Realignment surgery in adult spinal deformity : Prevalence and risk factors for proximal junctional kyphosis.

Although surgical techniques pertaining to adult spinal deformity (ASD) have advanced over the last decade, proximal junctional kyphosis (PJK) is still a complication following surgery for ASD that continues to significantly challenge clinicians. This article aimed to report on the prevalence of PJK as well as enhance understanding of surgically modifiable and non-modifiable risk factors of PJK to guide management of this postoperative complication of ASD. As the understanding of the pathogenesis as well as surgical modifications aimed at reducing the incidence of PJK have advanced, so too should clinicians' ability to implement more patient-specific operative plans and improve outcomes following realignment surgery for ASD.

X-ray solution scattering reveals conformational changes upon iron uptake in lactoferrin, serum and ovo-transferrins.

X-ray solution scattering has been used for studying the structural changes that take place upon uptake and release of iron from serum and chicken ovo-transferrin and human lactoferrin. In the case of chicken ovo-transferrin, data have been obtained for both the intact protein and the isolated N and C-lobes with and without iron. These studies reveal that both lobes undergo a change that is consistent with an opening of the inter-domain cleft when iron is removed from the protein. We suggest that the conformational change of the protein increases the specificity of receptor binding and that the closed configuration of the iron-loaded protein is one, or perhaps the, decisive step in the mechanism for receptor-mediated endocytosis.

Intraoperative monitoring of motor evoked potentials: a review of 116 cases.

We reviewed the results of motor evoked potential (MEP) and somatosensory evoked potential (SEP) monitoring during 116 operations on the spine or spinal cord. We monitored MEPs by electrically stimulating the spinal cord and recording compound muscle action potentials from lower extremity muscles and monitored SEPs by stimulating posterior tibial or peroneal nerves and recording both cortical and subcortical evoked potentials. We maintained anesthesia with an N2O/O2/opioid technique supplemented with a halogenated inhalational agent and maintained partial neuromuscular blockade using a vecuronium infusion. Both MEPs and SEPs could be recorded in 99 cases (85%). Neither MEPs nor SEPs were recorded in eight patients, all of whom had preexisting severe myelopathies. Only SEPs could be recorded in two patients, and only MEPs were obtained in seven cases. Deterioration of evoked potentials occurred during nine operations (8%). In eight cases, both SEPs and MEPs deteriorated; in one case, only MEPs deteriorated. In four cases, the changes in the monitored signals led to major alterations in the surgery. We believe that optimal monitoring during spinal surgery requires recording both SEPs and MEPs. This provides independent verification of spinal cord integrity using two parallel but independent systems, and also allows detection of the occasional insults that selectively affect either motor or sensory systems.

Three dimensional variability in patient positioning using bite block immobilization in 3D-conformal radiation treatment for ENT-tumors.

BACKGROUND AND PURPOSE: The aim of this prospective study was to analyze the three-dimensional (3D) reproducibility of the isocenter position and of patient positioning with the use of bite block immobilization by means of a simple verification procedure for a complex beam arrangement applied for ENT-tumors. MATERIALS AND METHODS: We analyzed the positioning data of 29 consecutive patients treated for ENT-tumors at the Department of Radiotherapy and Oncology of the University of Wurzburg. A total of 136 treatment sessions were analyzed. Patients were positioned and immobilized using an individualized bite block system and a head and neck support. A complex beam arrangement was applied combining two offset rotational and two oblique wedge fields on a 5 MV linear accelerator. Orthogonal verification films were taken once weekly. Four to six film pairs per patient were obtained (during 4-6 weeks) with a mean number of 4.7 film pairs per patient. These were compared to the corresponding orthogonal simulator films taken during primary simulation. Deviations of the verified isocenter from the isocenter on the simulator film were measured and analyzed in three dimensions in terms of overall, systematic and random categories. A 3D-deviation vector was calculated from these 3D data as well as a 2D-deviation vector (for comparison with literature data) from the lateral verification films. RESULTS: The overall setup deviation showed standard deviations (SD) of 2.5, 2.7 and 3.1 mm along the cranio-caudal, anterior-posterior and medio-lateral axes, respectively. The random component ranged from SD 1.9 to 2.1 mm and the systematic component ranged from SD 1.8 to 2.2 mm. The mean length of the 3D-vector was 3.1 mm for the systematic as well as the random component. Ninety percent of 3D systematic and random deviations were less than 5 mm. The mean length of the 2D-vector was 2.4 mm for the random component and 2.2 mm for the systematic component. Ninety percent of 2D-random and systematic variations were less than 4 mm. CONCLUSIONS: The presented individualized bite block immobilization device provides an accurate and reproducible patient positioning for 3D-conformal radiation therapy in the head and neck. Random and systematic deviations in each of the three directions are in the range of +/-4 mm (2 SD, comprising 95% of the deviations) and are within the range or even less than deviations described for most thermoplastic or PVC-mask fixation devices. These deviations should be taken into account during definition of planning target volume in head and neck tumors.

Noninvasive assessment of impotence.

The examinations described provide quantitative data on hemodynamics of the erectile process. Comprehensive study cannot be totally noninvasive because it does require measurements of intracavernous pressure. Patients selected for invasive study should exhibit normal neurologic function. These tests generally do not display anatomy underlying the physiologic disorder, although ultrasound has great promise in this regard. Angiography is needed for rational planning of operative procedures. Angiographic examination that includes arteriography of large and small arteries and delineation of cavernosal venous drainage or cavernosography defines both the location and the nature of defects causing erectile failure. It is our belief that both noninvasive and invasive tests (physiologic measurements to assess penile blood flow and cavernosal competence and comprehensive angiography using artificial erection) must be obtained prior to operation.

Management of flatback and related kyphotic decompensation syndromes.

STUDY DESIGN: The authors, in this retrospective study, examined a group of patients with flatback syndrome and a related kyphotic decompensation syndrome. Results of nonrealignment treatment as well as revision surgery with sagittal realignment were reviewed. OBJECTIVES: To determine effectiveness of physical therapy and limited surgical (instrumentation removal) as well as major realignment surgical treatment in the sagittally malaligned spine. SUMMARY OF BACKGROUND DATA: Flatback is a sagittal plane deformity associated with distraction instrumentation for scoliosis correction. Kyphotic decompensation syndrome involves malaligned fusions from the sacrum for disease other than scoliosis. Several studies describe surgical realignment for flatback involving instrumentation systems no longer commonly applied. Guidelines for a systematic approach to flatback and kyphotic decompensation syndromes are lacking. METHODS: Forty-eight patients with flatback and kyphotic decompensation syndromes were reviewed. Treatment groups were defined by treatment approach and level of previous fusion. Effectiveness of treatment was reviewed in terms of radiographic sagittal alignment and self-reported pain. RESULTS: Twenty patients were treated without realignment revision surgery. Twenty-eight patients were treated with anterior and posterior osteotomies and realignment with instrumentation. For patients originally fused to the sacrum, realignment averaged 12 cm. Pain was reduced from 7 to 3 (10-point scale). In patients fused to L4 or L5, realignment averaged 7 cm. Pain was reduced from 6 to 2. Magnetic resonance imaging revealed viable caudal discs in four patients who were consequently spared extension of fusion to the sacrum. CONCLUSIONS: Treatment without realignment surgery demonstrated long-term success in 27% of cases. The latter all had two intact discs below the previous fusion and sagittal malalignment less than 4 cm. Realignment surgery effectively reduced pain in patients failing a conservative approach.

Effects of spinal instrumentation on fusion of the lumbosacral spine.

STUDY DESIGN: This study retrospectively, reviewed the effects of pedicle screw fixation on lumbosacral fusion for degenerative conditions. The records and radiographs of a group of patients treated by wide decompression and fusion of the lumbosacral spine and by one surgeon were studied. Two treatment groups were identified by fusion technique; one group received autologous bone graft only, and second group was treated by autologous bone grafting supplemented with pedicle screw fixation. OBJECTIVES: The two study groups were compared to determine the effects of pedicle screw fixation on lumbosacral fusion for degenerative conditions after wide decompression. SUMMARY OF BACKGROUND DATA: The reported success rate of lumbar and lumbosacral fusion in the literature is variable. Although several studies have reported high fusion rates with internal fixation, few controlled studies have been published. A critical review of isolated lumbosacral fusions (for degenerative conditions) and the effects of instrumentation is necessary to determine the effectiveness and complications associated with pedicle screw systems in this setting. METHODS: This study reviewed 215 consecutive patients operated on from 1987 to 1992 for degenerative conditions of the lumbosacral spine. Group 1 included 126 patients who underwent autogenous posterolateral bone graft after decompression. Group 2 included 89 patients treated with Edwards instrumentation and autogenous bone graft. Fusion status was determined via radiographs. Clinical results were based on pain relief after a minimum 2-year follow-up period. RESULTS: In Group 1, an overall fusion rate of 65% was obtained. Clinically, 56% had good or excellent results. Complications included pseudarthroses (35%), dural tears (3.2%), and infection (2.4%). In Group 2, a fusion rate of 91% was achieved. In this group, 89% had a good or excellent clinical result. Complications included pseudarthroses (9%), dural tears (2.2%), and infection (2.2%). CONCLUSIONS: Use of pedicle screw and rod fixation with the Edwards system led to significantly improved results in lumbosacral fusions over autogenous bone graft alone, with a lower complication rate. The use of spinal is a valuable adjunct to achieve lumbosacral fusion in patients who have undergone decompressive surgery for the spine.

The sagittal pelvic tilt index as a criterion in the evaluation of spondylolisthesis. Preliminary observations.

STUDY DESIGN: Radiographic analysis of a pediatric population with spondylolisthesis was performed to examine sagittal plane pelvic rotation and degree of slip over time. OBJECTIVES: To determine whether the degree of standing sagittal offset of L5 with respect to the acetabulum correlated with slip progression and symptoms. SUMMARY OF BACKGROUND DATA: The natural history of isthmic spondylolisthesis remains unclear. Attempts to predict slip progression in the clinical setting, and thus the possible need for eventual surgical intervention, remain imprecise. Predicting slip progression based on sagittal alignment of the L5 vertebra with respect to the acetabulum has been proposed by some investigators. METHODS: Fifty-two children and adolescents were followed clinically and radiographically for an average of 5.6 years. Serial lateral standing radiographs that included the hips and lumbar spine were measured to compute a sagittal pelvic tilt index. The latter value is a ratio of relative distances from the center of S2 to the projection of L5 and the center of the femoral heads on the horizontal. RESULTS: Of the 52 patients studied, 38 have remained asymptomatic without significant slip progression or change in sagittal pelvic tilt index ratio. Of the original group, 13 patients had significant symptoms and revealed a decrease in the sagittal pelvic tilt index over time. Eight of the 13 stabilized at the end of adolescence, whereas 5 had continued decrease in the sagittal pelvic tilt index ratio. These five required operative treatment for pain and progressive slip. CONCLUSIONS: The sagittal pelvic tilt index gives the examiner an objective measure of the stability of the lumbosacral junction by quantifying the relationship between S2, the center of the hip, and L5. A decreasing sagittal pelvic tilt index ratio in this preliminary series correlated with slip progression and risk of conservative treatment failure, whereas those patients with a stable sagittal pelvic tilt index did not progress and remained clinically asymptomatic.

[Conformal irradiation technique for the peri- and retrobulbar space in endocrine orbitopathy]. / Konformations-Bestrahlungstechnik für den Peri- und Retrobulbärraum bei endokriner Orbitopathie.

The clinical target volume (CTV) for the irradiation of the endocrine orbitopathy (Graves ophthalmopathy) includes the peri- und retrobulbar space with the extraocular muscles. We present here a conformal irradiation technique aimed at optimal coverage of the CTV. The irradiation technique consists of two rotation fields with a central lens block and two lateral fixed fields with dorsal blocking. In each Gantry position, the lenses are faded out through the central lens block. The isocenter of the two rotation fields is located in the lenses. For quality assurance of this irradiation technique, verification of the dose distribution was performed by film dosimetry using the humanoid Aldersone phantom. The use of this irradiation technique yielded a dose distribution with conformal CTV coverage of the peri- and retrobulbar space and of the extraocular muscles. The film dosimetry of the Aldersone phantom showed a maximal deviation of 5% between the measured and the calculated dose distribution. The radiation load to the eye lenses was 25% of the applied total dose.

Endoscopic thoracoplasty and anterior spinal release in scoliotic deformity.

Severe rigid and complex deformities of the spine often require a first stage procedure to adequately mobilize the spine to provide adequate flexibility during the actual application of instrumentation for surgical correction. This first stage involves soft tissue releases and removal of intervertebral disks from the anterior spine. Exposure to the anterior spine has traditionally been accomplished through thoracotomy or a thoracolumbar incision. The open thoracotomy, however, has several disadvantages, such as post-thoracotomy pain, a large scar, and breathing difficulties. Since the first thoracoscopy at the beginning of this century, the procedure, at first limited by the available technology, has gradually gained more uses and favor among physicians. The last 10 years have seen significant improvement in optical technology and instrumentation. These advances have allowed the spine surgeon to begin performing anterior spinal releases using endoscopic techniques. These endoscopic techniques can carry the same efficacy as the open thoracotomy but less morbidity. Thoracoplasty, the resection of rib segments, is an excellent way to not only correct the convex rib deformities seen in scoliosis but it is also an excellent source of bone which can be used as a graft for fusion. Although traditionally, thoracoplasty has also been done through an open procedure, it can be performed endoscopically. This prospective study presents nine patients who underwent combined endoscopic anterior spinal release and thoracoplasty followed by same day posterior instrumentation and fusion for correction of their spinal deformities. All nine procedures were completed successfully endoscopically. It is our conclusion that in the hands of an experienced surgeon, the endoscopic technique is an excellent procedure providing the same efficacy as the open thoracotomy. There is however a learning curve associated with the procedure. In addition, a team approach in which the surgeon and an experienced anesthesiologist with experience with double lumen intubation and selective single lung ventilation and thoracoscopic surgery is crucial. Although there were no surgical complications related to the thoracoscopic technique one patient did require prolonged intubation postoperatively, which leads us to believe that single lung ventilation in and of itself is very demanding and each patient must be considered carefully prior to its undertaking.

Pulmonary air embolism: case report.

The authors encountered a patient with an indwelling central venous catheter who presented with pulmonary edema after the catheter hub was disconnected. Pulmonary arteriography demonstrated diffuse peripheral vasoconstriction, decreased arterial-to-venous transit time, and arterial occlusions. The former two findings allowed the authors to prospectively suggest the diagnosis of pulmonary air embolism.

Simultaneous anterior and posterior approaches for correction of late deformity due to thoracolumbar fractures.

Thirty-one patients with an average age of 27 years were included in this study to analyze the short-term results of simultaneous anterior and posterior approaches in the treatment of late complications of thoracolumbar fractures. The complications treated were pseudoarthrosis and malunion resulting in neurologic compromise and pain. There were 20 burst fractures, 2 fracture/dislocations, and 9 compression fractures in this group. Average preoperative Sagittal Index was 35 degrees, which improved to an average of 4 degrees after surgical treatment. The average Motor Index Score improved from 90 to 98 after surgery. Average follow-up was 16 months. Average estimated blood loss was 2000 ml and average operation time was 5 h. It was concluded that the late problems associated with thoracolumbar fractures can be addressed quite adequately with simultaneous anterior and posterior approaches. The simultaneous anterior and posterior approach is associated with decreases in operating time, blood loss, and hospital stay. Technical advantages of the simultaneous technique include elimination of acute instability between the stages, protection against dislodgment of the graft, and application of the posterior instrumentation under complete visualization of the anterior graft.

Reduction of cecal volvulus by multiple barium enemas.

It has been frequently stated that barium enema has no value in the treatment of cecal volvulus. We present a patient with cecal volvulus who was effectively treated by barium enema; however, multiple studies were required to achieve optimal results. In a subset of patients with cecal volvulus, laparotomy may be avoided by the use of barium enema.

CT of cerebral venous sinus thrombosis in a child with homocystinuria.

We describe a case of cerebral venous sinus thrombosis in a child with homocystinuria. We present both the classic CT findings of cerebral sinus thrombosis, and also the first report of the CT visualization of transdural venous collateral circulation.

The barium enema scout film: cost effectiveness and clinical efficacy.

The authors prospectively evaluated 1,001 consecutive double-contrast barium enema examinations to determine the efficacy of the preliminary film. The scout films were evaluated for the presence of unsatisfactory amounts of residual feces and clinically significant extracolonic abnormalities. The contrast studies were independently evaluated in a double-blind manner for satisfactory colonic preparation as well as extracolonic abnormalities. The routine use of the scout film resulted in an increase in health care charges and departmental costs. In addition, there was no significant increase in the detection of extracolonic abnormalities. Our data suggest that routine use of scout films prior to contrast studies is unnecessary, although selective use in some clinical situations may be justified.

Simultaneous anterior and posterior approaches to the spine for revision surgery: current indications and techniques.

Revision spinal surgery often requires attention to both the anterior and the posterior portions of the spine. Staged, sequential, and more recently simultaneous anterior and posterior approaches have been proposed. A simultaneous approach has the distinct advantage of allowing complete and constant control of the anterior and posterior portions of the spine during surgery. The simultaneous approach has been shown to offer decreased operating time, blood loss, complication rate, and hospital length of stay as compared with staged procedures. The evolution in spinal instrumentation and ancillary equipment has greatly advanced the simultaneous technique. The development of a special operating table has facilitated patient positioning and intraoperative patient adjustments, optimizing operative exposure for the anterior and posterior surgical teams. The two-rod and four-rod techniques offer the surgeon the possibility to safely address complex deformities, particularly in kyphosis.

Influence of protein dynamics on the metal-sites of ovotransferrin.

Using the perturbed angular correlations (PAC) technique, the formation of hafnium-ovotransferrin complexes has been studied. Two binding configurations at each of the two specific binding-sites of the protein have been observed. They are characterized by well-defined electric quadrupole frequencies. Information about the dynamics of the protein was derived from temperature dependent measurements of the relaxation constant. The well-resolved spectra taken with fast BaF2-detectors allow a precise determination of the relaxation behaviour of the protein. The results are compared with the predictions from a hydrodynamic model for the reorientation of macromolecules. Thus the hydrodynamic volume of ovotransferrin and its N-terminal half-molecule were determined. The ovotransferrin volume is in agreement with a value derived for human serum transferrin from small angle neutron scattering. From experiments with immobilized protein material there is evidence for internal protein dynamics which is probed by the Hf-ion bound to the specific metal-sites.

Preoperative and postoperative dynamic cavernosography and cavernosometry: objective assessment of venous ligation for impotence.

A total of 11 men (mean age 51.4 years, 1-year followup) with venous leakage impotence underwent surgical venous ligation. Of the men 8 had erections twice per week immediately after the procedure but at 3 months only 2 remained potent. Dynamic pharmacological cavernosography and cavernosometry were repeated 3 months postoperatively and 6 of the 11 men had venous leakage. These men with venous leakage underwent percutaneous embolization with platinum coils and 4 had successful results. Three additional men became potent after embolization. Of the 11 men 9 are documented to have normal dynamic cavernosography and cavernosometry findings after the combination of an operation and embolization, and 5 are potent. The postoperative and post-embolization dynamic cavernosometry data show that all 11 men have a marked decrease in the flow to maintain erection. Eight men have erections with papaverine or prostaglandin E1 intracorporeal injections. Postoperative dynamic cavernosography and cavernosometry can be diagnostic as well as therapeutic with embolization.

Vascular interventions for impotence: lessons learned.

PURPOSE: The purpose of this study was to analyze the results of vascular interventions for impotence in men with this complaint. METHODS: Between September 1983 and March 1993, 1094 men with the chief complaint of impotence (average age 54.5 years) were screened by use of penile plethysmography and penile brachial indexes: 635 were considered to have normal flow, and 459 were considered to have abnormal arterial flow, 12.2% of whom were found to have aortoiliac disease. Based on negative neural screening results, absence of erectile responses on increasing doses of intracavernously injected papaverine or prostaglandin E1 (ICI), surgical candidates for microvascular procedures were referred for dynamic infusion cavernosography (DICC) and pudendal arteriography. Operations for men discovered to have aortoiliac disease were based on conventional indications including aneurysm size or limb ischemia. None of the subjects had diabetes. Only those patients without diabetes and those not requiring blood pressure medications were selected for microvascular procedures. We report our experience and surgical outcomes at average follow-ups of 33 to 48 months. Four types of operations were performed on 67 men (age 18 to 79 years). These included 17 aortoiliac reconstructions, 11 dorsal penile artery bypasses, 12 dorsal vein arterializations, and 27 venous interruptions. Follow-up data were obtained by direct examination and noninvasive Doppler examinations; repeat arteriography (4 of 11); repeat DICC after venous ablation procedures (18 of 27) and postoperative ICI response. Mail questionnaires completed postoperative surveillance. RESULTS: Among 17 men undergoing aortoiliac intervention for aneurysms in eight and occlusive disease in nine, 58% functioned spontaneously after operation and 18% used ICI or vacuum constrictor devices at an average follow-up time of 38 months. Among 11 men with dorsal penile artery bypasses, 27% functioned spontaneously and 45% used ICI at an average follow-up time of 34.5 months. Among 12 men with dorsal vein arterialization, 33% functioned spontaneously, and 47% used ICI at an average follow-up time of 48 months. Among 27 with venous interruption, 33% functioned spontaneously and 44% used ICI. In seven of eight aneurysms of 4.5 to 6.0 cm in size, impotence workup led to discovery; probable embolic mechanisms existed in three. Venous interruption efficacy correlated with postoperative DICC results when flow to maintain erection was 40 ml or less. Apart from two cases of glans hyperemia, no surgical complications occurred in the microvascular procedures. There was one episode of bleeding caused by DICC after aortic reconstruction. There were no deaths. CONCLUSIONS: With prospective screening criteria, 6% to 7% of impotent men became candidates for vascular intervention. Including those functioning with ICI or vacuum constriction devices, about 70% of these men were functional after operation. Men undergoing aortoiliac reconstruction has a significantly higher rate (58%) of spontaneous function as compared with those undergoing microvascular procedures.