Micro-finite element analysis applied to high-resolution MRI reveals improved bone mechanical competence in the distal femur of female pre-professional dancers

Summary

Micro-finite element analysis applied to high-resolution (0.234-mm length scale) MRI reveals greater whole and cancellous bone stiffness, but not greater cortical bone stiffness, in the distal femur of female dancers compared to controls. Greater whole bone stiffness appears to be mediated by cancellous, rather than cortical bone adaptation.

Introduction

The purpose of this study was to compare bone mechanical competence (stiffness) in the distal femur of female dancers compared to healthy, relatively inactive female controls.

Methods

This study had institutional review board approval. We recruited nine female modern dancers (25.7?±?5.8 years, 1.63?±?0.06 m, 57.1?±?4.6 kg) and ten relatively inactive, healthy female controls matched for age, height, and weight (32.1?±?4.8 years, 1.6?±?0.04 m, 55.8?±?5.9 kg). We scanned the distal femur using a 7-T MRI scanner and a three-dimensional fast low-angle shot sequence (TR/TE?=?31 ms/5.1 ms, 0.234 mm?×?0.234 mm?×?1 mm, 80 slices). We applied micro-finite element analysis to 10-mm-thick volumes of interest at the distal femoral diaphysis, metaphysis, and epiphysis to compute stiffness and cross-sectional area of whole, cortical, and cancellous bone, as well as cortical thickness. We applied two-tailed t-tests and ANCOVA to compare groups.

Results

Dancers demonstrated greater whole and cancellous bone stiffness and cross-sectional area at all locations (p?<?0.05). Cortical bone stiffness, cross-sectional area, and thickness did not differ between groups (>0.08). At all locations, the percent of intact whole bone stiffness for cortical bone alone was lower in dancers (p?<?0.05). Adjustment for cancellous bone cross-sectional area eliminated significant differences in whole bone stiffness between groups (p?>?0.07), but adjustment for cortical bone cross-sectional area did not (p?<?0.03).

Conclusions

Modern dancers have greater whole and cancellous bone stiffness in the distal femur compared to controls. Elevated whole bone stiffness in dancers may be mediated via cancellous, rather than cortical bone adaptation.     

Architectural design of the pelvic floor is consistent with muscle functional subspecialization

Introduction and hypothesis

Skeletal muscle architecture is the strongest predictor of a muscle’s functional capacity. The purpose of this study was to define the architectural properties of the deep muscles of the female pelvic floor (PFMs) to elucidate their structure–function relationships.

Methods

PFMs coccygeus (C), iliococcygeus (IC), and pubovisceral (PV) were harvested en bloc from ten fixed human cadavers (mean age 85 years, range 55–102). Fundamental architectural parameters of skeletal muscles [physiological cross-sectional area (PCSA), normalized fiber length, and sarcomere length (L_s)] were determined using validated methods. PCSA predicts muscle-force production, and normalized fiber length is related to muscle excursion. These parameters were compared using repeated measures analysis of variance (ANOVA) with post hoc t tests, as appropriate. Significance was set to α?=?0.05.

Results

PFMs were thinner than expected based on data reported from imaging studies and in vivo palpation. Significant differences in fiber length were observed across PFMs: C?=?5.29?±?0.32 cm, IC?=?7.55?±?0.46 cm, PV?=?10.45?±?0.67 cm (p?<?0.001). Average L_s of all PFMs was short relative to the optimal L_s of 2.7 μm of other human skeletal muscles: C?=?2.05?±?0.02 μm, IC?=?2.02?±?0.02 μm, PC/PR?=?2.07?±?0.01 μm (p?=?<0.001 compared with 2.7 μm; p?=?0.15 between PFMs, power?=?0.46). Average PCSA was very small compared with other human muscles, with no significant difference between individual PFMs: C?=?0.71?±?0.06 cm², IC?=?0.63?±?0.04 cm², PV?=?0.59?±?0.05 cm² (p?=?0.21, power?=?0.27). Overall, C had shortest fibers, making it a good stabilizer. PV demonstrated the longest fibers, suggesting that it functions to produce large excursions.

Conclusions

PFM design shows individual muscles demonstrating differential architecture, corresponding to specialized function in the pelvic floor.     

Aneurysms of the anterior and posterior cerebral circulation: comparison of the morphometric features

Background

Intracranial aneurysms (IAs) located in the posterior circulation are considered to have higher annual bleed rates than those in the anterior circulation. The aim of the study was to compare the morphometric factors differentiating between IAs located in the anterior and posterior cerebral circulation.

Methods

A total number of 254 IAs diagnosed between 2009 and 2012 were retrospectively analyzed. All patients qualified for diagnostic, three-dimensional rotational angiography. IAs were assigned to either the anterior or posterior cerebral circulation subsets for the analysis. Means were compared with a t-test. The univariate and stepwise logistic regression analyses were used to determine the predictors of morphometric differences between the groups. For the defined predictors, ROC (receiver-operating characteristic) curves and interactive dot diagrams were calculated with the cutoff values of the morphometric factors.

Results

The number of anterior cerebral circulation IAs was 179 (70.5 %); 141 (55.5 %) aneurysms were ruptured. Significant differences between anterior and posterior circulation IAs were found for: the parent artery size (5.08?±?1.8 mm vs. 3.95?±?1.5 mm; p?Conclusions Aspect ratio and parent artery size were found to be predictive morphometric factors in differentiating between anterior and posterior cerebral IAs.     

Minimalinvasive,videoassistierte Schilddrüsenresektion

Background

This study retrospectively evaluated a series of patients who underwent minimally invasive video-assisted thyroidectomy (MIVAT) during the introduction stage of this surgical technique at the Martha-Maria Hospital in Nuremberg.

Patients and methods

The eligibility criteria for MIVAT were a thyroid volume <?25 ml, nodules <?30 mm, no thyroiditis, no preoperative evidence of carcinoma and no previous neck surgery. A retrospective evaluation was performed together with a control group of patients who underwent conventional thyroid surgery during the same time period and included a follow-up for general patient satisfaction and cosmetic results.

Results

Between August 2008 and July 2009 a total of 55 patients underwent MIVAT including 8 conversions to open surgery and 45 patients who underwent conventional surgery served as matched controls. No significant differences in terms of perioperative complication rates were found (e.g. recurrent laryngeal nerve palsy, hypocalcemia or secondary hemorrhage). The mean operating time was significantly longer in the MIVAT group (96.8?±?3.7 min vs. 69.8?±?2.3 min, p?=?0.001) whereas a significant decrease in the mean operating time for hemithyroidectomy after 5 months was observed (98.1?±?3.77 min vs. 76.0?±?4.98 min, p?=?0.013). Patients in the MIVAT group were more satisfied with the cosmetic outcome (8.5?±?0.3 vs. 8.2?±?0.2, p?=?0.05) as well as with the overall surgical procedure (9.0?±?0.3 vs. 8.6?±?0.2, p?=?0.02).

Conclusion

During introduction of the MIVAT procedure a learning effect can be observed which is hallmarked by a decrease in operating time and conversion rate to open surgery. Moreover, no significant differences in terms of main postoperative complications were found so that MIVAT can be considered a safe and feasible technique under the conditions of correct eligibility criteria.     

Angiographic characteristics of ruptured paraclinoid aneurysms: risk factors for rupture

Background

The diagnosis and treatment of unruptured paraclinoid aneurysms has been increasing with the recent advent of diagnostic tools and less invasive endovascular therapeutic options. Considering the low incidence of rupture, investigation of the characteristics of ruptured paraclinoid aneurysm is important to predict rupture risk of the paraclinoid aneurysms. The objective of this study is to evaluate probable factors for rupture by analyzing the characteristics of ruptured paraclinoid aneurysms.

Methods

A total of 2,276 aneurysms (1,419 ruptured and 857 unruptured) were diagnosed and treated endovascularly or microsurgically between 2001 and 2011. Among them, 265 were paraclinoid aneurysms, of which 37 were ruptured. Removing 12 blister-like aneurysms, 25 ruptured and 228 unruptured saccular aneurysms were included and the medical records and radiological images were retrospectively analyzed.

Results

Of 25 aneurysms, 16 (64.0 %) were located in the superior direction. Five were inferior located lesions (20 %) and four were medially located lesions (16.0 %). Laterally located lesions were not found. The mean size of aneurysms was 9.4?±?5.6 mm. Ten aneurysms (40.0 %) were ≥?10 mm in size. Thirteen aneurysms (52.0 %) were lobulated. The superiorly located aneurysms were larger than the other aneurysms (10.3?±?5.8 mm vs. 7.7?±?4.9 mm) and more frequently lobulated (ten of 16 vs. three of nine). In a comparative analysis, the ruptured aneurysms were located more in the superior direction compared with unruptured aneurysms (64 vs. 23.2 %, p?<?0.0001). Large aneurysms (36.0 vs. 7.9 %, p?<?0.0001), longer fundus diameter (mean 9.4?±?5.6 vs. 4.8?±?3.3 mm, p?=?0.001), dome-to-neck ratio (mean 1.8?±?0.9 vs. 1.2?±?0.5, p?<?0.0001), and lobulated shape aneurysms were more likely to be ruptured aneurysms (13 of 25 ruptured aneurysms, 52.0 %, p?=?0.001).

Conclusions

Rupture risk of the paraclinoid aneurysm is very low. However, superiorly located paraclinoid aneurysms appear more likely to rupture than other locations. Angiographically, more conservative indication for the treatment of paraclinoid aneurysm should be recommended except for superior located lesions.     

Outcomes of Laparoscopic Sleeve Gastrectomy in Patients Older than 60 Years

Background

Morbidity and mortality following laparoscopic sleeve gastrectomy (LSG) occur at acceptable rates, but its safety and efficacy in the elderly are unknown.

Methods

A retrospective review was performed of all patients aged >60 years who underwent LSG from 2008 to 2012. These patients were 1:2 matched, by gender and body mass index (BMI) to young patients, 18?<?age?<?50. Data analyzed included demographics, preoperative and postoperative BMI, postoperative complications, and improvement or resolution of obesity-related comorbidities.

Results

Fifty-two morbid obese patients older than 60 years underwent LSG (mean age, 62.9?±?0.3 years). These were matched to 104 young patients, age 18–50 years (mean age, 35.7?±?0.8 years). Groups did not differ in male gender (44 vs. 43 %, p?=?0.9), preoperative BMI (42.6?±?0.7 vs. 42.6?±?0.6, p?=?0.97), and length of follow-up (17?±?2 vs. 22?±?1.4 months, p?=?0.06). Obesity-related comorbidities were significantly higher in the older group (96 vs. 65 %, p?<?0.001). Excess weight loss (EWL) was higher in the younger group (75?±?2.4 vs. 62?±?3 %, p?=?0.001). Older patients had a significantly higher rate of a concurrent hiatal hernia repair (23 vs. 1.9 %, p?<?0.001). Overall postoperative minor complication rate was higher in the older group (25 vs. 4.8 %, p?<?0.001). This included atrial fibrillation (9.5 %), urinary tract infection (7 %), trocar site hernia (4 %), dysphagia, surgical site infection, bleeding, bowel obstruction, colitis, and nutritional deficiency (2 %, each). No perioperative mortality occurred. Comorbidity resolution or improvement was comparable between groups (88 vs. 80 %, p?=?0.13).

Conclusions

LSG is safe and very efficient in patients aged >60, despite higher rates of perioperative comorbidities.     

Using stress MRI to analyze the 3D changes in apical ligament geometry from rest to maximal Valsalva: a pilot study

Introduction and hypothesis

A method was developed using 3D stress magnetic resonance imaging (MRI) and was piloted to test hypotheses concerning changes in apical ligament lengths and lines of action from rest to maximal Valsalva.

Methods

Ten women with (cases) and ten without (controls) pelvic organ prolapse (POP) were selected from an ongoing case–control study. Supine, multiplanar stress MRI was performed at rest and at maximal Valsalva and was imported into 3D Slicer v. 3.4.1 and aligned. The 3D reconstructions of the uterus and vagina, cardinal ligament (CL), deep uterosacral ligament (USL_d), and pelvic bones were created. Ligament length and orientation were then measured.

Results

Adequate ligament representations were possible in all 20 study participants. When cases were compared with controls, the curve length of the CL at rest was 71 ±16 mm vs. 59?±?9 mm (p?=?0.051), and the USL_d was 38?±?16 mm vs. 36?±?11 mm (p?=?0.797). Similarly, the increase in CL length from rest to strain was 30?±?16 mm vs. 15?±?9 mm (p?=?0.033), and USL_d was 15?±?12 mm vs. 7?±?4 mm (p?=?0.094). Likewise, the change in USL_d angle was significantly different from CL (p?<?0.001).

Conclusions

This technique allows quantification of 3D geometry at rest and at strain. In our pilot sample, at maximal Valsalva, CL elongation was greater in cases than controls, whereas USL_d was not; CL also exhibited greater changes in ligament length, and USL_d exhibited greater changes in ligament inclination angle.     

Cervical extension magnetic resonance imaging in evaluating cervical spondylotic myelopathy

Background

Cervical spondylotic myelopathy (CSM) may be caused by static and dynamic spinal cord compression, particularly during neck extension. Dynamic compression may be better evaluated with dynamic magnetic resonance (MR) images. We performed a retrospective study to determine the clinical indication for dynamic MR imaging, and conducted a survey regarding image interpretation by clinicians.

Method

A total of 32 patients (M:F?=?20:12, 60.1?±?10.7 years) who had undergone neutral/extension cervical MR imaging were included. The study population consisted of 22 patients with signs of cervical myelopathy (M group) and 10 patients without signs of myelopathy (NM group). The number of compression levels (complete obliteration of the anterior and posterior subarachnoid space) was assessed at each level in mid-sagittal, T2-weighted, neutral and extension MR images. Reproduced images from 22 patients in the M group were randomly arranged, and four experienced spine surgeons at four different institutes interpreted them to reach a clinicians’ agreement. The agreements were then assessed with inter-rater correlation coefficients (ICC).

Results

Analysis with extension MR images found an increased number of compression levels in 23/32 (72 %) of patients; 20/22 in the M group and 3/10 in the NM group (p?<?0.01, chi-squared test), as compared to findings of the neutral MR images. Clinical factors for increased compression levels in extension MR images were age (p?<?0.01, 63.3?±?10.0 years vs. 51.9?±?8.1) and signs of myelopathy (p?<?0.01, odds ratio, 23.33). Clinician agreement was improved with extension MR images; ICC was 0.67 with neutral and 0.81 with extension MR images.

Conclusions

The evaluation of CSM may be improved with dynamic MR images. Dynamic MR scanning may be considered for elderly patients with signs of myelopathy, but an interpretation for asymptomatic spinal compression based exclusively on extension MR image should be made with caution.     

Retropatellare Denervierung

Background

The purpose of the study was to determine possible differences in the mid-term results of total knee arthroplasty in patients treated with and without denervation of the patella.

Patients and methods

This study included 80 total knee replacements in 71 patients who were treated with total knee replacement, either with (n?=?40) or without (n?=?40) simultaneous denervation of the patella out of a total population with 122 knee replacements in 100 patients. Comparability of both groups was achieved by applying matching criteria. All patients were reviewed by isokinetic tests, physical and radiological examination. The mean follow-up time was 2.2 years.

Results

The mean hospital for special surgery (HSS) score revealed no statistically significant differences between both groups (with denervation 77.9?±?11.1 and without denervation 77.8?±?11.0, p?=?0.976). The isokinetic torque measurements with low angle velocity (60°/s) indicated slightly higher values during extension (60.2?±?32.2 Nm versus 55.8?±?25.2 Nm, p?=?0.497) and flexion (52.4?±?28.3 Nm versus 46.1?±?22.3 Nm, p?=?0.272) movements of the affected knee joint. However, the differences did not reach statistical significance. At high angle velocity (180°/s) no differences could be found between both groups. No cases of postoperative necrosis of the patella were observed. Anterior knee pain after denervation was reported in 6 cases (15?%) compared to 10 cases (25?%) in patients who were treated without denervation (p?=?0.402).

Conclusion

No statistically significant differences could be found between patients with and without denervation of the patella for total knee arthroplasty.     

Feasibility of insertion of a microcatheter through a Y-stent in coil embolization of cerebral aneurysms and its detailed geometry by micro-computed tomography

Background

In Y-stent-assisted coil embolization for cerebral aneurysms, open or closed cell stents are used. Different microcatheters for coil insertion are available. We investigated which microcatheter could be navigated into an aneurysm through a Y-stent with different stents.

Methods

Double Neuroform open-cell stents or double Enterprise closed-cell stents were deployed in Y-configuration in a silicon model of a bifurcation aneurysm. Two endovascular neurosurgeons independently tried to navigate an SL-10 microcatheter for 0.010” coils or a PX Slim microcatheter for 0.020” Penumbra coils into the aneurysm through the Y-stent. In addition, we measured lengths of stent pores of the Y-stents with double Enterprise stents deployed in the model by micro-computed tomography.

Results

It was feasible to navigate an SL-10 microcatheter into the aneurysm through the Y-stent with Enterprise or Neuroform stents. Navigation of a PX Slim microcatheter was feasible in the Y-stents only with Neuroform stents. In the Y-stent with double Enterprise stents, the lengths of the second stent pores were significantly smaller than those of the first stent (0.41?±?0.18 mm vs 0.69?±?0.20 mm; P?=?0.008). The SL-10 microcatheter was smaller than approximately 80 % of the stent pores of the first stent and 30 % of those of the second stent. The PX Slim microcatheter was smaller than 20 % of the stent pores of the first stent and 0 % of those of the second stent.

Conclusions

It was feasible to insert an SL-10 microcatheter into the aneurysm through Y-stents with Enterprise or Neuroform stents. Navigation of a PX Slim microcatheter for 0.020” Penumbra coils was feasible in Y-stents with Neuroform stents, but not with double Enterprise stents. The measurements of stent pores by micro-computed tomography supported this feasibility study. These results may be helpful to select appropriate stents and microcatheters in Y-stent-assisted coil embolization, especially in case of retreatments.     

Barriers to medication adherence and its relationship with outcomes in pediatric dialysis patients

Background

Medication adherence is a major factor determining outcome in children with chronic disease. Children with end-stage renal disease are challenged with requirements for renal replacement therapy in addition to complicated medication regimens.

Methods

We assessed barriers to medication adherence in 22 pediatric patients receiving chronic dialysis [63.6 % hemodialysis (HD), 36.4 % peritoneal dialysis (PD); age 15.9?±?0.7 years, dialysis vintage 31.6?±?6.5 months]. Adherence was assessed by a 16-question survey with a maximum score (difficulty) of 64.

Results

The overall mean adherence score was 30.9?±?2.4 (range 16–49; median? 27.5). There was a trend for lower adherence scores in patients on HD (27.5?±?2.9) compared to those on PD (36.8?±?3.7) (p?=?0.06). Compared to HD patients, the mean score/question was significantly higher in PD patients (1.7?±?0.2 vs. 2.4?±?0.2, respectively; p?=?0.006). Of the 16 questions, HD and PD patients gave a mean response of ≤1.2 for five and zero questions, respectively. Neither gender, age nor dialysis vintage was related to adherence scores. There was also a trend for adherence scores to be higher in females (35.6?±?3.7) than in males (27.5?±?2.9) (p?=?0.1), but this difference did not reach statistical significance. Markers of mineral bone disease were similar in HD and PD patients. Among all targets in HD and PD patients combined, there was no relationship between adherence scores and number of targets reached (r?=??0.09, p?=?0.7).

Conclusion

There are many barriers to medication adherence in pediatric patients receiving dialysis. In our patient group the difficulties were more evident in patients receiving PD than in those receiving HD.     

The role of sympathectomy on the regulation of basilar artery volume changes in stenoocclusive carotid artery modeling after bilateral common carotid artery ligation: an animal model

Background

Stenoocclusive carotid artery disease causes important histomorphologic changes in all craniocervical vasculatures, such as luminal enlargement, vascular wall thinning, elongation, convolutions, and aneurysm formation in the posterior circulation. Although increased pressure, retrograde blood flow, and biochemical factors are described in the pathogenesis of vascular remodelisation, the vasoregulatory role of the autonomic nervous system has not been investigated thus far. We investigated the relationship between the sympathetic nervous system and the severity of histomorphologic alterations of basilar arteries after bilateral common carotid artery ligation (BCCAL).

Material and methods

This study was conducted on 21 rabbits. The rabbits were randomly divided into three groups: baseline group (n?=?5), sympathectomy non-applied group (SHAM; n?=?8), and sympathectomy applied group (n?=?8) before bilateral common carotid artery ligation. Permanent ligation of the prebifurcations of the common carotid arteries was performed to replicate stenoocclusive caroid artery disease. Basilar artery volumes were measured after ligation. Volumes of the basilar arteries were estimated by stereologic methods and compared between groups.

Results

Luminal enlargement, wall thinning, elongation, convolutions, and doligoectatic configurations were detected in the majority of basilar arteries. The mean basilar arterial volume was 4.27?±?0.22 mm3 in the baseline group; 5.28?±?0.67 mm³ in the SHAM group, and 8.84?±?0.78 mm3 in the study group. The severity of basilar enlargement was significantly higher in the study group compared with the SHAM (p?<?0.005) and baseline groups (p?<?0.001).

Conclusions

Sympathectomy causes basilar artery enlargment, which is beneficial for maintaining cerebral blood flow; however, it also causes wall thinning, elongation, convolution, and aneurysm formation, which may be hazardous in stenoocclusive carotid artery disease. Sympathectomy can prevent new vessel formation and hyperthyrophic changes at the posterior circulation. Neovascularisation is not detected adequately in sympathectomised animals.     

Offen anatomische Rekonstruktion der chronischen Akromioklavikularinstabilität

Objective

The aim of open anatomic reconstruction of the acromioclavicular (AC) joint is combined reconstruction of the AC and coracoclavicular ligaments using a tendon graft.

Indications

Symptomatic instabilities of the AC joint > type III.

Contraindications

Asymptomatic instabilities < type III and general contraindication against elective surgery.

Surgical technique

Through the open surgical approach, the exact anatomical insertion sites of the ligamentous structures can be reproduced. In addition, this approach enables accurate repositioning of the AC joint under direct vision (including possible debridement of the intraarticular discus) and an additional fixation of deltotrapezoidal fascia.

Postoperative management

Postoperatively, the arm is positioned in an abduction brace for 6–8 weeks. Passive exercises in flexion up to 90° and in external rotation up to 30° are permitted during this period. After 6–8 weeks, free and active motion is allowed.

Results

Between January 2003 and December 2010, 46 patients (9 women and 37 men, mean age 42?±?13 years) underwent AC combined reconstruction. Complete outcome data were available for 25 patients. Mean length of follow-up was 31?±?26 months. The mean preoperative coracoclavicular distance was 20.1?±?5.6 mm; postoperatively the mean distance was 7.1?±?3.0 mm (p?<?0.001) The mean clinical scores also statistically improved (p?<?0.001): American Shoulder and Elbow Score improved from 53.4?±?18.7 points preoperatively to 80.6?±?25.7 points postoperatively and the Constant Murley Score improved from 60.0?±?16.7 points preoperatively to 85.2?±?22.8 points postoperatively.     

A safety,length of stay,and cost analysis of minimally invasive microsurgery for anterior circulation aneurysms

Objectives

The aim of our study was to evaluate minimally invasive techniques for the treatment of anterior circulation aneurysms versus standard surgery, and to calculate the impact of these techniques on health resources, length of stay, and treatment costs.

Methods

A consecutive series of 24 patients with ruptured and 30 with unruptured anterior circulation aneurysms treated with minimally invasive microsurgery (MIM) by the same surgeon was compared with a matched series of standard microsurgeries (SM) conducted for 23 ruptured and 22 unruptured aneurysms. Complication rates, aneurysm obliteration, modified Rankin Scale (mRS) outcomes, length of stay, and treatment costs were assessed.

Results

Surgical complications, aneurysm obliteration rates and mRS outcomes were comparable between MIM and SM groups in ruptured and unruptured aneurysm cohorts. MIM resulted in shorter operative times both in unruptured (102.7?±?4.35 vs 194.7?±?10.26 min, p?<?0.0001) and ruptured aneurysms (124.3?±?827 vs 209?±?13.84 min, p?<?0.0001). Length of stay was reduced in patients with MIM for unruptured aneurysms (1.55?±?24 vs 4.28?±?0.71 days, p?<?0.000,1) but not in those with ruptured aneurysms. MIM reduced treatment costs of unruptured aneurysm patients, mainly through reduced utilization of inpatient resources (non-acute bed costs in CAD: 371.2?±?80.99 vs 1440?±?224.1, p?<?0.0001), whereas costs were comparable in patients with ruptured aneurysms.

Conclusion

Minimally invasive surgery is a safe and effective approach for the treatment of ruptured and unruptured aneurysms of the anterior circulation. In patients with unruptured aneurysms, reduced invasiveness and shorter operative times decreased length of stay, which reflects improved patient postoperative recovery. Overall, this translated into bed resource economy and cost reduction.     

Effects of polyunsaturated fatty acids (PUFAs) in the treatment of experimental chronic renal failure

Purpose

A diet with polyunsaturated fatty acid (PUFA) supplementation has been reported to reduce renal and cardiac diseases. This study sought to elucidate whether PUFAs derived from plant or marine oils could have beneficial effects on the progression of experimental chronic renal failure (CRF).

Methods

Experimental CRF was achieved by a 5/6 nephrectomy model. Male Wistar rats were divided into groups and given daily supplements of fish oil (group FO), flaxseed oil (group FXO), or soybean oil (control?Cgroup SO) for 30?days. Serum creatinine (sCr), 24-h proteinuria, total cholesterol, triglycerides, and creatinine clearance (CLcr) were measured at day 0 and 30?days after surgery when the rats were euthanized for histological analysis of the remnant kidney.

Results

After 30?days, we observed lower levels of sCr in the groups supplemented with PUFA when compared with the control group (FO: 0.92?±?0.13; FXO: 1.06?±?0.28; SO: 1.32?±?0.47?mg/dL) and significantly slower variations of sCr (??sCr) in the groups treated with PUFAs (FO?=?0.35?±?0.16; FXO?=?0.47?±?0.31; OS?=?0.72?±?0.43; mg/dL, P?=?0.041). Similarly, the CLcr of both of the groups that received PUFAs was significantly slower than the rats in the control group (FO: 0.45?±?0.15; FXO: 0.60?±?0.09; SO: 0.28?±?0.06?mL/min/day; P?=?0.01). The rats that received PUFA supplements also presented significantly less histological lesions compared with the control group.

Conclusions

These results suggest a beneficial effect of dietary supplementation with flaxseed or fish oil in rats with CRF.     

Infection surveillance in transsphenoidal pituitary surgery - comparison of lipopolysaccharide-binding-protein, interleukin 6, C-reactive protein, white blood cell count, erythrocyte sedimentation rate and body temperature

Background

One of the major concerns in transsphenoidal surgery are infections because the approach to the pituitary includes a route of microbial colonization. To minimize the associated morbidity and mortality, a surveillance program is crucial to monitor for perioperative infections.

Methods

For 1 year, we analysed body temperature (BT), erythrocyte sedimentation rate (ESR), white blood cell count (WBC), C-reactive protein (CRP), interleukin 6 (IL-6) and lipopolysaccharide-binding-protein (LBP) following elective transsphenoidal pituitary surgery. Samples were collected on admission, day 1, 3 and 7 as well as 3 months postoperatively.

Results

In 116 patients, all data were available. No postoperative infections occurred within the first postoperative week. BT (37.6?±?0.6, baseline 37.0?±?0.5 °C), WBC (11,366?±?2,541, baseline 6,861?±?2,123/μl), CRP (25.3?±?22.6, baseline 3.1?±?6 mg/l), IL-6 (12?±?13, baseline 2.7?±?2.6 pg/ml), and LBP (11.3?±?4.9, baseline 5.7?±?2.7 μg/ml) peaked on day 1 postoperatively (each p?=?0.001), while ESR peaked on day 3 (25?±?16, baseline 13?±?11 mm/h, p?=?0.001). BT and IL-6 normalized by day 3 and CRP by day 7, while ESR (23?±?16 mm/h, p?=?0.001), WBC (7,807?±?2,750/μl, p?=?0.001) and LBP (7.3?±?2.6 μg/ml, p?=?0.028) were still increased by day 7.

Conclusion

The present study establishes normative values for an infection surveillance following transsphenoidal pituitary surgery. CRP, a convenient and reasonable priced parameter, is affected by the procedure for the first postoperative week. IL-6 is more robust and allows a close monitoring on the expense of additional pricing. ESR, WBC and LBP are sustained affected by surgery, and do not offer any advantage. Since no infections were observed, we were unable to calculate the respective sensitivity and specificity.     

Blood perfusion and bone formation before and after minimally invasive periacetabular osteotomy analysed by Positron Emission Tomography combined with Computed Tomography

Purpose

Sufficient blood perfusion is essential for successful bone healing after periacetabular osteotomy (PAO). The purpose of this study was to quantify blood perfusion and bone formation before and after PAO analysed by positron emission tomography (PET) combined with computed tomography (CT).

Methods

Twelve dysplastic patients (nine women) were included consecutively in the study and all were operated upon by the senior author (KS). Median age was 33 (23–55) years. Initially, two patients were PET scanned in a pilot study to test our models for calculation of the physiological parameters. The following ten patients had their hip joints PET/CT scanned immediately before PAO and three to four weeks after. Oxygen-15-water was used to quantify blood perfusion and Flourine-18-fluoride was used to produce quantitative images interpreted as new bone formation in the acetabular fragment.

Results

The blood perfusion of the operated acetabulum before surgery was 0.07?±?0.02 ml/min/ml, and after surgery 0.19?±?0.03 ml/min/ml (p?=?0.0003). Blood perfusion of the non-operated acetabulum was 0.07?±?0.02 ml/min/ml before PAO and 0.07?±?0.02 ml/min/ml after surgery (p?=?0.47). The fluoride-clearance per volume bone of the operated acetabulum was 0.02?±?0.01 ml/min/ml preoperatively, and 0.06?±?0.01 ml/min/ml postoperatively (p?=?0.0005). Fluoride-clearance of the non-operated acetabulum was 0.01?±?0.01 ml/min/ml before PAO and 0.02?±?0.01 ml/min/ml after PAO (p?=?0.49).

Conclusion

Blood perfusion and new bone formation increased significantly in the acetabular fragment. Thus, the results of this study do not support the concern about surgically damaged vascularity after PAO.     

Forehead contour and hypotelorism in patients with metopic craniosynostosis: comparing minimally invasive and open treatments

Background

Patients with metopic craniosynostosis and trigonocephaly are classically treated with a fronto-orbital advancement. In contrast, a minimally invasive treatment entails a narrow ostectomy of the fused suture, followed by postoperative helmet molding. The goal of this project was to investigate the results of patients treated with minimally invasive techniques by quantifying the deformity of the forehead contour a year after their operation and comparing these measurements to patients who underwent an open operation as a control.

Methods

The 1-year postoperative computed tomography (CT) scans of patients treated with minimally invasive techniques for metopic craniosynostosis (n?=?10) were compared to CT scans of patients treated with an open operation (n?=?20). The straight line measurements between the zygomaticofrontal (ZF) sutures and between the dacryon bilaterally were recorded to assess the degree of hypotelorism. An axial plane two-dimensional angle between frontotemporale bilaterally and the glabella (FT_R-G-FT_L) was used as a measurement of the severity of trigonocephaly.

Results

The average age of patients at surgery for minimally invasive cases was 3.4?±?0.5 months old (mean ± standard error of the mean) compared with the age of patients for open cases at 11.3?±?0.6 months old. Seventy percent of the patients were males and 30 % were females in both the minimally invasive and open groups. The mean distance between the ZF sutures was 76.3?±?1.9 mm in the minimally invasive group and 75.9?±?1.2 mm in the open group (p?=?0.90). The mean distance between the dacryon bilaterally was 15.1?±?1.0 mm in the minimally invasive group and 14.5?±?0.6 mm in the open group (p?=?0.63). The FT_R-G-FT_L angle was 118.5°?±?13.2° in the minimally invasive group and 113.1°?±?2.0° in the open group (p?=?0.21).

Conclusions

In this small, retrospective series, minimally invasive treatment of metopic craniosynostosis appears to have equivalent results to open fronto-orbital advancement in terms of the acuity of trigonocephalic forehead angle and hypotelorism at 1-year follow-up. Additional studies are being conducted to better quantify, validate, and compare these measurements. The end goal is to elucidate the best methods of quantifying normal forehead contours and to determine if minimally invasive treatment is equivalent to the open approach. Level of Evidence: Level IV, therapeutic study.     

„Ligament bracing“ – die augmentierte Kreuzbandnaht

Background

In the context of acute knee dislocations, suture repair of ruptured cruciate ligaments leads to good clinical results in 80% of cases. Disadvantages are low primary stability and subsequently secondary elongation of the sutured ligaments. In the present study, we compared primary stability of suture repair, reinforced by different suture augments, to cruciate ligament reconstruction.

Objective

The concept of ligament bracing with transosseous suture repair of the cruciate ligaments and additional suture augmentation is biomechanically superior to cruciate ligament reconstruction.

Material and methods

A total of 42 porcine knee joints divided into seven groups were examined. The stability of four different suture/augmentation combinations were compared to cruciate ligament reconstruction with human hamstring tendons. The investigational setup consisted of testing 1000 cycles with 20 N to 154 N load in a.-p. translation and 60° flexion. Elongation and load to failure were measured.

Results

Neither reconstruction (3.13?±?1.65 mm; 362?±?51 N) nor augmented suture repair (1.89–2.5 mm; 464–624 N) achieved the primary stability of the intact cruciate ligament (0.63?±?0.34 mm, 1012?±?91 N). In comparison to ligament reconstruction, all four augmented suture repairs showed minor elongation in the cyclic test and a higher load to failure. The isolated suture repair showed poor results (6.79?±?4.86 mm, 177?±?73 N).

Conclusion

Augmented suture repair provides significantly higher stability compared with isolated suture repair and reconstruction with hamstring tendons. The concept of ligament bracing could be a promising future treatment option in acute knee dislocations. Clinical results remain to be seen.     

How to prevent injury to the palmar cutaneous branch of median nerve and ulnar nerve in a palmar incision in carpal tunnel release, a cadaveric study

Objective

To identify palmar cutaneous branches of median nerve and ulnar nerve (PCBMN and PCBUN) and try to find a safe path at wrist and forearm in the decompression procedure of carpal tunnel syndrome.

Materials and methods

Ten formalin-fixed and five fresh-frozen cadaveric forearms were included in the study. The cross point of longitude of middle finger and distal wrist crease was defined as 0 point. Distal wrist crease (DWC) and 0 point were chosen as references for measurements. Several points on the pathway of PCBMN and PCBUN were measured.

Results

The average distance between the origin of the PCBMN and PCBUN to the DWC was 4.95?±?0.88 cm, 10.12?±?1.50 cm, separately. The average distance between DWC and the point where PCBMN and PCBUN separated from their trunk was found to be 2.09?±?0.31 cm, 2.90?±?0.50 cm, separately. The distances between PCBMN, PCBUN and 0 point at DWC level was found to be 0.61?±?0.12 cm, 0.47?±?0.31 cm, separately. The diameters of two cutaneous branches were 0.10?±?0.02 cm, 0.11?±?0.04 cm, separately.

Conclusion

The general longitudinal palmar incision could avoid injuries to recurrent branch of median nerve and distal branches of palmar cutaneous nerve can be avoided macroscopically. The area about 5 mm ulnar and 6 mm radial to 0 point at wrist level was a relatively safe area.