Indication and Treatment of Adult Kyphoscoliosis

Detailed description 1 Indications and Treatment of Adult Kypho- Scoliosis (INTRAKS Study) 2. Background:New surgical techniques for osteotomies and promising equipment has led to a renaissance with broader indications, evoking the need for well-founded studies and quality registration of the adult kyphoscoliosis treatment to evaluate the risk of major complication, the benefit for the patients and socioeconomic burden. Prior randomized studies have had high crossover rates to surgical treatment, questioning the result of the studies. As a randomized controlled trial (RCT) will be difficult, the investigators plan to propensity match two cohorts and then compare the correctional surgery and non- surgical treatment at a 1 year follow-up.

2.1 Needs description:

1. Identify predictors for unsatisfactory outcome in adult kyphoscoliosis. This study aims to create a predictive model for unsatisfactory outcome after deformity surgery in adult kyphoscoliosis. A prospective multicenter observational effectiveness study is constructed to detect a < 30% improvement from baseline in Oswestry Disability Index (ODI) score at 12 months follow up. The predictive model can be a helpful tool in accessing the complexity of this patients and aid in shard decision making and improved surgical planning. Patients are grouped in: 1) unsatisfactory result (UR) < 30% increase from baseline ODI score, 2) satisfactory result (SR) ≥ 30% increase from baseline ODI score. A predictive model will be calculated for both kyphosis and scoliosis together and separately. The same criteria for inclusion are set in the non-surgical group as well as all the data collected, a predictive model will be created if the difference in outcome is significant. The investigators will also look at the patients with a > 10% worsening from baseline in ODI score at 12 months follow up.

2. A prospective multicenter observational effectiveness study of adult kyphoscoliosis treatment, surgical and non-surgical outcome with a 12 months follow up.

3. This part of the study will be looking at the effectiveness of surgery vs non-surgical treatment using the PROMS described in the protocol. It is outcome related, the planned follow up time is 12 months, but the investigators have ethical approval (REK) to continue the data recording for 24 months and more for a sufficient follow up time. It exceeds the time limit for the PhD candidates listed, but others will continue the work. It will contain all the patients included.

4. The subgroups of iatrogenic/degenerative kyphosis and scoliosis will be studied separately as it is known that the mainly scoliotic patients do better than the kyphotic once. Around 30-40 patients will be sufficient in each surgical subgroup, the same in the non-surgical.

5. The kyphotic healed high energy fracture. One of the subgroups to be investigated is the high energy fractures healed in kyphosis. High energy fractures are typical males in the age of 25-50. The fractures healed in kyphosis with a regional kyphotic angle of >20 degrees and a positive sagittal vertical axis of >4 cm can be included (the rest of the inclusion or exclusion criteria listed will be followed as for the whole study). As this is a subgroup, around 30-40 surgical patients will be sufficient. The investigators hope to have the same number in the non-surgical group to compare with. The main outcome parameter is ODI, but the investigators will also look into the results of the EQ-5D, SRS22 and the numeric rating scale (NRS). As this is a fracture resulting in a secondary deformity, the PROMS listed should be addressing the patient problems.

6. XLIF vs anterior-/transforaminal interbody fusion/pedicle subtraction osteotomy/Smith Petersen/Ponte (ALIF/TLIF/PSO/SP/Ponte).

There is a trend towards using XLIF and OLIF procedures for deformity cases. The investigating party will look into the patients operated using the lateral approaches and compare it towards the dorsal applied interventions (TLIF, PSO, Ponte/SP), if possible also ALIF patients. It should be at least 30-40 patients undergoing the lateral intervention to be able to make a comparison that could be statistical significant. 5. Socioeconomic study; surgery vs non-surgical for adult kyphoscoliosis. The correctional surgery is often of long duration with expensive implants and highly complicated with high risk of complications. It is costly and the investigators intend to evaluate the socioeconomic burden. The duration of surgery, cost of implants and duration of hospital stay will be registered, the readmission due to complications will be registered for the first 12 months. As EQ-5D is used as a PROM in this study, it will be used for the socioeconomic study. 6. Identify differences in indication, examination and treatment between a European and Asian population.