BACKGROUND CONTEXT:Multiple methods are used to measure proximal junctional angle (PJA) and diagnose proximal junctional kyphosis (PJK) after fusion for adolescent idiopathic scoliosis (AIS); however, there is no gold standard. Previous studies using the three most common measurement methods, upper-instrumented vertebra (UIV)+1, UIV+2, and UIV to T2, have minimized the difficulty in obtaining these measurements, and often exclude patients for which measurements cannot be recorded. PURPOSE:The purpose of this study is to assess the technical feasibility of measuring PJA and PJK in a series of AIS patients who have undergone posterior instrumented fusion and to assess the variability in results depending on the measurement technique used. STUDY DESIGN/SETTING:A retrospective cohort study was carried out. PATIENT SAMPLE:There were 460 radiographs from 98 patients with AIS who underwent posterior spinal fusion at a single institution from 2006 through 2012. OUTCOME MEASURES:The outcomes for this study were the ability to obtain a PJA measurement for each method, the ability to diagnose PJK, and the inter- and intra-rater reliability of these measurements. METHODS:Proximal junctional angle was determined by measuring the sagittal Cobb angle on preoperative and postoperative lateral upright films using the three most common methods (UIV+1, UIV+2, and UIV to T2). The ability to obtain a PJA measurement, the ability to assess PJK, and the total number of patients with a PJK diagnosis were tabulated for each method based on established definitions. Intra- and inter-rater reliability of each measurement method was assessed using intra-class correlation coefficients (ICCs). RESULTS:A total of 460 radiographs from 98 patients were evaluated. The average number of radiographs per patient was 5.3±1.7 (mean±standard deviation), with an average follow-up of 2.1 years (780±562 days). A PJA measurement was only readable on 13%-18% of preoperative filmsand 31%-49% of postoperative films (range based on measurement technique). Only 12%-31% of films were able to be assessed for PJK based on established definitions. The rate of PJK diagnosis ranged from 1% to 29%. Of these diagnoses, 21%-100% disappeared on at least one subsequent film for the given patient. ICC ranges for intra-rater and inter-rater reliability were 0.730-0.799 and 0.794-0.836, respectively. CONCLUSIONS:This study suggests significant limitations of the three most common methods of measuring and diagnosing PJK. The results of studies using these methods can be significantly affected based on the exclusion of patients for whom measurements cannot be made and choice of measurement technique.

Background: There has been an increasing use of national databases to conduct orthopaedic research. Questions regarding the validity and consistency of these studies have not been fully addressed. The purpose of this study was to test for similarity in reported measures between two national databases commonly used for orthopaedic research. Methods: A retrospective cohort study of patients undergoing lumbar spinal fusion procedures during 2009 to 2011 was performed in two national databases: the Nationwide Inpatient Sample and the National Surgical Quality Improvement Program. Demographic characteristics, comorbidities, and inpatient adverse events were directly compared between databases. Results: The total numbers of patients included were 144,098 from the Nationwide Inpatient Sample and 8434 from the National Surgical Quality Improvement Program. There were only small differences in demographic characteristics between the two databases. There were large differences between databases in the rates at which specific comorbidities were documented. Non-morbid obesity was documented at rates of 9.33% in the Nationwide Inpatient Sample and 36.93% in the National Surgical Quality Improvement Program (relative risk, 0.25; p < 0.05). Peripheral vascular disease was documented at rates of 2.35% in the Nationwide Inpatient Sample and 0.60% in the National Surgical Quality Improvement Program (relative risk, 3.89; p < 0.05). Similarly, there were large differences between databases in the rates at which specific inpatient adverse events were documented. Sepsis was documented at rates of 0.38% in the Nationwide Inpatient Sample and 0.81% in the National Surgical Quality Improvement Program (relative risk, 0.47; p < 0.05). Acute kidney injury was documented at rates of 1.79% in the Nationwide Inpatient Sample and 0.21% in the National Surgical Quality Improvement Program (relative risk, 8.54; p < 0.05). Conclusions: As database studies become more prevalent in orthopaedic surgery, authors, reviewers, and readers should view these studies with caution. This study shows that two commonly used databases can identify demographically similar patients undergoing a common orthopaedic procedure; however, the databases document markedly different rates of comorbidities and inpatient adverse events. The differences are likely the result of the very different mechanisms through which the databases collect their comorbidity and adverse event data. Findings highlight concerns regarding the validity of orthopaedic database research.

The field of spine surgery has seen a marked increase in the use of national databases to conduct research. Questions regarding the validity and consistency of such studies have not been fully addressed.

BACKGROUND CONTEXT: Magnetic resonance imaging (MRI) is frequently used in the evaluation of degenerative conditions in the lumbar spine. The relative interrater and intrarater agreements of MRI findings across different pathologic conditions are underexplored, as most studies are focused on specific findings.PURPOSE: The purpose of this study was to characterize the interrater and intrarater agreements of MRI findings used to assess the degenerative lumbar spine.STUDY DESIGN: A retrospective diagnostic study at a large academic medical center was undertaken with a panel of orthopedic surgeons and musculoskeletal radiologists to assess lumbar MRIs using standardized criteria.PATIENT SAMPLE: Seventy-five subjects who underwent routine lumbar spine MRI at our institution were included.OUTCOME MEASURES: Each MRI study was assessed for 10 lumbar degenerative findings using standardized criteria. Lumbar vertebral levels were assessed independently, where applicable, for a total of 52 data points collected per study.METHODS: T2-weighted axial and sagittal MRI sequences were presented in random order to the four reviewers (two orthopedic spine surgeons and two musculoskeletal radiologists) independently to determine interrater agreement. The first 10 studies were reevaluated at the end to determine intrarater agreement. Images were assessed using standardized and pilot-tested criteria to assess disc degeneration, stenosis, and other degenerative changes. Interrater and intrarater absolute percent agreements were calculated. To highlight the most clinically important MRI disagreements, a modified agreement analysis was also performed (in which disagreements between the lowest two severity grades for applicable conditions were ignored). Fleiss kappa coefficients for interrater agreement were determined.RESULTS: The overall absolute and modified interrater agreements were 76.9% and 93.5%, respectively. The absolute and modified intrarater agreements were 81.3% and 92.7%, respectively. Average Fleiss kappa coefficient was 0.431, suggesting moderate overall agreement. However, when stratified by condition, absolute interrater agreement ranged from 65.1% to 92.0%. Disc hydration, disc space height, and bone marrow changes exhibited the lowest absolute interrater agreements. The absolute intrarater agreement had a narrower range, from 74.5% to 91.5%. Fleiss kappa coefficients ranged from fair-to-substantial agreement (0.282-0.618).CONCLUSIONS: Even in a study using standardized evaluation criteria, there was significant variability in the interrater and intrarater agreements of MRI in assessing different degenerative conditions of the lumbar spine. Clinicians should be aware of the condition-specific diagnostic limitations of MRI interpretation. (C) 2014 Elsevier Inc. All rights reserved.

BACKGROUND CONTEXT: Prior studies on the impact of obesity on spine surgery outcomes have focused mostly on lumbar fusions, do not examine lumbar discectomies or decompressions, and have shown mixed results regarding complications. Differences in sample sizes and body mass index (BMI) thresholds for the definition of the obese versus comparison cohorts could account for the inconsistencies in the literature.PURPOSE: The purpose of the study was to analyze whether different degrees of obesity influence the complication rates in patients undergoing lumbar spine surgery.STUDY DESIGN/SETTING: This was a retrospective cohort analysis of prospectively collected data using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database from 2005 to 2010.PATIENT SAMPLE: Patients in the de-identified, risk-adjusted, and multi-institutional ACS NSQIP database undergoing lumbar anterior fusion, posterior fusion, transforaminal lumbar interbody fusion/posterior lumbar interbody fusion (TLIF/PLIF), discectomy, or decompression were included.OUTCOME MEASURES: Primary outcome measures were 30-day postsurgical complications, including pulmonary embolism and deep vein thrombosis, death, system-specific complications (wound, pulmonary, urinary, central nervous system, and cardiac), septic complications, and having one or more complications overall. Secondary outcomes were time spent in the operating room, blood transfusions, length of stay, and reoperation within 30 days.METHODS: Patients undergoing lumbar anterior fusion, posterior fusion, TLIF/PLIF, discectomy, or decompression in the ACS NSQIP, 2005 to 2010, were categorized into four BMI groups: nonobese (18.5-29.9 kg/m(2)), Obese I (30-34.9 kg/m(2)), Obese II (35-39.9 kg/m(2)), and Obese III (greater than or equal to 40 kg/m(2)). Obese I to III patients were compared with patients in the nonobese category using chi-square test and analysis of variance. Multivariate linear/logistic regression models were used to adjust for preoperative risk factors.RESULTS: Data were available for 10,387 patients undergoing lumbar surgery. Of these, 4.5% underwent anterior fusion, 17.9% posterior fusion, 6.3% TLIF/PLIF, 40.7% discectomy, and 30.5% decompression. Among all patients, 25.6% were in the Obese I group, 11.5% Obese II, and 6.9% Obese III. On multivariate analysis, Obese I and III had a significantly increased risk of urinary complications, and Obese II and III patients had a significantly increased risk of wound complications. Only Obese III patients, however, had a statistically increased risk of having increased time spent in the operating room, an extended length of stay, pulmonary complications, and having one or more complications (all p<.05).CONCLUSIONS: Patients with high BMI appear to have higher complication rates after lumbar surgery than patients who are nonobese. However, the complication rates seem to increase substantially for Obese III patients. These patients have longer times spent in the operating room, extended hospitals stays, and an increased risk for wound, urinary, and pulmonary complications and for having at least one or more complications overall. Surgeons should be aware of the increased risk of multiple complications for patients with BMI greater than or equal to 40 kg/m(2). (C) 2014 Elsevier Inc. All rights reserved.

Familial primary hyperparathyroidism (FPHPT) may occur due to an underlying germ-line mutation in the MEN1, CASR, or HRPT2/CDC73 genes. The disease may be undiagnosed in the absence of a history suggestive of FHPT. Young PHPT patients (≤45 years of age) are more likely to harbor occult FPHPT. A total of 1,161 (136 were ≤45 years of age) PHPT patients underwent parathyroidectomy from 2001 to 2009. Thirty-four patients declined participation. Sixteen patients were diagnosed in the clinical routine with FPHPT (11 MEN1, four MEN2A, and one HPT-JT) and were not included in the genetic analysis. Eighty-six young (≤45 years of age) patients with clinically non-syndromic PHPT underwent genetic analysis. Sanger sequencing of all coding regions of the MEN1, CASR, and the HRPT2/CDC73 genes was performed. Eight of 86 (9.3%) young patients with clinically non-familial PHPT displayed deleterious germ-line mutations in the susceptibility genes (4 MEN1, 3 CASR, and 1 HRPT2/CDC73). There was one insertion, one deletion, two nonsense, and four missense mutations, all predicted to be highly damaging to protein function and absent in 3,244 control chromosomes. Germ-line mutations in known susceptibility genes within young patients with PHPT, including those diagnosed in the clinical routine, was 24/102 (23.5%; 15 MEN1, four RET, three CASR, and two HRPT2/CDC73). We demonstrate that germ-line inactivating mutations in susceptibility genes are common in young patients with clinically non-familial PHPT. Thus, enhanced use of genetic analysis may be warranted in clinically non-familial young PHPT patients.

Spinal muscular atrophy is a genetic disorder that compromises motor strength and function and typically manifests in childhood. Patients with significant involvement will often develop scoliosis of neuromuscular origin as young children. In the past, brace treatment was of minimal benefit in halting curve progression and frequently added to respiratory compromise. Early spinal fusion surgery would limit trunk or sitting height and impair normal lung development. The strategy of using the growing rod distraction technique to permit longitudinal spinal growth while managing the spinal deformity has emerged as a viable means of managing scoliosis and spinal deformity in this challenging patient population.

Background: Lumbar total disc arthroplasty is often performed in patients with axial back pain. There are multiple etiologies for axial back pain, including disc degeneration and annular tears. The location of these annular tears can vary, producing differing preoperative symptomatology. Intraoperatively, disruptions in the annulus are identifiable, and it has been suggested that patients with discrete annular tears may have better clinical outcomes after surgery. The purpose of this study was to investigate whether the presence and location of annular tears have an effect on clinical outcomes after lumbar total disc arthroplasty.Methods: Patients undergoing a single-level anterior disc replacement from L3-S1 at a single site by a single surgeon were evaluated preoperatively for the presence or absence of annular tears with magnetic resonance imaging. All patients were part of either the ProDisc (n = 41) (Synthes, Paoli, Pennsylvania) or Activ-L (n = 19) (Aesculap [B. Braun Melsungen AG], Tuttlingen, Germany) lumbar prospective clinical trials. In those patients with annular tears, the location of the tear (central, paracentral, or lateral) was documented. Patients were assessed at 6 and 12 months after lumbar total disc arthroplasty with the Oswestry Disability Index (ODI), visual analog scale (VAS) score for back pain, VAS score for leg pain, and radiographic imaging. All radiographic evaluations were conducted by an attending neuroradiologist and an attending spinal surgeon, and reliability testing was performed. An analysis of variance was performed among the 3 anatomic locations of annular tears.Results: A total of 60 patients were included and had complete 12-month follow-up. The prevalence of annular tears among all patients was 42% (n = 25). Outcome data in patients without annular tears were as follows: ODI, 66% preoperatively and 26% postoperatively; VAS score for back pain, 8.0 preoperatively and 2.6 postoperatively; and VAS score for leg pain, 2.9 preoperatively and 1.2 postoperatively. Among those patients with tears, the prevalence of central tears was 80%, the prevalence of paracentral tears was 12%, and the prevalence of lateral tears was 8%. Outcome data in patients with central tears were as follows: ODI, 66% preoperatively and 26% postoperatively; VAS score for back pain, 7.8 preoperatively and 2.6 postoperatively; and VAS score for leg pain, 5.2 preoperatively and 0.5 postoperatively. Outcome data in patients with paracentral tears were as follows: ODI, 86% preoperatively and 59% postoperatively; VAS score for back pain, 8.8 preoperatively and 3.3 postoperatively; and VAS score for leg pain, 5.0 preoperatively and 5.4 postoperatively. Outcome data in patients with lateral tears were as follows: ODI, 6.5 preoperatively and 2.6 postoperatively; VAS score for back pain, 9.2 preoperatively and 0.2 postoperatively; and VAS score for leg pain, 1.4 preoperatively and 0.7 postoperatively. In those patients with paracentral tears, there was a significantly higher incidence of postoperative radicular symptoms both from an intensity standpoint and from a duration standpoint. Other complications did not vary among those patients with or without annular tears.Conclusions: Although patients with annular tears and patients without annular tears improve after lumbar artificial disc replacement, those with central annular tears or without tears have significantly lower disability scores than those with paracentral tears or lateral tears, whose outcome scores showed significantly less improvement (P <= .03). In particular, patients with central tears have less postoperative leg pain than those with paracentral annular tears. In this study the presence or absence of an annular tear on magnetic resonance imaging was not a significant predictive factor for clinical outcome. Further investigation regarding the effects of paracentral annular tears and surgical techniques should be explored. (C) 2012 ISASS - International Society for the Advancement of Spine Surgery. Published by Elsevier Inc. All rights reserved.

The clinical and pathological characteristics of hyperparathyroidism-induced hypercalcemic crisis (HIHC) are incompletely described. The present study was designed to elucidate the nature and effects of HIHC in patients undergoing parathyroidectomy in our unit.

Neurogenic claudication secondary to lumbar spinal stenosis (LSS) generally responds to conservative measures, but individuals with persistent symptoms or significant functional disability often require surgical intervention. Interspinous spacers (ISSs) have been introduced as a novel method for reproducing the postural relief that these individuals typically experience with lumbar flexion, which may avoid much of the morbidity of other operative procedures, such as a laminectomy. By distracting the interspinous space, ISSs have been shown to increase the dimensions of the spinal canal and foramina, thereby bringing about an “indirect” decompression of the neural elements. There is only one implant currently approved by the Food and Drug Administration for the treatment of intermittent neurogenic claudication arising from 1 or 2 levels of LSSs confirmed by appropriate imaging studies. As part of the surgical technique, the patient must be maintained in maximum flexion to facilitate the safe placement of the implant, and care must be taken to adequately preserve the interspinous ligament. Multiple in vitro and clinical investigations have established the safety and efficacy of ISS, but these devices are known to be associated with a number of complications, including spinous process and neurologic sequelae. Although additional prospective clinical trials are necessary to establish the long-term durability and cost-effectiveness of ISS, this strategy remains a viable, less invasive option for the treatment of symptomatic LSS compared with posterior decompression.

Purpose of review Differentiated thyroid cancer (DTC), with a rapidly increasing incidence is the most common endocrine malignancy, but with generally favorable survival. Total thyroidectomy with 'therapeutic' cervical lymph node dissection for involved lymph nodes is the standard of care. A more controversial topic is whether routine 'prophylactic' central lymph node dissection (CLND) in patients without evidence of lymph node metastasis should be performed in patients with DTC, as suggested by several recent management guidelines. Recent findings A number of retrospective studies suggest that regional lymph node metastases are associated with tumor recurrence and adverse survival. CLND is associated with a higher rate of postoperative athyroglobulinemia and may modify the indications for radioactive iodine treatment. Current guidelines from the American Thyroid Association suggest that prophylactic CLND may be performed for papillary thyroid cancer, especially for advanced tumors (T3 and T4). Summary Recent studies and the arguments for and against prophylactic CLND are reviewed. There is currently a trend toward more aggressive surgical therapy, including prophylactic CLND and avoidance of radioactive iodine treatment for DTC, when appropriate. Randomized prospective controlled trials are lacking at this point to determine the role of prophylactic CLND in the management of DTC.

H anbook of Sine Sugery Drawing on the experience of leaders in both neurosurgery and orthopedic surgery, Handbook of Spine Surgery is authoritative, concise, and portable—designed for use in a fast-paced clinical setting. Its coverage of both principles and techniques of contemporary spine surgery makes it a useful refresher before surgery, a digestible study guide, or a daily companion for physicians caring for patients with spinal disorders.