Impact of Various Weights in the Intraoperative Skull-Skeletal Traction on Correction of Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A retrospective study. OBJECTIVES: Intraoperative skull-skeletal traction (ISST) facilitates the surgical scoliosis correction, but it is also associated with neurological risk. The objective of the present study was to investigate the impact of various traction weights on neurophysiological change and curve correction in surgery for adolescent idiopathic scoliosis (AIS). METHODS: A retrospective review of a consecutive series of posterior spinal fusions for AIS patients undergoing corrections with the use of ISST by 2 surgeons in one institution was performed. Intraoperative prone, post-traction radiographs were performed on all cases. The cases were divided into 2 groups, high and low traction weights, based on whether the weight used was ≥35% or <35% of body weight. The frequency of neurophysiological changes and the curve correction were compared between the 2 groups. RESULTS: The intraoperative correction magnitudes by ISST were significantly larger in the high ISST group than in the low ISST group (35° vs 26°, P < .001). Changes in motor-evoked potential (MEP) were more frequently observed in the high ISST group (47% vs 26%, P = .049). A multivariate analysis showed that high ISST was associated with 3 times higher risk of MEP change (95% confidence interval = 1.1-8.0, P = .03) and higher final postoperative correction rates (68% vs 60%, P = .001). CONCLUSIONS: The high ISST for AIS was associated with increased intraoperative and ultimate curve corrections, and potentially facilitated better final correction. However, the high weight group was associated with an increased frequency of intraoperative MEP changes.

Postoperative Distal Coronal Decompensation After Fusion to L3 for Adolescent Idiopathic Scoliosis Is Affected by Sagittal Pelvic Parameters.

STUDY DESIGN: Retrospective study. OBJECTIVE: To identify on early postoperative radiographs the risk factors for late distal decompensation in adolescent idiopathic scoliosis (AIS) patients undergoing posterior fusion surgery to L3. SUMMARY OF BACKGROUND DATA: Sparing distal fusion levels in AIS surgery is considered beneficial for postoperative mobility and outcomes; nonetheless, late distal decompensation is of concern. L3 is often advocated as lower instrumented vertebra in posterior fusion, but progressive angulation of the L3/4 disc is commonly observed. METHODS: A retrospective analysis was conducted on 78 AIS patients who underwent posterior fusion to L3 from 2007 to 2014. Patients' demographic data, early and 2-year postoperative standing radiographs by biplanar imaging system were investigated. Late decompensation was defined as progressive increase of L3-4 disc wedging angle at 2-year follow-up. Coronal, sagittal, and rotational radiographic parameters were compared between those with and without decompensation. SRS-30 scores were reviewed. RESULTS: Mean age was 14.5-year, and fusion levels averaged 12.0 (range: 6-15); 43 out of 78 patients (55%) experienced progressive L3-4 disc wedging, with 6 showing wedging >5°. L3 translation from the central sacral vertical line (13.9 vs. 11.1 mm, P = 0.13) and increased pelvic tilt (13.3° vs. 8.6°, P = 0.06) on the early postoperative radiograph were associated with increased L3-4 disc wedging. Multivariate analysis revealed that larger pelvic tilt was a significant risk factor for decompensation (odds ratio = 1.1 per 1°, 95% confidence interval: 1.0-1.1, P = 0.04). SRS-30 scores did not differ significantly between the two groups (4.0 vs. 4.1, P = 0.44). CONCLUSIONS: Pelvic retroversion and increased translation of L3 from the central sacral line on the early postoperative radiograph were associated with late L3-4 disc wedging in AIS fusions to L3. Careful surgical planning and correction of sagittal alignment are imperative to ensure the long-term outcomes. LEVEL OF EVIDENCE: 4.

Three-dimensional EOS Analysis of Apical Vertebral Rotation in Adolescent Idiopathic Scoliosis.

BACKGROUND: Apical vertebral rotation (AVR) is increasingly recognized as one of the important radiographic parameters in adolescent idiopathic scoliosis (AIS). EOS enables us to precisely measure AVR by 3-dimensional reconstruction. The objective of the present study was to describe the postoperative correction and the long-term follow-up of AVR in posterior spinal fusion with direct vertebral rotation and elucidate the factors that affected the correction. METHODS: We retrospectively reviewed 153 consecutive posterior spinal fusion surgeries for AIS performed between 2009 and 2012. Among them, 55 patients who fulfilled the study inclusion criteria with complete preoperative, immediate postoperative, and last follow-up (>1 y) EOS images were included in the present study. EOS 3-dimentional reconstructions were undertaken for each patient. Postoperative AVR correction and the loss of correction were calculated. RESULTS: Preoperative AVR of the major curve averaged 19 degrees (SD=7 degrees), and AVR on immediate postoperative images averaged 9 degrees (SD=6 degrees, P<0.001). AVR at final follow-up averaged 11 degrees (SD=6 degrees, P=0.06). Postoperative correction was larger in all-screw construct than in hybrid construct (55% vs. 36%, P=0.03). CONCLUSIONS: The present study is the first study to measure AVR in a large population of AIS patients using EOS 3-dimensional reconstruction. We report the correction magnitude was significantly affected by the construct. LEVEL OF EVIDENCE: Level IV-therapeutic study (case series).

Building consensus: development of a Best Practice Guideline (BPG) for surgical site infection (SSI) prevention in high-risk pediatric spine surgery.

BACKGROUND: Perioperative surgical site infection (SSI) after pediatric spine fusion is a recognized complication with rates between 0.5% and 1.6% in adolescent idiopathic scoliosis and up to 22% in "high risk" patients. Significant variation in the approach to infection prophylaxis has been well documented. The purpose of this initiative is to develop a consensus-based "Best Practice" Guideline (BPG), informed by both the available evidence in the literature and expert opinion, for high-risk pediatric patients undergoing spine fusion. For the purpose of this effort, high risk was defined as anything other than a primary fusion in a patient with idiopathic scoliosis without significant comorbidities. The ultimate goal of this initiative is to decrease the wide variability in SSI prevention strategies in this area, ultimately leading to improved patient outcomes and reduced health care costs. METHODS: An expert panel composed of 20 pediatric spine surgeons and 3 infectious disease specialists from North America, selected for their extensive experience in the field of pediatric spine surgery, was developed. Using the Delphi process and iterative rounds using a nominal group technique, participants in this panel were as follows: (1) surveyed for current practices; (2) presented with a detailed systematic review of the relevant literature; (3) given the opportunity to voice opinion collectively; and (4) asked to vote regarding preferences privately. Round 1 was conducted using an electronic survey. Initial results were compiled and discussed face-to-face. Round 2 was conducted using the Audience Response System, allowing participants to vote for (strongly support or support) or against inclusion of each intervention. Agreement >80% was considered consensus. Interventions without consensus were discussed and revised, if feasible. Repeat voting for consensus was performed. RESULTS: Consensus was reached to support 14 SSI prevention strategies and all participants agreed to implement the BPG in their practices. All agreed to participate in further studies assessing implementation and effectiveness of the BPG. The final consensus driven BPG for high-risk pediatric spine surgery patients includes: (1) patients should have a chlorhexidine skin wash the night before surgery; (2) patients should have preoperative urine cultures obtained; (3) patients should receive a preoperative Patient Education Sheet; (4) patients should have a preoperative nutritional assessment; (5) if removing hair, clipping is preferred to shaving; (6) patients should receive perioperative intravenous cefazolin; (7) patients should receive perioperative intravenous prophylaxis for gram-negative bacilli; (8) adherence to perioperative antimicrobial regimens should be monitored; (9) operating room access should be limited during scoliosis surgery (whenever practical); (10) UV lights need NOT be used in the operating room; (11) patients should have intraoperative wound irrigation; (12) vancomycin powder should be used in the bone graft and/or the surgical site; (13) impervious dressings are preferred postoperatively; (14) postoperative dressing changes should be minimized before discharge to the extent possible. CONCLUSIONS: In conclusion, we present a consensus-based BPG consisting of 14 recommendations for the prevention of SSIs after spine surgery in high-risk pediatric patients. This can serve as a tool to reduce the variability in practice in this area and help guide research priorities in the future. Pending such data, it is the unsubstantiated opinion of the authors of the current paper that adherence to recommendations in the BPG will not only decrease variability in practice but also result in fewer SSI in high-risk children undergoing spinal fusion. LEVEL OF EVIDENCE: Not applicable.

Incidence of unintended durotomy in spine surgery based on 108,478 cases.

BACKGROUND: Unintended durotomy is a common complication of spinal surgery. However, the incidences reported in the literature vary widely and are based primarily on relatively small case numbers from a single surgeon or institution. OBJECTIVE: To provide spine surgeons with a reliable incidence of unintended durotomy in spinal surgery and to assess various factors that may influence the risk of durotomy. METHODS: We assessed 108,478 surgical cases prospectively submitted by members of the Scoliosis Research Society to a deidentified database from 2004 to 2007. RESULTS: Unintended durotomy occurred in 1.6% (1745 of 108 478) of all cases. The incidence of unintended durotomy ranged from 1.1% to 1.9% on the basis of preoperative diagnosis, with the highest incidence among patients treated for kyphosis (1.9%) or spondylolisthesis (1.9%) and the lowest incidence among patients treated for scoliosis (1.1%). The most common indication for spine surgery was degenerative spinal disorder, and among these patients, there was a lower incidence of durotomy for cervical (1.0%) vs thoracic (2.2%; P = .01) or lumbar (2.1%, P < .001) cases. Scoliosis procedures were further characterized by etiology, with the highest incidence of durotomy in the degenerative subgroup (2.2% vs 1.1%; P < .001). Durotomy was more common in revision compared with primary surgery (2.2% vs 1.5%; P < .001) and was significantly more common among elderly (> 80 years of age) patients (2.2% vs 1.6%; P = .006). There was a significant association between unintended durotomy and development of a new neurological deficit (P < .001). CONCLUSION: Unintended durotomy occurred in at least 1.6% of spinal surgeries, even among experienced surgeons. Our data provide general benchmarks of durotomy rates and serve as a basis for ongoing efforts to improve safety of care.

Short-term morbidity and mortality associated with correction of thoracolumbar fixed sagittal plane deformity: a report from the Scoliosis Research Society Morbidity and Mortality Committee.

STUDY DESIGN: Retrospective review. OBJECTIVE: Our objective was to assess the short-term complication rate in patients undergoing treatment of thoracolumbar fixed sagittal plane deformity (FSPD). SUMMARY OF BACKGROUND DATA: The reported morbidity and mortality for the surgical treatment of thoracolumbar FSPD is varied and based on studies with small sample sizes. Further studies are needed to better assess FSPD complication rate, and the factors that influence it. METHODS: The Scoliosis Research Society (SRS) Morbidity and Mortality Database was queried to identify cases of thoracolumbar FSPD from 2004 to 2007. Complications were analyzed based on correction technique, surgical approach, surgeon experience (SRS membership status used as a surrogate), patient age, and history of prior surgery. RESULTS: Five hundred and seventy-eight cases of FSPD were identified. Osteotomies were performed in 402 cases (70%), including 215 pedicle subtraction osteotomies (PSO), 135 Smith-Petersen osteotomies (SPO), 19 anterior discectomy with corpectomy procedures (ADC), 18 vertebral column resections (VCR), and 15 unspecified osteotomies. There were 170 complications (29.4%) in 132 patients. There were three deaths (0.5%). The most common complications were durotomy (5.9%), wound infection (3.8%), new neurologic deficit (3.8%), implant failure (1.7%), wound hematoma (1.6%), epidural hematoma (1.4%), and pulmonary embolism (1.0%). Procedures including an osteotomy had a higher complication rate (34.8%) than cases not including an osteotomy (17.0%, P < 0.001), and this remained significant after adjusting for the effects of patient age, surgeon experience, and history of prior surgery (P = 0.003, odds ratio = 2.070, 95% CI = 1.291-3.321). Not significantly associated with complication rate were patient age (P = 0.68), surgeon experience (P = 0.18), and history of prior surgery (P = 0.10). Complication rates were progressively higher from no osteotomy (17.0%), to SPO (28.1%), to PSO (39.1%), to VCR (61.1%). CONCLUSION: The short-term complication rate for treatment of FSPD is 29.4%. The complication rate was significantly higher in patients undergoing osteotomies, and more aggressive osteotomies were associated with progressively higher complication rates.

Morbidity and mortality in the surgical treatment of 10,242 adults with spondylolisthesis.

OBJECT: This is a retrospective review of 10,242 adults with degenerative spondylolisthesis (DS) and isthmic spondylolisthesis (IS) from the morbidity and mortality (M&M) index of the Scoliosis Research Society (SRS). This database was reviewed to assess complication incidence, and to identify factors that were associated with increased complication rates. METHODS: The SRS M&M database was queried to identify cases of DS and IS treated between 2004 and 2007. Complications were identified and analyzed based on age, surgical approach, spondylolisthesis type/grade, and history of previous surgery. Age was stratified into 2 categories: > 65 years and ≤ 65 years. Surgical approach was stratified into the following categories: decompression without fusion, anterior, anterior/posterior, posterior without instrumentation, posterior with instrumentation, and interbody fusion. Spondylolisthesis grades were divided into low-grade (Meyerding I and II) versus high-grade (Meyerding III, IV, and V) groups. Both univariate and multivariate analyses were performed. RESULTS: In the 10,242 cases of DS and IS reported, there were 945 complications (9.2%) in 813 patients (7.9%). The most common complications were dural tears, wound infections, implant complications, and neurological complications (range 0.7%-2.1%). The mortality rate was 0.1%. Diagnosis of DS had a significantly higher complication rate (8.5%) when compared with IS (6.6%; p = 0.002). High-grade spondylolisthesis correlated strongly with a higher complication rate (22.9% vs 8.3%, p < 0.0001). Age > 65 years was associated with a significantly higher complication rate (p = 0.02). History of previous surgery and surgical approach were not significantly associated with higher complication rates. On multivariate analysis, only the grade of spondylolisthesis (low vs high) was in the final best-fit model of factors associated with the occurrence of complications (p < 0.0001). CONCLUSIONS: The rate of total complications for treatment of DS and IS in this series was 9.2%. The total percentage of patients with complications was 7.9%. On univariate analysis, the complication rate was significantly higher in patients with high-grade spondylolisthesis, a diagnosis of DS, and in older patients. Surgical approach and history of previous surgery were not significantly correlated with increased complication rates. On multivariate analysis, only the grade of spondylolisthesis was significantly associated with the occurrence of complications.

Morbidity and mortality in the surgical treatment of 10,329 adults with degenerative lumbar stenosis.

OBJECT: The purpose of this study was to evaluate the prospectively collected Scoliosis Research Society (SRS) database to assess the incidences of morbidity and mortality (M&M) in the operative treatment of degenerative lumbar stenosis, one of the most common procedures performed by spine surgeons. METHODS: All patients who underwent surgical treatment for degenerative lumbar stenosis between 2004 and 2007 were identified from the SRS M&M database. Inclusion criteria for analysis included an age >or= 21 years and no history of lumbar surgery. Patients were treated with either decompression alone or decompression with concomitant fusion. Statistical comparisons were performed using a 2-sided Fisher exact test. RESULTS: Of the 10,329 patients who met the inclusion criteria, 6609 (64%) were treated with decompression alone, and 3720 (36%) were treated with decompression and fusion. Among those who underwent fusion, instrumentation was placed in 3377 (91%). The overall mean patient age was 63 +/- 13 years (range 21-96 years). Seven hundred nineteen complications (7.0%), including 13 deaths (0.1%), were identified. New neurological deficits were reported in 0.6% of patients. Deaths were related to cardiac (4 cases), respiratory (5 cases), pulmonary embolus (2 cases), and sepsis (1 case) etiologies, and a perforated gastric ulcer (1 case). Complication rates did not differ based on patient age or whether fusion was performed. Minimally invasive procedures were associated with fewer complications and fewer new neurological deficits (p = 0.01 and 0.03, respectively). CONCLUSIONS: The results from this analysis of the SRS M&M database provide surgeons with useful information for preoperative counseling of patients contemplating surgical intervention for symptomatic degenerative lumbar stenosis.

Importance of pelvic compensation in posture and motion after posterior spinal fusion using CD instrumentation for idiopathic scoliosis.

STUDY DESIGN: Posture and motion analysis after a Cotrel-Dubousset instrumentation. OBJECTIVES: To investigate the compensation role of pelvis. SUMMARY OF BACKGROUND DATA: Few existing studies found no compensation at the lower unfused level but did not investigate the pelvis. METHODS: Thirty patients were analyzed before surgery then at short-, medium-, and long-term postoperative follow-up. Calibrated x-rays with three-dimensional reconstruction yielded quantification of pelvic parameters. Noninvasive optoelectronic system allowed analyzing subjects first in standing position, then during flexion-extension, lateral bending, and axial rotation. Skin markers were used to quantify three-dimensional orientation of the shoulders, trunk and pelvis, and their range of motion (ROM). RESULTS: Ten patients among 21 had after surgery more than 5 degrees change of pelvic incidence. In flexion, global ROM decreased from preoperative to postoperative phase (P < 0.05). Global ROM variation was not correlated to that of lower unfused segment, while it was highly correlated to pelvic ROM variation (r = 0.78 at medium follow-up). CONCLUSION: This study underlines the central role of pelvis in balance and motion of the patients before and after surgery.