Proximal junctional failure in primary thoracolumbar fusion/fixation to the sacrum/pelvis for adult symptomatic lumbar scoliosis: long-term follow-up of a prospective multicenter cohort of 160 patients

The association between lower Hounsfield units of the upper instrumented vertebra and proximal junctional failure after limited lumbar fusion for adult spinal deformity

BACKGROUND

Limited lumbar fusion surgery for adult spinal deformity (ASD) increases the risk of proximal junctional failure (PJF) at the thoracolumbar junction due to preserved mobility in this region. The majority of the extant research on PJF focuses on cases where the upper instrumented vertebra (UIV) is in the thoracic spine, whereas the aim of this study was to evaluate the correlation between Hounsfield Unit (HU) values around the thoracolumbar junction and the incidence of PJF following limited lumbar fusion.

METHODS

A retrospective review identified patients aged ≥ 40 years who underwent fusion surgery spanning ≥ 3 levels with a UIV in the upper lumbar spine (L1-L3) and had a follow-up of at least two years. Demographic data, surgical factors, and spinopelvic parameters were analyzed. HU values were measured at the UIV, UIV + 1, and lower instrumented vertebra and were assessed for their association with PJF.

RESULTS

Of 50 patients, 46 were included after excluding 4 who required reoperation for distal junctional failure. The mean age was 65.9 years, with a mean follow-up of 6.3 years. PJF was observed in 17 patients (36.9%). While most demographic and surgical factors were similar between groups, age was significantly associated with PJF (p = 0.024). Preoperative parameters significantly differed, including PT (p = 0.011), PI-LL (p = 0.010), SVA (p = 0.008), and HU at UIV/UIV + 1 (p = 0.006). Postoperative differences included PT (p = 0.007), PI-LL (p = 0.005), proximal junctional angle (p = 0.021), SVA (p = 0.021), and the global alignment and proportion (GAP) score (p = 0.001). Logistic regression identified low HU at UIV/UIV + 1 as the only independent PJF risk factor (OR: 0.975, 95% CI: 0.950-0.996, p = 0.016), with a cutoff value of 97.8 HU (AUC = 0.745, p = 0.022). PJF rates were 73.3%, 26.7%, and 12.5% for patients with HU < 98, 98-134, and > 134, respectively.

CONCLUSION

Preoperative low HU values at UIV/UIV + 1 independently predict PJF risk. HU assessment via preoperative CT imaging offers a critical tool for surgical planning in ASD limited lumbar fusion cases.

CLINICAL TRIAL NUMBER

Not applicable.

Operative vs Nonoperative Treatment for Adult Symptomatic Lumbar Scoliosis at 8-Year Follow-Up: A Nonrandomized Clinical Trial

Importance

Long-term follow-up studies of operative and nonoperative treatment of adult symptomatic lumbar scoliosis (ASLS) are needed to assess benefits and durability.

Objective

To assess the durability of treatment outcomes for operative vs nonoperative treatment of ASLS.

Design, Setting, and Participants

The Adult Symptomatic Lumbar Scoliosis 1 (ASLS-1) study was a multicenter, prospective study with randomized and observational cohorts designed to assess operative vs nonoperative ASLS treatment. Operative and nonoperative patients were compared using as-treated analysis of combined randomized and observational cohorts. Patients with ASLS aged 40 to 80 years were enrolled at 9 centers in North America. Data were analyzed from November 2023 to July 2024.

Interventions

Operative and nonoperative treatment approaches.

Main Outcomes and Measures

Primary outcomes measures were the Oswestry Disability Index (ODI) and Scoliosis Research Society 22 (SRS-22) at 2-, 5-, and 8-year follow-up.

Results

The 286 enrolled patients (104 in the nonoperative group: median [IQR] age, 61.9 [54.4-68.8] years; 97 female [93%]; 182 in the operative group: median [IQR] age, 60.2 [53.5-66.6] years; 161 female [88%]) had follow-up rates at 2, 5, and 8 years of 90% (256 of 286), 70% (199 of 286), and 72% (205 of 286), respectively. At 2 years, compared with those in the nonoperative group, patients in the operative group had better ODI (mean difference = -12.98; 95% CI, -16.08 to -9.88; P < .001) and SRS-22 (mean difference = 0.57; 95% CI, 0.45-0.70; P < .001) scores, with mean differences exceeding the minimal detectable measurement difference (MDMD) for ODI (7) and SRS-22 (0.4). Mean differences at 5 years (ODI = -11.25; 95% CI, -15.20 to 7.31; P <.001; SRS-22 = 0.58; 95% CI, 0.44-0.72; P < .001) and 8 years (ODI = -14.29; 95% CI, -17.81 to -10.78; P <.001; SRS-22 = 0.74; 95% CI, 0.57-0.90; P < .001) remained as favorable as at 2 years without evidence of degradation. The treatment-related serious adverse event (SAE) incidence rates for operative patients at 2, 2 to 5, and 5 to 8 years were 22.24, 9.08, and 8.02 per 100 person-years, respectively. At 8 years, operative patients with 1 treatment-related SAE still had significant improvement, with mean treatment differences that exceeded MDMD (ODI = -9.49; 95% CI, -14.23 to -4.74; P < .001; SRS-22 = 0.62; 95% CI, 0.41-0.84; P < .001).

Conclusions and Relevance

Results of this nonrandomized clinical trial reveal that, on average, operative treatment for ASLS provided significantly greater clinical improvement than nonoperative treatment at 2-, 5- and 8-year follow-up, with no evidence of deterioration. Operative patients with a treatment-related SAE still maintained greater improvement than nonoperative patients. These findings suggest long-term durability of surgical treatment for ASLS and may prove useful for patient management and counseling.

Trial Registration

ClinicalTrials.gov Identifier: NCT00854828.

Anterior column realignment better restores sagittal alignment but carries higher risk of mechanical failures than lateral lumbar interbody fusion in patients with degenerative sagittal imbalance

BACKGROUND OF CONTEXT

Anterior column realignment (ACR), a modified lateral lumbar interbody fusion (LLIF), is an emerging, less invasive technique that allows greater lordosis correction by releasing anterior longitudinal ligament. However, long-term results have been poorly documented with regard to mechanical failure, such as proximal junctional kyphosis (PJK) and rod fracture (RF), and clinical outcomes.

PURPOSE

To compare the outcomes, primarily mechanical failure, in patients with degenerative sagittal imbalance (DSI) treated with ACR versus LLIF alone.

STUDY DESIGN/SETTING

Retrospective study.

PATIENT SAMPLE

Patients ≥60 years of age; severe DSI defined by pelvic incidence (PI) - lumbar lordosis (LL) ≥20°; performance of ≥2-level LLIF; and ≥5 total fused levels including the sacrum.

OUTCOME MEASURES

Mechanical failure such as PJK and RF; radiographic results; clinical outcomes METHODS: Enrolled patients were divided into two groups, based on whether their anterior reconstruction was accomplished with ACR or LLIF alone: ACR and LLIF groups. Mechanical failures were compared between the two groups as a composite outcome including PJK and /or RF. PJK was defined as proximal junctional angle (PJA) >28° and Δ PJA >22°. Only RFs developing at the level with corresponding procedures (ACR or LLIF) were included in the analysis. Logistic regression was performed to compare the relative risk of mechanical failure between the ACR and LLIF groups. The radiographic and clinical outcomes were also compared between the groups.

RESULTS

The final study cohort consisted of 210 patients. The mean age was 69.6 years, and there were 190 females (90.5%). There were 124 patients in the ACR group and 86 patients in the LLIF group. Perioperative changes for all sagittal parameters were significantly greater in the ACR group than in the LLIF group. Overall mechanical failure rates were significantly higher in the ACR group than in the LLIF group (32.3% vs 14.0%, p=.003). Multivariate regression analysis with adjusting potential confounders revealed that ACR carried a significantly higher risk of mechanical failure than LLIF (Odds ratio=5.6, 95% confidence interval=2.0-15.6, p<.001). The final clinical outcomes were worse in the ACR group than in the LLIF group.

CONCLUSION

ACR restored the sagittal malalignment more powerfully than did LLIF. However, compared to the LLIF, ACR was associated with a greater risk of mechanical failures and revision surgery. The final clinical outcomes in the ACR group were inferior to those in the LLIF group. Therefore, ACR should be left as a last resort for the cases where it is expected that an adequate correction cannot be achieved using LLIF alone. If ACR has to be performed, it is necessary to establish feasible surgical strategies to avoid mechanical failures.

Immediate Postoperative Change in the Upper Instrumented Screw-Vertebra Angle is a Predictor for Proximal Junctional Kyphosis and Failure

STUDY DESIGN

Retrospective review.

OBJECTIVES

To determine if change in position of upper instrumented vertebral (UIV) screw between intraoperative prone and immediate postoperative standing radiographs is a predictor for proximal junctional kyphosis or failure (PJK/PJF).

SUMMARY OF BACKGROUND DATA

Cranially directed UIV screws on postoperative radiographs have been found to be associated with PJK. Change in the screw position between intraoperative and immediate postoperative radiographs has not been studied.

MATERIALS AND METHODS

Patients with posterior fusion greater than or equal to three levels and UIV at or distal to T8, and minimum two-year follow-up were identified from a single-center database. Primary outcomes were radiographic PJK/PJF or revision for PJK/PJF. Demographic, surgical, and radiographic variables, including intraoperative screw-vertebra (S-V) angle, change in S-V angle, direction of UIV screw (cranial-neutral-caudal), and rod-vertebra (R-V) angle were collected.

RESULTS

Totally, 143 cases from 110 patients were included with a mean age of 62.9 years and a follow-up of 3.5 years. Fifty-four (38%) cases developed PJK/PJF, of whom 30 required a revision. Mean S-V angle was -0.9°±5.5° intraoperative and -2.8°±5.5° postoperative. The group with PJK/PJF had a mean S-V angle change of -2.5°±2.4 while the rest had a change of -1.0°±1.6 ( P =0.010). When the change in S-V angle was <5°, 33% developed PJK, this increased to 80% when it was ≥5° ( P =0.001). Revision for PJK/PJF increased from 16% to 60% when S-V angle changed ≥5° ( P =0.001). Regression analysis showed S-V angle change as a significant risk factor for PJK/PJF ( P =0.047, OR=1.58) and for revision due to PJK/PJF ( P =0.009, OR=2.21).

CONCLUSIONS

Change in the S-V angle from intraoperative prone to immediate postoperative standing radiograph is a strong predictor for PJK/PJF and for revision. For each degree of S-V angle change, odds of revision for PJK/PJF increases by x2.2. A change of 5° should alert the surgeon to the likely development of PJK/PJF requiring revision.

LEVEL OF EVIDENCE

Level II.

Hook Fixation at Uppermost Instrumented Vertebra +1 Reduced Proximal Junctional Failure in Adult Patients With Spinal Deformity Having Achieved Optimal Deformity Correction by Sagittal Age-Adjusted Score

BACKGROUND AND OBJECTIVES

Appropriate correction relative to the age-adjusted sagittal alignment target reduces the proximal junctional failure (PJF) risk. Nonetheless, a considerable number of patients suffer from PJF despite optimal correction. The aim of this study was to identify the risk factors of PJF that occurs despite optimal correction relative to the sagittal age-adjusted score (SAAS) in adult spinal deformity surgery.

METHODS

Patients aged 60 years or older with adult spinal deformity who underwent ≥5-level fusion to the sacrum were initially screened. Among them, only patients who achieved optimal sagittal correction relative to the SAAS were included in the study. Optimal correction was defined as the SAAS point between -1 and +1. Various clinical and radiographic factors were compared between the PJF and no PJF groups and were further evaluated using multivariate analysis.

RESULTS

The final study cohort comprised 127 patients. The mean age was 67 years, and there were 111 women (87.4%). A mean of total fusion length was 7.2. PJF occurred in 42 patients (33.1%), while 85 patients (66.9%) did not develop PJF. Multivariate analysis showed that a high body mass index (odds ratio [OR] = 1.153, 95% CI = 1.027-1.295, P = .016), a higher lordosis distribution index (LDI) (OR = 1.024, 95% CI = 1.003-1.045, P = .022), and no use of hook fixation (OR = 9.708, 95% CI = 1.121-76.923, P = .032) were significant risk factors of PJF development. In the receiver operating characteristic curve analysis, the cutoff value for the LDI was calculated as 61.0% (area under the curve = 0.790, P < .001).

CONCLUSION

PJF developed in a considerable portion of patients despite optimal correction relative to the age-adjusted alignment. The risk factors of PJF in this patient group were high body mass index, high LDI exceeding 61%, and no use of hook fixation. PJF could be further decreased by properly managing these risk factors along with optimal sagittal correction.

Proximal Junctional Degeneration and Failure Modes: A Novel Classification and Clinical Implications

STUDY DESIGN

Case-control study.

OBJECTIVE

To introduce a classification system that will include the major types of degenerative changes and failures related to the proximal junction, and to determine the clinical course and characteristics for the different types of proximal junctional degeneration.

BACKGROUND

Proximal junctional kyphosis and failures are well recognized after adult spinal fusion; however, a standardized classification is lacking.

MATERIALS AND METHODS

The proposed system identified 4 different patterns of proximal junctional degeneration: (1) Type 1 (multilevel symmetrical collapse), (2) Type 2 (single adjacent level collapse), (3) Type 3 (fracture), and (4) Type 4 (spondylolisthesis). A single-center database was reviewed from 2018 to 2021. Patients 18 years or older of age, who underwent posterior spinal fusion of ≥3 levels with an upper instrumented vertebral level between T8 and L2, and a follow-up of ≥2 years were included. Radiographic measurements, revision surgery, and time to revision were the primary outcomes.

RESULTS

One hundred fifty patients were included with a mean age of 65.1 (±9.8) years and a mean follow-up of 3.2 (±1) years. Sixty-nine patients (46%) developed significant degenerative changes in the proximal junction and were classified accordingly. Twenty (13%) were type 1, 17 (11%) were type 2, 22 (15%) were type 3, and 10 (7%) were type 4. Type 3 had a significantly shorter time to revision with a mean of 0.9 (±0.9) years. Types 3 and 4 had greater preoperative sagittal vertical axis, and types 1 and 3 had greater final follow-up lumbar lordosis. Bone density measured by Hounsfield units showed lower measurements for type 3. Types 1 and 4 had lower rates of developing proximal junctional kyphosis. Type 1 had the lowest revision rate with 40% (types 2, 3, and 4 were 77%, 73%, and 80%, respectively, P = 0.045).

CONCLUSION

This novel classification system defines different modes of degeneration and failures at the proximal junction, and future studies with larger sample sizes are needed for validation.

LEVEL OF EVIDENCE

Level III.

How Good Are Surgeons at Achieving Their Preoperative Goal Sagittal Alignment Following Adult Deformity Surgery?

STUDY DESIGN

Multicenter, prospective cohort.

OBJECTIVES

Malalignment following adult spine deformity (ASD) surgery can impact outcomes and increase mechanical complications. We assess whether preoperative goals for sagittal alignment following ASD surgery are achieved.

METHODS

ASD patients were prospectively enrolled based on 3 criteria: deformity severity (PI-LL ≥25°, TPA ≥30°, SVA ≥15 cm, TCobb≥70° or TLCobb≥50°), procedure complexity (≥12 levels fused, 3-CO or ACR) and/or age (>65 and ≥7 levels fused). The surgeon documented sagittal alignment goals prior to surgery. Goals were compared with achieved alignment on first follow-up standing radiographs.

RESULTS

The 266 enrolled patients had a mean age of 61.0 years (SD = 14.6) and 68% were women. Mean instrumented levels was 13.6 (SD = 3.8), and 23.2% had a 3-CO. Mean (SD) offsets (achieved-goal) were: SVA = -8.5 mm (45.6 mm), PI-LL = -4.6° (14.6°), TK = 7.2° (14.7°), reflecting tendencies to undercorrect SVA and PI-LL and increase TK. Goals were achieved for SVA, PI-LL, and TK in 74.4%, 71.4%, and 68.8% of patients, respectively, and was achieved for all 3 parameters in 37.2% of patients. Three factors were independently associated with achievement of all 3 alignment goals: use of PACs/equivalent for surgical planning (P < .001), lower baseline GCA (P = .009), and surgery not including a 3-CO (P = .037).

CONCLUSIONS

Surgeons failed to achieve goal alignment of each sagittal parameter in ∼25-30% of ASD patients. Goal alignment for all 3 parameters was only achieved in 37.2% of patients. Those at greatest risk were patients with more severe deformity. Advancements are needed to enable more consistent translation of preoperative alignment goals to the operating room.

Lumbar pedicle subtraction osteotomy: techniques and outcomes

Pedicle subtraction osteotomy has been thoroughly described and studied over the past 2 decades, being applied mainly in the lumbar spine, followed by the thoracic spine. Our better understanding of alignment biomechanics, and the progressive refinements of the surgical technique over time made it a very efficient procedure for the management of fixed sagittal malalignment. However, a long learning curve is mandatory to mitigate the associated risks particularly neurological deficits and achieve satisfactory clinical and radiological outcomes with an acceptable rate of complications.

Different characteristics between acute and delayed proximal junctional failure in elderly patients undergoing corrective surgery for adult spinal deformity: comparative analysis of risk factor, failure mode, and clinical consequences

BACKGROUND CONTEXT

While numerous studies have been conducted on proximal junctional failure (PJF), the clinical significance of acute and delayed PJF remains poorly understood.

PURPOSE

The primary object of this study is to investigate the risk factors separately for acute and delayed PJF. Secondly, we aim to assess the incidence of each failure mode and their clinical consequences in relation to acute and delayed PJF.

STUDY DESIGN/SETTING

Retrospective comparative study.

PATIENT SAMPLE

Patients aged ≥60 years who underwent deformity correction with ≥5-level fusion to sacrum.

OUTCOME MEASURES

Risk factor, failure modes, and patient-reported outcome measure (PROM).

METHODS

Acute PJF is defined as PJF occurring within 6 months, while delayed PJF occurring after 6 months. Risk factors were analyzed by comparing various clinical and radiographic parameters among 3 groups: no, acute, and delayed PJF groups. The failure modes, including soft tissue failure, vertebral fracture, fixation failure, and myelopathy, were compared among these groups. The clinical subsequences after PJF development were evaluated by assessing the change in proximal junctional angle (PJA), revision rate, and patient-reported outcome measure (PROM).

RESULTS

A study cohort of 363 patients was included in the analysis. Among them, 156 patients experienced PJF, with 87 patients (55.8%) in the acute PJF group and 69 patients (44.2%) in the delayed PJF group. Multivariate analyses showed that older age (Odds ratio [OR] = 1.057, 95% confidence interval [CI] = 1.002-1.118), osteoporosis (OR=2.149, 95% CI = 1.074-4.300), high American Society of Anesthesiology ASA score (OR=2.150, 95% CI = 1.089-4.245), and overcorrection relative to the age-adjusted pelvic incidence - lumbar lordosis target (OR=4.031, 95% CI = 1.962-8.280) were identified as risk factors for the development of acute PJF. On the other hand, a high body mass index (OR=1.150, 95% CI = 1.049-1.251) and an uppermost instrumented vertebra located at ≤T10 (OR=2.267, 95% CI = 1.205-4.268) were found to be associated with delayed occurrence of PJF. No radiographic parameters were found to be related to the development of delayed PJF. In terms of failure modes, vertebral fracture and fixation failure were more commonly observed in acute PJF, while soft tissue failure and myelopathy were more predominant in delayed PJF. The clinical course was more aggressive in the acute PJF group compared to the delayed PJF group, as evidenced by a greater increase in PJA, a higher revision rate, and worse PROM.

CONCLUSIONS

This study demonstrated different risk factors between the acute and delayed PJF. It was found that overcorrection relative to the age-adjusted PI-LL target increased the risk of acute PJF, but had no impact on the development of delayed PJF. Therefore, a different surgical strategy needs to be established to mitigate both acute and delayed PJF.

Proximal junctional kyphosis after adult spinal deformity operated patients with long fusion to the pelvis. Does the type of proximal anchor matter?

PURPOSE

To assess, in a large population of Adult Spinal Deformity (ASD) patients, the true interest of varying the upper anchors as a protective measure against Proximal Junctional Kyphosis (PJK), by analyzing and comparing 2 groups of patients defined according to their proximal construct. Another objective of the study is to look for any other factors, radiological or clinical, that would affect the occurrence of the proximal failure.

METHODS

Retrospective review of a prospective ASD database collected from 5 centers. Inclusion criteria were age of at least 18 years, presence of a spinal deformity with instrumentation from T12 or above to the pelvis, with minimum 2 years of follow-up. Demographic data, spinopelvic parameters, functional outcomes and complications were collected. Multiple logistic regression analysis was performed to identify the risk factors that would affect the occurrence of PJK.

RESULTS

254 patients were included. 166 in the group "screws proximally" (SP) and 88 in the group "hooks proximally" (HP). There was no difference between both groups for PJK (p = 0.967). The occurrence of PJK was rather associated with greater age and BMI, higher preoperative kyphosis, worst preoperative SRS22 and SF36 scores, greater postoperative Sagittal Vertical Axis (SVA), coronal malalignment and kyphosis.

CONCLUSION

The use of proximal hooks was not effective to prevent PJK after ASD surgery, when compared to proximal screws. Worse preoperative functional outcomes and worse postoperative sagittal and also coronal malalignment were the main drivers for the occurrence of PJK regardless the type of proximal implant.

Early Experience with Prone Lateral Interbody Fusion in Deformity Correction: A Single-Institution Experience

Background/Objectives: Lateral spine surgery offers effective minimally invasive deformity correction, but traditional approaches often involve separate anterior, lateral, and posterior procedures. The prone lateral technique streamlines this process by allowing single-position access for lateral and posterior surgery, potentially benefiting from the lordosing effect of prone positioning. While previous studies have compared prone lateral to direct lateral for adult degenerative diseases, this retrospective review focuses on the outcomes of adult deformity patients undergoing prone lateral interbody fusion. Methods: Ten adult patients underwent single-position prone lateral surgery for spine deformity correction, with a mean follow-up of 18 months. Results: Results showed significant improvements: sagittal vertical axis decreased by 2.4 cm, lumbar lordosis increased by 9.1°, pelvic tilt improved by 3.3°, segmental lordosis across the fusion construct increased by 12.2°, and coronal Cobb angle improved by 6.3°. These benefits remained consistent over the follow-up period. Correlational analysis showed a positive association between improvements in PROs and SVA and SL. When compared to hybrid approaches, prone lateral yielded greater improvements in SVA. Conclusions: Prone lateral surgery demonstrated favorable outcomes with reasonable perioperative risks. However, further research comparing this technique with standard minimally invasive lateral approaches, hybrid, and open approaches is warranted for a comprehensive evaluation.

Three-column osteotomy in long constructs has lower rates of proximal junctional kyphosis and better restoration of lumbar lordosis than anterior column realignment

PURPOSE

Three-column osteotomies (TCOs) and minimally invasive techniques such as anterior column realignment (ACR) are powerful tools used to restore lumbar lordosis and sagittal alignment. We aimed to appraise the differences in construct and global spinal stability between TCOs and ACRs in long constructs.

METHODS

We identified consecutive patients who underwent a long construct lumbar or thoracolumbar fusion between January 2016 and November 2021. "Long construct" was any construct where the uppermost instrumented vertebra (UIV) was L2 or higher and the lowermost instrumented vertebra (LIV) was in the sacrum or ileum.

RESULTS

We identified 69 patients; 14 (20.3%) developed PJK throughout follow-up (mean 838 days). Female patients were less likely to suffer PJK (p = 0.009). TCO was more associated with open (versus minimally invasive) screw/rod placement, greater number of levels, higher UIV, greater rate of instrumentation to the ilium, and posterior (versus anterior) L5-S1 interbody placement versus the ACR cohort (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.005, respectively). Patients who developed PJK were more likely to have undergone ACR (12 (32.4%) versus 2 (6.3%, p = 0.007)). The TCO cohort had better improvement of lumbar lordosis despite similar preoperative measurements (ACR: 16.8 ± 3.78°, TCO: 23.0 ± 5.02°, p = 0.046). Pelvic incidence-lumbar lordosis mismatch had greater improvement after TCO (ACR: 14.8 ± 4.02°, TCO: 21.5 ± 5.10°, p = 0.042). By multivariate analysis, ACR increased odds of PJK by 6.1-times (95% confidence interval: 1.20-31.2, p = 0.29).

CONCLUSION

In patients with long constructs who undergo ACR or TCO, we experienced a 20% rate of PJK. TCO decreased PJK 6.1-times compared to ACR. TCO demonstrated greater improvement of some spinopelvic parameters.

Patient Optimization for the Prevention of Proximal Junctional Kyphosis

Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are well-recognized challenges of surgery for adult spinal deformity (ASD). Multiple risk factors have been identified for PJK/PJF, including osteoporosis, frailty, neurodegenerative disease, obesity, and smoking. Several surgical techniques to mitigate risk of PJK/PJF have been identified; however, patient optimization is also critical. This review summarizes the data behind these 5 risk factors (osteoporosis, frailty, neurodegenerative disease, obesity, and smoking) and details the related recommendations for patients undergoing surgery for ASD.