The impact of body mass index on hospital stay and complications after spinal fusion.

BACKGROUND: Obesity is a dominant public health concern and risk factor for disability, with few studies examining its impact in spinal surgery. Patients with a higher body mass index (BMI) have lower functional status, increased pain, and worse physical condition than those with ideal weight. OBJECTIVE: To determine associations between BMI categories on adverse patient outcomes after long-segment spinal fusions. METHODS: Consecutive, open, elective fusions (interbody and/or posterolateral arthrodesis) of more than 5 levels from 2007 to 2010 were retrospectively analyzed with follow-up of more than 1 year. Bivariate analyses examined outcome variables based on BMI categories. Linear regression analysis evaluated BMI, hospital stay, and complications at 1 and 2 years, controlling for confounders. Mean and median follow-up lengths were 2.1 and 2.0 years, respectively. RESULTS: A total of 189 surgeries on 112 patients, with a mean age of 59.5 years and a mean BMI of 29.8 kg/m, were analyzed. Morbidly obese patients had longer hospitalizations, worse Oswestry Disability Index (ODI), and more complications at 1 and 2 years than ideal weight patients. Multivariate linear regression modeling revealed sex, cardiac medications, cerebrospinal fluid leak, and BMI category of ideal vs nonideal influenced hospitalization length. Multivariate analysis showed BMI greater than 30 kg/m, preoperative ODI, and pedicle subtraction osteotomy influenced all complications at 1 year. Mean complications at 2 years for the morbidly obese were 3 times more than those underweight and 8 times more than those with ideal weight. Controlling for age, sex, and length of stay, obese and morbidly obese patients had more complications at 2 years; morbidly obese patients had a worse 2-year ODI. CONCLUSION: BMI is an independent predictor of hospitalization length and all complications at 1 and 2 years in patients receiving long-segment fusions.

Redefining global spinal balance: normative values of cranial center of mass from a prospective cohort of asymptomatic individuals.

STUDY DESIGN: Prospective radiographical analysis of cranial center of mass (CCOM), C2, and C7 plumb lines in young and elderly asymptomatic individuals. OBJECTIVE: To establish a normal range for craniosagittal balance for both young and elderly asymptomatic individuals. SUMMARY OF BACKGROUND DATA: Global sagittal balance must account for the position of the head in relation to the spine and pelvis. The C7 plumb line defines thoracolumbar sagittal balance and has been shown to have significant impact on patient outcomes. However, the C7 plumb line fails to take into consideration the position of the head in relation to the pelvis. METHODS: A total of 100 asymptomatic 20- to 40-year-old patients and 100 asymptomatic 60- to 80-year-old patients were enrolled. Standing plain radiographs of 14 × 36 in were obtained. CCOM, C2, and C7 plumb lines were drawn and measured from the superoposterior endplate of S1. RESULTS: A total of 78 asymptomatic 20- to 40-year-old patients and 62 asymptomatic 60- to 80-year-old patients had adequate radiographs. The mean plumb line values in the 20- to 40-year-old patients and 60- to 80-year-old patients, respectively, were as follows; CCOM 9.0 mm (SD, 31.5 mm) and 41.2 mm (SD, 35.7 mm); C2 -2.7 mm (SD, 32.7 mm) and 32.1 mm (SD, 33.6 mm); and C7 -16.4 mm (SD, 31.5 mm) and 10.6 mm (SD, 27.8 mm). One-way analysis of variance and Student t tests confirmed that these mean plumb line values were significantly different between young and elderly patients (P < 0.001). The change at each level over time was highly correlated with the other levels (r > 0.97; P < 0.001) as did the degree of change between groups (r > 0.90, P < 0.001). CONCLUSION: Spinopelvic alignment in conjunction with CCOM has increased our understanding of spinal balance by including the head and may better represent true global spinal balance. CCOM is an easily measured parameter by using the nasion-inion technique.

Rapidly progressive Scheuermann's disease in an adolescent after pectus bar placement treated with posterior vertebral-column resection: case report and review of the literature.

STUDY DESIGN: Case report and review of the literature. OBJECTIVE: This case illustrates the importance of the costosternal complex in maintaining the stability and alignment of the thoracic spine. The patient was iatrogenically destabilized by placement of a pectus bar leading to rapid symptomatic progression of his Scheuermann's kyphosis, ultimately requiring surgical correction. SUMMARY OF BACKGROUND DATA: Scheuermann's kyphosis is a disease process defined by strict radiographical and clinical criteria. Surgical treatment is generally recommended for curves greater than 75°. This case demonstrates the critical role of the costosternal complex in maintaining the stability of the thoracic spine. The patient described in this report underwent placement of a pectus bar for correction of symptomatic pectus excavatum. He subsequently developed a progressive symptomatic Scheuermann's kyphosis as a result of the destabilization of his costosternal complex. This patient ultimately required removal of the pectus bar and posterior instrumented kyphosis correction. METHODS: Progressive symptomatic Scheuermann's kyphosis (105°) corrected by removal of the pectus bar, T11 posterior vertebral-column resection and T4-L3 instrumented posterior spinal fusion. RESULTS: The patient had an uneventful immediate postoperative course. He was discharged neurologically intact with dramatic kyphosis correction and significant symptomatic improvement. Radiographs obtained 3 years postoperatively reveal stable thoracolumbar correction. CONCLUSION: The costosternal complex plays a critically important role in the intrinsic stability of the thoracic spine. Iatrogenic disruption of the costosternal complex can result in rapid progression of thoracic/thoracolumbar kyphosis in the setting of Scheuermann's disease.

Major complications and comparison between 3-column osteotomy techniques in 105 consecutive spinal deformity procedures.

STUDY DESIGN: A retrospective review. OBJECTIVE: To characterize the risk factors for the development of major complications in 3-column osteotomies and determine whether the presence of a major complication affects ultimate clinical outcomes. SUMMARY OF BACKGROUND DATA: Three-column spinal osteotomies, including pedicle subtraction osteotomy (PSO) and vertebral column resection (VCR), are common techniques to correct severe and/or rigid spinal deformities. METHODS: Two hundred forty consecutive PSO (n = 156) and VCR (n = 84) procedures in 237 patients were performed at a single institution between 1995 and 2008. Of these, 105 patients (87 PSOs, 18 VCRs) had complete preoperative and minimum 2-year postoperative clinical outcomes data available for analysis. Using established criteria, we reported complications as major or minor and further stratified complications as surgical versus medical and permanent versus transient. Risk factors for complications and their effect on Scoliosis Research Society (SRS) clinical outcomes at baseline and at 2 years or more were assessed. RESULTS: Major medical and surgical complications occurred at similar rates in both PSOs and VCRs (38%, 33 of 87 vs. 22%, 4 of 18; P = 0.28). Overall, 24.8% (26 of 105) experienced major surgical complications (3 permanent) and 15.2% (16 of 105) experienced major medical complications (4 permanent). Patients with PSO were older (53 vs. 29 yr; P < 0.001), had greater estimated blood loss (1867 vs. 1278 mL; P = 0.02), and showed a trend toward fewer fused levels (10.1 vs. 12.2; P = 0.06). Risk factors for major complications included preoperative sagittal imbalance of 40 mm or more (P = 0.01), age 60 years and older (P = 0.01), and the presence of 3 or more medical comorbidities (P = 0.04). Both groups improved significantly from baseline in SRS subscores; however, patients with PSO started off worse but improved more than VCRs in both the pain (+1.0 vs. +0.1; P < 0.001) and function (+0.6 vs. +0.2; P = 0.01) domains, with no differences in final satisfaction (4.1 vs. 4.3; P = 0.54). PSO and VCR patients with no complications had slightly higher satisfaction scores than patients with minor-only complications, major transient complications, and major permanent complications. There were no significant differences among the groups with respect to change in SRS subscores from baseline, and all complication groups improved significantly from baseline (P = 0.04). CONCLUSION: Major complications occurred in 35% of 3-column osteotomies and at similar rates for both PSO (38%) and VCR (22%) procedures. The presence of a major complication did not affect the ultimate clinical outcomes at 2 years or more.

Comprehensive assessment of prophylactic preoperative inferior vena cava filters for major spinal reconstruction in adults.

STUDY DESIGN: A retrospective data analysis. OBJECTIVE: To report a comprehensive assessment of preoperative prophylactic inferior vena cava (IVC) filter placement in spine surgery. SUMMARY OF BACKGROUND DATA: Venous thromboembolism (VTE) is a serious complication after major spinal reconstructive surgery in adults. Specifically, pulmonary embolism (PE) can result in significant morbidity and mortality, and it has been reported in up to 13% of patients. Prophylactic IVC filter placement was initiated for all "high-risk" spinal surgery patients after a pilot study demonstrated decreased VTE-related morbidity and mortality. METHODS: After institutional review board approval, the medical records of all patients receiving an IVC filter at a single institution from 2000 to 2007 were reviewed. Age, sex, surgical approach, postoperative deep vein thrombosis (DVT), postoperative superficial thrombus, presence of pulmonary or paradoxical embolus, mortality, and IVC filter complications were all evaluated. Indications for IVC filter placement included history of DVT or PE, malignancy, hypercoagulability, prolonged immobilization, staged procedures of longer than 5 segment levels, combined anterior-posterior approaches, iliocaval manipulation during exposure, and anesthetic time of more than 8 hours. Descriptive statistics were used for the analysis of patient characteristics. Nonparametric frequency statistics (odds ratios [OR], χ) were used for analysis of main outcomes. RESULTS: A total of 219 patients (150 women, 69 men) with a mean age of 58.8 (range, 17-86) years, were analyzed. There were 2 complications from IVC filter placement (66 Greenfield filters; 157 retrievable filters). The incidence of lower extremity DVT was 18.7% (41/219) in 36 patients. PE incidence was 3.7% (8/219 patients), and the paradoxical embolus rate was 0.5% (1 patient). Prophylactic IVC filter use reduced the odds of developing a pulmonary embolus (OR = 3.7, P < 0.05) compared with population controls. Patients receiving Greenfield filters had significantly higher VTE incidence than those receiving retrievable filters (OR = 2.8, P = 0.008). Anesthesia duration of more than 8 hours significantly increases VTE incidence (P = 0.029). No statistical significance (P < 0.05) was noted with combined anterior-posterior approach (118 patients) versus posterior-only approach (101 patients) and the incidence of DVT (24/118, 20.3% for former; 17/101, 16.8% for latter). There were a total of 14 deaths; none related to PE or paradoxical embolism during an 8-year period. Mean and median follow-up was 2.8 and 2.4 years, respectively, with 126 achieving 2 or more years of follow-up. CONCLUSION: VTE-related morbidity and mortality have heightened the awareness within the spine community to the perioperative management of patients undergoing major spinal reconstruction. Prophylactic IVC filter placement significantly lowers VTE-related events, including PE development, than population controls.

Does a long-fusion "T3-sacrum" portend a worse outcome than a short-fusion "T10-sacrum" in primary surgery for adult scoliosis?

STUDY DESIGN: Retrospective clinicoradiographic analysis. OBJECTIVE: To compare the upper thoracic (UT) and lower thoracic (LT) spines as the upper instrumented vertebra in primary fusions to the sacrum for adult scoliosis. SUMMARY OF BACKGROUND DATA: The optimal level at which a fusion to the sacrum is terminated proximally for adult scoliosis remains controversial. We hypothesized that (1) UT spine would have an increased pseudarthrosis, more perioperative complications, and worse outcomes and (2) LT spine would have more proximal junctional kyphosis. METHODS: Patients who underwent primary surgery for adult scoliosis between 2002 and 2006 were studied. UT and LT groups were matched cohorts. Minimum follow-up for all patients was 2 years. Scoliosis Research Society scores and Oswestry Disability Index were the clinical outcome measures. RESULTS: Fifty-eight patients (UT = 20, LT = 38) with a mean age of 55.7 years were followed for an average of 3.0 ± 1.1 years. The UT group had greater preoperative thoracic kyphosis and coronal Cobb values (P < 0.05). Diagnoses were idiopathic scoliosis (75.9%) and degenerative scoliosis (24.1%). The UT cohort had a greater number of levels fused (15.8 vs. 8.6) and higher blood loss (1350 mL vs. 811 mL). Operative time, recombinant human bone morphogenetic protein-2 per level, and caudal interbody grafting (80.0% UT vs. 89.5% LT) were similar. The UT group experienced an increased number of perioperative complications (30.0% vs. 15.8%), more pseudarthrosis (20.0% vs. 5.3%), and a higher prevalence of revision surgery (20.0% vs. 10.5%). The LT group had more proximal junctional kyphosis (18.4% vs. 10.0%). Scoliosis Research Society scores and Oswestry Disability Index were improved in both cohorts in all domains (P < 0.001), except function (P = 0.07) and mental health (P = 0.27), which were not significantly improved in the UT group. CONCLUSION: With long fusions to the sacrum, one should anticipate more perioperative complications, a higher pseudarthrosis rate, and perhaps more revision surgery than short fusions. Short fusions may result in a more proximal junctional kyphosis, only rarely requiring revision surgery.

Should symptomatic iliac screws be electively removed in adult spinal deformity patients fused to the sacrum?

STUDY DESIGN: Retrospective, single-institution review of adult deformity patients who underwent iliac screw (IS) removal placed during fusion to the sacrum. OBJECTIVE: To demonstrate whether IS removal offered benefit in terms of hip/buttock pain overlying the IS and whether IS could be removed without significant complications. SUMMARY OF BACKGROUND DATA: ISs are effective at countering cantilever forces imparted on sacral pedicle screws. Despite the efficacy of IS fixation, pain or implant prominence can lead to elective IS removal. There has been no study about IS removal in adult spinal deformity patients. METHODS: A total of 395 consecutive walking adult spinal deformity patients fused to the sacrum with IS fixation and minimum 2-year follow-up met study inclusion criteria. Clinical/radiographical data were analyzed. Because there is no validated pain outcomes instrument specific to this situation, an 8-question IS removal questionnaire was designed and used for the sole purpose of this inquiry, within which a universally accepted numeric rating scale for pain was included. RESULTS.: Twenty-four of 395 (6.1%) patients (2 men and 22 women) with mean age of 50.5 ± 10.8 years underwent elective IS removal at mean 2.6 ± 1.3 years from index surgery. Mean follow-up from initial surgery was 6.3 ± 4.0 years. Symptoms included hip/buttock pain in all 24 patients and IS prominence in 5 patients (20.8%). Screw removal was bilateral in 18 (75%) patients and unilateral in 6 (25%) patients. Using a numeric rating pain scale (0-10), hip/buttock pain improved after IS removal: preoperative 6.9 ± 1.8, postoperative 2.0 ± 2.7 (P < 0.05). Patients reported hip/buttock symptoms post-IS removal as "much improved" (78.3%), "somewhat improved" (8.7%), and "unchanged" (13.0%). Two of 24 (8.3%) patients sustained complications from IS removal (wound infection, n = 1; coronal/sagittal imbalance, n = 1). Presented with the same set of circumstances, 22 of 24 (91.7%) patients would have their IS removed again, including one of the patients who had a complication. CONCLUSION: Of 395 consecutive walking patients who had ISs placed during fusion to the sacrum for adult spinal deformity, 24 (6.1%) underwent elective removal. Patients had a statistically significant improvement in hip/buttock pain after IS removal, and a low prevalence of complications after the procedure was observed.