Morphology of the atlas pedicle revisited: a morphometric CT-based study on 120 patients

Purpose

To quantify the dimensions of the atlas pedicles and to analyze the relationship between extra medullary height (EMH) with intra medullary height (IMH) of the atlas pedicle.

Methods

The images of the patients who had CT scanning and three-dimensional (3D) reconstruction involving atlantoaxial complex between June 2011 and April 2012 and meet our inclusion criteria were studied retrospectively. After reformatting the original images, the EMH and IMH of the atlas pedicles were measured.

Results

Extra medullary height and IMH were, respectively, 4.83 ± 1.13 and 1.29 ± 1.10 mm for males and 3.75 ± 0.93 and 0.60 ± 0.83 mm for females, with statistical difference (P < 0.05). EMH and IMH had some correlation (correlation coefficient r = 0.804) but showed a large variability. Of 240 pedicles of 120 cases, 47.92 % (115 pedicles) were ≥1 mm; 12.08 % (29 pedicles) were between 0 and 1 mm; and 40 % (96 pedicles) were 0.

Conclusion

The EMH and the IMH of the atlas pedicles were measured by using CT images of the atlas, providing anatomic parameters for surgery. They showed a certain correlation but with a high variability. C1 pedicle screw fixation was well performed when the medullary canal was ≥1 mm, but the surgical procedure should be careful when it was between 0 and 1 mm, and avoided when there was no medullary canal in the atlas pedicle! So 3D CT reconstruction should be conducted to obtain data and establish individualized fixation strategy preoperatively.     

Small Cell Carcinoma of the Esophagus: A SEER Database Analysis

Background

Small cell cancer (SCC) of the esophagus is an uncommon malignancy with perceived poor prognosis, but there are few data to guide therapeutic decisions. We examined the Surveillance, Epidemiology, and End Results (SEER) database to identify prognostic factors for survival.

Methods

All patients with esophageal cancer in the SEER database between 1973 and 2009 were included. Univariate and multivariate analyses were performed in patients with and without SCC, examining the relationship of small cell histology, surgery, and other potential prognostic factors with overall survival (censored at 72 months).

Results

Of 64,799 esophageal cancer patients identified in the SEER database, 387 (0.6 %) had small cell histology. As compared with non-small cell histology, patients with small cell histology were similar in age and race but had a higher proportion of women (p < 0.001), had a higher stage at diagnosis (p < 0.001), and were less likely to undergo surgical resection (p < 0.01). Multivariate predictors associated with poor survival in the overall cohort included age, female gender, black race, and stage. In patients treated with surgery, multivariate predictors associated with poor survival included age, male gender, race, and stage but not small cell histology. In patients with small cell histology, both age and stage were associated with poor survival, but surgery and preoperative radiotherapy were associated with improved survival.

Conclusions

SCC of the esophagus presents at an advanced stage and confers a poor prognosis. The survival benefit of surgery and radiotherapy suggests that all esophageal SCC patients should be considered for preoperative radiotherapy and surgery in a stage-appropriate fashion.     

Validation of a CT-based determination of the glenohumeral index

The amount of bony support by the glenoid can be determined using the glenohumeral index, i.e. the maximum anteroposterior (AP) diameter of the humeral head divided by the maximum AP dimension of the glenoid. This index has been described theoretically, but has never been validated in practice. In this study we used 20 cadaver shoulders to determine the glenohumeral index in two different ways. One method evaluated the glenohumeral index on a CT scan of the shoulders. The second method determined the anatomical glenohumeral index of the same shoulders by direct measurement of anatomical specimens using a digital caliper. All CT and caliper measurements were repeated by three different investigators. We used the Wilcoxon Signed Rank Test, to calculate the statistical significance of intra-observer and inter-observer differences in measurements on CT and with the caliper. Statistical analysis showed no significant differences between CT scan and caliper measurements for each investigator separately, but we found a statistically significant inter-observer variability concerning the caliper measurements obtained by two different investigators. This study demonstrates that a two-dimensional CT scan of the shoulder is a reliable and very accurate tool to calculate the glenohumeral index, as the values measured for the AP diameter of the humeral head and the AP dimension of the glenoid compare well with those measured in vitro on anatomical specimens.     

Incidence of Acute Nonperforated and Perforated Appendicitis: Age-specific and Sex-specific Analysis

n = 544 (37%)] were analyzed with regard to prehospitalization duration of symptoms and in-hospital observation time. The crude incidence of acute appendicitis was 86 per 100,000 per year. Although the incidence of nonperforated appendicitis was highest among adolescents and young adults (13–40 years of age), perforated appendicitis occurred at almost the same incidence in all sex and age groups. The diagnostic accuracy was 76%. Perforated appendicitis occurred in 19%, with higher rates in small children and the elderly, irrespective of gender. A high diagnostic accuracy was not associated with an increased rate of perforation. In small children and the elderly, the diagnostic accuracy was low and the perforation rate high. Patients with perforation had a significantly longer duration of symptoms as well as in-hospital observation time than did patients with nonperforated appendicitis. Perforated appendicitis showed a different incidence pattern than nonperforated appendicitis and was associated with a significantly longer duration of symptoms and in-hospital observation time, probably due to patient-related factors. We suggest this observation deserves attention regarding clinical diagnosis and treatment decision-making for patients with suspected acute appendicitis.     

Analysis of cover of the femoral head in normal and dysplastic hips: new CT-based technique

We present a new CT-based method which measures cover of the femoral head in both normal and dysplastic hips and allows assessment of acetabular inclination and anteversion. A clear topographical image of the head with its covered area is generated. We studied 36 normal and 39 dysplastic hips. In the normal hips the mean cover was 73% (66% to 81%), whereas in the dysplastic group it was 51% (38% to 64%). The significant advantage of this technique is that it allows the measurements to be standardised with reference to a specific anatomical plane. When this is applied to assessing cover in surgery for dysplasia of the hip it gives a clearer understanding of where the corrected hip stands in relation to normal and allows accurate assessment of inclination and anteversion.     

Ideal angle of syndesmotic screw fixation: A CT-based cross-sectional image analysis study

Without clear reference, the precision of syndesmotic screw placement cannot be guaranteed and malposition of these screws leads to poor results. Therefore, to prevent malpositioning of syndesmotic screws, an improved understanding of the orientation of tibiofibular syndesmosis is essential. We analyzed cross-sectional computed tomography (CT) scans of the foot and ankle to identify precise screw positions for the treatment of syndesmotic injuries. A total of 134 calcaneal fractures with intact tibiofibular syndesmosis were enrolled in this retrospective study. We measured the angle between the perpendicular line of the second proximal phalanx and the line start apex of the lateral cortex of the fibula bisecting the tibial incisura and crossing the center of the tibia in neutral ankle joints, with the second toe positioned anteriorly using a short leg splint. The second toe was used as the reference for clarity and applicability. The ideal angle of syndesmotic screw placement in cross-sectional CT images was 18.8 ± 5.6° (mean ± standard deviation) and did not differ according to independent variables (P > 0.05). In neutral ankle joints with the second toe positioned anteriorly, the ideal angle of syndesmotic screw placement is 18.8°, which is less than that currently in used in conventional methods.     

Robotic total knee arthroplasty: the accuracy of CT-based component placement

BACKGROUND: Accurate alignment of the components in total knee arthroplasty is important. By use of postoperative CT controls, we studied the ability of a robotic effector to accurately place and align total knee arthroplasty (TKA) components according to a purely CT-based preoperative plan. PATIENTS AND METHODS: Robotic TKA was performed in 13 patients (6 men) with primary gonarthrosis. Locator screws were placed into femur and tibia under spinal anesthesia. A CT-scan including the femoral head, knee and ankle was performed. In the preoperative planning software, virtual components were positioned into the CT volume. In a second operation, the robot milled femur and tibia with a high-speed milling tool according to the preoperative plan. On the 10th day, CT controls were performed following the same protocol as preoperatively. RESULTS: The mean deviation of the postoperative from the preoperatively planned mechanical axis was 0.2 degrees (95% CI: -0.1 degrees to 0.5 degrees ). The accuracy of angular component placement in frontal, sagittal and transverse planes was within +/-1.2 degrees , and the accuracy of linear component placement in mediolateral, dorsoventral and caudocranial directions was within +/-1.1 mm. INTERPRETATION: Robotic TKA allows placement of components with unparalleled accuracy, but further development is mandatory to integrate soft-tissue balancing into the procedure and make it faster, easier and cheaper.     

Impact of Postoperative Zolpidem Use on Primary Total Knee Arthroplasty: A Retrospective Matched-Controlled Analysis of a Private Insurance Database

IntroductionZolpidem has gained popularity as a pharmaceutical therapy for insomnia, being the most prescribed hypnotic in the United States today. However, it is associated with increased mortality and morbidity. Literature regarding zolpidem use in the total knee arthroplasty (TKA) population is limited. The aim of the study was to analyze postoperative zolpidem use in the TKA population regarding medical and implant complications, falls, and readmission.MethodsThe study group was queried according to zolpidem use. Controls consisted of patients who underwent primary TKA without a history of hypnotic drug use. Study group patients were matched to controls in a 1:5 ratio by demographics and comorbidities. Results yielded 99,178 study participants and 495,795 controls. Primary endpoints included 90-day medical and implant complications, fall risk, and readmission. Chi-squared test was used to compare categorical variables. Multivariate logistic regression was used to calculate odds (OR) for complications, fall risk, and readmission. A P value less than 0.05 was considered statistically significant.ResultsStudy group patients had increased odds of medical complications (OR: 1.76, 95% CI: 1.71-1.82, P < .0001) and implant complications (OR: 1.35, 95% CI: 1.23-1.47, P < .0001) compared to controls. Furthermore, patients in the study group were found to have an increased risk of 90- day falls (OR: 1.16, 95% CI: 1.11-1.21, P < .0001). Readmission was similar to controls (5.10% vs 4.84%, P = .12).ConclusionZolpidem use following primary TKA is associated with the risk of morbidity and falls. The findings are consistent with the literature regarding zolpidem. These findings may affect discussion between orthopedic surgeons and patients in the decision-making process prior to undergoing TKA.     

Prediction of proximal femur strength using a CT-based nonlinear finite element method: Differences in predicted fracture load and site with changing load and boundary conditions

The annual occurrence of hip fracture due to osteoporosis as of 2002 had reached 120,000 in Japan. The increase has been very rapid. From a biomechanical perspective, hip fractures are thought to be caused in real settings by different directions of loading. Thus, clarification of the loading directions under which the proximal femur is most vulnerable to fracture would be helpful for elucidating fracture mechanics and establishing preventive interventions. The purpose of the current study was to clarify the influence of loading direction on strength and fracture site of the proximal femur using the CT-based nonlinear FE method to determine loading directions under which the proximal femur is most vulnerable to fracture. Contralateral femora were analyzed in 42 women with hip fracture (mean age, 82.4 years), comprising 20 neck fractures and 22 trochanteric fractures. Within 1 week after fracture, quantitative CT of the contralateral femur was performed in each patient and 3-dimensional FE models were created. One stance loading configuration (SC) and four different fall loading configurations (FC) were assigned. Nonlinear FE analysis was performed. Differences in fracture loads depending on differences in loading direction were analyzed and correlations among fracture loads in different loading directions were assessed. Next, fracture sites were also analyzed. Mean predicted fracture load in the SC was 3150 N. Mean fracture loads were 2270 N in FC1, 1060 N in FC2, 980 N in FC3, and 710 N in FC4. The correlation between predicted fracture loads in SC and those in each FC was significant with a correlation coefficient of 0.467–0.631. Predicted fracture sites in the SC appeared at the subcapital region in all patients and were categorized as neck fracture. However, trochanteric fractures occurred in all fall configurations except FC1. In FC1, a significant correlation was seen between real fracture type and predicted type. The current investigation could contribute to the acquisition of useful knowledge allowing the establishment of more efficacious means of preventing hip fractures.     

Pediatric Septic Arthritis and Osteomyelitis in the USA: A National KID Database Analysis

HSS Journal ® -     

Pediatric Septic Arthritis and Osteomyelitis in the USA: A National KID Database Analysis

Background

Prior reports suggest that osteoarticular infections may be increasing over time.

Questions/Purposes

We sought to determine if incidence rates, median in-hospital costs, and length of stay (LOS) of osteomyelitis, septic arthritis (SA), and combined infections have changed over time for pediatric patients, and how they compare to previously reported rates.

Methods

The Kids’ Inpatient Database (KID), a US national sample of pediatric hospital discharge records from 1997, 2000, 2003, 2006, 2009, and 2012, was used to determine yearly estimated counts of infections in children 20 years of age or younger. US census data was used to calculate yearly incidence rates. Trend tests using linear contrast analysis were used to compare estimated median LOS and inflation-adjusted median costs over time for each type of infection.

Results

From 1997 through 2012, the incidence rate of osteomyelitis increased from 7.9 to 10.5 per 100,000, SA was unchanged from 5.3 to 5.2 per 100, and combined infections increased from 0.8 to 1.3 per 100,000. Median LOS from 1997 to 2012 showed no significant change for osteomyelitis (5.0 to 4.9 days), SA (4.4 to 4.1 days), or combined infections (6.5 to 6.8 days). Median in-hospital costs from 1997 to 2012 increased for osteomyelitis ($7735 to $11,823), SA ($5041 to $10,574), and combined infections ($12,691 to $16,260).

Conclusion

In pediatric patients, the estimated incidence rate of SA appeared stable, while rates of osteomyelitis and combined infections increased. These estimated rates fall within previously reported ranges. Despite stable LOS, costs have increased over time.

     

Risk Prediction Model for Survival of Wait-List Patients on Axial CF-LVAD: A UNOS Database Analysis

BackgroundContinuous flow left ventricular assist devices (CF-LVADs) have become a viable option for patients with end-stage heart failure as a bridge to transplantation or the destination therapy.MethodsAdult patients listed for heart transplantation (2010-2015) with an axial CF-LVAD on the wait list were obtained from the UNOS database. The multivariate Cox regression model was used to predict the probability of survival after listing. Patients were divided into derivation (80%) and validation (20%) groups. Receiver operating characteristics curves and area under curves were used to define the strength of the model.ResultsRisk factors on multivariate analyses were diabetes type I (hazard ratio [HR], 2.5; P = .018), presence of inotropes (HR, 1.6; P = .005), creatinine at listing (HR, 1.2; P < .001). No significant differences were observed between the derivation and validation groups for any of the variables. The area under the curve at 3, 6, and 12 months on the wait list was 0.69, 0.65, 0.63, respectively in the training set and 0.71, 0.65, 0.60, respectively in the validation set. Survival analyses showed that patients implanted with Heartmate II before listing had a better survival than those who were implanted after being on the wait list (HR, 0.78; P = .048).ConclusionTo our knowledge, this was the first time a risk prediction model was generated for wait-list survival of Heartmate II patients. A significant difference in survival was noted between patients who received their Heartmate II before being put on a wait list vs those who were implanted while on the list.     

意外甲状腺癌的临床病理特点及预测因素：附523例报告

目的:通过超声影像和病理特征探讨意外甲状腺癌预测因素。方法:回顾性分析2014年1月—2014年10月期间于哈尔滨医科大学附属第一医院收治的523例甲状腺癌患者的临床病理资料,其中意外甲状腺癌患者108例(观察组),非意外甲状腺癌患者415例(对照组),比较两组患者之间临床病理特点的差异。结果:两组在年龄、病灶数量、病理分型、病变结构、是否合并良性甲状腺疾病、是否钙化、癌灶颜色、纵横比、弹性评分、边界情况、回声强度、是否清扫中央组淋巴结的构成比均有统计学差异(均P0.05);Logistic回归分析显示,滤泡状癌、无钙化、纵横比1、边界清晰、非低回声、弹性评分3、癌灶直径与癌灶所在结节的直径比值30%是意外甲状腺癌发生的预测因素(均P0.05)。结论:滤泡状甲状腺癌、无钙化、纵横比1、边界清晰、非低回声、弹性评分3、癌径比30%等是意外甲状腺癌的预测因素。     

Primary Squamous Cell Carcinoma in the Thyroid Gland: A Population-Based Analysis Using the SEER Database

World Journal of Surgery - To evaluate prognostic factors and treatment outcomes of primary squamous cell carcinoma in thyroid (PSCCTh) over the past decades using a large national database. All...     

The Impact of Discharge Timing on Readmission Following Hepatopancreatobiliary Surgery: a Nationwide Readmission Database Analysis

Objective

Decreasing hospital length-of-stay (LOS) may be an effective strategy to reduce costs while also improving outcomes through earlier discharge to the non-hospital setting. The objective of the current study was to define the impact of discharge timing on readmission, mortality, and charges following hepatopancreatobiliary (HPB) surgery.

Methods

The Nationwide Readmissions Database (NRD) was used to identify patients undergoing HPB procedures between 2010 and 2014. Length of stay (LOS) was categorized as early discharge (4–5 days), routine discharge (6–9 days), and late discharge (10–14 days). Univariable and multivariable analyses were utilized to identify factors associated with 90-day readmission.

Results

A total of 28,114 patients underwent HPB procedures. Overall median LOS was 7 days (IQR 5–11); 10,438 (37.1%) patients had an early discharge, while 13,665 (48.6%) and 4011 (14.3%) patients had a routine or late discharge. The probability of early discharge increased over time (referent 2010: 2011–4% (OR 1.04, 95% CI 0.96–1.15) vs. 2012–10% (OR 1.10, 95% CI 1.01–1.20) vs. 2013–21% (OR 1.21, 95% CI 1.11–1.32) vs. 2014–32% (OR 1.32, 95% CI 1.21–1.44)) (p?<?0.001). Early discharge was associated with insurance status, diagnosis (benign vs. malignant disease), general health, and overall hospital volume (all p?<?0.05). Among patients who had an early discharge, 30- and 90-day readmission was 11.5 and 17.4%, respectively. In contrast, 30- and 90-day readmission was 16.9 and 24.7%, respectively, among patients who had a routine discharge group (p?<?0.001). Among patients readmitted within 90 days, in-hospital mortality was similar among patients who had early (n?=?43, 2.4%) versus routine discharge (n?=?65, 1.9%). Median charges were lower among patients who had an early versus routine versus late discharge ($54,476 [IQR 40,053–79,100] vs. $75,192 [IQR 53,296–113,123] vs. $115,061 [IQR 79,162–171,077], respectively) (p?<?0.001).

Conclusions

Early discharge after HPB surgery was not associated with increased 30- or 90-day readmission. Overall 90-day in-hospital mortality following a readmission was comparable among patients with an early, routine, and late discharge, while median charges were lower in the early discharge group.

     

Complications Following Outpatient Total Joint Arthroplasty: An Analysis of a National Database

Background

As outpatient total hip (THA) and knee arthroplasties (TKA) increase in popularity, concerns exist about the safety of discharging patients home the same day. The purpose of this study is to determine the complications associated with outpatient total joint arthroplasty (TJA) and to identify high-risk patients who should be excluded from these protocols.

Accuracy of MRI-based vs. CT-based patient-specific instrumentation in total knee arthroplasty: A meta-analysis

Introduction

The technical objective of total knee arthroplasty (TKA) is to restore normal mechanical parameters to the knee. Patient-specific instrumentation (PSI) was developed to streamline the operative process and improve accuracy. PSI produces individualized cutting guides based on three-dimensional models of the patient's anatomy acquired from computed-tomography (CT) or magnetic-resonance imaging (MRI). However, the superiority of one modality over the other remains unclear. Therefore, we aimed to compare the accuracy of patient-specific cutting guides produced from MRI or CT imaging methods in TKA.

Efficacy of anterior odontoid screw fixation in the elderly patient: a CT-based biometrical analysis of odontoid fractures

In the elderly population, reported union rates with anterior odontoid screw fixation (AOSF) for odontoid fracture (OF) treatment vary between 23 and 93% when using plain radiographs. However, recent research revealed poor interobserver reliability for fusion assessment using plain radiographs compared to CT scans. Therefore, union rates in patients aged ≥60 years treated with AOSF have to be revisited using CT scans and factors for non-union to be analysed. Prospectively gathered consecutively treated patients using AOSF for odontoid fracture with age ≥60 years were reviewed. Medical charts were assessed for demographics, clinical outcomes and complications. Patients’ preoperative radiographs and CT scans were analysed to characterize fracture morphology and type, fracture displacement, presence of atlanto-dental osteoarthritis as well as a detailed morphometric assessment of fracture surfaces (in mm²). CT scans performed after a minimum of 3 months postoperatively were analysed for fracture union. Those patients not showing CT-based evidence of completely fused odontoid fracture were invited for radiographic follow-up at a minimum of 6 months follow-up. Follow-up CT-scan were studied for odontoid union as well as the number of screws used and the square surface of screws used for AOSF and the related corticocancellous osseous healing surface of the odontoid fragment (in %) were calculated. Patients were stratified whether they achieved osseous union or fibrous non-union. Patients with a non-union were subjected to flexion–extension lateral radiographs and the non-union defined as stable if no motion was detected. The sample included 13 male (72%) and 5 female (18%) patients. The interval from injury to AOSF was 4.1 ± 5.3 days (0–16 days). Age at injury was 78.1 ± 7.6 years (60–87 years) and follow-up was 75.7 ± 50.8 months (4.2–150.2 months). 10 patients had dislocated fractures, 14 had Type II and 4 “shallow” Type III fractures according to the Anderson classification, 2 had stable C1-ring fractures, 8 had displayed atlanto-dental osteoarthritis. Fracture square surface was 127.1 ± 50.9 mm² (56.3–215.9 mm²) and osseous healing surface was 84.0 ± 6.8% (67.6–91.1%). CT-based analysis revealed osseous union in 9 (50%) and non-union in 9 patients (50%). Union rates correlated with increased fracture surface (P = 0.02). Statistical analysis revealed a trend that the usage of two screws with AOSF correlates with increased fusion rates (P = 0.06). Stability at C1–2 was achieved in 89% of patients. CT scans are accepted as the standard of reference to assess osseous union. The current study offers an objective insight into the union rates of odontoid fractures treated with AOSF using CT scans in consecutive series of 18 patients ≥60 years. Literature serves evidence that elderly patients with unstable OF benefit from early surgical stabilization. However, although using AOSF for unstable OF yields segmental stability at C1–2 in a high number of patients as echoed in the current study, our analysis stressed that using follow-up CT scans in comparison to biplanar radiographs dramatically reduces osseous union rates compared to those previously reported for AOSF.