Evaluate surgical treatment outcomes and identify best practice guidelines for complex adult spinal deformity (ASD) patients treated with minimally invasive approach, including radiographic and clinical outcomes, surgical and postoperative complications, risk factors for and revision surgery rates, and the role of standard work to improve patient outcomes and reduce surgical and postoperative complications.

Specific Aims:

• Evaluate surgical treatment outcomes and identify best practice guidelines for complex adult spinal deformity (ASD) patients treated with minimally invasive approach, including radiographic and clinical outcomes, surgical and postoperative complications, risk factors for and revision surgery rates, and the role of standard work to improve patient outcomes and reduce surgical and postoperative complications.

  a. Complex ASD patients will be defined based upon clinical, radiographic and/or procedural criteria.

• Develop and validate a standardized, universal complications classification system for minimally invasive spine surgery

• Evaluate perioperative blood management approaches, transfusion requirements, including variance in thresholds for blood transfusion and associated complications for minimally invasive adult spinal deformity surgery

• Evaluate clinical outcomes utilizing legacy patient reported outcome measures (PROMs) including Scoliosis Research Society 22r (SRS 22r) modified Oswestry Disability Index (mODI), Veterans RAND-12 (VR-12), and numeric pain rating scale (NRS), and patient reported outcome measurement information system (PROMIS).

• Evaluate clinical outcomes stratifying by patient chronological and physiological age

• Evaluate the cost for episode of care for minimally invasive CADS surgery and cost per QALY gain compared to open surgery for CADS

• Evaluate the contribution of patient frailty to patient outcomes, cost of care, disability, and complications

• Evaluate incidence of and risk factors for mental health (MH) compromise among ASD patients treated with MIS techniques, and establish best practice guidelines for assessing MH

• Evaluate the association of MH with surgical complications, outcomes, hospital length of stay and cost for MIS ASD surgery

• Evaluate the association of social health surgical complications, outcomes, hospital length of stay and cost for MIS ASD surgery and risk factors for routine (home) discharge vs. skilled nursing facility (SNF)/rehabilitation facility

• Broaden the evaluation of the minimally invasive surgically treated ASD patient to maximize evaluation of the entirety of the episode of care to include steps that can be taken prior to surgery including "prehabilitation," pain management, and MH care to improve treatment outcomes, reduce cost, reduce hospital length of stay, reduce non-routing discharge and reduce early and late complications

• Establish a core set of standard work guidelines to clinically and radiographically evaluate and treat ASD patients and evaluate the utility of standard work to improve outcomes for ASD and formulate best practice guidelines for minimally invasive surgical treatment of ASD

• Evaluate the use of robotic techniques in minimally invasive spine surgery for ASD, and its impact on radiographic parameters and clinical outcomes

• Evaluate the use of expandable cages in minimally invasive spine surgery for ASD, and its impact on radiographic parameters and clinical outcomes

• Evaluate the OR efficiency, morbidity of surgery, and cost per episode of care relating to single-position vs. multi-position CADS surgery

• Evaluate the prevalence and incidence of sacroiliac pain before/after complex adult spinal deformity surgery.

Inclusion Criteria:

1. >18 years of age at the time of treatment

2. Diagnosis of adult congenital, degenerative, idiopathic, neuromuscular, inflammatory or iatrogenic spinal deformity

3. EOS full body or standing 36" AP & Lateral images of entire spine

4. Surgery to be schedule to take place within 6 months (otherwise PROMs/Radiographic images to be recollected)

   AND Either:

5. One of the following Radiographic criteria:

   1. PI-LL ≥ 25 degrees
   2. Thoracolumbar/lumbar scoliosis ≥ 20 degrees
   3. SVA >10cm
   4. PT > 30 OR

6. One of the Following Procedural criteria:

   1. Surgery to include > 3 levels percutaneous posterior spinal instrumentation or 3 level stand-alone interbody. (Levels = vertebra (i.e. percutaneous screws at L2, L3, L4 would be eligible for posterior instrumentation and/or L3-L4, L4-L5 would be eligible as stand-alone for interbodies)
   2. Posterior UIV and LIV must be placed percutaneously
   3. Single-position surgery ≥ 3 levels fused (Levels=vertebra; S1 is counted as a level; S2 &/or pelvis/ilium is not)
   4. Staged ≥ 3 levels fused with percutaneous pedicle screws
   5. 3 column osteotomy with percutaneous fixation
   6. ACR incorporating open or percutaneous fixation as long as UIV and LIV are percutaneous screws

Exclusion Criteria:

1. Deformity due to acute trauma
2. Active spine tumor or infection
3. Patient is unwilling or unable to complete questionnaires
4. Women who are pregnant
5. Prisoners
6. Open Posterior spinal fusion is planned (Open Anterior, i.e. ALIF, is acceptable)

Multi-center, prospective, non-randomized analysis of surgically treated complex adult spinal deformity (ASD) patients