Anterior Cervical Infection: Presentation and Incidence of an Uncommon Postoperative Complication.

STUDY DESIGN: Retrospective multi-institutional case series. OBJECTIVE: The anterior cervical discectomy and fusion (ACDF) affords the surgeon the flexibility to treat a variety of cervical pathologies, with the majority being for degenerative and traumatic indications. Limited data in the literature describe the presentation and true incidence of postoperative surgical site infections. METHODS: A retrospective multicenter case series study was conducted involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network, selected for their excellence in spine care and clinical research infrastructure and experience. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, inclusive, were reviewed to identify the occurrence of 21 predefined treatment complications. Patients who underwent an ACDF were identified in the database and reviewed for the occurrence of postoperative anterior cervical infections. RESULTS: A total of 8887 patients were identified from a retrospective database analysis of 21 centers providing data for postoperative anterior cervical infections (17/21, 81% response rate). A total of 6 postoperative infections after ACDF were identified for a mean rate of 0.07% (range 0% to 0.39%). The mean age of patients identified was 57.5 (SD = 11.6, 66.7% female). The mean body mass index was 22.02. Of the total infections, half were smokers (n = 3). Two patients presented with myelopathy, and 3 patients presented with radiculopathic-type complaints. The mean length of stay was 4.7 days. All patients were treated aggressively with surgery for management of this complication, with improvement in all patients. There were no mortalities. CONCLUSION: The incidence of postoperative infection in ACDF is exceedingly low. The management has historically been urgent irrigation and debridement of the surgical site. However, due to the rarity of this occurrence, guidance for management is limited to retrospective series.

Esophageal Perforation Following Anterior Cervical Spine Surgery: Case Report and Review of the Literature.

STUDY DESIGN: Multicenter retrospective case series and review of the literature. OBJECTIVE: To determine the rate of esophageal perforations following anterior cervical spine surgery. METHODS: As part of an AOSpine series on rare complications, a retrospective cohort study was conducted among 21 high-volume surgical centers to identify esophageal perforations following anterior cervical spine surgery. Staff at each center abstracted data from patients' charts and created case report forms for each event identified. Case report forms were then sent to the AOSpine North America Clinical Research Network Methodological Core for data processing and analysis. RESULTS: The records of 9591 patients who underwent anterior cervical spine surgery were reviewed. Two (0.02%) were found to have esophageal perforations following anterior cervical spine surgery. Both cases were detected and treated in the acute postoperative period. One patient was successfully treated with primary repair and debridement. One patient underwent multiple debridement attempts and expired. CONCLUSIONS: Esophageal perforation following anterior cervical spine surgery is a relatively rare occurrence. Prompt recognition and treatment of these injuries is critical to minimizing morbidity and mortality.

C5 Palsy After Cervical Spine Surgery: A Multicenter Retrospective Review of 59 Cases.

STUDY DESIGN: A multicenter, retrospective review of C5 palsy after cervical spine surgery. OBJECTIVE: Postoperative C5 palsy is a known complication of cervical decompressive spinal surgery. The goal of this study was to review the incidence, patient characteristics, and outcome of C5 palsy in patients undergoing cervical spine surgery. METHODS: We conducted a multicenter, retrospective review of 13 946 patients across 21 centers who received cervical spine surgery (levels C2 to C7) between January 1, 2005, and December 31, 2011, inclusive. P values were calculated using 2-sample t test for continuous variables and χ2 tests or Fisher exact tests for categorical variables. RESULTS: Of the 13 946 cases reviewed, 59 patients experienced a postoperative C5 palsy. The incidence rate across the 21 sites ranged from 0% to 2.5%. At most recent follow-up, 32 patients reported complete resolution of symptoms (54.2%), 15 had symptoms resolve with residual effects (25.4%), 10 patients did not recover (17.0%), and 2 were lost to follow-up (3.4%). CONCLUSION: C5 palsy occurred in all surgical approaches and across a variety of diagnoses. The majority of patients had full recovery or recovery with residual effects. This study represents the largest series of North American patients reviewed to date.

Spinal Implant Density and Postoperative Lumbar Lordosis as Predictors for the Development of Proximal Junctional Kyphosis in Adult Spinal Deformity.

OBJECTIVE: To evaluate spinal implant density and proximal junctional kyphosis (PJK) in adult spinal deformity (ASD). METHODS: Consecutive patients with ASD receiving ≥5 level fusions were retrospectively analyzed between 2007 and 2010. INCLUSION CRITERIA: ASD, elective fusions, minimum 2-year follow-up. EXCLUSION CRITERIA: age <18 years, neuromuscular or congenital scoliosis, cervical or cervicothoracic fusions, nonelective conditions (infection, tumor, trauma). Instrumented fusions were classified by the Scoliosis Research Society-Schwab ASD classification. Statistical analysis consisted of descriptives (measures of central tendency, dispersion, frequencies), independent Student t tests, χ2, analysis of variance, and logistic regression to determine association of implant density [(number of screws + number of hooks)/surgical levels of fusion] and PJK. Mean and median follow-up was 2.8 and 2.7 years, respectively. RESULTS: Eighty-three patients (17 male, 66 female) with a mean age of 59.7 years (standard deviation, 10.3) were analyzed. Mean body mass index (BMI) was 29.5 kg/m2 (range, 18-56 kg/m2) with mean preoperative Oswestry Disability Index of 48.67 (range, 6-86) and mean preoperative sagittal vertical axis of 8.42. The mean levels fused were 9.95 where 54 surgeries had interbody fusion. PJK prevalence was 21.7%, and pseudoarthrosis was 19.3%. Mean postoperative Oswestry Disability Index was 27.4 (range, 0-74). Independent Student t tests showed that PJK was not significant for age, gender, BMI, rod type, mean postoperative sagittal vertical axis, or Scoliosis Research Society-Schwab ASD classification; but iliac fixation approached significance (P = 0.077). Implant density and postoperative lumbar lordosis (LL) were predictors for PJK (P = 0.018 and 0.045, respectively). Controlling for age, BMI, and gender, postoperative LL (not implant density) continued to show significance in multivariate logistic regression model. CONCLUSIONS: PJK, although influenced by a multitude of factors, may be statistically related to implant density and LL.

Cranial Center of Mass Compared to C7 Plumb Line Alignment in Adult Spinal Deformity.

OBJECTIVE: To report the cranial center of mass (CCOM) progression in surgically treated patients for adult spinal deformity (ASD). The C7 plumb line/sagittal vertical axis (SVA) has important relationships with patient-reported outcomes; however, this has not yet been defined for CCOM. METHODS: Patients with consecutive ASD who were undergoing surgery greater than 5 levels of fusion between 2007 and 2012 and had radiographic, clinical, and outcomes data spanning ≥2 years were analyzed, retrospectively. Radiographic parameters were obtained preoperatively and at 6 weeks, 1 year, and 2 years postoperatively. Statistical analysis included descriptives (measures of central tendency, dispersion, frequencies), independent Student t tests, χ(2) square, Pearson correlation, and Kaplan-Meyer curve. RESULTS: Fifty-eight patients (10 male, 48 female) with a mean age of 60.5 years (range, 27-81 years) were reviewed. The mean preoperative SVA was 7.40 cm (SD = 5.51; 37/58 [63.8%] malalignment), and mean CCOM was 10.0 cm (SD = 6.58; 47/58 [81%] malalignment). Six-week postoperative SVA and CCOM was -0.17 cm (SD = 3.3) and 2.5 cm (SD = 4.11), respectively. SVA malalignment was 12.7% and CCOM malalignment was 38.2% at 6 weeks postop. Six week (absolute), 6-week change, and patient number at 6 weeks who were CCOM malaligned was significant compared with SVA (P = 0.003, P < 0.001, P < 0.001, respectively). SRS appearance worsened as preoperative SVA and CCOM increased (P < 0.05), and 2-year SRS appearance and mental health was worsened as 2-year SVA and CCOM increased (P < 0.05). SVA malalignment was 8 and 10 at 1 and 2 years, respectively, and CCOM malalignment was 24 and 32, respectively. Kaplan-Meier curve demonstrates persistent malalignment of CCOM at 6 weeks if not corrected. CONCLUSION: CCOM alignment restoration is an important parameter in ASD, and malalignment is consistent over time.

Context Matters: Support for Leader Developmental Readiness.

Leader developers need to consider support for leader developmental readiness by examining organizational culture, job design and rewards, social support, and availability and structure of leader development programming.

Time to Event Analysis for the Development of Venous Thromboembolism After Spinal Fusion ≥ 5 Levels.

OBJECTIVE: Venous thromboembolism (VTE) is an important complication after spine surgery with an incidence of 31%. To our knowledge, no study has reported a time-dependent examination of factors influencing VTE. We report factors influencing first and multiple VTE events and perform a time-dependent analysis. METHODS: A retrospective analysis was performed of consecutive, "high-risk" patients receiving multilevel spinal fusion and an inferior vena cava (IVC) filter during the period 2000-2008. Descriptive statistics and frequencies were examined. Student t tests and logistic regression analysis identified confounders influencing development of acute VTE. Kaplan-Meier survival and Cox proportional hazard model evaluated time-dependent risk factors. Multivariate linear regression model analyzed multiple acute VTE events. RESULTS: There were 218 patients (149 women and 69 men) with an average age of 59.2 years (range, 18-86 years) who had 252 hospitalizations with an average stay of 20.3 days (SD = 15.6). There were 72 VTE events, with mean time to VTE of 15 days (SD = 18.1). Logistic regression identified factors influencing development of acute VTE, including sex (P = 0.04, OR = 0.243), VTE history (P = 0.001, OR = 8.0), IVC filter type (P = 0.050, OR = 15.6), chemoprophylaxis (P = 0.013, OR = 0.82), and hospital stay (P < 0.001, OR = 0.16). Kaplan-Meier curve revealed VTE history increased the rate of VTE development (P = 0.003). Cox proportional hazard model demonstrated IVC filter type (P = 0.003, hazard ratio = 5.042) and VTE history (P = 0.001, hazard ratio = 4.187) were significant for first VTE events. Linear regression analysis identified factors influencing development of multiple VTE events during a hospitalization, including VTE history (P < 0.01), chemoprophylaxis (P = 0.003), IVC filter type (P = 0.015), and hospital stay (P < 0.001). Mean and median follow-up were 3.3 years and 2.8 years, respectively. CONCLUSIONS: Sex, VTE history, IVC filter type, chemoprophylaxis, and hospital stay influenced development of VTE. Time to VTE correlated with DVT history and IVC filter type, whereas VTE history and hospital stay influenced multiple VTE events.

Renin-angiotensin system inhibitors and troponin elevation in spinal surgery.

Renin-angiotensin system (RAS) inhibition by angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) has been shown to reduce cardiovascular mortality and non-fatal myocardial infarction (MI) in high-risk surgical patients. However, their effect in spinal surgery has not been explored. Our objective was to determine the effect of RAS inhibitors on postoperative troponin elevation in spinal fusions, and to examine their correlation with hospital stay. We retrospectively analyzed 208 consecutive patients receiving spinal fusions ⩾5 levels between 2007-2010 with a mean follow-up of 1.7 years. Inclusion criteria were age ⩾18 years, elective fusions for kyphoscoliosis, and semi-elective fusions for tumor or infection. Exclusion criteria were trauma and follow-up <1 year. Descriptives, frequencies, and logistic and linear regression were used to analyze troponin elevation (⩾0.04 ng/mL), peak troponin level, and hospital stay. The results featured 208 patients with a mean body mass index (BMI) 28.5 kg/m(2) who underwent 345 spinal fusions. ACEI/ARB were withheld the day prior to surgery in 121 patients with 11 patients noteworthy for intra-operative electrocardiogram changes, 126 patients with troponin elevation, and 14 MI identified prior to discharge. Multivariate logistic regression identified BMI (p=0.04), estimated blood loss (p=0.015), and preoperative ACEI/ARB (p=0.015, odds ratio=2.7) as significant independent predictors for postoperative troponin elevation. Multivariate linear regression showed preoperative Oswestry Disability Index (p=0.002), unplanned return to operating room (p=0.007), pneumonia prior to hospital discharge (p<0.01), and preoperative ACEI/ARB to be associated with hospital stay. In patients with spinal fusions ⩾5 levels, ACEI/ARB are independently associated with postoperative troponin elevation and increased hospital stay.

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.