Type of intrinsic resistant starch type 3 determines in vitro fermentation by pooled adult faecal inoculum.

Resistant starch (RS) results in relatively high health-beneficial butyrate levels upon fermentation by gut microbiota. We studied how physico-chemical characteristics of RS-3 influenced butyrate production during fermentation. Six highly resistant RS-3 substrates (intrinsic RS-3, 80-95 % RS) differing in chain length (DPn 16-76), Mw distribution (PI) and crystal type (A/B) were fermented in vitro by pooled adult faecal inoculum. All intrinsic RS-3 substrates were fermented to relatively high butyrate levels (acetate/butyrate ≤ 2.5), and especially fermentation of A-type RS-3 prepared from polydisperse α-1,4 glucans resulted in the highest relative butyrate amount produced (acetate/butyrate: 1). Analysis of the microbiota composition after fermentation revealed that intrinsic RS-3 stimulated primarily Lachnospiraceae, Bifidobacterium and Ruminococcus, but the relative abundances of these taxa differed slightly depending on the RS-3 physico-chemical characteristics. Especially intrinsic RS-3 of narrow disperse Mw distribution stimulated relatively more Ruminococcus. Selected RS fractions (polydisperse Mw distribution) obtained after pre-digestion were fermented to acetate and butyrate (ratio ≤ 1.8) and stimulated Lachnospiraceae and Bifidobacterium. This study indicates that especially the α-1,4 glucan Mw distribution dependent microstructure of RS-3 influences butyrate production and microbiota composition during RS-3 fermentation.

Human milk oligosaccharides, antimicrobial drugs, and the gut microbiota of term neonates: observations from the KOALA birth cohort study.

The infant gut microbiota affects childhood health. This pioneer microbiota may be vulnerable to antibiotic exposures, but could be supported by prebiotic oligosaccharides found in breast milk and some infant formulas. We sought to characterize the effects of several exposures on the neonatal gut microbiota, including human milk oligosaccharides (HMOs), galacto-oligosaccharides (GOS), and infant/maternal antimicrobial exposures. We profiled the stool microbiota of 1023 one-month-old infants from the KOALA Birth Cohort using 16S rRNA gene amplicon sequencing. We quantified 15 HMOs in breast milk from the mothers of 220 infants, using high-performance liquid chromatography-mass spectrometry. Both breastfeeding and antibiotic exposure decreased gut microbial diversity, but each was associated with contrasting shifts in microbiota composition. Other factors associated with microbiota composition included C-section, homebirth, siblings, and exposure to animals. Neither infant exposure to oral antifungals nor maternal exposure to antibiotics during pregnancy were associated with infant microbiota composition. Four distinct groups of breast milk HMO compositions were evident, corresponding to maternal Secretor status and Lewis group combinations defined by the presence/absence of certain fucosylated HMOs. However, we found the strongest evidence for microbiota associations between two non-fucosylated HMOs: 6'-sialyllactose (6'-SL) and lacto-N-hexaose (LNH), which were associated with lower and higher relative abundances of Bifidobacterium, respectively. Among 111 exclusively formula-fed infants, the GOS-supplemented formula was associated with a lower relative abundance of Clostridium perfringens. In conclusion, the gut microbiota is sensitive to some prebiotic and antibiotic exposures during early infancy and understanding their effects could inform future strategies for safeguarding a health-promoting infant gut microbiota.

Digestibility of resistant starch type 3 is affected by crystal type, molecular weight and molecular weight distribution.

Resistant starch type 3 (RS-3) holds great potential as a prebiotic by supporting gut microbiota following intestinal digestion. However the factors influencing the digestibility of RS-3 are largely unknown. This research aims to reveal how crystal type and molecular weight (distribution) of RS-3 influence its resistance. Narrow and polydisperse α-glucans of degree of polymerization (DP) 14-76, either obtained by enzymatic synthesis or debranching amylopectins from different sources, were crystallized in 12 different A- or B-type crystals and in vitro digested. Crystal type had the largest influence on resistance to digestion (A >>> B), followed by molecular weight (Mw) (high DP >> low DP) and Mw distribution (narrow disperse > polydisperse). B-type crystals escaping digestion changed in Mw and Mw distribution compared to that in the original B-type crystals, whereas A-type crystals were unchanged. This indicates that pancreatic α-amylase binds and acts differently to A- or B-type RS-3 crystals.

The influence of α-1,4-glucan substrates on 4,6-α-d-glucanotransferase reaction dynamics during isomalto/malto-polysaccharide synthesis.

Starch-based isomalto/malto-polysaccharides (IMMPs) are soluble dietary fibres produced by the incubation of α-(1 → 4) linked glucans with the 4,6-α-glucanotransferase (GTFB) enzyme. In this study, we investigated the reaction dynamics of the GTFB enzyme by using isoamylase debranched starches as simplified linear substrates. Modification of α-glucans by GTFB was investigated over time and analysed with 1H NMR, HPSEC, HPAEC combined with glucose release measurements. We demonstrate that GTFB modification of linear substrates followed a substrate/acceptor model, in which α-(1 → 4) linked glucans DP ≥ 6 functioned as donor substrate, and α-(1 → 4) linked malto-oligomers DP < 6 functioned as acceptor. The presence of α-(1 → 4) linked malto-oligomers DP < 6 resulted in higher GTFB transferase activity, while their absence resulted in higher GTFB hydrolytic activity. The information obtained in this study provides a better insight into GTFB reaction dynamics and will be useful for α-glucan selection for the targeted synthesis of IMMPs in the future.

Enzymatic fingerprinting of isomalto/malto-polysaccharides.

In this study, we present an enzymatic fingerprinting method for the characterization of isomalto/malto-polysaccharides (IMMPs). IMMPs are produced by the modification of starch with the 4,6-α-glucanotransferase (GTFB) enzyme and consist of α-(1→4), α-(1→6) and α-(1→4,6) linked glucoses. Enzymes were used separately, simultaneously or in successive order to specifically degrade and/or reveal IMMP substructures. The enzymatic digests were subsequently analysed with HPSEC and HPAEC to reveal the chain length distribution (CLD) of different IMMP substructures. The presence of amylose in the substrate resulted in the formation of linear α-(1→6) linked glycosidic chains (13.5 kDa) in the former amylopectin fraction. The length of these chains indicates that GTFB transferase activity on amylopectin is more likely to elongate single amylopectin chains than to provide an even distribution. Enzymatic fingerprinting also revealed that the GTFB enzyme is capable of introducing large (20 kDa) linear α-(1→6) linked glycosidic chains in the α-glucan substrate.

Staphylococcus aureus in the nose and throat of Iowan families.

The study objective was to determine the prevalence of Staphylococcus aureus colonisation in the nares and oropharynx of healthy persons and identify any risk factors associated with such S. aureus colonisation. In total 263 participants (177 adults and 86 minors) comprising 95 families were enrolled in a year-long prospective cohort study from one urban and one rural county in eastern Iowa, USA, through local newspaper advertisements and email lists and through the Keokuk Rural Health Study. Potential risk factors including demographic factors, medical history, farming and healthcare exposure were assessed. Among the participants, 25.4% of adults and 36.1% minors carried S. aureus in their nares and 37.9% of adults carried it in their oropharynx. The overall prevalence was 44.1% among adults and 36.1% for minors. Having at least one positive environmental site for S. aureus in the family home was associated with colonisation (prevalence ratio: 1.34, 95% CI: 1.07-1.66). The sensitivity of the oropharyngeal cultures was greater than that of the nares cultures (86.1% compared with 58.2%, respectively). In conclusion, the nares and oropharynx are both important colonisation sites for healthy community members and the presence of S. aureus in the home environment is associated with an increased probability of colonisation.

[Transpedicular osteotomy with dorsal wedge osteotomy: treatment of post-traumatic or postinfection kyphotic malalignment of the thoraco-lumbar spine]. / Pedikelsubtraktionsosteotomie mit dorsaler Wedge-Osteotomie : Behandlung von posttraumatischen bzw. postinfektiösen kyphotischen Fehlstellungen in der thorakolumbalen Wirbelsäule.

BACKGROUND: The purpose of the study was to evaluate the clinical and radiological follow-up of patients suffering from fixed post-traumatic and postinflammatory kyphotic deformities of the thoracic and lumbar spine and treated by posterior transpedicular wedge resection osteotomy of the spine. METHODS: A total of 28 patients received a posterior transpedicular wedge resection osteotomy. A prospective follow-up was performed preoperatively, postoperatively and after 3, 6 and 12 months. The kyphotic angle of the fractured segment was evaluated as well as the clinical parameters the self-reported visual analog scale (VAS) and the Oswestry score. RESULTS: The median pain scores (VAS) and the Oswestry disability scores (p<0.05) decreased significantly from pretreatment to post-treatment. Postoperatively a significant correction of the kyphotic angle could be achieved with a mean of 28 degrees (range 14-44 degrees ). In the follow-up after 1 year there was a 7 degrees increase in kyphosis. CONCLUSIONS: Transpedicular wedge resection osteotomy of the thoracic and lumbar spine offers a safe surgical technique for the treatment of fixed postinflammatory kyphotic deformities.

Balloon kyphoplasty in the treatment of metastatic disease of the spine: a 2-year prospective evaluation.

There is currently little data on the longer term efficacy and safety of balloon kyphoplasty (BKP) in patients with metastatic vertebral compression fractures (VCFs). To prospectively assess the long-term efficacy and safety of BKP in treating thoracic and lumbar spinal metastatic fractures that result in pain or instability. Sixty-five patients (37 men, mean age: 66 years) underwent 99 BKP procedures. Patient-related outcomes of pain visual analogue scale (VAS) and Oswestry Disability Index were assessed pre- and post-operatively and after 3, 6, 12 and 24 months. Correction of vertebral height and kyphotic deformity were assessed by radiographic measurements. Mean pain VAS and Oswestry Disability Index significantly improved from pre- to post-treatment (P < 0.0001), this improvement being sustained up to 24-month follow up. A gain in height restoration and a reduction of the post-operative kyphotic angle were seen post-operatively and at 3 months although these radiographic outcomes returned to pre-operative levels at 12 months. BKP was associated with a rate of cement leakage and incidence vertebral fracture of 12 and 8%, respectively. No symptomatic cement leaks or serious adverse events were seen during the 24 months of follow up. BKP is a minimally invasive procedure that provides immediate and long-term pain relief and improvement in functional ability in selected patients with metastatic VCFs. The procedure appears to have good long-term safety.

[A prospective two-year follow-up of thoracic and lumbar osteolytic vertebral fractures caused by multiple myeloma treated with balloon kyphoplasty]. / Zwei Jahre prospektive Nachuntersuchung von thorakalen und lumbalen osteolytischen Wirbelkörperfrakturen in Patienten mit einem multiplen Myelom--behandelt mittels Ballon-Kyphoplastie.

PURPOSE: Balloon kyphoplasty is a minimally invasive procedure for the stabilization of osteoporotic and osteolytic vertebral fractures. The purpose of this prospective study was to evaluate this operative procedure in the treatment of osteolytic vertebral fractures with regard to the reduction of pain and functional improvement of the patients and further to evaluate the restoration of vertebral height postoperatively. MATERIALS AND METHODS: In this study 26 patients (21 male, 5 female) with osteolytic vertebral fractures were treated with balloon kyphoplasty. In total, 59 vertebral fractures were treated with balloon kyphoplasty. Preoperatively conventional radiographs in lateral and a. p. views, CT and/or MRI were preformed. Pre- and postoperatively the clinical parameters using VAS (visual analogue scale) and the Oswestry score were evaluated. Radiographic scans were performed pre- and postoperatively and after 3, 6, 12 and 24 months. The vertebral height and endplate angles were measured. RESULTS: The median pain scores (VAS) decreased from pre- to post-treatment significantly (p < 0.05) as also did the Oswestry score (p < 0.05). Balloon kyphoplasty led to a significant and sustained reduction of pain resulting in a significant functional improvement for the patients. A significant restoration of vertebral height and reduction of the kyphotic angle could be achieved with the balloon technique (p < 0.05). Furthermore, the minimal-invasive procedure was able to stabilize the spine also over a longer period of 24 months. A radiation therapy and/or chemotherapy could be performed without loss of time. CONCLUSION: In the treatment of osteolytic vertebral fractures balloon kyphoplasty led to a quick and sustained reduction of pain and as well as a functional improvement for the patients. A restoration of the vertebral height and reduction of the kyphotic angle was especially attributable to the balloon technique. The balloon kyphoplasty was able to stabilize the fractured vertebrae in the long-term and was able to prevent an increase of kyphotic deformity. Balloon kyphoplasty is an outstanding alternative in comparison to the established therapeutic concepts in the treatment of osteolytic vertebral fractures.

Incidence of adjacent vertebral fractures in patients treated with balloon kyphoplasty: two years' prospective follow-up.

PURPOSE: To evaluate the long-term outcomes of 37 patients with 60 osteoporotic vertebral fractures, located in the thoracic and lumbar spine, treated with balloon kyphoplasty. MATERIAL AND METHODS: Fourty-two patients (15 males and 27 females) with 67 osteoporotic vertebral fractures were treated with balloon kyphoplasty. We were able to have 2-year follow-up of 37 patients with 60 treated vertebrae. Baseline fracture rate in these 37 patients was 1.9 (60 fresh fractures and 11 old fractures already healed). Symptomatic levels were identified by correlating the clinical presentation with conventional radiographs, computed tomography (CT), and/or magnetic resonance imaging (MRI). During the 2-year follow-up, reduction in pain was determined. The effects on pain symptoms were measured on a self-reported visual analog scale (VAS) and the Oswestry score was documented to assess disability. Radiographic scans were performed pre- and postoperatively, and after 3, 6, 12, and 24 months. The vertebral height and endplate angles were measured to assess the restoration of the sagittal alignment. RESULTS: The median pain scores (VAS) decreased significantly from pre- to post-treatment as did the Oswestry Disability Score (P<0.05). This improvement was maintained at 2-year follow-up. In eight patients (21.6%) (five female, three male), an adjacent fracture occurred in 11 vertebrae (18.3%) within 3 weeks to 22 months of follow-up (after 22 months no adjacent fracture occurred). This makes an annualized refracture rate of 10% (18.3/22 x 12). In three patients the adjacent fractures were asymptomatic. Five patients with symptomatic adjacent fractures (eight vertebrae) wanted to be treated again with balloon kyphoplasty. Clinically asymptomatic cement leakage occurred in nine of 67 vertebral bodies (13.4%). During 2-year follow-up, this surgical technique demonstrated restoration and stabilization of the height of the vertebral body. CONCLUSION: Balloon kyphoplasty is an effective, minimally invasive procedure for the stabilization of osteoporotic vertebral fractures, leading to a statistically significant reduction of pain status.

Maintained pain reduction in five patients with multiple myeloma 12 months after treatment of the involved cervical vertebrae with vertebroplasty.

PURPOSE: To evaluate in a prospective study the clinical and radiographic outcome of vertebroplasty in patients with osteolytic lesions of the cervical spine caused by multiple myeloma. MATERIAL AND METHODS: Pathological vertebral fractures associated with multiple myeloma were treated in five patients. Vertebroplasty was performed in 12 vertebral bodies. Symptomatic levels were identified by correlating the clinical presentation with magnetic resonance imaging (MRI), conventional radiographs, and computed tomography (CT). During the 12-month follow-up, pain symptoms were measured on a self-reported visual analog scale (VAS), neck pain disability index (NPDI, range 0-100%), and cervical spine functional score (CSFS, range 0-100). Medical imaging was performed pre- and postoperatively and after 3, 6, and 12 months. The vertebral height was measured to assess the restoration of the sagittal alignment. RESULTS: The median pain scores (VAS) as well as the NPDI and CSFS decreased significantly after vertebroplasty (P<0.05). Cement leakage occurred in two of 12 vertebral bodies (16.6%), without clinical relevance. The vertebral body height was stabilized during follow-up. CONCLUSION: Vertebroplasty in the cervical spine is an effective open surgical procedure for the stabilization of pathological vertebral fractures caused by multiple myeloma leading to a statistically significant reduction of pain status. Vertebral body height is stabilized and further deformities are avoided.

Percutaneous balloon kyphoplasty in the treatment of pathological vertebral body fracture and deformity in multiple myeloma: a one-year follow-up.

PURPOSE: To evaluate the clinical and radiographic outcomes of balloon kyphoplasty in patients with fractures of the thoracic and lumbar spine caused by multiple myeloma. MATERIAL AND METHODS: Vertebral fractures due to multiple myeloma were treated by balloon kyphoplasty (20 patients, 48 vertebral bodies). Symptomatic levels were identified by clinical presentation, magnetic resonance imaging (MRI), radiographs, and computed tomography (CT). During the following year, visual analog scale (VAS) and Oswestry disability score were documented. Radiographs were taken pre- and postoperatively at 3, 6, and 12 months. Vertebral height and kyphotic deformity were measured to assess restoration of the sagittal alignment. RESULTS: The median pain scores (VAS) decreased significantly from pre- to posttreatment, as did the Oswestry disability score (p < 0.05). Clinically asymptomatic cement leakage occurred at 5 fracture levels (10.4%). During 1-year follow-up, this surgical technique demonstrated restoration and stabilization of the height of the vertebral body. CONCLUSION: Balloon kyphoplasty is an effective minimally invasive procedure for stabilizing pathological vertebral fractures caused by multiple myeloma and leading to a statistically significant reduction of pain status. Balloon kyphoplasty stabilizes the vertebral body height, but is only partially able to prevent further kyphotic deformities.

[Vertebroplasty and kyphoplasty in osteoporotic fractures of vertebral bodies -- a prospective 1-year follow-up analysis]. / Vertebroplastie und Kyphoplastie bei osteoporotischen Wirbelkörperfrakturen -- Eine prospektive Analyse der Einjahresergebnisse.

PURPOSE: Kyphoplasty and vertebroplasty offer two minimally invasive operative stabilization procedures for vertebral compression fractures. The purpose of this prospective study was to investigate whether both procedures are able to reduce pain and to preserve postoperative vertebral height during a 1-year follow up. MATERIALS AND METHODS: Osteoporotic vertebral fractures were treated in 42 cases, 20 patients (15 female, 5 male) underwent vertebroplasty, 22 patients (14 female, 8 male) underwent kyphoplasty. 32 vertebral fractures were treated with vertebroplasty and 35 vertebral fractures were treated with kyphoplasty. Symptomatic levels were identified by correlating the clinical presentation with conventional radiographs, CT or/and MRI. During the follow up reduction of pain was determined. Radiographic scans were performed pre- and postoperatively and after 3, 6 and 12 months. The vertebral height and endplate angles were measured to assess the restoration of the sagittal alignment. The effects on pain symptoms were measured on a self-reported Visual Analog Scale (VAS) and the Oswestry score was documented. RESULTS: The median pain scores (VAS) decreased significantly for kyphoplasty and vertebroplasty from pre- to post-treatment, as did the Oswestry score (p < 0.05). No significant differences could be found between both groups for the median pain score (VAS) and the Oswestry score. Kyphoplsty led to a significant restoration of the vertebral height and reduction of kyphosis (p < 0.05). During the 1-year follow up both operation techniques were able to stabilize the height of the vertebral body. CONCLUSION: Kyphoplasty and vertebroplasty are effective minimally invasive procedures for the stabilization of osteoporotic vertebral fractures leading to a statistically significant reduction in pain. Kyphoplasty restores significantly vertebral body height in fresh fractures. The restoration of vertebral height and reduction of kyphosis may have an influence on the long term clinical outcome. This has to be evaluated in a long term prospective study.

[Expandable cages: biomechanical comparison of different cages for ventral spondylodesis in the thoracolumbar spine]. / Expandierbare Cages als Wirbelkörperersatz. Biomechanischer Vergleich verschiedener Cages für die ventrale Spondylodese im thorakolumbalen Ubergang der Wirbelsäule.

INTRODUCTION: Due to a recent increase in the commercial availability of expandable cages for vertebral body replacement, this study was designed to gain more information about their biomechanical properties. All three expandable cages evaluated in this study are approved for clinical use, but little knowledge about their biomechanical properties exists. MATERIAL AND METHODS: Human thoracolumbar spines (T11 to L3) ( n=32) were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive stiffness method. Three-dimensional displacement was measured using an optical measurement system. All motion segments were tested intact. After L1 corporectomy, cages were implanted and the following groups ( n=8 each) were tested: (1) meshed titanium cage (nonexpandable cage, DePuy Acromed), (2) X-tenz (expandable cage, DePuy Acromed), (3) Synex (expandable Cage, Synthes), and (4) VBR (expandable cage, Ulrich). Finally, posterior stabilization and posterior-anterior stabilization, both using USS (Synthes), and anterior plating (LCDCP, Synthes) was applied. The mean apparent stiffness values, ranges of motion, and neutral and elastic zones were calculated from the corresponding load/displacement curves. RESULTS: No significant differences were found between the in vitro biomechanical properties of expandable and nonexpandable cages. Compared to the intact motion segment, isolated anterior stabilization using cages and anterior plating significantly decreased stiffness and increased range of motion in all directions. Additional posterior stabilization significantly increased stiffness and decreased range of motion in all directions compared to the intact motion segment. Combined anterior-posterior stabilization demonstrated the greatest stiffness results. CONCLUSION: Design variations of expandable cages for vertebral body replacement do not show any significant effect on the biomechanical results. There was no significant difference found, between the biomechanical properties of expandable and non-expandable cages. After corporectomy, isolated implantation of expandable cages plus anterior plating was not able to restore normal stability of the motion segment. As a consequence, isolated anterior stabilization using cages plus LCDCP should not be used for vertebral body replacement in the thoraco-lumbar spine.

[Vertebral body replacement in spine surgery]. / Wirbelkörperersatz in der Wirbelsäulenchirurgie.

Autografts and allogeneous bone grafts as well as cages are used for the reconstruction of the anterior column after corpectomy. Recently, expandable cages for vertebral body replacement have been developed. Based on our own experience, the purpose of this study was to summarize the available biomechanical and clinical data of expandable corpectomy cages and to compare it with established fixation techniques. If used correctly, expandable cages offer several surgical advantages in comparison to non-expandable cages. However there were no significant differences between the biomechanical properties of expandable and non-expandable cages. Additionally, design variations of expandable corpectomy cages did not show any significant impact on the biomechanical stability. Currently available mid-term clinical and radiological data on the treatment of fractures, metastasis and infection of the cervical, thoracic and lumbar spine demonstrated no significant difference between expandable and non-expandable cages. However, the increased stress-shielding effect of expandable cages compared to non-expandable cages might result in a deterioration of the long-term clinical outcome.

Osseous integration of hydroxyapatite grafts in metaphyseal bone defects of the proximal tibia (CT-study).

PURPOSE OF THE STUDY: The purpose of the study was the examination of the osseous integration of hydroxyapatite grafts used for the filling of metaphyseal bone defects in tibia head fractures. MATERIAL: Four patients with lateral tibia plateau fractures AO-type B3 (12) were included in the study. Patients were treated by arthroscopically assisted reduction and percutaneous screw fixation. The metaphyseal bone defects were filled with prepared solid hydroxyapatite graft blocks (Endobon Fa. Merk Darmstadt, Germany). In all of the patients a CT study for the osseous integration of hydroxyapatite grafts used for the filling of metaphyseal bone defects in tibial head fractures was performed. Measurements of density were performed of the implant region, the periimplant region, the distant periimplant region and the fibula bone. Follow-up CT examinations of these specific regions were performed 6 and 12 months postoperative. RESULTS: In all cases an increase of density of the hydroxyapatite graft after 6 months and 12 months follow-up was detected. The periimplant region showed in all cases a decrease of density. A progressive decrease of the periimplant and the distant cancellous tibial bone region was also detectable after 6 and 12 months post-op. A similar decrease of density was visible in the region of the cancellous bone of the fibula. In the interface region a direct bone formation between the hydroxyapatite graft and the adjected cancellous bone was visible in all cases during follow-up. CONCLUSION: The increase of density of the hydroxyapatite grafts and the direct bone formation in the interface region between the hydroxyapatite graft and the adjacent cancellous bone are clear radiomorphological signs for an osteointegration of hydroxyapatite grafts in the metaphyseal region.

Screw placement in transoral atlantoaxial plate systems: an anatomical study.

OBJECT: The placement of an anterior atlantoaxial plate after transoral odontoid resection has been described by Harms. Recently, the authors of biomechanical and clinical studies have shown that this procedure, especially in combination with posterior wiring, is a good alternative to established, isolated posterior atlantoaxial fixation techniques. Reports on the anatomy of the atlas and axis primarily focus on the posterior surgical approach. Scarce research regarding the quantitative anatomy of the anterior aspect of C-1 and C-2 has been reported. This study was undertaken to measure relevant dimensions of C-1 and C-2 and their relation to the anterior transoral approach. The aim of the study was to determine "safe zones" for screw placement in anterior atlantoaxial plate fixation. METHOD: Fifty human dry C-1 and C-2 vertebrae were obtained for direct anatomical, radiographic, and computerized tomography (CT) measurements. Thirty-two linear and four angular parameters were evaluated. All measurements were made using a digital caliper, ruler, or goniometer. Anatomical measurements were correlated with radiographic (anteroposterior, lateral, and craniocaudal) and CT (0.5-mm-slice thickness) measurements of the corresponding vertebrae. Additionally, bone mineral density (BMD) measurements of C-1 and C-2 were obtained in 20 patients. A safe zone for anterior screw placement in an atlas of bilateral trapezoid shape could be characterized. The average medial and lateral height of the trapezoid was 4.1 +/- 1.01 mm (range 1.4-6.7 mm) and 12.9 +/- 1.73 mm (range 8.7-17.4 mm), respectively. The distance between the sagittal plane and the medial and lateral walls of the trapezoid was 10.2 +/- 1.42 mm (range 8.9-12.8 mm) and 23.5 +/- 2.98 mm (range 21.7-30.7 mm), respectively. The average depth of the lateral masses was 22.3 +/- 2.04 mm (range 17.0-26.7 mm) in the sagittal plane. The average BMD in the safe zone of C-1 was 0.89 +/- 0.11 g/cm3 (range 0.75-1.01 g/cm3). Bone mineral density measurements at C-2 revealed a spheroid zone of low density at the basis of the dens (0.68 +/- 0.09 g/cm3). In contrast, high zones of BMD were found near the articular surfaces (C1-2: 0.97 +/- 0.11 g/cm3; C2-3: 0.94 +/- 0.12 g/cm3). The safe zone for anterior axis screw placement was V-shaped, limited cranially by a zone of low bone density and laterally by the vertebral artery groove. Correlations between radiographic and anatomical measurements were generally good (r2 = 0.78-0.95), but they were higher between CT and anatomical measurements (r2 = 0.86-0.99). CONCLUSIONS: A quantitative understanding of the anterior anatomy of C-1 and C-2 is necessary when considering anterior atlantoaxial plate fixation after transoral odontoid resection. In this study the authors defined safe zones for anterior atlas and axis screw placement. The anterior atlantoaxial plate, as originally described by Harms, only partially respects these safe zones.

Clinical characteristics and outcome of a cohort of 101 patients with hepatocellular carcinoma.

AIM: To conduct a cohort study of 101 patients with hepatocellular carcinoma (HCC) presenting to a tertiary care medical referral center in Germany between 1997 and 1999. METHODS AND RESULTS: Data were retrospectively analyzed by chart review. In 95 cases (72 males and 23 females) sufficient data were available for analysis. Twenty five (29%) of 85 patients were HBsAg or anti HBc positive, 21/85 (25%) were anti HCV positive, and 6/85 (7%) were positive for both HBV and HCV-markers. Age was significantly lower in HBV positive patients than in the other two groups. Thirty one (34%) of 90 patients had histories of alcohol abuse. In 79/94 (84%) patients, cirrhosis was diagnosed. Of these cirrhotic patients, 29/79 (37%) belonged to Child Pugh's group (CHILD) A, 32/79 (40%) to CHILD B, and 18/79 (23%) to CHILD C. AFP was elevated in 61/91 (67%) patients. A single tumor nodule was found in 38/94 (40%), more than one nodule in 31/94 (34%), and 25/94 (26%) had a diffusely infiltrating tumor, i.e. the tumor margins could not be seen on imaging procedures. Portal vein thrombosis was present in 19/94 (20%). Imaging data consistent with lymph node metastases were found in 10/92 (11%), while distant metastases were found in 8/93 (9%). According to Okuda 28/94 (30%) were grouped to stage I, 53/94 (56%) were grouped to stage II, and 13/94 (14%) were grouped to stage II. Survival data were available for 83 patients. The Kaplan-Meier estimate for median survival was 8 4 months. Factors influencing survival were the Okuda score, the presence of portal vein thrombosis, and the presence of ascites. The presence of non complicated liver cirrhosis by itself, distant metastases, or infection with hepatitis viruses did not influence survival. AFP positivity by itself did not influence survival, though patients with an AFP value greater than 100 microg/L did experience shortened survival. Treatment besides tamoxifen or supportive care was associated with prolonged survival. The influence of therapy on survival was most pronounced in Okuda stage II patients. There was longer survival in those Okuda stage II patients who were treated with percutaneous ethanol injection. CONCLUSION: Even in a low incidence area such as Germany, the majority of HCC is caused by viral hepatitis and therefore potentially preventable. Reflecting the high proportion of advanced stage tumors in our patients, the median survival was poor. Patients who received active therapy had a longer survival.

[Transoral atlanto-axial plate fixation in the treatment of a malunited dens fracture and secondary atlanto-axial instability]. / Transorale atlanto-axiale Plannenspondylodese in der Behandlung einer fehlverheilten Densfraktur mit sekundärer atlanto-axialer Instabilität.

INTRODUCTION: A case of a 22-year-old patient with a malunited dens fracture and secondary atlanto-axial instability is presented. The significant narrowing of the spinal canal due to the atlanto-axial instability was associated with anterior myelon compression and neurological deficit. METHODS: A transoral approach with odontoid resection and anterior atlanto-axial plate fixation was performed. With this technique the atlanto-axial subluxation was reduced and the myelon was decompressed. RESULTS: The postoperative course was uneventful. The follow-up showed a complete remission of the neurological deficit and a bony fusion of the atlanto-axial joints. CONCLUSIONS: The presented case illustrates the importance of an accurate initial diagnosis of the degree of instability and the need for short-term follow-up examinations. If atlanto-axial pseudarthrosis or malunion with anterior spinal cord compression occurs, a transoral procedure with odontoid resection and atlanto-axial plate fixation seems to be an excellent salvage procedure.