Incidence of Congenital Spinal Abnormalities Among Pediatric Patients and Their Association With Scoliosis and Systemic Anomalies.

BACKGROUND: Congenital abnormalities when present, according to VACTERL theory, occur nonrandomly with other congenital anomalies. This study estimates the prevalence of congenital spinal anomalies, and their concurrence with other systemic anomalies. METHODS: A retrospective cohort analysis on Health care Cost and Utilization Project's Kids Inpatient Database (KID), years 2000, 2003, 2006, 2009 was performed. ICD-9 coding identified congenital anomalies of the spine and other body systems. OUTCOME MEASURES: Overall incidence of congenital spinal abnormalities in pediatric patients, and the concurrence of spinal anomaly diagnoses with other organ system anomalies. Frequencies of congenital spine anomalies were estimated using KID hospital-and-year-adjusted weights. Poisson distribution in contingency tables tabulated concurrence of other congenital anomalies, grouped by body system. RESULTS: Of 12,039,432 patients, rates per 100,000 cases were: 9.1 hemivertebra, 4.3 Klippel-Fiel, 56.3 Chiari malformation, 52.6 tethered cord, 83.4 spina bifida, 1.2 absence of vertebra, and 6.2 diastematomyelia. Diastematomyelia had the highest concurrence of other anomalies: 70.1% of diastematomyelia patients had at least one other congenital anomaly. Next, 63.2% of hemivertebra, and 35.2% of Klippel-Fiel patients had concurrent anomalies. Of the other systems deformities cooccuring, cardiac system had the highest concurrent incidence (6.5% overall). In light of VACTERL's definition of a patient being diagnosed with at least 3 VACTERL anomalies, hemivertebra patients had the highest cooccurrence of ≥3 anomalies (31.3%). With detailed analysis of hemivertebra patients, secundum ASD (14.49%), atresia of large intestine (10.2%), renal agenesis (7.43%) frequently cooccured. CONCLUSIONS: Congenital abnormalities of the spine are associated with serious systemic anomalies that may have delayed presentations. These patients continue to be at a very high, and maybe higher than previously thought, risk for comorbidities that can cause devastating perioperative complications if not detected preoperatively, and full MRI workups should be considered in all patients with spinal abnormalities. LEVEL OF EVIDENCE: Level III.

Full-Body Radiographic Analysis of Postoperative Deviations From Age-Adjusted Alignment Goals in Adult Spinal Deformity Correction and Related Compensatory Recruitment.

BACKGROUND: Full-body stereographs for adult spinal deformity (ASD) have enhanced global deformity and lower-limb compensation associations. The advent of age-adjusted goals for classic ASD parameters (sagittal vertical axis, pelvic tilt, spino-pelvic mismatch [PI-LL]) has enabled individualized evaluation of successful versus failed realignment, though these remain to be radiographically assessed postoperatively. This study analyzes pre- and postoperative sagittal alignment to quantify patient-specific correction against age-adjusted goals, and presents differences in compensation in patients whose postoperative profile deviates from targets. METHODS: Single-center retrospective review of ASD patients ≥ 18 years with biplanar full-body stereographic x-rays. Inclusion: ≥ 4 levels fused, complete baseline and early (≤ 6-month) follow-up imaging. Correction groups generated at postoperative visit for actual alignment compared to age-adjusted ideal values for pelvic tilt, PI-LL, and sagittal vertical axis derived from clinically relevant formulas. Patients that matched exact ± 10-year threshold for age-adjusted targets were compared to unmatched cases (undercorrected or overcorrected). Comparison of spinal alignment and compensatory mechanisms (thoracic kyphosis, hip extension, knee flexion, ankle flexion, pelvic shift) across correction groups were performed with ANOVA and paired t tests. RESULTS: The sagittal vertical axis, pelvic tilt, and PI-LL of 122 patients improved at early postoperative visits (P < .001). Of lower-extremity parameters, knee flexion and pelvic shift improved (P < .001), but hip extension and ankle flexion were similar (P > .170); global sagittal angle decreased overall, reflecting global postoperative correction (8.3° versus 4.4°, P < .001). Rates of undercorrection to age-adjusted targets for each spino-pelvic parameter were 30.3% (sagittal vertical axis), 41.0% (pelvic tilt), and 43.6% (PI-LL). Compared to matched/overcorrections, undercorrections recruited increased posterior pelvic shift to compensate (P < .001); knee flexion was recruited in undercorrections for sagittal vertical axis and pelvic tilt; thoracic hypokyphosis was observed in PI-LL undercorrections. All undercorrected groups displayed consequentially larger global sagittal angle (P < .001). CONCLUSIONS: Global alignment cohort improvements were observed, and when comparing actual to age-adjusted alignment, undercorrections recruited pelvic and lower-limb flexion to compensate. LEVEL OF EVIDENCE: 3.

Measurement of Spinopelvic Angles on Prone Intraoperative Long-Cassette Lateral Radiographs Predicts Postoperative Standing Global Alignment in Adult Spinal Deformity Surgery.

STUDY DESIGN: Retrospective review from a single institution. OBJECTIVES: To evaluate intraoperative T1-pelvic angle (TPA), T4PA, and T9PA as predictors of postoperative global alignment after adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA: Malalignment following adult spinal surgery is associated with disability and correlates with health-related quality of life. Preoperative planning and intraoperative verification are crucial for optimal postoperative outcomes. Currently, only pelvic incidence minus lumbar lordosis (PI-LL) mismatch has been used to assess intraoperative correction. METHODS: Patients undergoing ≥4-level spinal fusion with full-length pre-, intra-, and first postoperative calibrated radiographs were included from a single institution. Alignment measurements were obtained for sagittal vertical axis (SVA), PI-LL, TPA, T4PA, and T9PA. The whole cohort was divided into upper thoracic (UT: UIV > T7) and lower thoracic fusions (LT: UIV < T7). Change was assessed between phases, and a subanalysis was included for UT and LT groups to compare alignment changes for differing extent of proximal fusion in the sagittal plane. RESULTS: Eighty patients (mean 63.4 years, 70% female, mean levels fused 11.9) underwent significant ASD correction (ΔPI-LL = 22.1°; ΔTPA = 13.8°). For all, intraoperative TPA, T4PA, and T9PA correlated with postoperative SVA (range, r = 0.41-0.59), whereas intraoperative PI-LL correlated less (r = 0.38). For UT (n = 49), all spinopelvic angles and LL were similar intraoperative to postoperatively (p > .09). For LT (n = 31), intraoperative and postoperative T9PA and LL were similar (p > .10) but TPA and T4PA differed (p < .02). For UT, all intraoperative and postoperative spinopelvic angles strongly correlated (r = 0.8-0.9). For LT, intraoperative to postoperative T9PA strongly correlated (r = 0.83) and TPA, T4PA, and LL correlated moderately (r = 0.65-0.70). LT trended toward more reciprocal kyphosis postoperatively (8.1° vs. 2.6°; p = .059). CONCLUSIONS: Intraoperative measurements of TPA, T4PA, and T9PA correlated better with postoperative global alignment than PI-LL, demonstrating their utility in confirming alignment goals. When comparing intraoperative to postoperative films, only T9PA was similar in LT whereas all spinopelvic angles were similar in UT. Reciprocal kyphosis in unfused segments of LT fusions may account for difference in TPA and T4PA from intraoperative to postoperative films. LEVEL OF EVIDENCE: Level III.

Defining the Role of the Lower Limbs in Compensating for Sagittal Malalignment.

MINI: Despite differences in sagittal malalignment, antero-posterior pelvic translation maintained the position of T9 in line with the ankles, independently of sagittal vertical axis. Pelvic tilt was directly predicted by lower limb compensatory mechanisms. Therefore, these adaptation mechanisms being included in pelvic tilt analysis, it does not need additional consideration in the surgical planning. STUDY DESIGN: Retrospective review. OBJECTIVE: To investigate the role of lower limbs compensation with progressive sagittal malalignment. SUMMARY OF BACKGROUND DATA: Although lower limb compensatory mechanisms are established response to progressive sagittal malalignment, their specific role and potential impact on surgical planning has not been evaluated. METHODS: Single center retrospective review of full body x-rays was performed in patients of age >20 years. Parameters were measured with dedicated software. Population was stratified by 50 mm intervals of sagittal vertical axis (SVA) and one-way ANOVA was performed to compare P.shift (P.shift = anteroposterior translation of the pelvis vs. the feet) across SVA groups. Anteroposterior offset of each vertebra in relation to a vertical line extended from the distal tibial metaphysis (TM) was investigated. Linear regression was performed to predict pelvic tilt (PT) using Knee angle (KA) and P.shift, whereas controlling for pelvic incidence minus lumbar lordosis mismatch (PI-LL) and SVA. RESULTS: A total of 2124 patient visits were included (PI = 55.1 ±â€Š14.1°, PT=21.0 ±â€Š11°, PI-LL=6.3 ±â€Š17.3°, SVA = 29 ±â€Š51 mm). With progressively increased SVA, P.shift decreased from 30 to -100 mm (all P < 0.005). Analysis of vertebral offset from the distal tibial metaphysis revealed that T9 was aligned with the TM line across all SVA groups. Prediction of PT based on PI-LL and SVA yielded R=0.76 (P < 0.001). Subsequent addition of KA and P.shift as independent parameters using hierarchical multiple regression led to significant improvement in R, demonstrating the independent role of lower limbs parameters in PT prediction. KA and P.shift had a positive standardized coefficient (all P < 0.05). CONCLUSION: Lower limb compensatory mechanisms increase with progressive sagittal malalignment. Anteroposterior translation of pelvis allows the T9 vertebra to remain in line with the ankle ("conus of economy"). Lower limb compensatory mechanisms are positive predictors of PT and thus do not require additional consideration in surgical realignment planning. LEVEL OF EVIDENCE: 3.

The Effect of Smoking on Spinal Fusion.

BACKGROUND: Spinal fusion surgery is performed about half a million times per year in the United States and millions more worldwide. It is an effective method for reducing pain, increasing stability, and correcting deformity in patients with various spinal conditions. In addition to being a well-established risk factor for a variety of medical conditions, smoking has deleterious effects on the bone healing of spinal fusions. This review aims to specifically analyze the ways in which smoking affects the outcomes of spinal fusion and to explore ways in which these negative consequences can be avoided. PURPOSE: This article provides a complete understanding of the ways smoking affects spinal fusion from a biochemical and clinical perspective. Recommendations are also provided for ways in which surgeons can limit patient exposure to the most serious negative outcomes associated with cigarette smoking. STUDY DESIGN/SETTING: This study was a retrospective literature review done using the NCBI database. The research was compiled at NYU Hospital for Joint Diseases and the NYU Center for Musculoskeletal Care. METHODS: A comprehensive literature review was done spanning research on a variety of subjects related to smoking and spinal fusion surgery. The biochemistry of smoking and fusion healing were examined in great detail. In addition, both in vivo animal studies and human clinical studies were evaluated to explore fusion success related to the effects of smoking and its biochemical factors on spinal fusion surgery. RESULTS: Smoking significantly increases the risk of pseudoarthrosis for patients undergoing both lumbar and cervical fusions. In addition to nonunion, smoking also increases the risk of other perioperative complications such as infection, adjacent-segment pathology, and dysphagia. Treatment options are available that can be explored to reduce the risk of smoking-related morbidity, such as nicotine replacement therapy and use of bone morphogenetic proteins (BMPs). CONCLUSIONS: It has been clearly demonstrated from both a biochemical and clinical perspective that smoking increases the rate of perioperative complications for patients undergoing spinal fusion surgery, particularly pseudoarthosis. It has also been shown that there are certain approaches that can reduce the risk of morbidity. The most important recommendation is smoking cessation for four weeks after surgery. In addition, patients may be treated with certain surgical techniques, including the use of BMPs, to reduce the risk of pseudoarthrosis. Lastly, nicotine replacement therapy is an area of continued interest in relation to spinal fusion outcomes and more research needs to be done to determine its efficacy moving forward.

Is There a Gender-Specific Full Body Sagittal Profile for Different Spinopelvic Relationships? A Study on Propensity-Matched Cohorts.

DESIGN: Retrospective review. OBJECTIVE: To evaluate gender-related differences in compensatory recruitment to progressive sagittal malalignment. SUMMARY OF BACKGROUND DATA: Recent research has elucidated compensatory mechanisms recruited in response to sagittal malalignment, but gender-specific differences in compensatory recruitment patterns is unknown. METHODS: Single-center study of patients with full body x-rays. A female group was propensity matched by age, body mass index (BMI), and pelvic incidence (PI) to a male group. Patients were then stratified into five groups of progressive PI-lumbar lordosis (LL) mismatch (<0°, 0°-10°, 10°-20°, 20°-30°, >30°). Differences between PI-LL groups were assessed with analysis of variance, and between genders by unpaired t test. Knee flexion to pelvic tilt (PT) ratio was computed and compared between genders. Multivariate regression to develop predictive models for PT was performed for each gender, first with spinopelvic parameters and subsequently with inclusion of lower limb parameters. RESULTS: A total of 942 patient visits were included: 471 females (mean age 54 years, BMI 27, PI 51°) and 471 males (mean age 52 years, BMI 27, PI 51°). At the lowest level of malalignment, females had greater PT and less knee flexion. With progressive malalignment, females continued to exhibit a pattern of greater pelvic retroversion and less knee flexion compared to males. Hip extension was higher in females with progressive PI-LL mismatch groups. Both genders progressively recruited knee flexion and pelvic retroversion with increased PI-LL mismatch, except that at the higher PI-LL mismatch groups, only males continued to recruit knee flexion (all p < .05). Inclusion of lower limbs in the regression for PT markedly improved correlation coefficients for females but not for males. CONCLUSIONS: With progressive sagittal malalignment, men recruit more knee flexion and women recruit more pelvic tilt and hip extension. Knee flexion is a possible mechanism to gain pelvic tilt for females whereas for males, knee flexion is an independent compensatory mechanism.

Effect of Antifibrinolytic Therapy on Complications, Thromboembolic Events, Blood Product Utilization, and Fusion in Adult Spinal Deformity Surgery.

STUDY DESIGN: A multicenter, prospective, consecutive database of surgical patients with adult spinal deformity (ASD). OBJECTIVE: This study investigated the use of antifibrinolytic (AF) therapy in ASD surgery. SUMMARY OF BACKGROUND DATA: AF therapy has been shown to be effective in preventing blood loss in some settings. Its effect on major and minor perioperative complications, blood product utilization, vascular events, and postoperative fusion in patients undergoing ASD surgery remains unclear. METHODS: All patients with data on AF use were included. Parameters of blood utilization included transfusion rates and units of packed red blood cells and fresh frozen plasma transfused. Thromboembolic events included stroke, deep vein thrombosis, and pulmonary embolus. Multivariate regression was used, accounting for confounders. RESULTS: Four hundred three patients were included. One hundred thirty-seven patients received aminocaproic acid (EACA), 81 received tranexamic acid (TXA), and 185 received no AFs. The use of AF was associated with a decrease in transfusion (EACA: odds ratio [OR] = 0.38, P = 0.043; TXA: OR = 0.31, P = 0.047), a decrease in the number of units of packed red blood cells transfused (EACA: incidence risk ratio [IRR] = 0.45, P = 0.0005; TXA: IRR = 0.7, P = 0.0005), and a decrease in the number of fresh frozen plasma transfused (EACA: IRR = 0.65, P = 0.003; TXA: IRR = 0.67, P = 0.006). AF use was associated with an increase in minor intraoperative complications (EACA: IRR = 2.15, P = 0.008; TXA: IRR = 2.12, P = 0.011). TXA use (but not EACA) was associated with a decrease in the incidence of major perioperative complications compared with no AF (IRR = 0.37, P = 0.019). There was no difference in the incidence of thromboembolic events. CONCLUSION: TXA or EACA use was associated with increased minor intraoperative complications. TXA was associated with decreased major perioperative complications. AF was associated with decreased utilization of blood products without an increased rate of thromboembolic events. Given the nature of this study, transfusion threshold was not standardized. Future studies with rigid criteria for transfusion should be prospectively performed to better evaluate the impact of AF during ASD surgery. LEVEL OF EVIDENCE: 3.

Global sagittal axis: a step toward full-body assessment of sagittal plane deformity in the human body.

OBJECTIVE Sagittal malalignment requires higher energy expenditure to maintain an erect posture. Because the clinical impact of sagittal alignment is affected by both the severity of the deformity and recruitment of compensatory mechanisms, it is important to investigate new parameters that reflect both disability level and compensatory mechanisms for all patients. This study investigated the clinical relevance of the global sagittal axis (GSA), a novel measure to evaluate the standing axis of the human body. METHODS This is a retrospective review of patients who underwent full-body radiographs and completed health-related quality of life (HRQOL) questionnaires: Oswestry Disability Index (ODI), Scoliosis Research Society-22, EuroQol-5D (EQ-5D), and the visual analog scale for back and leg pain. The GSA was defined as the angle formed by a line from the midpoint of the femoral condyles to the center of C-7, and a line from the midpoint between the femoral condyles to the posterior superior corner of the S-1 sacral endplate. After evaluating the correlation of GSA/HRQOL with sagittal parameters, linear regression models were generated to investigate how ODI and GSA related to radiographic parameters (T-1 pelvic angle, pelvic retroversion, knee flexion, and pelvic posterior translation). RESULTS One hundred forty-three patients (mean age 44 years) were included. The GSA correlated significantly with all HRQOL (up to r = 0.6 with EQ-5D) and radiographic parameters (up to r = 0.962 with sagittal vertical axis). Regression between ODI and sagittal radiographic parameters identified the GSA as an independent predictor (r = 0.517, r2 = 0.267; p < 0.001). Analysis of standardized coefficients revealed that when controlling for deformity, the GSA increased with a concurrent decrease in pelvic retroversion (-0.837) and increases in knee flexion (+0.287) and pelvic posterior translation (+0.193). CONCLUSIONS The GSA is a simple, novel measure to assess the standing axis of the human body in the sagittal plane. The GSA correlated highly with spinopelvic and lower-extremities sagittal parameters and exhibited remarkable correlations with HRQOL, which exceeded other commonly used parameters.

Predicting Cervical Alignment Required to Maintain Horizontal Gaze Based on Global Spinal Alignment.

STUDY DESIGN: A retrospective cohort. OBJECTIVE: The aim of this study was to investigate the cervical alignment necessary for the maintenance of horizontal gaze that depends on underlying thoracolumbar alignment. SUMMARY OF BACKGROUND DATA: Cervical Sagittal Curve (CC) is affected by thoracic and global alignment. Recent studies suggest large variability in normative CC ranging from lordotic to kyphotic alignment. No previous studies have assessed the effect of global spinal alignment on CC in maintenance of horizontal gaze. METHODS: Patients without previous history of spinal surgery and able to maintain their horizontal gaze while undergoing full body imaging were included. Patients were stratified on the basis of thoracic kyphosis (TK) into (<30, 30-40, 40-50, and >50) and then by SRS-Schwab sagittal vertical axis (SVA) modifier into (posterior alignment SVA <0, aligned 0-50, and malaligned >50 mm). Cervical alignment was assessed among SVA grade in TK groups. Stepwise linear regression analysis was applied on random selection of 60% of the population. A simplified formula was developed and validated on the remaining 40%. RESULTS: In each TK group (n = 118, 137, 125, 197), lower CC (C2-C7) was significantly more lordotic by increased Schwab SVA grade. T1 slope and cervical SVA significantly increased with increased thoracolumbar (C7-S1) SVA. Upper CC (C0-C2) and mismatch between T1 slope and CC (T1-CL) were similar. Regression analysis revealed LL minus TK (LL-TK) as an independent predictor (r = 0.640, r = 0.410) with formula: CC = 10- (LL-TK)/2. Validation revealed that the absolute difference between the predicted CC and the actual CC was 8.5°. Moreover, 64.2% of patients had their predicted C2-C7 values within 10° of the actual CC. CONCLUSION: Cervical kyphosis may represent normal alignment in a significant number of patients. However, in patients with SVA >50 and greater thoracic kyphosis, cervical lordosis is needed to maintain the gaze. Cervical alignment can be predicted from underlying TK and lumbar lordosis, which may be clinically relevant when considering correction for thoracolumbar or cervical deformityLevel of Evidence: 3.

When is compensation for lumbar spinal stenosis a clinical sagittal plane deformity?

BACKGROUND CONTEXT: Degenerative lumbar stenosis (DLS) patients have been reported to lean forward in an attempt to provide neural decompression. Spinal alignment in patients with DLS may resemble that of adult spinal deformity (ASD). No previous studies have compared and contrasted the compensatory mechanisms of DLS and ASD patients. PURPOSE: This study aimed to determine the differences in compensatory mechanisms between DLS and ASD patients with increasing severity of sagittal spinopelvic malalignment. Contrasting these compensatory mechanisms may help determine at what severity sagittal malalignment represents a clinical sagittal deformity rather than a compensation for neural compression. STUDY DESIGN/SETTING: This is a retrospective clinical and radiological review. PATIENT SAMPLE: Baseline x-rays in patients without spinal instrumentation, with the clinical radiological and diagnoses of DLS or ASD, were assessed for patterns of spinopelvic compensatory mechanisms. Patients were stratified by sagittal vertical axis (SVA) according to the Scoliosis Research Society-Schwab [SRS-Schwab] classification. OUTCOME MEASURES: Radiographic spinopelvic parameters were measured in the DLS and ASD groups, including SVA, pelvic incidence-lumbar lordosis mismatch (PI-LL), T1 spinopelvic inclination (T1SPi), T1 pelvic angle (TPA), and pelvic tilt (PT). METHODS: The two diagnosis cohorts were propensity-matched for PI and age. Each group contained 125 patients and was stratified according to the SRS-Schwab classification. Regional spinopelvic,lower limb, and global alignment parameters were assessed to identify differences in compensatory mechanisms between the two groups with differing degrees of deformity. No funding was provided by any third party in relation to carrying out this study or preparing the manuscript. RESULTS: With mild to moderate malalignment (SRS-Schwab groups "0," or "+" for PT, PI-LL, or SVA), DLS patients permit anterior truncal inclination and recruit posterior pelvic shift instead of pelvic tilt to maintain balance, while providing relief of neurologic symptoms. Adult spinal deformity patients with mild to moderate deformity recruit pelvic tilt earlier than DLS patients. With moderate to severe malalignment, no significant difference was found in compensatory mechanisms between DLS and ASD patients. CONCLUSIONS: Patients with DLS permit mild to moderate deformity without recruiting compensatory mechanisms of PT, reducing truncal inclination and thoracic hypokyphosis to achieve neural decompression. However, with moderate to severe deformity, their desire for upright posture overrides the desire for neural decompression, evident by the adaptation of compensatory mechanisms similar to that of ASD patients.

Variability Over Time of Preoperative Sagittal Alignment Parameters: Radiographic and Clinical Considerations.

STUDY DESIGN: Retrospective review. OBJECTIVE: To evaluate preoperative variability in radiographic sagittal parameters in adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA: In ASD surgical planning, deformity magnitude is determined from preoperative radiographs. There are no studies evaluating the clinical relevance and timing to repeat radiographs during interval clinic visits and timing to repeat radiograph for preoperative planning. METHODS: A total of 139 patients with ASD with minimum two preoperative full-body spine x-rays were included. Cervical, thoracic, lumbar, pelvic, and hip/knee sagittal alignment parameters were analyzed using dedicated spine measurement software. Patients were grouped by time intervals between x-rays: A: 8 weeks or lesser, B: 10 to 20 weeks, and C: 21 weeks or more. Changes in sagittal parameters were correlated to age and deformity magnitude (T1 pelvic angle or pelvic tilt [PT] >20°). RESULTS: The cohort had mean age 59 years, mean body mass index 27, 30% men, 95 patients with no prior spine surgery, and 44 patients at minimum 9 months since prior spine surgery. There were 25 patients in group A, 38 in B, and 71 in C. All radiographic measures showed good time-based consistency at intervals less than 21 weeks (groups A and B). Group C had significant increases in PT (1.5°) and hip extension (2.1°) (P < 0.05). These changes were greater in group C patients with previous surgery (PT 3.7°; P < 0.006, hip extension 3.2°; P < 0.025). Greater interval changes in parameters were also associated with higher magnitudes of deformity and younger patient ages. CONCLUSION: All sagittal radiographic parameters were statistically consistent at intervals of less than 21 weeks. In patients with more than 21 weeks between interval x-rays, change in PT was greater than the standard error of measurement for patients with prior surgery or severe deformity. Consideration should be made to obtain new x-rays for patients with ASD when the interval between clinical visits exceeds 5 months. LEVEL OF EVIDENCE: 4.

Pars Injuries in Athletes.

Pars injuries are common causes of low back pain in adolescent athletes. Workup traditionally has included lumbar radiographs with oblique views and single-photon emission computed tomography (SPECT). However, recent literature has demonstrated the accuracy of MRI as a diagnostic modality. Acute injuries may be amenable to bracing with the goal of a healed lesion. Most cases of spondylolysis will result in asymptomatic non-union, though pars repair is an option for symptomatic pars defects without spondylolisthesis.

Abnormal glucose tolerance testing after gastric bypass.

BACKGROUND: Symptoms secondary to dumping have been suggested to help patients refrain from simple carbohydrate ingestion after Roux-en-Y gastric bypass (RYGB). During follow-up examinations, we noted many patients with weight regain complaining of fatigue shortly after eating. Thus, we decided to study the glucose tolerance test (GTT) results in a cohort of post-RYGB patients. METHODS: A total of 63 RYGB patients, >6 months postoperatively, were studied with a GTT and measurement of insulin levels. The mean age was 48.5 ± 10.8 years, mean preoperative body mass index was 49.0 ± 6.5 kg/m(2), mean percentage of excess body mass index lost was 64.5% ± 29.0%, mean weight regain at follow-up was 11.6 ± 12.4 lb, and mean follow-up period was 47.9 months. RESULTS: Of the 63 patients, 49 had abnormal GTT results. Of the 63 patients, 6 were diabetic; however, only 1 of these patients had an elevated fasting glucose level. All 6 patients were diabetic preoperatively. Of the 63 patients, 43 had evidence of reactive hypoglycemia at 1-2 hours after the glucose load. Of these patients, 22 had a maximum/minimum glucose ratio >3:1, including 7 with a ratio >4:1. CONCLUSION: The results of the present study have demonstrated that an abnormal GTT result is a common finding after RYGB. Reactive hypoglycemia was found in 43 of 63 patients, with insulin values that do not support nesidioblastosis. It is our hypothesis, that rather than preventing simple carbohydrate ingestion, the induced hypoglycemia that occurs might contribute to weight regain and maladaptive eating in certain post-RYGB patients.