Kinetic magnetic resonance imaging analysis of lumbar segmental mobility in patients without significant spondylosis

Purpose

The purpose of this study was to examine lumbar segmental mobility using kinetic magnetic resonance imaging (MRI) in patients with minimal lumbar spondylosis.

Methods

Mid-sagittal images of patients who underwent weight-bearing, multi-position kinetic MRI for symptomatic low back pain or radiculopathy were reviewed. Only patients with a Pfirrmann grade of I or II, indicating minimal disc disease, in all lumbar discs from L1–2 to L5–S1 were included for further analysis. Translational and angular motion was measured at each motion segment.

Results

The mean translational motion of the lumbar spine at each level was 1.38 mm at L1–L2, 1.41 mm at L2–L3, 1.14 mm at L3–L4, 1.10 mm at L4–L5 and 1.01 mm at L5–S1. Translational motion at L1–L2 and L2–L3 was significantly greater than L3–4, L4–L5 and L5–S1 levels (P < 0.007). The mean angular motion at each level was 7.34° at L1–L2, 8.56° at L2–L3, 8.34° at L3–L4, 8.87° at L4–L5, and 5.87° at L5–S1. The L5–S1 segment had significantly less angular motion when compared to all other levels (P < 0.006). The mean percentage contribution of each level to the total angular mobility of the lumbar spine was highest at L2–L3 (22.45 %) and least at L5/S1 (14.71 %) (P < 0.001).

Conclusion

In the current study, we evaluated lumbar segmental mobility in patients without significant degenerative disc disease and found that translational motion was greatest in the proximal lumbar levels whereas angular motion was similar in the mid-lumbar levels but decreased at L1–L2 and L5–S1.     

The spectrum of segmental colitis associated with diverticulosis

Background Segmental colitis associated with diverticulosis (SCAD) has been defined as chronic colonic inflammation surrounding diverticula with rectal sparing. Distinguishing this condition from inflammatory bowel disease may be difficult. Our aim was to evaluate the epidemiological and clinical characteristics of SCAD in our area.Methods Retrospective case identification with prospective follow-up was done. Patients with endoscopic findings suggestive of SCAD were enrolled. The epidemiological, clinical, and histological characteristics of these patients were analyzed.Results Out of 605 patients with diverticulosis, 23 cases of SCAD were identified (3.8%). Four patients had histological characteristics suggestive of ulcerative colitis, in 1 case the histology was suggestive of ischemic colitis, 6 patients had histology compatible with SCAD, and the remaining patients had either transitional mucosa or minimal lesions. Four cases were refractory to conservative treatment (mesalamine and antibiotics) and surgery was required. No cases of extension of colonic inflammation in diverticula-free areas were found.Conclusions Segmental colitis associated with diverticulosis is not a rare disorder. It may occur with a spectrum of clinical and histologic features and may be confused with ulcerative colitis. The majority of the cases respond to medical therapy with antibiotics and/or mesalamine, whereas few cases are refractory and need surgery. No evolution to inflammatory bowel disease was observed.     

Precise Segmental Renal Artery Clamping Under the Guidance of Dual-source Computed Tomography Angiography During Laparoscopic Partial Nephrectomy

Background

Minimizing warm ischemic (WI) injury is one technical focus of partial nephrectomy (PN). Inducing regional ischemia in the tumor area by clamping segmental renal arteries has become an alternative method to decrease WI injury.

Objective

To study the technical feasibility of precise segmental artery clamping under the guidance of dual-source computed tomography (DSCT) angiography during laparoscopic partial nephrectomy (LPN) and to analyze the factors affecting surgical outcomes.

Design, setting, and participants

Retrospective analysis of 125 patients with unilateral kidney tumor treated from December 2009 to November 2011 with a mean follow-up of 18 mo.

Intervention

All patients received retroperitoneal LPN with the feeding segmental arteries precisely clamped. Most of the target branches were dissected close to the hilar parenchyma. The tumor was excised after precise clamping and renorrhaphy was performed.

Outcome measurements and statistical analysis

Univariable and multivariable logistic regression analyses were performed for categorical variables, and continuous variables were analyzed by linear regression.

Results and limitations

The target branches were isolated and clamped successfully in all patients without clamping the main renal artery. Median estimated blood loss (EBL) was 200 ml, and nine patients received blood transfusion. The accuracy of feeding artery orientation by DSCT angiography reached 93.6%. Tumor size, location, and growth pattern independently influenced the number of clamped branches. The number of clamped branches was significantly associated with postoperative renal function and EBL. Limitations of this study include its retrospective nature and that data are from a single-surgeon series.

Conclusions

The precise segmental artery clamping technique under the guidance of DSCT angiography is feasible and efficient to excise the tumor and to protect the normal parenchyma. The number of clamped branches is associated with tumor characteristics and can predict EBL and loss of renal function.     

International Study Group of Pancreatic Surgery type 3 and 4 venous resections in patients with pancreatic adenocarcinoma:the Paoli-Calmettes Institute experience

IntroductionA new neoadjuvant regimen, together with more aggressive surgeries, appears to have increased the resectability rate in patients with pancreatic ductal adenocarcinoma (PDAC). Our study aimed to evaluate the outcomes of patients who underwent venous resection (VR) during pancreatectomies for PDAC.Materials and methodsBetween 2005 and 2017, 130 patients underwent pancreatectomies with type 3 or 4 (i.e., segmental resection without or with graft interposition, respectively) VR for PDAC. Patients’ characteristics, surgical techniques, perioperative management, pathological findings, and outcomes were recorded and compared during 2 inclusion periods: the landmark year for the introduction of the FOLFIRINOX regimen and the hyperspecialization of our pancreatic-surgery team was 2010.ResultsPerformance of pancreatectomies with VR steadily increased through the 2 inclusion periods. In the overall series (n = 130), the median overall survival time and the 5-year survival proportion were 26.3 months and 21%, respectively. Upon multivariate analysis, ASA score 3 (P = 0.01) and R1 resection margins (P < 0.01) were found to be negative independent factors influencing survival. Patients who underwent upfront VR (n = 47) had survival rates similar to those of patients who received neoadjuvant treatment (n = 83). After 2010, more complex VR were performed; however, no difference was found between the 2 periods with respect to postoperative courses, pathologic findings, or survival after a matching process based on patients’ characteristics and tumor stages.ConclusionOver the last 2 decades, VR during pancreatectomy has been confirmed as a safe procedure despite the increase in technical complexity. Disappointingly, we did not observe any dramatic survival improvement.     

Detailed pathological changes of human lumbar facet joints L1–L5 in elderly individuals

Facet joints play an important role in intervertebral load transmission and are crucial for rotational kinematics. Clinically, the role of facet joints as a possible source of low back pain is seen as controversial and at present is not sufficiently investigated. In this study, human lumbar facet (zygapopyhysial) joints from donors with advanced age were analyzed macroscopically, for degenerative changes. The aim was to determine the extent and morphology of degenerative changes in these joints. Lumbar facet joints (L1–L5) of 32 donors were studied (mean age 80.1±11.2 years). Joint capsules were carefully removed and joint surfaces (5 zones) examined using magnifying glasses and probes. In the result, the majority of facet joints showed cartilage defects of varying extent. Defects were located mostly at the margins of the articular surface, the central zone being relatively well preserved. Defect localization was different between superior (most cartilage defects in superior zone) and inferior (most defects inferiorly) facets. Further, defects were more severe caudal (level of L5) and in older persons. Osteophytes were present in up to 30%, located mostly at the latero-dorsal enthesis of the joint capsule on the superior facet. In conclusion, most margins of the articular facets are subject to degenerative changes in the lumbar spine of elderly persons, the topographical pattern being different in superior and inferior facets. This observation can be explained by the segmental motion patterns during extension/flexion movements of the facets. Sometimes, due to the marginal extension, it is obvious that not all changes can be assessed by CT or MRI.     

Segmental anatomy of the liver: a review and a proposal for an international working nemenclature

The segmental anatomy of the human liver has become a field of increasing interest to radiologists during the past the past few years. The number of different terminologies which have been used since the topic has been systematically investigated is, however, a source of serious confusion. The present paper describes the reasons why the authors plead for an international working nomenclature which distinguishes a right hemiliver consisting of a right posterior and a right anterior segment, formed by subsegments 6 and 7, and 5 and 8, respectively, and a left hemiliver consisting of a left medial and a left lateral segment, the former corresponding to segment 4, and the latter to subsegments 2 and 3. This basic concept, however, must be carefully tailored to the highly variable individual anatomy of each patient. Furthermore, some aspects of hepatic segmentation are not yet understood and require additional anatomical investigation.Correspondence to: J. H. D. Fasel     

The in vitro stabilising effect of polyetheretherketone cages versus a titanium cage of similar design for anterior lumbar interbody fusion

This biomechanical study was performed to test the primary segmental in vitro stabilising effect of a standard and large footprint radiolucent poly-ether-ether-ketone (PEEK) box cage versus a titanium box cage for anterior lumbar interbody fusion. Eighteen L2-L3 and sixteen L4-L5 cadaveric motion segments were divided into three groups and received a titanium cage or a radiolucent PEEK cage with standard or large footprint. All specimens were tested in three testing conditions: intact, stand-alone anterior cage and finally with supplemental translaminar screw fixation. Full range of motion and neutral zone measurements were determined and anterior cage pull out force was tested. The titanium design was significantly more effective in reducing the range of motion only in axial rotation. The larger footprint radiolucent cage did not increase stability as compared to the standard footprint. The titanium cage pull out force was significantly (P=0.0002) higher compared to both radiolucent cage constructs. Clinical relevance: Supplemental posterior fixation is strongly recommended to increase initial stability of any anterior interbody fusion cage construct. Although the biomechanical stability necessary to achieve spinal fusion is not defined, the radiolucent designs tested in this study, with a standard footprint as well as with a larger footprint, may be insufficiently stabilised with translaminar screws as compared to the titanium implant. Supplemental pedicle screw fixation may be required to obtain adequate stabilisation in the clinical setting.     

Inertial properties of the human trunk of males determined from magnetic resonance imaging

The purpose of this study was to evaluate the segmental parameters of the human trunk of malesin vivo using magnetic resonance imaging (MRI). In addition, the efficacy of volumetric estimation and existing prediction formulas to produce segmental properties similar to those produced by MRI was evaluated. As opposed to finding one representative normal value for these parameters, a range of normal values was defined. For instance, the average trunk mass was 42.2%±3.5% (x±SD) of body mass, but values ranged from 35.8% to 48.0%. To account for segment parameters more accurately, specific anthropometric measures need to be considered in addition to overall measures of body height and mass. These specific measures included segment length, circumference, width, and depth. Studies reporting general percentages based on height and/or mass were found to be inadequate predictors of segmental parameters of the trunk compared with MRI estimates. Volumebased estimates, which assume a uniform density distribution within a segment, were found to correspond closely to MRI values except for the thorax. However, the use of density values reflective of the livingin vivo state would likely alleviate this disparity, thus indicating that the volumetric technique may be effective for deriving segmental parameters for large segments of the trunk. Future research should adopt noninvasive techniques such as MRI and/or volumetric estimation to enhance the predictability of segmental parameters of the body for specific population groups characterized by gender, developmental age, body type, and fitness level. Further efforts should be made to establish standardized boundary definitions for trunk segments to avoid unnecessary confusion, from which substantial errors may be introduced into biomechanical linked-segment analyses of human movement.