Interspinous Distance Research Articles

The relationship between anthropometric measurements and the bony pelvis in African American and European American women

The bony pelvis anatomy is highly variable. This study aims to examine the relationship between anthropometric measurements and the size of the adult female bony pelvis. Three-dimensional points of all pertinent landmarks of 96 adult female bony pelvises were obtained and the true conjugate, interspinous distance, intertuberous distance, and pelvic inlet and outlet areas were calculated. The relationship between these measurements and height and multiple anthropometric measurements were evaluated using Pearson's correlation coefficient (r). Multiple anthropometric measurements were significantly correlated with the true conjugate and pelvic inlet and outlet areas, but not with the interspinous or intertuberous widths. Height had a greater correlation with pelvic areas than any other anthropometric measure considered, even after controlling for race. There were no significant differences in pelvic areas between races. Height and other anthropometric measurements were significantly correlated with the true conjugate and pelvic inlet and outlet areas.

Reference data for interpreting widening between spinous processes in the lumbar spine

Background ContextTraumatic injury to the lumbar spine is evaluated and treated based on the perceived stability of the spine. Recent classification schemes have established the importance of evaluating the posterior ligamentous complex (PLC) to fully comprehend stability. There are a variety of techniques to evaluate the PLC, including assessment of interspinous distance. However reference data to define normal widening are poorly developed. PurposeDefine normal interspinous widening in the lumbar spine. Study designBiomechanical and observational. To establish reference data for asymptomatic population and use the reference data to suggest criteria for routine clinical practice to be validated in future studies. MethodsInterspinous distances were measured from lateral lumbar X-rays of 157 asymptomatic volunteers. Measurements from the asymptomatic population were used to define normal limits and create a simple screening tool for clinical use. Distances were calculated from the relative position of landmarks at each intervertebral level. The distances were normalized to the anterior-posterior width of the superior end plate of L3. The change in interspinous process distance from flexion to extension was calculated, and the change in interspinous widening between flexion and extension with respect to widening at the adjacent levels was also calculated. ResultsSeven hundred seventy-two thoracolumbar levels were available for analysis. The observed interspinous motion was slightly more than the interlaminar motion. However, the tips of the spinous processes were more difficult to identify in some images, so the interlaminar line distances were considered more reliable. Significant difference in interlaminar distances was not found between levels. The upper limit (UL) of normal spacing measured between the interlaminar lines was approximately 85% of the L3 end plate width at all levels except L5–S1, which was 105%. The UL of normal for interlaminar displacements between flexion and extension was 30% of the L3 end plate width at L1–L2 to L4–L5 and 40% at L5–S1. ConclusionsThis study provides normative data and methods that can be used in developing guidelines to objectively assess interspinous process widening. Simple rules can be applied to quickly assess interspinous widening. Additional research is required to validate these guidelines. A simple measurement such as spinous process widening is unlikely to be proven as an isolated clinically effective screening test but combining that with other patient evaluation’s screening modalities may prove to be a sensitive evaluation protocol for the screening of injuries to the PLC.

Facetal distraction as treatment for single- and multilevel cervical spondylotic radiculopathy and myelopathy: a preliminary report

The authors discuss their successful preliminary experience with 36 cases of cervical spondylotic disease by performing facetal distraction using specially designed Goel cervical facet spacers. The clinical and radiological results of treatment are analyzed. The mechanism of action of the proposed spacers and the rationale for their use are evaluated. Between 2006 and February 2010, 36 patients were treated using the proposed technique. Of these patients, 18 had multilevel and 18 had single-level cervical spondylotic radiculopathy and/or myelopathy. The average follow-up period was 17 months with a minimum of 6 months. The Japanese Orthopaedic Association classification system, visual analog scale (neck pain and radiculopathy), and Odom criteria were used to monitor the clinical status of the patient. The patients were prospectively analyzed. The technique of surgery involved wide opening of the facet joints, denuding of articular cartilage, distraction of facets, and forced impaction of Goel cervical facet spacers into the articular cavity. Additionally, the interspinous process ligaments were resected, and corticocancellous bone graft from the iliac crest was placed and was stabilized over the adjoining laminae and facets after adequately preparing the host bone. Eighteen patients underwent single-level, 6 patients underwent 2-level, and 12 patients underwent 3-level treatment. The alterations in the physical architecture of spine and canal dimensions were evaluated before and after the placement of intrafacet joint spacers and after at least 6 months of follow-up. All patients had varying degrees of relief from symptoms of pain, radiculopathy, and myelopathy. Analysis of radiological features suggested that the distraction of facets with the spacers resulted in an increase in the intervertebral foraminal dimension (mean 2.2 mm), an increase in the height of the intervertebral disc space (range 0.4-1.2 mm), and an increase in the interspinous distance (mean 2.2 mm). The circumferential distraction resulted in reduction in the buckling of the posterior longitudinal ligament and ligamentum flavum. The procedure ultimately resulted in segmental bone fusion. No patient worsened after treatment. There was no noticeable implant malfunction. During the follow-up period, all patients had evidence of segmental bone fusion. No patient underwent reexploration or further surgery of the neck. Distraction of the facets of the cervical vertebra can lead to remarkable and immediate stabilization-fixation of the spinal segment and increase in space for the spinal cord and roots. The procedure results in reversal of several pathological events related to spondylotic disease. The safe, firm, and secure stabilization at the fulcrum of cervical spinal movements provided a ground for segmental spinal arthrodesis. The immediate postoperative improvement and lasting recovery from symptoms suggest the validity of the procedure.

Computed tomography pelvimetry as a predictor of technical difficulty in total mesorectal excision

To investigate the limiting effect of pelvic diameters on the technical difficulty of total mesorectal excision(TME) for rectal cancer by computed tomography pelvimetry. From January 2009 to January 2011, 69 patients with rectal cancer underwent TME in the Department of Proctology at the Changhai Hospital in Shanghai. There were 55 males and 14 females. Using three dimensional reconstruction software, pelvic dimensions of rectal cancer patients were measured based on pelvic MDCT thin-slice computed tomography. All the patients were measured for 15 pelvic parameters, including the length of pelvic inlet, the length of pubic symphysis, the interspinous distance, the distance from sacral promontory to tip of coccyx, etc. All the procedures were open surgery, including anterior resection(n=19), low anterior resection and ileostomy(n=29) and abdominal perineal resection(n=21). Duration of the operation and blood loss at surgery were recorded as evaluation indicators of the technical difficulty of total mesorectal excision. By univariate analysis significant pelvic parameters were selected. Multiple regression analysis was used to investigate the relationship between pelvic parameters and blood loss or duration of operation. The mean operative time was(139.9±32.4) min and the mean intraoperative blood loss was (228.8±150.6) ml. Multivariate analysis showed that the interspinous distance, the length of pelvic inlet, the distance from sacral promontory to the tip of coccyx were the main factors affecting the operation time, and that the length of pubic symphysis and the distance from sacral promontory to the tip of coccyx were the main factors affecting the amount of blood loss (all P<0.05). Among the 3 procedures, the multivariate analysis for low anterior resection appeared to be most valuable, in which operative time was associated with the distance from sacral promontory to the tip of coccyx and the interspinous distance (adjusted coefficient of determination of the regression equation, Rc(2)=0.460, P=0.003). Factors associated with intraoperative blood loss were the length of pelvic inlet, the distance from sacral promontory to the tip of coccyx, and the sacrum-pubis angle(Rc(2)=0.358, P=0.022). Comprehensive analysis of the measurement parameters showed that the ratio between the length of pelvic inlet and the distance from sacral promontory to the tip of coccyx was associated with the operative time and blood loss. This ratio was significantly higher in female patients than that in males. In females with a ratio greater than 1, the operative time was significantly shorter(P=0.050), and the intraoperative blood loss was significantly less in males with a ratio greater than 0.9(P=0.021). Operative time and intraoperative blood loss for total mesorectal excision are more favorable in patients with a wide and shadow pelvis. Surgical difficulty is increased in deep and narrow pelvis or those with major sacrum curvature. The difficulty of total mesorectal excision procedure can be predicted by measuring the length of pelvic inlet and the distance from sacral promontory to the tip of coccyx.

Subsidence and Nonunion after Anterior Cervical Interbody Fusion Using a Stand-Alone Polyetheretherketone (PEEK) Cage

BackgroundThe purposes of the present study are to evaluate the subsidence and nonunion that occurred after anterior cervical discectomy and fusion using a stand-alone intervertebral cage and to analyze the risk factors for the complications.MethodsThirty-eight patients (47 segments) who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage and an autologous cancellous iliac bone graft from June 2003 to August 2008 were enrolled in this study. The anterior and posterior segmental heights and the distance from the anterior edge of the upper vertebra to the anterior margin of the cage were measured on the plain radiographs. Subsidence was defined as ≥ a 2 mm (minor) or 3 mm (major) decrease of the segmental height at the final follow-up compared to that measured at the immediate postoperative period. Nonunion was evaluated according to the instability being ≥ 2 mm in the interspinous distance on the flexion-extension lateral radiographs.ResultsThe anterior and posterior segmental heights decreased from the immediate postoperative period to the final follow-up at 1.33 ± 1.46 mm and 0.81 ± 1.27 mm, respectively. Subsidence ≥ 2 mm and 3 mm were observed in 12 segments (25.5%) and 7 segments (14.9%), respectively. Among the expected risk factors for subsidence, a smaller anteroposterior (AP) diameter (14 mm vs. 12 mm) of cages (p = 0.034; odds ratio [OR], 0.017) and larger intraoperative distraction (p = 0.041; OR, 3.988) had a significantly higher risk of subsidence. Intervertebral nonunion was observed in 7 segments (7/47, 14.9%). Compared with the union group, the nonunion group had a significantly higher ratio of two-level fusion to one-level fusions (p = 0.001).ConclusionsAnterior cervical fusion using a stand-alone cage with a large AP diameter while preventing anterior intraoperative over-distraction will be helpful to prevent the subsidence of cages. Two-level cervical fusion might require more careful attention for avoiding nonunion.

The effects of anterior cervical discectomy and fusion with stand-alone cages at two contiguous levels on cervical alignment and outcomes

Anterior cervical discectomy and fusion (ACDF) using stand-alone cages is an effective method of treating degenerative disease. However, stand-alone cages are reported to have a relatively high incidence of implant subsidence with secondary kyphotic deformity particularly after multilevel ACDF. The purpose of our article was to investigate clinical and radiological outcomes after ACDF using stand-alone cages, at two contiguous levels, with a particular focus on changes in regional alignment and the correlation between alignment of the operated cervical levels and the entire cervical spine. Twenty-seven patients with 54 levels and a mean age of 50.8years were enrolled between January 2005 and August 2006. They underwent ACDF using polyetheretherketone cages packed with demineralized bone matrix without plate fixation at two contiguous levels. Mean follow-up period was 25.5months (range, 13-60). Clinical outcome was evaluated using two Visual Analog Scales and the Neck Disability Index (NDI). We assessed fusion, regional alignment (RA) of the operated levels and cervical global alignment (GA) preoperatively in the immediate 1-week postoperative period and at the final follow-up. An interspinous distance ≥2mm was used as an indicator of pseudoarthrosis at each level. All patients showed improvements in clinical outcome, with 96% of patients showing mild NDI scores (<14). Radiological solid fusion was obtained at 48 of 54 levels (88.9%) and in 21 of 27 patients (77.8%). Lower cervical levels were significantly more vulnerable to pseudoarthrosis (100%). Fusion rate had no significant correlation with outcome (p > 0.05). RA of the operated levels was improved at the final follow-up compared with preoperatively in 76% of patients, although it had decreased compared with the immediate postoperative period due to subsidence in 84% of patients. In total, 80.8% of patients showed improvements in GA. Furthermore, improvements in RA showed a significant positive correlation with those in GA (p = 0.001), although improvement in RA and GA did not correlate significantly with clinical outcome (p > 0.05). Though some degree of subsidence occurred in most cases, RA had improved at the last follow-up compared with preoperatively, which contributed to the significant improvement in GA. However, improvement of RA and GA was not correlated with outcomes.

The Role of Preoperative Endo-rectal Coil Magnetic Resonance Imaging in Predicting Surgical Difficulty for Robotic Prostatectomy

To determine whether pelvimetry on endo-rectal coil magnetic resonance imaging (eMRI) predicts surgical difficulty of robot-assisted laparoscopic prostatectomy (RALP). Patients' records with preoperative eMRI in our RALP database from April 2008 thru May 2009 were reviewed. Demographic, preoperative clinical data, and eMRI anatomic measurements, including calculated prostate volume (PV) and the pelvic cavity index (PCI), were recorded. PCI is the pelvic inlet multiplied by the interspinous distance and divided by the pelvic depth; PCI estimates the robotic working space. Correlative and multiple regression analyses of clinical and pelvimetric data were performed for prediction of estimated blood loss (EBL), operative time (OT), positive surgical margin (PSM), and transfusion rate as surrogates of surgical difficulty. Prostatic transverse diameter, PV, and the PV-to-PCI ratio were significantly correlated with both OT and EBL (P < .05). Body mass index also correlated with EBL (P < .05). Multiple linear regression analysis demonstrated that the PV-to-PCI ratio significantly predicts OT and EBL. No factor significantly predicted PSM status or transfusion rate on regression analysis. Analysis within the PSM group revealed that those with an apical PSM had statistically narrower and deeper pelvises. Patients with larger prostates and with narrow, deep pelvises are predicted to have a more difficult RALP. The PV-to-PCI ratio statistically predicts lengthier and bloodier procedures. However, that ratio does not predict PSM or transfusion risk on regression analysis. The eMRI predicts the level of surgical difficulty and is a valuable adjunctive study to obtain before RALP.

The depth of the prostatic apex is an independent predictor of positive apical margins at radical prostatectomy

To determine the effect of a deep and narrow pelvis on apical positive surgical margins (PSM) at radical prostatectomy (RP), controlling for other clinical and pathological variables and surgical approach, i.e. open retropubic (RRP) vs laparoscopic (LRP), as apical dissection is expected to be more challenging at RP with a prostate situated deep in a narrow pelvis. From July 2003 to January 2005, 512 consecutive patients with preoperative prostate magnetic resonance imaging (MRI) underwent RRP or LRP with no previous radio- or hormonal therapy. An additional 74 patients with preoperative MRI undergoing RP from December 2001 to June 2007 who had an apical PSM were also included, with 586 patients comprising the study population. Bony and soft-tissue pelvic dimensions, including interspinous distance (ISD), bony (BFW) and soft tissue (SW) pelvic width, apical prostate depth (AD) and symphysis pubis angle, were measured on preoperative MRI. The pelvic dimension index (PDI), bony width index (BWI) and soft-tissue width index (SWI) were defined as ISD/AD, BFW/AD and SW/AD, respectively. Multivariate logistic regression was used to assess the effect of pelvic dimensions on apical PSM, controlling for surgical approach and clinical and pathological variables. There was no significant difference in ISD, BFW, SW or symphysis angle between patients with and without apical PSM. The AD was significantly greater in men with an apical PSM and consequently PDI, BWI and SWI were significantly lower in men with an apical PSM. Each of PDI, AD, BWI and SWI was a significant independent predictor of apical PSM, independent of surgical approach, and other clinicopathological variables. The main limitations of the study were that it was retrospective, and the relatively few patients with apical PSM. Apical prostate depth is an independent risk factor for apical PSM at RP. MRI pelvimetry might allow for preoperative planning of the approach to RP.

Reliability of inter-anterior superior iliac spinous distance as compared to foot length for stature estimation in South Indians

Estimation of stature from isolated body parts is especially important to forensic scientists and anthropologists. The aims of this study were, to evaluate the accuracy of inter-anterior superior iliac spinous distance in determining stature of an individual as compared to foot length, and to note sex differences in the above mentioned parameters. One hundred normal healthy adult subjects from South India consisting of 50 males and 50 females were studied. The height, interspinous distance, and foot length of the subjects were measured. The mean and standard deviation of the height, interspinous distance, foot length and proportions of interspinous distance and foot length to height were calculated and significance testing done for sex differences. The correlation between stature and interspinous distance and stature and foot length was estimated, and linear regression equations for stature estimation were calculated. The height, interspinous distance and foot length were significantly greater in males. The proportion of interspinous distance to stature was significantly greater in females. Foot length showed a stronger positive correlation with stature compared to interspinous distance. When the sexes were considered separately the accuracy of stature estimation from interspinous distance increased greatly. Though interspinous distance is not as reliable as foot length in stature estimation, it could provide valuable data regarding the stature when isolated pelvises are available.

Dislocation of the Cervical Spine

A 22-year-old man presented with a 10-day history of torticollis. Two months before presentation, he had fallen from standing height but did not report subsequent cervical pain, weakness, or paresthesia. On examination, there was a reduced range of movement of the cervical spine without other neurologic deficits. Radiography of the cervical spine showed a marked reversal of the cervical lordosis, anterior displacement of 60% of C4 on C5, anterior callus formation, bilateral facet dislocation, and increased posterior interspinous distance (double arrow) (Panel A). Magnetic resonance imaging was performed. Sagittal T2-weighted imaging revealed a spinal cord angulation with mild . . .

Magnetic resonance (MR) pelvimetry as a predictor of difficulty in laparoscopic operations for rectal cancer

Laparoscopic surgery for rectal cancer is now well estab-lished. Recent studies have shown no difference in survivalor oncologic outcomes when laparoscopic surgery iscompared to open procedures [1, 2]. The laparoscopicapproach does, however, present the surgeon with inherentchallenges. Previous abdominal surgery, tumours closer tothe anal verge, high body mass index (BMI), and preop-erative radiotherapy have been shown to increase the dif-ficulty of laparoscopic procedures in the pelvis [3–6].It is often assumed that laparoscopic resections for rectalcancer are also complicated by a deep, narrow pelvis inwhich access and vision are both restricted by pelvicanatomy. Although a majority of patients undergo preop-erative pelvic magnetic resonance (MR) staging, radio-logical measurement of the bony pelvis––pelvimetry––hasnot been fully assessed as a predictor of difficult laparo-scopic operations.Male sex has been shown to correlate with surgeons’perceived difficulty of laparoscopic resections, althoughmore objective evidence of increased difficulty, in the formof longer operating times or more frequent involvement ofthe circumferential resection margin (CRM), is sparse [6].Indeed, while some authors have demonstrated significantdifferences in pelvic measurements between the sexes [7,8], others have shown considerable overlap [9], suggestingthat the measurements themselves may be a more usefulpredictor of difficulty than sex alone.MR pelvimetry has been evaluated for potential appli-cation in predicting the technical difficulty and outcomes ofopen rectal resection and prostatectomy [3, 4, 7, 10].Various dimensions of the bony pelvis thought to be ofimportance during surgery were studied; all studies used acombination of anteroposterior (AP) measurements in themid-sagittal plane and some form of transverse measure-ment to describe the breadth and depth of the pelvis. Someauthors measured angles and dimensions on the mid-sag-ittal slices to define the acuity of the sacral curve and theother boundaries of the pelvis [3, 7, 10]. One author wentfurther, developing a synthetic measurement designed tobetter describe the pelvic depth observed by the surgeonperforming open radical prostatectomy––the apical depthof the pelvis divided by the transverse interspinous distance[11]. None of these measurements were shown to signifi-cantly predict any objective or subjective measure ofoperative difficulty and pelvimetry seems to have beenabandoned as a predictor in open resections.It is reasonable to expect that pelvic anatomy may bemore important in laparoscopic resections. A prominentsacral promontory, an acutely curved sacrum, or a pelvisparticularly narrow in the transverse plane could conceiv-ably represent anatomical bottlenecks, impeding vision,access, and space in which instruments can be manipulated.Indeed, initial research has shown correlations betweenlonger operating times and a larger pelvic outlet [4] and asmaller lower pelvis diameter [5] and between CRMinvolvement and shorter transverse interspinous distances[12]. Further ascertainment of the influence of pelvic

Positioning for Lumbar Puncture in Children Evaluated by Bedside Ultrasound

Lumbar punctures are commonly performed in the pediatric emergency department. There is no standard, recommended, optimal position for children who are undergoing the procedure. To determine a position for lumbar punctures where the interspinous space is maximized, as measured by bedside ultrasound. A prospective convenience sample of children under age 12 was performed. Using a portable ultrasound device, the L3-L4 or L4-L5 interspinous space was measured with the subject in 5 different positions. The primary outcome was the interspinous distance between 2 adjacent vertebrae. The interspinous space was measured with the subject sitting with and without hip flexion. In the lateral recumbent position, the interspinous space was measured with the hips in a neutral position as well as in flexion, both with and without neck flexion. Data were analyzed by comparing pairwise differences. There were 28 subjects enrolled (13 girls and 15 boys) at a median age of 5 years. The sitting-flexed position provided a significantly increased interspinous space (P < .05). Flexion of the hips increased the interspinous space in both the sitting and lateral recumbent positions (P < .05). Flexion of the neck, did not significantly change the interspinous space (P = .998). The interspinous space of the lumbar spine was maximally increased with children in the sitting position with flexed hips; therefore we recommend this position for lumbar punctures. In the lateral recumbent position, neck flexion does not increase the interspinous space and may increase morbidity; therefore, it is recommended to hold patients at the level of the shoulders as to avoid neck flexion.

2016 PREDICTING ROBOTIC PROSTATECTOMY DIFFICULTY FROM PREOPERATIVE MAGNETIC RESONANCE IMAGING

You have accessJournal of UrologyImaging/Radiology: Uroradiology I1 Apr 20102016 PREDICTING ROBOTIC PROSTATECTOMY DIFFICULTY FROM PREOPERATIVE MAGNETIC RESONANCE IMAGING Barry Mason, David Faleck, Abraham Hakimi, Marc Feder, Victoria Chernyak, Alla Rozenblit, and Reza Ghavamian Barry MasonBarry Mason More articles by this author , David FaleckDavid Faleck More articles by this author , Abraham HakimiAbraham Hakimi More articles by this author , Marc FederMarc Feder More articles by this author , Victoria ChernyakVictoria Chernyak More articles by this author , Alla RozenblitAlla Rozenblit More articles by this author , and Reza GhavamianReza Ghavamian More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.2049AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Pelvic magnetic resonance imaging (MRI) is often part of the preoperative evaluation of patients undergoing robot assisted laparoscopic prostatectomy (RALP). We sought to determine whether there are certain anatomic features that can reliably predict surgical difficulty. METHODS All patients who had a preoperative MRI in our RALP database from April 2008 thru May 2009 were reviewed. We recorded patient age, preoperative PSA, Gleason score, and body mass index (BMI). Anatomic factors included the MRI calculated prostate volume (PV) and bony pelvic measurements. A new parameter to estimate the pelvic volume is the pelvic cavity index (PCI), as a surrogate of the pelvic working space for the robotic arms. The PCI represents the pelvic inlet multiplied by the interspinous distance and divided by the pelvic depth. These parameters were analyzed for statistically significant correlations and used in multivariate regression analysis with estimated blood loss (EBL), operative time, surgical margin status, and transfusion rate as markers of surgical difficulty. RESULTS Of 100 patients that had a RALP in the study period, 76 had an MRI. Patients averaged 61 years old, a preoperative PSA of 8.6, a Gleason score of 6.4, and a BMI of 27. The average calculated prostate volume was 45 grams. The average operative time and EBL were 173 minutes and 144 ml, respectively. The prostatic transverse diameter (p=0.0218), PV (p=0.0000882), and ratio of PV to PCI (p=0.000156) were significantly correlated with operative time. The BMI (p=0.00316), prostate transverse diameter (p=0.0191), PV (p=0.0002), interspinous distance (p=0.0321), and PV to PCI ratio (p=0.0000509) were all significantly correlated with EBL. Using multiple linear regression analysis, the PV and the ratio of the PV to PCI were significantly predictive of more lengthy operative times. Similarly, the ratio of PV to PCI was predictive of increased EBL. However, multiple logistic regression analysis revealed that neither prostate volume nor PCI were predictive of positive surgical margin or transfusion rate, but BMI was significantly correlated to transfusion rate (p=.00025). CONCLUSIONS Patients with larger prostates and those with short, narrow pelvises can be predicted to have a more difficult robotic prostatectomy. Creating a ratio of the PV to PCI statistically predicts a lengthier and bloodier procedure. However, those factors do not predict positive surgical margins or risk of transfusion. From these analyses, the pelvic MRI continues to demonstrate its utility in the evaluation of a patient with prostate cancer. Bronx, NY© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e782 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Barry Mason More articles by this author David Faleck More articles by this author Abraham Hakimi More articles by this author Marc Feder More articles by this author Victoria Chernyak More articles by this author Alla Rozenblit More articles by this author Reza Ghavamian More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Reference data for assessing widening between spinous processes in the cervical spine and the responsiveness of these measures to detecting abnormalities

Background context Traumatic injury to the spine is evaluated and treated based on the perceived stability of the spine. Recent classification schemes have established the importance of evaluating the discoligamentous complex to fully comprehend stability. There are a variety of techniques to evaluate the discoligamentous complex, including assessment of interspinous distance. However, there currently are no clinically validated methods to define and assess abnormal interspinous widening. Purpose The purpose of the study was to provide reference data and evidence to support the objective use of spinous process widening in the diagnosis of cervical spine injury and instability. Study design The study was designed to be biomechanical and observational. Methods Distances between spinous processes were measured from lateral flexion-extension X-rays of 156 skeletally mature asymptomatic subjects who reported never having had neck symptoms as well as 12 whole human cadavers before and after creating increasingly severe damage to posterior structures. Cervical interspinous distances were measured and then normalized to the width of the C4 vertebral end plate. The change in the distance from flexion to extension was also calculated. Results Descriptive statistics, including the 95% confidence intervals for each cervical level were tabulated for 863 levels in 149 analyzable asymptomatic volunteers. In the simulated cadaver model, interspinous widening was highly specific and mildly sensitive for detecting damage to the posterior structures of the cervical spine. Conclusions This study provides reference data that can be used to quantitatively assess interspinous process widening in the cervical spine. Application of the reference data to a cadaver model of cervical trauma suggests that although objective evidence of abnormal widening may be uncommon, when present, it is suggestive of extensive damage to the cervical spine. Derived from this data were two “rule of thumb” criteria to identify abnormal interspinous widening in flexion X-rays; when greater than 30% relative to an adjacent level (40% between C1–C2 and C2–C3) or greater than 50% of the anterior-posterior width of the C4 vertebral body (30% for C2–C3).

Unilateral Lumbar Spondylolysis on Radiography and MRI: Emphasis on Morphologic Differences According to Involved Segment

The objective of our study was to retrospectively compare the radiography and MRI findings of unilateral spondylolysis in the upper lumbar segment and in the lower lumbar segment and to consider how these radiologic findings can be applied in the diagnosis of unilateral spondylolysis. Thirty patients with unilateral lumbar spondylolysis were categorized into one of two groups according to the lumbar levels involved with pars interarticularis defects: group A (L1, L2, and L3) or group B (L4 and L5). On radiographs, we evaluated contour bulging of the affected pars interarticularis, reactive sclerosis in the contralateral pedicle, anterolisthesis of the involved vertebra, and deviation of the spinous process. On MRI, we assessed pseudoarticulation of the pars interarticularis defect, uneven distribution of posterior epidural fat, the interspinous distance between adjacent segments, facet and disk degeneration in adjacent segments, and other anomalous changes. Among the 63 patients with unilateral spondylolysis, the upper lumbar segment was involved in 29 and the lower lumbar segment, in 34. Group A often displayed contour bulging of the affected pars interarticularis, reactive sclerosis of the contralateral pedicle, and contralateral deviation of the spinous process, all of which were easily detectable on radiography. Group B frequently showed anterolisthesis, pseudoarticulation of the pars interarticularis defect, adjacent facet-disk degeneration, and other anomalous changes that were well observed on MRI. Unilateral lumbar spondylolysis displayed radiologic differences in morphology of the isthmic defect itself and in ancillary findings of the adjacent structures based on the segment involved. Recognition of different ancillary features of unilateral spondylolysis with the use of a feasible diagnostic tool can be helpful for the diagnosis of cases in which a direct sign of isthmic defect is equivocal.

Dimensions of the myopectineal orifice: a human cadaver study

In mesh implantations, there needs to be a balance between mass and the size of the meshes. However, the mesh size should allow for adequate prevention of hernia recurrence by sufficient coverage of the entire myopectineal orifice (MPO). The aim was to determine the MPO dimensions and several pelvic parameters. Thirty-two inguinal regions were assessed in 16 embalmed cadavers. The MPO averaged 7.8 cm (+/-3.0) in width and 6.5 cm (+/-1.9) in height. The weak inguinal area cranially to the inguinal ligament was 4.5 cm (+/-1.7) high. We found significant gender differences: MPOs in males showed the same width and height (7.6 x 7.6 cm), whereas in females, the MPO width was greater than its height (8.1 x 5.3 cm). Noticeable correlations of the MPO parameters to constitutional parameters were found for body size versus the height of the MPO (r = 0.5005) and interspinous distance versus the height of the MPO (r = 0.7653). A mesh measuring 10 x 8 cm is suitable for both genders: in females, it will cover the whole MPO, including the infraligamental part, whereas in males, the weak inguinal area is preferentially covered.

Effect of bony pelvic dimensions measured by preoperative magnetic resonance imaging on performing robot‐assisted laparoscopic prostatectomy

To evaluate the effect of bony pelvic dimensions measured by preoperative magnetic resonance imaging (MRI) on performing robot-assisted laparoscopic prostatectomy (RALP). In this exploratory study, we analysed the data of 141 patients who underwent RALP for clinically localized prostate cancer after undergoing MRI at our institution. Associations of various clinicopathological factors were analysed, including pelvic dimensions measured by preoperative MRI, with operative duration, estimated blood loss (EBL), surgical margin status, and postoperative urinary continence and erectile function. For operative duration, no pelvic dimension had a significant association on univariate analysis, with only the newly developed variable of pelvic cavity index approaching significance (P=0.071). Only prostate volume had a significant association with operative duration on multivariate analysis (P=0.015). For EBL, no bony pelvic dimension had a significant association on univariate analysis, with only intertuberous distance and interspinous distance approaching significance (P=0.087 and P=0.072, respectively). Again, only prostate volume was significantly associated with EBL on univariate analysis (P=0.045). No pelvic dimension had any significant effect on surgical margin status, recovery of urinary continence or erectile function at 6 months after RALP. Bony pelvic dimensions may not be a significant factor contributing to the technical difficulty of RALP among Korean patients compared with other patient-related factors such as prostate volume.

Maternal Pelvic Size Not Predictive of Daughter's Breast Cancer or Ovarian Cancer in a Large Swedish Cohort

Recent studies from Finland reported that maternal pelvic size predicted daughters' breast and ovarian cancer, possibly because maternal pelvic size is a marker for in utero hormone exposure. We sought to replicate this association in 3,845 women born between 1915 and 1929 in Uppsala, Sweden, and followed from 1960 to 2002. Archived obstetric records provided the standard measures of maternal pelvic size (intercristal distance, interspinous distance, the intercristal-interspinous difference, and the external conjugate distance). The Swedish Cancer Registry ascertained cancer incidence, with 273 cohort members developing primary breast cancer, and 52 developing primary ovarian cancer during the follow-up period. There was no evidence (P > 0.1) of an association between any measure of maternal pelvic size and incidence of either breast or ovarian cancer. This was true both before and after adjustment for various characteristics of the women and their mothers, and in analyses stratified by age at diagnosis (<50 versus >or=50 years of age, as a proxy for premenopausal and postmenopausal ages). There was also no evidence of an association in subgroup analyses restricted specifically to those groups in which the Finnish data found the greatest effect. Our study is of comparable size to the Finnish studies and was highly powered (>99%) to detect effects of the magnitude they reported. Our nonreplication therefore casts doubt on the link between maternal pelvic size and risk of breast and ovarian cancer in the offspring.

Radiographic assessment of cervical subaxial fusion

The objective of this systematic review was to use evidence-based medicine to identify the best methodology for radiographic assessment of cervical subaxial fusion. The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical fusion. Abstracts were reviewed and studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Pseudarthrosis is best assessed through the absence of motion detected between the spinous processes on dynamic radiographs (Class II). The measurement of interspinous distance on dynamic radiographs of >or= 2 mm is a more reliable indicator for pseudarthrosis than angular motion of 2 degrees based on Cobb angle measurements (Class II). Similarly, it is also understood that the pseudarthrosis rate will increase as the threshold for allowable motion on dynamic radiographs decreases. The combination of interspinous distance measurements and identification of bone trabeculation is unreliable when performed by the treating surgeon (Class II). Identification of bone trabeculation on static radiographs should be considered a less reliable indicator of cervical arthrodesis than dynamic films (Class III). Consideration should be given to dynamic radiographs and interspinous distance when assessing for pseudarthrosis.

ANALYSIS OF COMPLICATIONS IN PATIENTS TREATED WITH THE X-STOP INTERSPINOUS PROCESS DECOMPRESSION SYSTEM

The X-Stop Interspinous Process Decompression System (St. Francis Medical Technologies, Concord, CA) is an interspinous device used with increasing frequency in the treatment of degenerative lumbar spine conditions. To date, limited data are available on complications observed in association with X-Stop procedures, and even less information exists on their underlying causes. The aim of this study was to analyze a series of complications occurring at a single institution and their potential causes and propose an anatomic scoring system that may help to classify patients and prevent complications. Sixty-nine patients were treated with the X-Stop. Forty-six single-level and 23 double-level operations (92 devices) were performed according to recommended indications. The mean follow-up duration was 23 months. Eight complications were recorded: 4 device dislocations and 4 spinous process (SP) fractures, including 2 spontaneous fractures of the L4 SP in patients treated at L3-L4 and L4-L5. The following anatomic variants were demonstrated: markedly decreased interspinous distance (kissing spine-like), with concomitant facet joint hypertrophy, a posterior V-shaped interspinous area, limited accessibility of the space between the base and the tip of the SP because of facet joint hypertrophy and variations in the shape of the inferior surface of the cranial SP. This is the first study focusing on interspinous distractor complications and the anatomic features of the SP and interspinous areas of the patients, which could potentially be the underlying causes for those complications. The X-Stop can be an effective treatment option, but it is not a panacea for all patients with degenerative lumbar spine conditions. Not only do the clinical indications deserve attention, but also, and most importantly, the patient's anatomic characteristics.