Utilization trends of pedicle subtraction osteotomies compared to posterior spinal fusion for deformity: a national database analysis between 2008-2011

Have We Made Advancements in Optimizing Surgical Outcomes and Enhancing Recovery for Patients With High-Risk Adult Spinal Deformity Over Time?

BACKGROUND AND OBJECTIVES

The spectrum of patients requiring adult spinal deformity (ASD) surgery is highly variable in baseline (BL) risk such as age, frailty, and deformity severity. Although improvements have been realized in ASD surgery over the past decade, it is unknown whether these carry over to high-risk patients. We aim to determine temporal differences in outcomes at 2 years after ASD surgery in patients stratified by BL risk.

METHODS

Patients ≥18 years with complete pre- (BL) and 2-year (2Y) postoperative data from 2009 to 2018 were categorized as having undergone surgery from 2009 to 2013 [early] or from 2014 to 2018 [late]. High-risk [HR] patients met ≥2 of the criteria: (1) ++ BL pelvic incidence and lumbar lordosis or SVA by Scoliosis Research Society (SRS)-Schwab criteria, (2) elderly [≥70 years], (3) severe BL frailty, (4) high Charlson comorbidity index, (5) undergoing 3-column osteotomy, and (6) fusion of >12 levels, or >7 levels for elderly patients. Demographics, clinical outcomes, radiographic alignment targets, and complication rates were assessed by time period for high-risk patients.

RESULTS

Of the 725 patients included, 52% (n = 377) were identified as HR. 47% (n = 338) had surgery pre-2014 [early], and 53% (n = 387) underwent surgery in 2014 or later [late]. There was a higher proportion of HR patients in Late group (56% vs 48%). Analysis by early/late status showed no significant differences in achieving improved radiographic alignment by SRS-Schwab, age-adjusted alignment goals, or global alignment and proportion proportionality by 2Y (all P > .05). Late/HR patients had significantly less poor clinical outcomes per SRS and Oswestry Disability Index (both P < .01). Late/HR patients had fewer complications (63% vs 74%, P = .025), reoperations (17% vs 30%, P = .002), and surgical infections (0.9% vs 4.3%, P = .031). Late/HR patients had lower rates of early proximal junctional kyphosis (10% vs 17%, P = .041) and proximal junctional failure (11% vs 22%, P = .003).

CONCLUSION

Despite operating on more high-risk patients between 2014 and 2018, surgeons effectively reduced rates of complications, mechanical failures, and reoperations, while simultaneously improving health-related quality of life.

The Surgical Outcomes of Pedicle Subtraction Osteotomy per Different First Assistant: Retrospective Analysis of 312 Cases

INTRODUCTION

Pedicle subtraction osteotomies (PSOs) are complex spinal deformity surgeries that are associated with high complication rates. They are typically done by an experienced spine surgeon with another attending, resident, or physician assistant serving as the first assistant. The purpose of this study was to determine whether selecting a surgical team for single-level PSO based on case difficulty and fusion length could equalize intraoperative and perioperative outcomes among three groups: dual-attending (DA), attending and orthopaedic resident (RS), and attending and physician assistant (PA).

METHODS

This study was a retrospective cohort analysis of 312 patients undergoing single-level thoracic or lumbar PSO from January 2007 to December 2020 by a fellowship-trained orthopaedic spine surgeon. Demographic, intraoperative, and perioperative data within 30 days and 2 years of the index procedure were analyzed.

RESULTS

Patient demographics did not markedly differ between surgical groups. The mean cohort age was 64.5 years with BMI 31.9 kg/m 2 . Patients with the DA approach had a significantly longer surgical time (DA = 412 min vs. resident = 372 min vs. physician assistant = 323 min; P < 0.001). Patients within the DA group experienced a significantly lower rate of infection (DA = 2.1% [3/140] vs. RS = 7.9% [9/114] vs. PA = 1.7% [1/58], P = 0.043), surgical complication rate (DA = 26% [37/140] vs. RS = 41% [47/114] vs. PA = 33% [19/58], P < 0 .001), and readmission rate (DA = 6.4% [9/140] vs. RS = 12.3% [14/114] vs. PA = 19% [11/58] P = 0.030) within 30 days of surgery. No notable differences were observed among groups in 2-year complication, infection, readmission, or revision surgery rates.

CONCLUSIONS

These study results support the DA surgeon approach. Resident involvement, even in less complex cases, can still negatively affect perioperative outcomes. Additional selection criteria development is needed.

Complication rate evolution across a 10-year enrollment period of a prospective multicenter database

OBJECTIVE

Adult spinal deformity is a complex pathology that benefits greatly from surgical treatment. Despite continuous innovation, little is known regarding continuous changes in surgical techniques and the complications rate. The objective of the current study was to investigate the evolution of the patient profiles and surgical complications across a single prospective multicenter database.

METHODS

This study is a retrospective review of a prospective, multicenter database of surgically treated patients with adult spinal deformity (thoracic kyphosis > 60°, sagittal vertical axis > 5 cm, pelvic tilt > 25°, or Cobb angle > 20°) with a minimum 2-year follow-up. Patients were stratified into 3 equal groups by date of surgery. The three groups' demographic data, preoperative data, surgical information, and complications were then compared. A moving average of 320 patients was used to visualize and investigate the evolution of the complication across the enrollment period.

RESULTS

A total of 928/1260 (73.7%) patients completed their 2-year follow-up, with an enrollment rate of 7.7 ± 4.1 patients per month. Across the enrollment period (2008-2018) patients became older (mean age increased from 56.7 to 64.3 years) and sicker (median Charlson Comorbidity Index rose from 1.46 to 2.08), with more pure sagittal deformity (type N). Changes in surgical treatment included an increased use of interbody fusion, more anterior column release, and a decrease in the 3-column osteotomy rate, shorter fusion, and more supplemental rods and bone morphogenetic protein use. There was a significant decrease in major complications associated with a reoperation (from 27.4% to 17.1%) driven by a decrease in radiographic failures (from 12.3% to 5.2%), despite a small increase in neurological complications. The overall complication rate has decreased over time, with the lowest rate of any complication (51.8%) during the period from August 2014 to March 2017. Major complications associated with reoperation decreased rapidly in the 2014-2015. Major complications not associated with reoperation had the lowest level (21.0%) between February 2014 and October 2016.

CONCLUSIONS

Despite an increase in complexity of cases, complication rates did not increase and the rate of complications leading to reoperation decreased. These improvements reflect the changes in practice (supplemental rod, proximal junctional kyphosis prophylaxis, bone morphogenetic protein use, anterior correction) to ensure maintenance of status or improved outcomes.

Medical optimization of modifiable risk factors before thoracolumbar three-column osteotomies: an analysis of 195 patients

PURPOSE

To determine the rate of preoperative modifiable laboratory abnormalities (both major and minor) and the association with early postoperative medical and surgical complications.

METHODS

All patients undergoing thoracolumbar three-column osteotomy between 2013 and 2016 with preoperative laboratory data were identified. Potential preoperative modifiable laboratory abnormalities (major and minor) were assessed including hyponatremia (sodium < 130 and < 135 mEq/L), anemia (hematocrit < 25% and < 30%), renal insufficiency (creatinine ≥ 1.8 and ≥ 1.2 mg/dL), coagulopathy (INR ≥ 1.8 and ≥ 1.2), and hypoalbuminemia (albumin < 2.5 and < 3.5 g/dL). Multivariate logistic regression was used to determine associations with 30-day complications after controlling for possible confounding factors.

RESULTS

A total of 195 patients were identified. The rates of major and minor preoperative laboratory abnormalities were 7.7% and 31.3%, respectively. The rates of serious medical, minor medical, and surgical complications over 30-days were 6.7%, 21.5%, and 10.3%, respectively. In multivariate analysis the presence of major preoperative laboratory abnormalities had a significant association with serious medical complications (odds ratio [OR] 77.8, P < 0.001), and minor medical complications (OR 13.3, P < 0.001), but not surgical complications (P = 0.243). The presence of minor preoperative laboratory abnormalities had a significant association with serious medical complications (OR 10.4, P = 0.041) and minor medical complications (OR 2.4, P = 0.045), but not surgical complications (P = 0.490).

CONCLUSIONS

While major laboratory abnormalities had a strong association with complications, even minor modifiable laboratory abnormalities had a significant association with both serious and minor medical complications.

Rotational thromboelastometry-guided transfusion during lumbar pedicle subtraction osteotomy for adult spinal deformity: preliminary findings from a matched cohort study

OBJECTIVESignificant blood loss and coagulopathy are often encountered during adult spinal deformity (ASD) surgery, and the optimal intraoperative transfusion algorithm is debatable. Rotational thromboelastometry (ROTEM), a functional viscoelastometric method for real-time hemostasis testing, may allow early identification of coagulopathy and improve transfusion practices. The objective of this study was to investigate the effect of ROTEM-guided blood product management on perioperative blood loss and transfusion requirements in ASD patients undergoing correction with pedicle subtraction osteotomy (PSO).METHODSThe authors retrospectively reviewed patients with ASD who underwent single-level lumbar PSO at the University of Virginia Health System. All patients who received ROTEM-guided blood product transfusion between 2015 and 2017 were matched in a 1:1 ratio to a historical cohort treated using conventional laboratory testing (control group). Co-primary outcomes were intraoperative estimated blood loss (EBL) and total blood product transfusion volume. Secondary outcomes were perioperative transfusion requirements and postoperative subfascial drain output.RESULTSThe matched groups (ROTEM and control) comprised 17 patients each. Comparison of matched group baseline characteristics demonstrated differences in female sex and total intraoperative dose of intravenous tranexamic acid (TXA). Although EBL was comparable between ROTEM versus control (3200.00 ± 2106.24 ml vs 3874.12 ± 2224.22 ml, p = 0.36), there was a small to medium effect size (Cohen's d = 0.31) on EBL reduction with ROTEM. The ROTEM group had less total blood product transfusion volume (1624.18 ± 1774.79 ml vs 2810.88 ± 1847.46 ml, p = 0.02), and the effect size was medium to large (Cohen's d = 0.66). This difference was no longer significant after adjusting for TXA (β = -0.18, 95% confidence interval [CI] -1995.78 to 671.64, p = 0.32). More cryoprecipitate and less fresh frozen plasma (FFP) were transfused in the ROTEM group patients (cryoprecipitate units: 1.24 ± 1.20 vs 0.53 ± 1.01, p = 0.03; FFP volume: 119.76 ± 230.82 ml vs 673.06 ± 627.08 ml, p < 0.01), and this remained significant after adjusting for TXA (cryoprecipitate units: β = 0.39, 95% CI 0.05 to 1.73, p = 0.04; FFP volume: β = -0.41, 95% CI -772.55 to -76.30, p = 0.02). Drain output was lower in the ROTEM group and remained significant after adjusting for TXA.CONCLUSIONSFor ASD patients treated using lumbar PSO, more cryoprecipitate and less FFP were transfused in the ROTEM group compared to the control group. These preliminary findings suggest ROTEM-guided therapy may allow early identification of hypofibrinogenemia, and aggressive management of this may reduce blood loss and total blood product transfusion volume. Additional prospective studies of larger cohorts are warranted to identify the appropriate subset of ASD patients who may benefit from intraoperative ROTEM analysis.

Surgeon-specific risk stratification model for early complications after complex adult spinal deformity surgery

STUDY DESIGN

Retrospective outcome analysis of a prospectively collected single-surgeon cases OBJECTIVES: Identify risk factors for complications in adult surgical spine deformity patients, develop a surgeon-specific risk stratification model, and predict the likelihood of 6-week postoperative complications based on prospectively collected preoperative measures. Adult spinal deformity surgery is challenging technically as well as economically. Although many risk factors are well known for spine surgery, complications after complex spine deformity surgery remain a significant problem worldwide.

METHODS

We reviewed 124 consecutive adult patients who have undergone instrumented spinal fusion with nine or more levels over a 21-month period in a single institution. We extracted data from patient medical records. Complications within the 6 weeks after surgery were identified. Univariate and logistic regression analyses (LRAs) were implemented. We generated a formula based on the LRA predictive algorithm-a numeric probabilistic likelihood statistic representing an individual patient's risk of developing a complication.

RESULTS

A total of 34 (27%) patients had complications that were categorized into either 21 (17%) medical or 17 (13.7%) surgical complications, including 3 (2.4%) proximal junctional kyphosis, 8 (6.4%) neurologic deficit, and 9 (6.5%) any wound issue. The predictive model was significant and calibrated using area under the receiver operating characteristics curve analysis. The model correctly classified 83.1% cases. Patients with a three-column osteotomy or history of deep vein thrombosis have 6 and 19 times higher overall complications, respectively, compared with patients without. Patients with a three-column osteotomy or body mass index > 30, respectively, are 24 and 11 times more likely to develop a wound complication. Patients with a three-column osteotomy have 10 times higher rates of surgical complication.

CONCLUSIONS

Complex spine deformity is often associated with complications. No single variable effectively predicts postoperative complications for such a complicated situation. However, when all risk factors are considered, patients with three-column osteotomy have a significantly higher chance to develop early complications.

LEVEL OF EVIDENCE

Level IV.

Radiographic and Clinical Outcomes Following Pedicle Subtraction Osteotomy : Minimum 2-Year Follow-Up Data

Objective

The purpose of this study was to report the results of pedicle subtraction osteotomy (PSO) for fixed sagittal imbalance with a minimum 2-year follow-up. Besides, authors evaluated the effect of adjunctive multi-level posterior column osteotomy (PCO) on achievement of additional lumbar lordosis (LL) during PSO.

Methods

A total of 31 consecutive patients undergoing PSO for fixed sagittal imbalance were enrolled and analyzed. Correction angle of osteotomized vertebra (PSO angle) and other radiographic parameters including pelvic incidence (PI), thoracic kyphosis, LL, and sagittal vertical axis (SVA) were evaluated. Clinical outcomes and surgical complications were also assessed.

Results

The mean age was 66.0±9.3 years with a mean follow-up period of 33.2±10.5 months. The mean number of fused segments was 9.6±3.5. The mean operative time and surgical bleeding were 475.9±160.5 minutes and 1406.1±932.1 mL, respectively. The preoperative SRS-22 score was 2.3±0.7 and improved to 3.2±0.8 at the final follow-up. The mean PI was 54.5±9.5°. LL was changed from 7.0±28.9° to -50.2±13.2°. The PSO angle was 33.7±13.5° (15.6±20.1° preoperatively, -16.1±19.4° postoperatively). The difference of correction angle of LL (57.3°) was greater about 23.6° than which of PSO angle (33.7°). SVA was improved from 189.5±93.0 mm, preoperatively to 12.4±40.8 mm, postoperatively. There occurred six, eight, and 14 cases of complications at intraoperative, early (<2 weeks) postoperative, and late (≥2 weeks) postoperative period, respectively. Additional operations were needed in nine patients due to the complications.

Conclusion

PSO could provide satisfactory results for patients with fixed sagittal imbalance regarding clinical and radiographic outcomes. Additional correction of LL could be achieved with conduction of adjunctive multi-level PCOs during PSO.

Evolution in Surgical Approach, Complications, and Outcomes in an Adult Spinal Deformity Surgery Multicenter Study Group Patient Population

STUDY DESIGN

Retrospective review of a prospectively collected multicenter database.

OBJECTIVES

To evaluate the evolution of surgical treatment strategies, complications, and patient-reported outcomes for adult spinal deformity (ASD) patients.

SUMMARY OF BACKGROUND DATA

ASD surgery is associated with high complication rates. Evolving treatment strategies may reduce these risks.

METHODS

Adult patients undergoing ASD surgery from 2009 to 2016 were analyzed (n = 905). Preoperative and surgical parameters were compared across years. Subgroup analysis of 436 patients with minimum two-year follow-up was also performed.

RESULTS

From 2009 to 2016, there was a significant increase in the mean preoperative age (52 to 63.1, p < .001), body mass index (26.3 to 32.2, p = .003), Charlson Comorbidity index (1.4 to 2.2, p < .001), rate of previous spine surgery (39.8% to 53.1%, p = .01), and baseline disability (visual analog scale [VAS] back and leg pain) scores (p < .01), Oswestry Disability Index, and 22-item Scoliosis Research Society Questionnaire scores (p < .001). Preoperative Schwab sagittal alignment modifiers and overall surgical invasiveness index were similar across time. Three-column osteotomy utilization decreased from 36% in 2011 to 16.7% in 2016. Lateral lumbar interbody fusion increased from 6.4% to 24.1% (p = .004), anterior lumbar interbody fusion decreased from 22.9% to 16.7% (p = .043), and transforaminal lumbar interbody fusion/posterior lumbar interbody fusion utilization remained similar (p = .448). Use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in 2012 was 84.6%, declined to 58% in 2013, and rebounded to 76.3% in 2016 (p = .006). Tranexamic acid use increased rapidly from 2009 to 2016 (13.3% to 48.6%, p < .001). Two-year follow-up sagittal vertical axis, pelvic tilt, pelvic incidence-lumbar lordosis, and maximum Cobb angles were similar across years. Intraoperative complications decreased from 33% in 2010 to 9.3% in 2016 (p < .001). Perioperative (<30 days, <90 days) complications peaked in 2010 (42.7%, 46%) and decreased by 2016 (24.1%, p < .001; 29.6%, p = .007). The overall complication rate decreased from 73.2% in 2008-2014 patients to 62.6% in 2015-2016 patients (p = .03). Two-year health-related quality of life outcomes did not significantly differ across the years (p > .05).

CONCLUSIONS

From 2009 to 2016, despite an increasingly elderly, medically compromised, and obese patient population, complication rates decreased. Evolving strategies may result in improved treatment of ASD patients.

LEVEL OF EVIDENCE

Level IV.

Controlled Pedicle Subtraction Osteotomy Site Closure Using Flexible Hinge-Powered Operating Table

BACKGROUND AND IMPORTANCE

Pedicle subtraction osteotomy (PSO) is a 3-column osteotomy used to correct rigid, large magnitude sagittal spinal deformity. PSO is an inherently destabilizing procedure intraoperatively, with high risk of neurological deficits from vertebral body subluxation or translation during osteotomy closure. Traditionally, PSO closure has been performed utilizing compression or cantilevering forces across adjacent level instrumentation. Such forces can loosen the instrumentation or cause abrupt subluxation or translation due to the magnitude of force required for PSO closure, resulting in neurological injury. Here, we report using a flexible hinge-powered operating table for controlled closure of PSO in 1º increments via remote-control power of the table, without compression or cantilevering force required across implants.

CLINICAL PRESENTATION

The patient is a 68-yr-old man with a history of prior L2-S1 anterior-posterior fusion, healed sacral fracture, and left sacroiliac joint fusion presenting to our institution with severe back pain while standing. X-rays demonstrated significant sagittal malalignment with pelvic incidence (PI) of 79º and lumbar lordosis (LL) of 37º, while computed tomography scan confirms complete bone healing around prior interbody fusion sites, resulting in rigid sagittal deformity. Due to rigid PI-LL mismatch of 42º, we planned for L2-pelvis revision fusion with L4 PSO.

CONCLUSION

Here we demonstrate the utility of a flexible hinge-powered operating table for closure of PSO site. This technique eliminates force application to adjacent implants, minimizing vertebral body subluxation, or translation. We believe this allows for safer, more controllable osteotomy closure that minimizes risk of neurological injury.

Risk Factors for 30-Day Readmissions and Reoperations After 3-Column Osteotomy for Spinal Deformity

STUDY DESIGN

Retrospective study of a prospectively collected database.

OBJECTIVE

To investigate the rate and risk factors for 30-day readmissions and reoperations after 3-column osteotomy (3CO).

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database (2012-2014) was reviewed. Inclusion criteria were adult patients who underwent 3CO. The rate of 30-day readmission/reoperation was examined, and the association between patient/operative characteristics and outcome was investigated via multivariate analysis.

RESULTS

There were 299 patients who underwent a 3CO for spinal deformity. The rate of 30-day readmission and reoperation was 11.0% and 8.4%, respectively; 7.7% of readmissions were related to the primary procedure and 3.3% were unrelated. The most common unique cause for readmission was wound infection in 27.2% of cases. Among reoperations, the most common unique indications were wound infection (20.0%) and implant-related complications (20.0%). On multivariate analysis, obesity (odds ratio [OR] = 2.96; 95% CI = 1.06-8.25; P = .038), chronic obstructive pulmonary disease (OR = 20.8; 95% CI = 3.49-123.5; P = .001), and fusion of 13 or more spinal levels were independent predictors of readmission (OR = 4.86; 95% CI = 1.21-19.5; P = .025). On the other hand, independent predictors of reoperation included chronic obstructive pulmonary disease (OR = 6.33; 95% CI = 1.16-34.5; P = .033) and chronic steroid use (OR = 6.69; 95% CI = 1.61-27.7; P = .009).

CONCLUSION

Wound complications and short-term implant-related complications are important causes of readmission and/or reoperation after 3CO. Preoperative factors such as obesity, chronic lung disease, chronic steroid use, and long-segment fusion procedures may significantly increase the risk of 30-day morbidity following high-grade osteotomies.

Predictors of Postoperative Recovery Based on Health-Related Quality of Life in Patients after Degenerative Lumbar Scoliosis Surgery

OBJECTIVE

To investigate the factors associated with the recovery process of elderly patients after degenerative lumbar scoliosis surgery.

METHODS

A total of 213 elderly patients who had undergone surgical treatment for degenerative lumbar scoliosis from 2011 to 2015 were included retrospectively in this study. Clinical data and demographics were collected for logistic regression analysis.

RESULTS

Among 213 eligible patients, 77 (38.5%) were classified as being in the excellent group, 70 (35%) as showing improvement, 24 (12%) as showing no change, and 29 (14.5%) as having deteriorated. At baseline, patients differed significantly from matched normative data in all Scoliosis Research Society domains. Larger differences from normative values were found for pain and activity domains. After surgery, each domain improved significantly. In the multivariate logistic regression, age 60-70 years (odds ratio [OR], 2.431; 95% confidence interval [CI], 1.143-5.174), and American Society of Anesthesiologists grade <3 (OR, 2.987; 95% CI, 1.519-5.874) may be predictive factors for a satisfying recovery, whereas presence of complications (OR, 0.342; 95% CI, 0.153-0.765), fusion to the sacrum (OR, 0.200; 95% CI, 0.076-0.523), and more osteotomies (OR, 0.360; 95% CI, 0.132-0.985) have negative effects on the recovery process.

CONCLUSIONS

The factors that affect postoperative recovery in elderly patients with degenerative lumbar scoliosis are age, American Society of Anesthesiologists grade, distal fusion level, presence of complications, and number of osteotomies.