Incidence and Risk Factors for Early Postoperative Complications and Mortality Following Adult Spinal Deformity Surgery: Data From the National Surgical Quality Improvement Program From 2011 to 2013

Risk Factors for and Prediction of Early Thromboembolic Disease Following Adult Spinal Deformity Surgery: An Analysis of >7,400 Patients with Spinal Deformity

BACKGROUND

The aim of this study was to determine the risk factors associated with deep vein thrombosis (DVT) or pulmonary embolism (PE) within 30 days after multilevel adult spinal deformity (ASD) surgery and to develop risk prediction models.

METHODS

A retrospective observational study was conducted using the American College of Surgeons National Surgical Quality Improvement Program database from 2010 to 2019. Current Procedural Terminology (CPT) codes 22843 and 22844 were used to query the database and to identify patients who underwent surgical correction of ASD with ≥7 levels of posterior instrumentation. The primary outcomes were the incidences of, and risk factors for, postoperative DVT and PE. Multiple logistic regression was utilized to identify variables associated with an elevated risk of DVT or PE within 30 days after surgery and to develop prediction models for assessing risk.

RESULTS

A total of 7,445 patients (56% female; 73% Caucasian; mean age, 61 years) met the inclusion criteria. Postoperatively, the rate of any venous thromboembolism (VTE; i.e., DVT or PE) was 3.4% (254 patients), the rate of DVT was 2.0% (151 patients), and the rate of PE was 1.7% (127 patients). The following independent predictors of any VTE were identified: weight (odds ratio [OR], 1.054; 95% confidence interval [CI]: 1.027 to 1.081), age per decade of life (OR, 1.106; 95% CI: 1.012 to 1.209), body mass index (BMI; OR, 1.032; 95% CI: 1.015 to 1.049), medicated hypertension (OR, 1.523; 95% CI: 1.168 to 1.987), chronic corticosteroid use (OR, 2.654; 95% CI: 1.848 to 3.812), American Society of Anesthesiologists (ASA) class (OR, 1.768; 95% CI: 1.426 to 2.192), and total operative time (OR, 1.002; 95% CI: 1.002 to 1.003) (p < 0.05 for all). When incorporated into a single model, total operative time, BMI, ASA class, and chronic corticosteroid use were associated with VTE risk.

CONCLUSIONS

Four major risk factors were identified as being associated with postoperative VTE risk in patients undergoing surgery for ASD. Corticosteroid use for a chronic medical condition was the strongest predictor of VTE risk, followed by ASA class, BMI, and operative time. Knowledge of these risk factors can aid in preoperative risk assessment, informed consent, and medical decision-making, such as in determining the clinical thresholds for VTE testing and chemoprophylaxis.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Case for Operative Efficiency in Adult Spinal Deformity Surgery: Impact of Operative Time on Complications, Length of Stay, Alignment, Fusion Rates, and Patient-Reported Outcomes

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To analyze the impact of operative room (OR) time in adult spinal deformity (ASD) surgery on patient outcomes.

BACKGROUND

It is currently unknown if OR time in ASD patients matched for deformity severity and surgical invasiveness is associated with patient outcomes.

MATERIALS AND METHODS

ASD patients with baseline and two-year postoperative radiographic and patient-reported outcome measures (PROM) data, undergoing a posterior-only approach for long fusion (>L1-Ilium) were included. Patients were grouped into short OR time (<40th percentile: <359 min) and long OR time (>60th percentile: >421 min). Groups were matched by age, baseline deformity severity, and surgical invasiveness. Demographics, radiographic, PROM data, fusion rate, and complications were compared between groups at baseline and two years follow-up.

RESULTS

In total, 270 patients were included for analysis: the mean OR time was 286 minutes in the short OR group versus 510 minutes in the long OR group ( P <0.001). Age, gender, percent of revision cases, surgical invasiveness, pelvic incidence minus lumbar lordosis, sagittal vertical axis, and pelvic tilt were comparable between groups ( P >0.05). Short OR had a slightly lower body mass index than the short OR group ( P <0.001) and decompression was more prevalent in the long OR time ( P =0.042). Patients in the long group had greater hospital length of stay ( P =0.02); blood loss ( P <0.001); proportion requiring intensive care unit ( P =0.003); higher minor complication rate ( P =0.001); with no significant differences for major complications or revision procedures ( P >0.5). Both groups had comparable radiographic fusion rates ( P =0.152) and achieved improvement in sagittal alignment measures, Oswestry disability index, and Short Form-36 ( P <0.001).

CONCLUSION

Shorter OR time for ASD correction is associated with a lower minor complication rate, a lower estimated blood loss, fewer intensive care unit admissions, and a shorter hospital length of stay without sacrificing alignment correction or PROMs. Maximizing operative efficiency by minimizing OR time in ASD surgery has the potential to benefit patients, surgeons, and hospital systems.

Implant-Related Complications after Spinal Fusion: A Multicenter Study

STUDY DESIGN

Retrospective analysis of prospectively database.

OBJECTIVE

Implant-related complications are an extremely important issue because they pose a burden to patients who underwent surgery. An understanding of these complications can help improve the postoperative management of patients undergoing spinal surgery. The current large-scale multicenter study aimed to identify postoperative implant-related complications that may require revision surgery.

METHODS

In total, 3447 patients who underwent spinal fusion surgery were included in the analysis. Data about age at surgery, sex, preoperative diagnosis, surgical level, type of implant-related complications, causes of reoperation, and time from the initial to revision surgery were reviewed. Moreover, the characteristics of reoperation in 3 periods (within 30, 31-90, and over 90 days) were assessed.

RESULT

The overall incidence of implant-related complications was 4.6%. Adult spinal deformity was the most common diagnosis (9.9%), and thoracic-lumbar-sacral (42.9%) was the most common surgical level among patients with implant-related complications. Further, screw malposition was the most frequent implant-related complication (42.8%). In total, 89 (2.6%) patients underwent reoperation due to implant-related complications. The main causes of reoperation within 30, 31-90, and over 90 days were screw malposition (72.2%), screw loosening or pull out (81.8%), and rod or screw fracture (60.9%), respectively.

CONCLUSION

To the best of our knowledge, this was the first large-scale multicenter study that assessed the characteristics of patients who underwent reoperation due to spinal implant-related complications. The study results could improve the preoperative informed consent procedure about spinal fusion.

Postoperative coronal malalignment after adult spinal deformity surgery: incidence, risk factors, and impact on 2-year outcomes

PURPOSE

To evaluate the incidence, risk factors, and patient-reported outcomes (PROs) of adult spinal deformity (ASD) patients with postoperative coronal malalignment.

METHODS

A single-institution, retrospective cohort study of ASD patients undergoing ≥ 6 level fusions from 2015 to 2019 was undertaken. The primary outcome was postoperative coronal malalignment, defined as C7-coronal vertical axis (CVA) > 3 cm. Secondary outcomes included: complications, readmissions, reoperations, and 2-year PROs.

RESULTS

A total of 243 ASD patients undergoing spinal surgery had preoperative and immediate postoperative measurements, and 174 patients (72%) had 2-year follow-up. Mean age was 49.3 ± 18.3yrs and mean instrumented levels was 13.5 ± 3.9. Mean preoperative CVA was 2.9 ± 2.7 cm, and 90 (37%) had preoperative coronal malalignment. Postoperative coronal malalignment occurred in 43 (18%) patients. Significant risk factors for postoperative coronal malalignment were: preoperative CVA (OR 1.21, p = 0.001), preoperative SVA (OR 1.05, p = 0.046), pelvic obliquity (OR 1.21; p = 0.008), Qiu B vs. A (OR 4.17; p = 0.003), Qiu C vs. A (OR 7.39; p < 0.001), lumbosacral fractional (LSF) curve (OR 2.31; p = 0.021), max Cobb angle concavity opposite the CVA (OR 2.10; p = 0.033), and operative time (OR 1.16; p = 0.045). Postoperative coronal malalignment patients were more likely to sustain a major complication (31% vs. 14%; p = 0.01), yet no differences were seen in readmissions (p = 0.72) or reoperations (p = 0.98). No significant differences were seen in 2-year PROs (p > 0.05).

CONCLUSIONS

Postoperative coronal malalignment occurred in 18% of ASD patients and was most associated with preoperative CVA/SVA, pelvic obliquity, Qiu B/C curves, LSF curve concavity to the same side as the CVA, and maximum Cobb angle concavity opposite side of the CVA. Postoperative coronal malalignment was significantly associated with increased complications but not readmission, reoperation, or 2-year PROs.

Kickstand rods and correction of coronal malalignment in patients with adult spinal deformity

PURPOSE

Coronal malalignment (CM) is a challenging spinal deformity to treat. The kickstand rod (KR) technique is powerful for correcting truncal shift. This study tested the hypothesis that the KR technique provides superior coronal alignment correction in adult deformity compared with traditional rod techniques.

METHODS

A retrospective evaluation of a prospectively collected multicenter database was performed. A 2:1 matched cohort of non-KR accessory rod and KR patients was planned based on preoperative coronal balance distance (CBD) and a vector of global shift. Patients were subgrouped according to CM classification with a 30-mm CBD threshold defining CM, and comparisons of surgical and clinical outcomes among groups was performed.

RESULTS

Twenty-one patients with preoperative CM treated with a KR were matched to 36 controls. KR-treated patients had improved CBD compared with controls (18 vs. 35 mm, P < 0.01). The postoperative CBD did not result in clinical differences between groups in patient-reported outcomes (P ≥ 0.09). Eight (38%) of 21 KR patients and 12 (33%) of 36 control patients with preoperative CM had persistent postoperative CM (P = 0.72). CM class did not significantly affect the likelihood of treatment failure (postoperative CBD > 30 mm) in the KR cohort (P = 0.70), the control cohort (P = 0.35), or the overall population (P = 0.31).

CONCLUSIONS

Application of the KR technique to coronal spinal deformity in adults allows for successful treatment of CM. Compared to traditional rod techniques, the use of KRs did not improve clinical outcome measures 1 year after spinal deformity surgery but was associated with better postoperative coronal alignment.