Vaccine development to prevent Staphylococcus aureus surgical-site infections.

BACKGROUND: Staphylococcus aureus surgical-site infections (SSIs) are a major cause of poor health outcomes, including mortality, across surgical specialties. Despite current advances as a result of preventive interventions, the disease burden of S. aureus SSI remains high, and increasing antibiotic resistance continues to be a concern. Prophylactic S. aureus vaccines may represent an opportunity to prevent SSI. METHODS: A review of SSI pathophysiology was undertaken in the context of evaluating new approaches to developing a prophylactic vaccine to prevent S. aureus SSI. RESULTS: A prophylactic vaccine ideally would provide protective immunity at the time of the surgical incision to prevent initiation and progression of infection. Although the pathogenicity of S. aureus is attributed to many virulence factors, previous attempts to develop S. aureus vaccines targeted only a single virulence mechanism. The field has now moved towards multiple-antigen vaccine strategies, and promising results have been observed in early-phase clinical studies that supported the recent initiation of an efficacy trial to prevent SSI. CONCLUSION: There is an unmet medical need for novel S. aureus SSI prevention measures. Advances in understanding of S. aureus SSI pathophysiology could lead to the development of effective and safe prophylactic multiple-antigen vaccines to prevent S. aureus SSI.

[Cement augmentation of pedicle screws : Pros and cons]. / Zementaugmentation von Pedikelschrauben : Vorteile und Nachteile.

Cement augmentation of pedicle screws biomechanically increases screw purchase in the bone. However, clinical complications may occur. The pros and cons of the technique are discussed from different clinical perspectives.

[Benign and semimalignant spinal tumors. Characteristics in children and adults]. / Benigne und semimaligne Tumoren der Wirbelsäule. Besonderheiten im Kindes- und Erwachsenenalter.

Diagnostic radiology and magnetic resonance imaging (MRI) are the most important imaging tools in the evaluation of benign bone tumors. Computed tomography (CT) is an additional tool for bony lesions, such as in cases of confirmation of the diagnosis of osteoid osteomas. For benign bony lesions three-stage skeletal scintigraphy is an optional additional diagnostic tool. The identification of benign or semimalignant bone tumors is not always clear; therefore percutaneous biopsy is necessary in most cases. In benign spinal tumors an intralesional curettage with reconstruction and stabilization is sufficient. In cases of semimalignant tumors, e.g. giant cell tumors localized in the spine, an en bloc resection is necessary because of the high recurrence rate.

[Specific spondylitis]. / Spezifische Spondylitis.

Tuberculosis of the spine usually occurs with a latency period after primary infection with tuberculosis (TB) and the most frequent agent is Mycobacterium tuberculosis. The rate of TB has increased due to the impact of acquired immunodeficiency syndrome (AIDS) and more than 50% of skeletal tuberculosis is localized in the spine. Spinal tuberculosis was discovered by Pott in 1776. Magnetic resonance imaging (MRI) with gadolineum is the most sensitive imaging method. Diagnostic accuracy is given by direct detection of Mycobacterium tuberculosis by punction or biopsy. Granuloma of the spine can lead to abscesses, severe spinal deformity with instability and potentially paraplegia. Chemotherapy is effective with a minimum duration of 6-12 months. In cases with neurological deficits and severe deformity there is an additional indication for surgical therapy. In the acute phase a posterior instrumentation, anterior debridement and reconstruction of the defect is indicated. After recovery of the spinal tuberculosis Pott's kyphosis could remain and operative correction can be managed by pedicle substraction osteotomy.

Shorter and sweeter: the 16-item version of the SRS questionnaire shows better structural validity than the 20-item version in young patients with spinal deformity.

PURPOSE: In patients with adult spinal deformity, it was previously shown that 16 of the non-management items of the SRS-instrument showed a better fit to the theoretical four-factor model (pain, function, self-image, mental health) than did all 20 items. Whether the same phenomenon is observed in data from younger (< 20y) patients, for whom the questionnaire was originally designed, is not currently known. METHODS: Confirmatory factor analysis was used to evaluate the factor structure of the 20 non-management items of the SRS-instrument completed by 3618 young patients with spinal deformity (75.5% female; mean age, 15.0 ± 2.0 years) and of its equivalence across language versions (2713 English-speaking, 270 Spanish, 264 German, 223 Italian, and 148 French). The root mean square error of approximation (RMSEA) and comparative fit index (CFI) indicated model fit. RESULTS: Compared with the 20-item version, the 16-item solution significantly increased the fit (p < 0.001) across all language versions, to achieve good model fit (CFI = 0.96, RMSEA = 0.06). For both 16-item and 20-item models, equivalence across languages was not reached, with some items showing weaker item-loading for some languages, in particular German and French. CONCLUSION: In patients with adolescent idiopathic scoliosis, the shorter 16-item version showed a better fit to the intended 4-factor structure of the SRS-instrument. The wording of some of the items, and/or their equivalence across language versions, may need to be addressed. Questionnaire completion can be a burden for patients; if a shorter, more structurally valid version is available, its use should be encouraged.

[Pedicle screw augmentation from a biomechanical perspective]. / Pedikelschraubenaugmentation aus biomechanischer Sicht.

Severe osteoporosis is a serious problem in the instrumentation during spine surgery. Besides kyphosis, adjacent vertebral fractures and of course pedicle screw loosening and implant pullout are frequent challenges in instrumentation of the osteoporotic spine. In addition to screw diameter and length, bone mineral density has the most important impact on the stability of a pedicle screw. In cases of severe osteoporosis cement augmentation increases the stability of a pedicle screw. Pullout force can be increased with augmentation by 96-278%. Nowadays, there are two different procedures for augmentation: cement augmentation of the vertebra before inserting the screw into the soft, fresh cement or augmentation via a perforated screw that has already been inserted.The main problem in augmentation techniques are cement leakages. In both techniques leakages may occur. The problem of leakages seems to be less severe in the augmentation technique via the perforated screw, because cement application can be stopped immediately if the onset of leakage is noticed. Even surgical revision of cement augmented screws is not a major clinical problem based on recent biomechanical studies. The revision screw can be chosen 1 mm thicker and can be cement augmented again without technical problems.

Current surgical strategies for treating spinal tumors: Results of a questionnaire survey among members of the German Spine Society (DWG).

PURPOSE: Questionnaire survey among the members of the German Spine Society (Deutsche Wirbelsäulen-Gesellschaft, DWG) to objectify oncological infrastructure and current standard of care in spinal tumor treatment in Germany. METHODS: All DWG-members were contacted via the society's e-mail and asked to respond in anonymized form to a related questionnaire. Questions were asked regarding surgical specialty, type of institution involved, numbers of spinal procedures, as well as questions on treatment for primary tumors, whether the respondent belonged to a tumor center, decision-making procedures for surgery, and the type of procedure. RESULTS: 84 centers providing surgical treatment for spinal tumors in their departments were identified. 52.6% were carrying out more than 500 spinal procedures per year. There was a significant association (P ≤ 0.05) between the numbers of spinal surgeries, the number of treated tumor patients per year, the organisation in a tumor center and the treatment of primary tumors. 76% are part of a local tumor center for interdisciplinary decision making (i.e.surgical treatment and adjuvant therapy). 74% of the institutions stated that conventional postoperative radiotherapy is standardly administered in the case of secondary lesions, with 24% of them referring patients to external services for radiotherapy. CONCLUSION: In spite of often large numbers of spinal operations, the centers perform relatively small numbers of tumor operations, particularly for primary tumors. A nearly three-quarter majority of the departments are integrated into interdisciplinary tumor care. However, there is a marked number that do not belong to an interdisciplinary organisation. Further advances in multidisciplinarity and oncology training are a continuous issue to increase treatment quality in spinal tumor patients.

[Selective fusion of idiopathic scoliosis with respect to the Lenke classification]. / Selektive Fusionsmöglichkeiten der idiopathischen Skoliose unter kritischer Würdigung der Lenke-Klassifikation.

Indications for surgical treatment of idiopathic scoliosis are progressive curves greater than 40-50 degrees. In most cases, fusion of only the primary (structural) curve(s) is sufficient due to the flexibility and spontaneous correction of the secondary curves. Therefore, it is crucial to identify both primary and secondary curves. According to the Lenke classification, all curves with a residual curve of more than 25 degrees on the bending films and those with a pathological kyphosis are regarded as structural and should be fused, whereas the nonstructural curves can be left unfused. However, according to reports in the literature and to the author's experience, clinical parameters such as shoulder level and rib or lumbar hump as well as radiometric criteria such as rotation are relevant as well. In summary, the Lenke classification is an important and helpful tool for analysing idiopathic curves and determining fusion length, even though each scoliosis case needs to be evaluated individually, especially taking clinical parameters into account.

[Bone substitutes in scoliosis surgery]. / Knochenersatzstoffe in der Skoliosechirurgie.

In spinal fusion procedures, the local bone that is resected serves as the base bone graft for attaining biological fusion. The local bone is frequently not sufficient and requires supplementary grafting. Autologous bone transplantation is still regarded as the gold standard but might cause additional complications; also, autograft resources are limited. Alternatively, allografts and a wide variety of different bone substitutes are available.The bone substitutes currently used in scoliosis surgery are presented, and their clinical significance is elucidated by a review of the literature. Furthermore, our own experiences and clinical practice are compared with those in the literature and are critically discussed. The recently growing number of scientific publications reporting on bone substitutes reflects the immense interest and relevance of this issue. In scoliosis surgery, calcium phosphate ceramics together with bone marrow aspirate are increasingly applied.Although harvesting of autologous bone continues to be the accepted standard to extend the local autograft in scoliosis surgery, there is a clear trend toward the use of bone substitutes.

[Posterior operative correction of idiopathic scoliosis. Value of pedicle screws versus hooks]. / Dorsale operative Korrektur der idiopathischen Skoliose. Stellenwert von Pedikelschrauben vs. Haken.

Posterior correction and fusion of scoliosis with multisegmental instrumentation systems was developed by Cotrel-Dubousset in the 1980s. Initially correction and instrumentation was performed using hooks only. Later pedicle screws were implemented first for the lumbar and then for the thoracic spine. Nowadays instrumentation based on pedicle screws only is well established for posterior scoliosis surgery. Biomechanical studies demonstrated higher pull-out forces for pedicle than for hook constructs.In clinical studies several authors reported better Cobb angle correction of the primary and the secondary curves and less loss of correction in pedicle screw versus hook instrumentations. Furthermore, pedicle screw instrumentation allows fewer segments to be fused, especially caudally, and thus saving mobile segments. In most of these publications there were no differences in operation time, blood loss and complication rates. In summary, there is better curve correction without an increased risk using multisegmental pedicle screw instrumentation in modern posterior scoliosis surgery.

[Scoliosis surgery in children from the viewpoint of anaesthesiology]. / Skoliosechirurgie bei Kindern aus anästhesiologischer Sicht.

Anaesthesia for scoliosis surgery in children is a challenge for the paediatric anaesthesiologist. The large range of underlying pathologies causing deranged physiology in an inhomogeneous patient group ranging from neonates to adolescents necessitates diligent and individual preparation for each case. Due to the invasiveness of the operation demanding anaesthetic care is necessary. This review highlights current approaches to monitoring, anaesthetic regimen, positioning of the patient, blood conservation and transfusion, age-related pathophysiology, ventilation and postoperative pain therapy. The introduction of neurophysiologic spinal cord monitoring requires certain adaptations of the anaesthetic regimen to suit technological advances.

[Recommendations on sport activities for patients with idiopathic scoliosis]. / Empfehlungen zur Sportausübung bei Patienten mit idiopathischer Skoliose.

The idiopathic scoliosis is a three dimensional spinal deformity mostly occurring in female adolescents. Untreated it can progress and result in back pain, impaired lung capacity and psychosocial disorders due to the cosmetic appearance of the deformed trunk. The treatment depends on the severity of the curve and ranges from physiotherapy and observation, brace treatment to surgical treatment with partial correction and fusion of the primary curve. Patients with an idiopathic scoliosis should be encouraged to actively take part in sports activities. Positive influences on the general fitness including the lung function, on the trunk muscles and on the psyche can be expected. There are no scientific data indicating that any kind of sport activities alter the natural history of idiopathic scoliosis.

Pedicle screw instrumentation of the thoracic spine in idiopathic scoliosis.

STUDY DESIGN: A prospective study of the accuracy of thoracic pedicle screw placement in patients with idiopathic scoliosis. OBJECTIVES: To evaluate the accuracy of thoracic pedicle screw placement in the surgical management of idiopathic scoliosis and to establish its risks and benefits. SUMMARY OF BACKGROUND DATA: Lumbar pedicle screw instrumentation has proven to be reliable and effective in the surgical management of scoliosis. No reports exist on the accuracy and benefits of pedicle screw instrumentation of the thoracic spine in scoliosis surgery. METHODS: One hundred and twenty thoracic pedicle screws in 32 consecutively treated patients with idiopathic scoliosis were investigated immediately after surgery by computed tomography scans that were analyzed by three examiners. RESULTS: Thirty (25%) of the screws penetrated the pedicle cortex or the vertebral body anterior cortex. Ten screws (8.3%) penetrated the medial cortex of the pedicle by an average of 1.5 mm and a maximum of 3.0 mm. Seventeen screws (14.2%) penetrated laterally by an average of 2.1 mm. There were two cases of caudad penetration. Three screws penetrated the anterior vertebral cortex, of which two also penetrated the pedicle cortex. Also, one of these three screws was replaced because of its direct proximity to the thoracic aorta. There were no neurologic complications. The correlation between the pedicle cortical penetration rate and the preoperative Cobb angle, vertebral rotation or level, or site of screw insertion was statistically insignificant (P > 0.05). Curve correction in the cases of mainly hook instrumentation averaged 52.5% versus 59.2% in the cases of mainly screw instrumentation. This difference was statistically insignificant (P > 0.05). CONCLUSIONS: Pedicle or vertebral body cortical penetration occurred with 25% of the screws but with no neurologic compromise. Curve correction was slightly greater than with hooks, but not to a statistically significant extent.

Morphometric analysis of thoracic and lumbar vertebrae in idiopathic scoliosis.

STUDY DESIGN: Prospective study on the morphometry of 337 pedicles in 29 patients with idiopathic scoliosis. OBJECTIVES: To analyze by means of computed tomographic scans the vertebral morphometry in idiopathic scoliosis treated by pedicle screw instrumentation. SUMMARY OF BACKGROUND DATA: Although several studies exist on the vertebrae's morphometry in normal spines, little is known concerning the morphometry of scoliotic vertebrae. METHODS: The pedicles' morphometry between T5 and L4 was analyzed by computed tomographic scans in 29 surgically treated patients with idiopathic right thoracic scoliosis. Measurements included chord length, endosteal transverse pedicle width, transverse pedicle angle, and pedicle length. RESULTS: The endosteal transverse pedicle width was significantly smaller (P < 0.05) on the concavity in the apical region of the thoracic spine and measured between 2.5 and 4.2 mm in the middle thoracic spine (T5-T9) and between 4.2 and 5.9 mm in the lower thoracic spine (T10-T12). In the lumbar spine, the width varied between 4.8 and 9.5 mm without significant differences between the concave and convex sides (P > 0.05). The chord length was shortest at T5, measuring 37 mm and increased gradually to 50 mm at L3 with significantly larger dimensions in male patients and on the concavity of the apical region in the thoracic spine (P < 0.05). The pedicle length varied minimally, with a range of between 20 and 22 mm, and was relatively consistent throughout the thoracic and lumbar spine. The transverse pedicle angle varied between 6 degrees in the lower thoracic spine and 12 degrees in the upper thoracic and lower lumbar spine. CONCLUSION: The morphometry in scoliotic vertebrae is substantially different from that of vertebrae in normal spines, with an asymmetrical intravertebral deformity shown in scoliotic vertebrae. Pedicle screw instrumentation on the concavity in the apical region of thoracic curves appears critical because of the small endosteal pedicle width.

Percutaneous facet coagulation: indication, technique, results, and complications.

Literature has suggested that the facet joint is responsible for at least some low back pain. This article discusses the history, neuroanatomy, pain formation in the joints, definition of facet syndrome, diagnostics, therapy, a review of the literature, and complications of facet coagulation.

Morphometric analysis of thoracic and lumbar vertebrae in idiopathic scoliosis.

The aim of this paper was to analyse the vertebral morphometry in idiopathic scoliosis with respect to pedicle screw instrumentation by means of computed tomography scans. The pedicle morphometry between T5 and L4 was analysed by computed tomography scans in 29 surgically treated patients with idiopathic right thoracic scoliosis. Measurements included chord length, endosteal transverse pedicle diameter and transverse pedicle angle. The endosteal transverse pedicle diameter was significantly smaller (P<0.05) on the concavity in the apical region of the thoracic spine. The chord length was the shortest at the fifth thoracic vertebra with significantly larger dimensions on the concavity of the apical region in the thoracic spine (P<0.05). The transverse pedicle angle varied between 6 degrees in the lower thoracic spine and 12 degrees at the upper thoracic and lower lumbar spine. The morphometry in scoliotic vertebrae is substantially different from those in normal spines with an asymmetrical intra-vertebral deformity. Pedicle screw instrumentation in the middle thoracic spine appears critical due to the small endosteal pedicle diameter, especially on the concave side.

Pullout strength of pedicle screws versus pedicle and laminar hooks in the thoracic spine.

While the biomechanical properties of pedicle screws have proven to be superior in the lumbar spine, little is known concerning pullout strength of pedicle screws in comparison to hooks in the thoracic spine. In vitro biomechanical pullout testing was performed to evaluate the axial pullout strength of pedicle screws versus pedicle and laminar hooks in the thoracic spine with regard to surgical correction techniques in scoliosis. Nine human cadaveric thoracic spines were harvested and disarticulated. To simulate a typical posterior segmental scoliosis instrumentation, standard pedicle hooks were used between T4 and T8 and supralaminar hooks between T9 and T12 and tested against pedicle screws. The pedicle screws were loaded strictly longitudinal to their axis; the hooks were loaded perpendicular to the intended rod direction. In total, 90 pullout tests were performed. Average pullout strength of the pedicle screws was significantly higher than in the hook group (T4-T8: 531 N versus 321 N, T9-T12: 807 N versus 600 N, p < 0.05). Both screw diameter and the bone mineral density (BMD) had significant influence on the pullout strength in the screw group. For scoliosis correction, pedicle screws might be beneficial, especially for rigid thoracic curves, since they are significantly more resistant to axial pullout than both pedicle and laminar hooks.

[Effects of different sterilization procedures on degree of oxidation of ultra-high molecular weight polyethylene]. / Auswirkungen unterschiedlicher Sterilisationsverfahren auf den Oxidationsgrad von ultrahochmolekularem Polyethylen (UHMWPE).

We investigated the influence of different sterilization techniques on the degree of oxidation of UHMWPE. Oxidation effects were documented by infrared spectroscopy. The UHMWPE was sterilized with the aid of gamma radiation (2.5 Mrad) in air, gamma radiation in argon, ethylene oxide and autoclaving. Non-sterilized UHMWPE served as control material. The results showed significant differences for the various sterilization techniques employed. The highest degree of oxidation was seen after autoclaving, but gamma radiation was also associated with a significant degree of oxidation. Using gamma radiation in argon, the degree of oxidation was significantly reduced. Following sterilization with ethylene oxide, no oxidation was to be found. In view of these facts, UHMWPE should be sterilized only with ethylene oxide or with gamma radiation in argon.

Augmentation of ventral derotation spondylodesis according to Zielke with double-rod instrumentation. Preliminary report on two-year results of thoracolumbar curves.

The advantages of VDS according to Zielke with excellent 3-dimensional correction and shorter fusion levels in comparison to posterior instrumentation techniques are well known. A disadvantage is the necessity of long postoperative immobilization in a body cast or brace due to lack of primary stability. The aim of the VDS double-rod instrumentation is augmentation of the system with the possibility of postoperative treatment without plaster cast or braces. Following thoracolumbophrenotomy and ligation of the segmental vessels double-hole vertebra clamps are inserted. First VDS screws are placed in the posterior holes of these plates. With a 4-mm threaded compression rod correction is obtained by centripetal compressive forces on the nuts. Next VDS screws for the 5-mm threaded rod are inserted into the anterior holes of the vertebral clamps. The rod is implanted in a slightly compressive manner and augments the system. In a prospective study 8 patients, 4 with idiopathic and 4 with neuromuscular scoliotic deformities, underwent this surgical procedure and now have a follow-up of 2 years. Curves ranged from 45 degrees to 131 degrees Cobb angle. All patients were treated without plaster casts or braces postoperatively, but with only a semielastic vest for 4 to 6 months. Unusual intra- and postoperative complications have not been noted. Correction of the primary curve averaged 69.4% at follow-up. Tilt of the caudal end vertebra was corrected 75% to an average of 6.3 degrees. Spontaneous partial correction of the upper secondary curve was noted in all cases. Rod fracture of the 5-mm rod without fracture of the 4-mm rod at this level was seen in 1 patient without loss of correction. Solid fusion was achieved at every level in all patients. The sagittal plane was not adversely affected by the instrumentation. However, larger patient numbers and a longer follow-up are necessary.