addition, the lowest instrumented vertebra (LIV) used for thoracic curvature is highly dependent on the surgical technique and the type, extent, and rotation of the lumbar countercurvature. Thus, no general conclusion can be drawn as to whether posterior spinal fusion has to be inherently longer than anterior spinal fusion.

There is no strong evidence regarding the indication for soft tissue releases, osteotomies, thoracoplasties, or preoperative halo traction preparation, so these remain decisions made on a case-by-case basis.

6.3. Alternative surgical interventions

Based on the current state of evidence, growth-friendly or growth-modulating techniques are mainly indicated for managing scoliosis in children younger than 10 years of age (Early Onset Scoliosis). Generally, AIS patients are not candidates for this approach, with indications restricted to rare cases exhibiting substantial remaining growth potential.

The following recommendations were made by the authors of the guidelines regarding alternative surgical methods for AIS:

• The Posterior Dynamic Deformity Correction Device, and the Growth-Guiding Procedure should not be used with AIS.

• Traditional Growing Rods (TGR) and Magnetically Controlled Growing Rods (MCGR) may only be considered in individual cases for AIS.

  • A general recommendation for or against the “Vertebral Body Tethering” (VBT) method cannot be made at present in patients with AIS.

  • The VBT system should not be used after growth has ended.

6.4. Intraoperative neuromonitoring (IONM)

For corrective AIS surgery, a form of IONM should be used. Although the benefits of IONM have long been recognised in everyday routine, there is still no consensus on mandatory nationwide implementation, quality standards for implementation and personnel qualifications. In Germany, the use of IONM in AIS operations is currently not mandatory, although it is clearly recommended.

The intraoperative wake-up test is a possible alternative to IONM and is beneficial when IONM results are unclear, unreproducible or in cases where there are contraindications.

The surgeon responsible for deformity correction should be familiar with the capabilities and limitations of IONM and ensure that the person assigned to IONM is professionally qualified to perform and interpret it.

7. Scoliosis in Everyday Life

Regarding career choice, there are no scientifically substantiated recommendations for or against specific occupations for AIS patients. Career counselling for an AIS patient should be individualised and take into account the degree of curvature, progression, and clinical symptoms.

In principle, it should be noted that, from a therapeutic perspective, only cautious guidance should be provided regarding career choice. The career choice is very personal and individual and the study and data situation does not allow clear recommendations in one direction or another.

With regard to the spine, work capacity is predominantly affected by pain symptoms and spinal rigidity. The following may be problematic:

• frequent bending

• heavy lifting and carrying medium and heavy loads

• continuous standing, especially on ladders or scaffolding

• continuous walking

• monotonous postures and forced positions, without the opportunity to change position or alternate between sitting, standing, and walking

A full shift of light to moderately heavy work is possible without restricting the workflow.

Body perception is often altered in AIS patients and can lead to psychosocial stress. Psychosocial support should be initiated early in these cases to ensure comprehensive patient care.

AIS is not an obstacle to normal pregnancy and natural birth.

Whether an increase in curvature occurs as a result of pregnancy is not clearly established and is debated in the literature.

8. AIS Patients and Sports

Physical activity and exercise recommendations in AIS are generally based on expert opinions and are not based on a well-founded study; the level of evidence in the published literature is relatively low. In particular, there is no reliable evidence that certain sports cause an increase in curvature in pre-existing scoliosis. There is generally little solid scientific evidence on this subject. A systematic review of the literature has shown that scoliosis patients treated with a brace or surgery can be just as physically active as healthy control subjects.

The following recommendations were made in the guideline with regard to sport and AIS:

• AIS patients should be physically active.

• A general ban on individual sports is not justified and should not be introduced.

• Exercise is important and recommended for AIS patients.

• There is no established scientific evidence to support the negative impact of exercise on scoliosis.

• Exercise does not cause idiopathic scoliosis.

Participation

Primary professional associations

German Spinal Society (www.dwg.org; Deutsche Wirbelsäulengesellschaft, DWG)

German Society of Orthopaedics and Orthopaedic Surgery (www.dgooc.de; Deutsche Gesellschaft für Orthopädie und Orthopädische Chirurgie, DGOOC)

Association for Children’s Orthopaedics (www.kinderorthopaedie.org; Vereinigung für Kinderorthopädie, VKO)

Guideline coordinators and lead authors

Anonymised

Associations Involved

Federal Guild Association for Orthopaedic Technology (Bundesinnungsverband für Orthopädie-Technik)

Federal Association for Self-Help with Scoliosis (Bundesverband Skoliose-Selbsthilfe e. V. [Patient representation])

German Society of Paediatric Medicine (Deutsche Gesellschaft für Kinder- und Jugendmedizin)

German Society of Manual Medicine (Deutsche Gesellschaft für Manuelle Medizin)

German Society of Orthopaedics and Orthopaedic Surgery (Deutsche Gesellschaft für Orthopädie und Orthopädische Chirurgie, DGOOC)

German Society for Physical Medicine and Rehabilitation (Deutsche Gesellschaft für Physikalische Medizin und Rehabilitation, DGPMR)

German Radiological Society (Deutsche Röntgengesellschaft e. V., DRG)

German Physiotherapy Association (Deutscher Verband für Physiotherapie e. V., ZVK)

German Spinal Society (Deutsche Wirbelsäulengesellschaft, DWG)

Society of Paediatric Radiology (Gesellschaft für Pädiatrische Radiologie)

Society for Transition Medicine (Gesellschaft für Transitionsmedizin e. V., GfTM)

Association for Paediatric Orthopaedics (Vereinigung für Kinderorthopädie, VKO)

German Society for Clinical Neurophysiology and Functional Imaging (Deutsche Gesellschaft für Klinische Neurophysiologie und Funktionelle Bildgebung, DGKN)

Guideline group (co-authors) in alphabetical order

Anonymised

Methodological support

Anonymised

Note: The current review work is only a compressed explanation of the original version. Only by consulting the full guideline and the literature cited therein can readers access all relevant information.

Contributorsʼ Statement

Kiril Mladenov: Conceptualization, Data curation, Formal analysis, Methodology, Writing - original draft, Writing - review & editing. Bernd Wiedenhöfer: Conceptualization, Data curation, Formal analysis, Methodology, Project administration, Writing - original draft, Writing - review & editing. Tobias Schulte: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Supervision, Validation, Writing - original draft, Writing - review & editing.

Conflict of Interest

The authors declare that they have no conflict of interest.

• References/Literatur

• Please refer to the bibliography of the published long version of the AWMF guideline./Es wird auf die Bibliografie der veröffentlichten Langversion der AWMF-Leitlinie verwiesen.

Publication History

Received: 22 June 2025

Accepted after revision: 05 December 2025

Article published online:
27 January 2026