Selective thoracolumbar fusion in adult spinal deformity double curves with circumferential minimally invasive surgery: 2-year minimum follow-up.

OBJECTIVE: Selection of the upper instrumented vertebra (UIV) level for adult spinal deformity (ASD) remains controversial. Although selective fusion attempts have been described for fractional curves or adolescent curves, no authors have described selective thoracolumbar fusion performance for ASD with double curves. This study evaluated the clinical impact of selective fusion constructs within the lower thoracic and/or lumbar spine on ASD with double curves. METHODS: A retrospective review was performed on an ASD (Cobb angle > 20°, sagittal vertical axis [SVA] > 50 mm, and pelvic incidence minus lumbar lordosis mismatch [PI-LL] > 10°) database consisting of 438 patients who underwent correction with circumferential minimally invasive surgery (CMIS) between 2007 and 2020. The inclusion criteria were ASD double curves (lumbar Cobb angle > 35° and thoracic Cobb angle > 30°), 4 or more levels fused, and minimum 2-year follow-up. Analyses were performed on spinopelvic data and clinical outcome scores. Complications were recorded, specifically the need for revision surgery and hardware-related complications. RESULTS: Twenty-one ASD double curve patients underwent selective correction with a mean ± SD (range) follow-up of 91 ± 43 (24-174) months. A total of 141 levels were fused with a mean of 6.7 ± 1.3 (4-8) levels. T10 was the most proximal and most common UIV (10/21 [48%]). Pelvic fixation was performed in 12 patients (57%). Significant improvements in lumbar Cobb angle, thoracic Cobb angle, coronal balance, lumbar lordosis, thoracic kyphosis, SVA, and PI-LL were achieved. The uninstrumented thoracic spine demonstrated 14.5° of mean coronal correction and a mean increase of 9.4° in kyphosis. Significant improvements in visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were observed. Four patients required revision for the following reasons: 1) superficial wound infection requiring irrigation and debridement; 2) bilateral L5 pars fractures requiring L5-S1 anterior lumbar interbody fusion and pelvic fixation; 3) adjacent-segment degeneration at L5-S1 requiring anterior lumbar interbody fusion and pelvic fixation; and 4) proximal junctional kyphosis requiring revision fusion to include the entire thoracic curve. There were no instances of hardware failure such as rod breakage or screw loosening. CONCLUSIONS: Selective thoracolumbar fusion with CMIS for ASD double curves can provide significant clinical improvements. Despite limiting fusion constructs to within the lower thoracic and/or lumbar spine, significant correction can be observed in the uninstrumented thoracic curve. The rate of mechanical complications was low, and the 2-year follow-up results suggested that limited fusion constructs are viable options for ASD double curve patients.

Do peri-operative parathyroid hormone (PTH) analogues improve bone density and decrease mechanical complications in spinal deformity correction?-a minimum 2-year radiological study measuring Hounsfield units.

OBJECTIVE: To delineate whether use of a PTH analogue in the 1-year peri-operative period improves lumbar bone density. METHODS: A prospectively collected data registry of 254 patients who underwent CMIS correction of ASD (Cobb angle > 20 or SVA > 50 mm or (PI-LL) > 10) from Jan 2011 to Jan 2020 was analysed. Patients who were placed on PTH analogues for one year in conjunction with surgery were included in the study. Ultimately, 41 patients who had pre- and two-year post-operative CT scans for review were included in this study. Hounsfield units were measured off of the L1-L3 levels for all patients before and after surgery on pre-op and post-op CT scans. RESULT: The mean age of patients in this study was 70 (52-84, SD 7). Mean follow-up was 66 (24-132, SD 33) months. Twenty-three patients met criteria for severe deformity (Cobb angle > 50 degrees or SVA > 95 mm or PI/LL mismatch > 20 or PT > 30). Based off 2-year post-op CT scan, there were significant improvements in L1 Hounsfield units when comparing pre-op values (96; SD 55) to post-op values (185 SD 102); p. < 0.05. There was no screw loosening or screw pull out. There were 2 patients with PJF (4.8%). Both these patients had not completed their PTH treatment: one only took PTH for 3 months (PJF at 2-year post-op) and the other one took it only for 1 month (PJF at 1-year post-op). No increase in bone density was noted (based off of Hounsfield units) in five patients (12%) despite completion of their PTH therapy. Only one patient experienced nausea from PTH therapy. There were no other PTH related adverse events. CONCLUSION: The incidence of PTH analogues failing to increase bone density in our series was low at 12%. This study shows that PTH analogues may be a powerful adjunct for increasing bone density and may help to mitigate the risk of mechanical complications in patients undergoing deformity correction with minimally invasive techniques. Future comparative studies are warranted to confirm these latter findings and to potentially protocolize the ideal peri-operative bone health optimization strategy.

Spinal Deformity Complexity Checklist for Minimally Invasive Surgery: Expert Consensus from the Minimally Invasive International Spine Study Group.

BACKGROUND: We developed a spinal deformity complexity checklist (SDCC) to assess the difficulty in performing a circumferential minimally invasive surgery (MIS) for adult spinal deformity. METHODS: A modified Delphi method of panel experts was used to construct an SDCC checklist of radiographic and patient-related characteristics that could affect the complexity of surgery via MIS approaches. Ten surgeons with expertise in MIS deformity surgery were queried to develop and refine the SDCC with 3 radiographic categories (x-ray, magnetic resonance imaging, computed tomography) and 1 patient-related category. Within each category, characteristics affecting MIS complexity were identified by initial roundtable discussion. Second-round discussion determined which characteristics substantially impacted complexity the most. RESULTS: Thirteen characteristics within the x-ray category were determined. Spinopelvic characteristics, endpoints of instrumentation, and prior hardware/fusion were associated with increased complexity. Vertebral body rotation-as reflected by the Nash-Moe grade-added significant complexity. Psoas anatomy and spinal stenosis added the most complexity for the 5 magnetic resonance imaging characteristics. There were 3 characteristics in the CT category with pre-exisiting fusion, being the variable most highly selected. Of the 5 patient-related characteristics, osteoporosis and BMI were found to most affect complexity. CONCLUSIONS: The SDCC is a comprehensive list of pertinent radiographic and patient-related characteristics affecting complexity level for MIS deformity surgery. The value of the SDCC is that it allows rapid assessment of key factors when determining whether MIS surgery can be performed effectively and safely. Patients with scores of 4 in any characteristic should be considered challenging to treat with MIS; open surgery may be a better alternative.

Does the Global Alignment and Proportion score predict mechanical complications in circumferential minimally invasive surgery for adult spinal deformity?

OBJECTIVE: The Global Alignment and Proportion (GAP) score was developed to serve as a tool to predict mechanical complication probability in patients undergoing surgery for adult spinal deformity (ASD), serving as an aid for setting surgical goals to decrease the prevalence of mechanical complications in ASD surgery. However, it was developed using ASD patients for whom open surgical techniques were used for correction. Therefore, the purpose of this study was to assess the applicability of the score for patients undergoing circumferential minimally invasive surgery (cMIS) for correction of ASD. METHODS: Study participants were patients undergoing cMIS ASD surgery without the use of osteotomies with a minimum of four levels fused and 2 years of follow-up. Postoperative GAP scores were calculated for all patients, and the association with mechanical failure was analyzed. RESULTS: The authors identified 182 patients who underwent cMIS correction of ASD. Mechanical complications were found in 11.1% of patients with proportioned spinopelvic states, 20.5% of patients with moderately disproportioned spinopelvic states, and 18.8% of patients with severely disproportioned spinopelvic states. Analysis with a chi-square test showed a significant difference between the cMIS and original GAP study cohorts in the moderately disproportioned and severely disproportioned spinopelvic states, but not in the proportioned spinopelvic states. CONCLUSIONS: For patients stratified into proportioned, moderately disproportioned, and severely disproportioned spinopelvic states, the GAP score predicted 6%, 47%, and 95% mechanical complication rates, respectively. The mechanical complication rate in patients undergoing cMIS ASD correction did not correlate with the calculated GAP spinopelvic state.

Prevalence and Modes of Posterior Hardware Failure With a Staged Protocol for Circumferential Minimally Invasive Surgical Correction of Adult Spinal Deformity: A 13-Year Experience.

BACKGROUND: One of the common complications of adult spinal deformity (ASD) correction is the failure to relieve pain. This may result from the failure of implanted hardware to provide adequate stabilization. While numerous studies exist, characterizing complications that can occur with minimally invasive correction of ASD and data regarding hardware failure in this setting are limited. OBJECTIVE: This article characterizes the rate and mode of posterior hardware failure in the setting of circumferential minimally invasive surgery (CMIS) for ASD correction. METHODS: Patients undergoing staged CMIS correction of ASD from January 2007 to September 2018 were identified. Patients with a minimum 2-year follow-up were included in the study. RESULT: A total of 263 patients (168 women and 95 men) were included in the study. The mean age of patients was 64 years (21-85, SD 13.7), and the mean length of follow-up was 90 months (24-164, SD 40.2). An average of 6 levels (3-16, SD 3.15) was fused per patient.Eight patients had a mechanical hardware failure and required revision surgery (3.04%). No catastrophic failures were noted in our series. Hardware failures were characterized as follows: 2 patients with broken screws, 5 patients with loose screws, and 1 patient who had symptomatic T12-L1 and L5-S1 nonunion with bilateral distal rod fractures, iliac set screw loosening, and proximal T12 screw loosening. Following revision surgery, all of these patients had confirmed solid fusion on computed tomography (CT) scan at their latest follow-up visit.Interestingly, 3 other patients had loosening of the set screw on their iliac bolts. Five patients had rod fractures between L5 and S1 or below S1. All 8 of these patients were asymptomatic with confirmed fusion at L5-S1 on CT scans. CONCLUSION: The prevalence of clinically significant hardware failure needing revision in our series was low at 3.04%. Symptomatic hardware prominence requiring revision was 2.3%. Specifically, rod fractures were not common (2.2%). Our study suggests that in the appropriately selected patient, CMIS to correct ASD without osteotomies may result in acceptable rates of hardware failure. Future studies should compare the results of CMIS deformity correction to a matched population of patients undergoing open deformity correction. CLINICAL RELEVANCE: This study suggests that in the appropriately selected patient, CMIS to correct ASD without osteotomies may result in acceptable rates of hardware failure.

Management of severe adult spinal deformity with circumferential minimally invasive surgical strategies without posterior column osteotomies: a 13-year experience.

OBJECTIVE: To evaluate the mid- to long-term clinical outcomes of circumferential minimally invasive surgery (CMIS) without posterior column osteotomies for severe adult spine deformity (ASD) correction. METHODS: All patients with a minimum of 2-year follow-up undergoing staged CMIS correction of ASD from January 2007 to July 2018 were identified. All included patients had fusion of 3 or more interbody levels that spanned the L5-S1 junction. Only patients with severe deformity, Coronal Cobb > 50° or at least one SRS-Schwab ++ sagittal modifier (SVA > 95 mm, or PI-LL > 20, or PT > 30) were included. All complications were noted. RESULT: 136 patients met inclusion criteria; mean age of patients was 63.6 years (21-85, SD 13.7). The mean follow-up was 82.8 months (24-159, SD 36.6). The mean number of levels fused was 7 (3-16, SD 3). A total of 40 (29.4%) major complications were noted at final follow-ups: 2 (1.4%) intra-operative, 12 (8.9%) peri-operative (≤ 6 weeks from index), 26 (19.1%) post-operative (> 6 weeks from index). There was a total of 53 (40.0%) minor complications. Seven (5.1%) patients who developed radiographic proximal junctional kyphosis. Three patients (2.2%) developed proximal junctional failure. There were 8 (5.9%) cases of pseudarthrosis. Five of these occurred in patients undergoing AxiaLIF. All patients experienced improvements in patient-perceived outcomes (VAS, TIS, ODI, and SRS-22) and radiographic parameters at last follow-up when compared to pre-op (p < 0.05). CONCLUSION: Rates of complications with CMIS correction of severe ASD are lower than published rates of complications seen with open ASD correction. Specifically, the incidence of catastrophic complications is lower. Furthermore, CMIS is associated with significant improvements in clinical and functional outcomes, low rates of pseudarthrosis and proximal junctional kyphosis. Therefore, in the appropriately selected patient, CMIS may be an excellent alternative approach to addressing severe ASD.

The prevalence of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in patients undergoing circumferential minimally invasive surgical (cMIS) correction for adult spinal deformity: long-term 2- to 13-year follow-up.

OBJECTIVES: This aim of this study is to evaluate the prevalence of PJK and PJF in patients who underwent circumferential minimally invasive surgery (cMIS) for ASD. METHODS: A prospective database of patients who underwent cMIS correction of ASD from November 2006 to July 2018 was queried. PJK was defined as angle > 10° and at least 10° greater than the baseline when measuring UIV to UIV + 2. PJF was defined as any type of symptomatic PJK which required surgery. Pre-op, latest and delta SVA and PI-LL mismatch were compared between patients with PJK and without. Only patients instrumented at 4 or more levels with full length 36″ films and a minimum 2-year follow-up were included. RESULTS: A total of 184 patients met inclusion criteria for this study. Mean follow-up time was 85.2 months (24-158.9 months, SD 39.1). Mean age was 66 years (22-85 years). The mean number of operated levels was 6.9 levels (4-16 levels, SD 2.8). A total of 21 patients (10.8%) met PJK criteria. Only 10 (4.9%) were symptomatic (PJF) and underwent revision surgery. The other 11 patients remained asymptomatic. Comparing PJK to non-PJK patients, there was no statistically significant difference in the post-op SVA, delta SVA, post-op PI/LL and delta PI/LL between the two groups. CONCLUSION: Our study would suggest that in the appropriately selected and well-optimized patient, CMIS deformity correction is associated with a low prevalence of PJK and PJF.

Analysis of Spino-Pelvic Parameters and Segmental Lordosis with L5-S1 Oblique Lateral Interbody Fusion at the Bottom of a Long Construct in Circumferential Minimally Invasive Surgical Correction of Adult Spinal Deformity.

BACKGROUND: Lateral interbody fusion (LIF) is an effective adjuvant for circumferential minimally invasive surgery (CMIS) treatment of adult spinal deformity (ASD). Accessing L5-S1 via an oblique LIF (OLIF) approach (OLIF 5-1) allows for anterior LIF (ALIF) at the lumbosacral junction without repositioning the patient. We review the early outcomes and complications of OLIF 5-1 at the bottom of a long construct for an MIS approach to treat ASD. METHODS: We queried a prospectively collected registry of 111 consecutive patients with ASD (Cobb angle >20°, sagittal vertical alignment [SVA] >50, or pelvic incidence [PI]-lumbar lordosis [LL] mismatch>10) patients who underwent CMIS correction between January 2015 and January 2019. Sixty patients had ≥4 levels fused and OLIF 5-1. Multilevel pre-psoas LIF + OLIF 5-1 were performed in the first stage. Three days later, stage 2 involved MIS installation of pedicle screws with aggressive rod contouring and derotation/translation. RESULTS: The mean patient age was 66.8 years (range, 48-79 years), and the mean duration of follow-up was 24 months (range, 3-60 months). A mean of 7 levels were fused (range, 4-9). Significant improvements in L5-S1 segmental lordosis (SL), LL, SVA, PI-LL mismatch, and pelvic tilt were seen following the first stage (P < 0.05). There was no intraoperative vascular, ureteral, or sympathetic chain injury, and no transient or permanent lumbar plexopathy. In 2 patients, OLIF 5-1 was abandoned due to difficult access, and transforaminal LIF was done at L5-S1 at the second stage. Five patients required intraoperative transfusion. No patient experienced postoperative ileus or L5-S1 pseudarthrosis. Significant improvements in visual analog scale pain score, Oswestry Disability Index, 36-Item Short Form Health Survey, and Scoliosis Research Society Outcomes Questionnaire were found. CONCLUSIONS: A single-position MIS OLIF 5-1 at the bottom of a long construct in conjunction with multilevel pre-psoas LIF seems to be a safe and effective technique for improving SL, global LL, and SVA with a low risk of perioperative and postoperative complications.

The Influence of Lordotic cages on creating Sagittal Balance in the CMIS treatment of Adult Spinal Deformity.

BACKGROUND: CMIS techniques are heavily dependent on placement of lateral interbody cages. Cages with an increased lordotic angle are being advocated to improve segmental lordosis and SVA. We assessed the segmental lordosis achieved with the individual cages. We further studied three variables and the effect each had on segmental lordosis: the lordosis angle of the cage, the position of the cage in the intervertebral space, and the level that it has been placed. METHODS: This is a retrospective study of 66 consecutive patients who underwent lateral interbody fusion using lordotic cages as part of CMIS correction of scoliosis from June 2012 to January 2016. Standing radiographs at pre op and 6-week follow-up were reviewed to identify the position of the cage in the intervertebral space and the amount of segmental lordosis achieved. RESULTS: A total of 224 cages were placed. The 6°, 10°, 12°, and 20° cages achieved a mean segmental lordosis of 9.00°, 13.09°, 13.23°, and 18.32°, respectively (P < .05). Additionally, cages placed in the anterior, middle, and posterior 3rd of the disk space produced 13.02°, 11.47°, and 8.23° of lordosis, respectively (P < .05). Stratifying by level, cages placed at T12-L1, L1-2, L2-3, L3-4, and L4-5 translated to mean segmental lordotic values of 8.43°, 10.02°, 11.38°, 12.91°, and 14.58°, respectively (P < .05). CONCLUSIONS: The angle of the cage had an impact on segmental lordosis. Achieved segmental lordosis was notably more when the cage was placed in lower lumbar levels. Additionally, cages placed in the posterior 3rd of the intervertebral space had significantly worse segmental lordosis compared to those placed in the anterior or middle 3rd. Our study shows that an average delta change of 8.03° can be achieved with 12° cages and this when done at each subsequent level results in a progressive harmonious creation of lordosis. IRB approval was obtained for this study.

Comparison of a Newer Versus Older Protocol for Circumferential Minimally Invasive Surgical (CMIS) Correction of Adult Spinal Deformity (ASD)-Evolution Over a 10-Year Experience.

STUDY DESIGN: Retrospective. OBJECTIVES: Compare circumferential minimally invasive surgical (CMIS) correction outcomes of patients treated for adult spinal deformity (ASD) with a newer versus older protocol SUMMARY OF BACKGROUND DATA: CMIS techniques have become increasingly popular. Increasing experience and learning curve may help improve outcomes. METHODS: A prospectively collected database was queried for all patients who underwent CMIS correction of ASD (Cobb angle >20° or sagittal vertical axis [SVA] >50 mm or pelvic incidence-lumbar lordosis mismatch >10) at 3+ levels. Those without a full-length radiograph or 2-year follow-up were excluded. Patients were compared based on treatment using our original or newer protocol. RESULTS: The original protocol had 76 patients with an average age of 66.99 years (range 46-81, standard deviation [SD] 9.03), and the new protocol had 53 patients with average age of 65.85 years (range 48-85, SD 8.08). Preoperative and latest visual analog scale (VAS) scores in the original were 6.85 and 3.45 (p = .001) and in the new were 6.19 and 2.27 (p = .004). Delta-VAS scores were 3.27 and 4.27. The Oswestry disability index (ODI) reduced from 45.84 to 32.91 (p = .041) in the original and from 44.21 to 25.39 (p = .017) in the new. Average delta-ODIs were 22.25 and 24.01. Preoperative, latest, and delta-SF physical component scores for the original were 35.38, 42.42, and 10.06 and for the new, 30.89, 39.49, and 11.93. SF mental component scores were 50.96, 55.19, and 12.84 and 50.12, 52.99, and 8.85. The original and new protocols had latest Cobb angles of 11.54° and 11.12° (p = .789), delta-Cobb angles of 14.51° and 20.03° (p < .05), latest SVAs of 42.85 and 30.58 mm (p < .05) and latest PI-LL mismatch of 15.49 and 9.00 mm (p < .05). In the original and the new, the average preoperative SVAs that reliably achieved a postoperative SVA of 50 mm or less were 84 and 119 mm, respectively, and the maximum delta-SVAs were 89 and 120 mm. The new protocol had fewer surgical complications (p < .05). CONCLUSION: Improvements in radiographic scores, functional outcomes, and limits of SVA correction and lower complication rates suggest that the new protocol may help improve outcomes. These findings may be a reflection of our 10-year experience and advances in the learning curve. LEVEL OF EVIDENCE: Level IV.

Thirty-Day Reoperation and Readmission Rates After Correction of Adult Spinal Deformity via Circumferential Minimally Invasive Surgery-Analysis of a 7-Year Experience.

STUDY DESIGN: Single-center retrospective analysis of consecutive patients who have undergone circumferential minimally invasive surgery (cMIS) for correction of adult spinal deformity (ASD). OBJECTIVES: To study the rates of reoperations and readmissions within the first 30 days following cMIS for correction of ASD. BACKGROUND: Hospital readmission and reoperation rates have been emphasized as an important measure of quality and cost-effectiveness of care. However, there is little information about the readmission rates following cMIS correction of ASD. METHODS: This is a retrospective cohort study of 214 consecutive patients with ASD who underwent correction using cMIS involving at least 2 levels. Major complications encountered during surgery or within 30 days following the index procedure that needed reoperation or readmission were recorded. The primary outcomes measured were early readmission, and early reoperation. RESULTS: An average of 4 levels were fused. Nineteen complications were noted in the 30-day period following the index surgery, giving an early complication rate of 8.9%. Twelve of those complications occurred during the initial hospitalization and 7 complications occurred after the patient had been discharged home. Forty-seven percent of the complications occurred within the first 3 years of our experience, 37% in the next 2 years, and only 16% in the following 3 years. The 30-day readmission rate was 3.3%, which showed no statistically significant difference based on the number of levels fused. CONCLUSIONS: Our study delivers significant evidence that efforts to reduce hospital readmissions for ASD patients should begin by concentrating on the postoperative complications. Although minimally invasive approaches will not eliminate all complications, they may have an effect on reducing the rate of major complications, most notably the rate of postoperative infection. This in turn can lead to a substantially lower readmission and reoperation rate as is reported in our study. LEVEL OF EVIDENCE: Level IV, case series.

Evidence basis/outcomes in minimally invasive spinal scoliosis surgery.

Traditional adult scoliosis surgery is associated with long-term patient improvement in clinical and radiographic outcome measures, significant blood loss, and high likelihood of medical complications. Because the patient population undergoing adult scoliosis surgery is often elderly with medical comorbidities, minimally invasive spinal surgery (MISS) for adult scoliosis is theoretically appealing, because it is associated with less tissue trauma and reduced blood loss. Nevertheless, limitations exist with current techniques as far as the achievable degree of coronal and sagittal plane deformity correction. MISS scoliosis correction is reviewed, specifically regarding outcomes and complications. Limitations of current techniques and future directions are discussed.

Long-term 2- to 5-year clinical and functional outcomes of minimally invasive surgery for adult scoliosis.

STUDY DESIGN: A retrospective study. OBJECTIVE: We assess MIS technique's clinical and functional outcomes during a 2- to 5-year period. SUMMARY OF BACKGROUND DATA: Traditional surgical approaches for adult scoliosis are associated with significant blood loss and morbidity, in a population that is often elderly with multiple medical comorbidities. Minimally invasive surgery (MIS) represents a newer method of achieving similar long-term outcomes but considerably lower morbidity and complication rates. METHODS: We reviewed 71 patients who underwent MIS correction of spinal deformity with fusion of 2 or more levels including: degenerative scoliosis (54), idiopathic scoliosis (11), and iatrogenic scoliosis (6). All underwent a combination of 3 MIS techniques: direct lateral interbody fusion (66), axial lumbar interbody fusion (34), and posterior instrumentation (67). Thirty-six patients were staged with direct lateral interbody fusion done first followed by the posterior instrumentation and fusion including axial lumbar interbody fusion done 3 days later. RESULTS: Mean age was 64 years (20-84 yr). Mean follow-up was 39 months (24-60 mo). Patients with 1-stage same-day surgery had a mean blood loss of 412 mL and a mean surgical time of 291 minutes. Patients with 2-stage surgery had a mean blood loss of 314 mL and surgical time of 183 minutes for direct lateral interbody fusion and 357 mL and 243 minutes, respectively for posterior instrumentation and axial lumbar interbody fusion. Mean hospital stay was 7.6 days (2-26 d). The mean preoperative Cobb angle was 24.7° (8.3°-65°), which corrected to 9.5° (0.6°-28.8°). Mean preoperative Coronal balance was 25.5 mm, which corrected to 11 mm. Mean preoperative sagittal balance was 31.7 mm and corrected to 10.7 mm. The mean preoperative lumbar apical vertebral translation was 24 mm and corrected to 12 mm. Fourteen patients had adverse events requiring intervention: 4 pseudarthrosis, 4 persistent stenosis, 1 osteomyelitis, 1 adjacent segment discitis, 1 late wound infection, 1 proximal junctional kyphosis, 1 screw prominence, 1 idiopathic cerebellar hemorrhage, and 2 wound dehiscence. CONCLUSION: A combination of 3 novel MIS techniques allows comparable correction of adult spinal deformity, with low pseudarthrosis rates, significantly improved functional outcomes, and excellent clinical and radiological improvement, but considerably lowers morbidity and complication rates at early and long-term follow-up.