Early stage disc degeneration does not have an appreciable affect on stiffness and load transfer following vertebroplasty and kyphoplasty.

Vertebroplasty and kyphoplasty have been reported to alter the mechanical behavior of the treated and adjacent-level segments, and have been suggested to increase the risk for adjacent-level fractures. The intervertebral disc (IVD) plays an important role in the mechanical behavior of vertebral motion segments. Comparisons between normal and degenerative IVD motion segments following cement augmentation have yet to be reported. A microstructural finite element model of a degenerative IVD motion segment was constructed from micro-CT images. Microdamage within the vertebral body trabecular structure was used to simulate a slightly (I = 83.5% of intact stiffness), moderately (II = 57.8% of intact stiffness), and severely (III = 16.0% of intact stiffness) damaged motion segment. Six variable geometry single-segment cement repair strategies (models A-F) were studied at each damage level (I-III). IVD and bone stresses, and motion segment stiffness, were compared with the intact and baseline damage models (untreated), as well as, previous findings using normal IVD models with the same repair strategies. Overall, small differences were observed in motion segment stiffness and average stresses between the degenerative and normal disc repair models. We did however observe a reduction in endplate bulge and a redistribution in the microstructural tissue level stresses across both endplates and in the treated segment following early stage IVD degeneration. The cement augmentation strategy placing bone cement along the periphery of the vertebra (model E) proved to be the most advantageous in treating the degenerative IVD models by showing larger reductions in the average bone stresses (vertebral and endplate) as compared to the normal IVD models. Furthermore, only this repair strategy, and the complete cement fill strategy (model F), were able to restore the slightly damaged (I) motion segment stiffness above pre-damaged (intact) levels. Early stage IVD degeneration does not have an appreciable effect in motion segment stiffness and average stresses in the treated and adjacent-level segments following vertebroplasty and kyphoplasty. Placing bone cement in the periphery of the damaged vertebra in a degenerative IVD motion segment, minimizes load transfer, and may reduce the likelihood of adjacent-level fractures.

Long-term outcome of primary endoresection of choroidal melanoma.

BACKGROUND: Endoresection of choroidal melanoma may offer the best hope of conserving vision in some patients but is controversial because of concerns regarding iatrogenic tumour dissemination. METHODS: Retrospective, non-randomised study of consecutive patients who underwent endoresection for choroidal melanoma at the Liverpool Ocular Oncology Centre between 1996 and 2010. RESULTS: The study included 71 patients with a mean age of 58.7 years. The tumour extended within 2 disc diameters of the optic disc in 46 (65%) eyes, involving the disc in 24 (34%) eyes. The mean largest basal tumour diameter and tumour thickness were 9.5 mm and 4.4 mm, respectively. The median follow-up was 4.1 years. The visual acuity at the latest follow-up was better than 6/30 in 31% eyes. The main causes of visual loss were foveal excision, rhegmatogenous retinal detachment (RD) and proliferative vitreo-retinopathy (PVR). Local recurrence developed in two patients (3%), who were treated by enucleation and proton beam radiotherapy, respectively. RD occurred in 16 cases (22%). Three (4%) eyes were enucleated, two because of PVR and one because of local tumour recurrence. Five patients died of metastatic disease. CONCLUSIONS: Endoresection achieved high rates of local tumour control. This operation would seem to be a useful alternative to radiotherapy as a means of conserving vision in eyes with juxtapapillary melanoma.

The role of laparoscopic biopsies in lumbar spondylodiscitis.

The infection of an intervertebral disk is a serious condition. The diagnosis often is elusive and difficult to make. It is imperative to have appropriate microbiologic specimens before the initiation of treatment. We report the case of a 51-year-old woman with lumbar spondylodiscitis caused by infection after the placement of an epidural catheter for postoperative analgesia. A spinal magnetic resonance imaging (MRI) scan confirmed the diagnosis, but computed tomography (CT)-guided fine-needle biopsy did not yield adequate material for a microbiologic diagnosis. Laparoscopic biopsies of the involved disk provided good specimens and a diagnosis of Propionibacterium acnes infection. We believe that this minimally invasive procedure should be performed when CT-guided fine-needle biopsy fails to yield a microbiologic diagnosis in spondylodiscitis.

Cefuroxime prophylaxis is effective in noninstrumented spine surgery: a double-blind, placebo-controlled study.

STUDY DESIGN: Double-blind, placebo-controlled randomized clinical trial. OBJECTIVE: To assess the efficacy of 1 preoperative 1.5 g dose of cefuroxime in preventing surgical site infection after surgery for herniated disc. SUMMARY OF BACKGROUND DATA: Antibiotic prophylaxis was only tested in nonconclusive trials in this setting. METHODS: The study was conducted in 2 university hospitals in Switzerland. Patients were assessed for occurrence of surgical site infection (defined by the criteria of the Centers for Diseases Control and Prevention), other infections, or adverse events up to 6 months after surgery. Outcome measures were compared in a univariate, per-protocol analysis. RESULTS: Baseline characteristics were similar in patients allocated to cefuroxime (n = 613) or placebo (n = 624). Eight (1.3%) patients in the cefuroxime group and 18 patients (2.8%) in the placebo group developed a surgical site infection (P = 0.073). A diagnosis of spondylodiscitis or epidural abscess was made in 9 patients in the placebo group, but none in the cefuroxime group (P < 0.01), which corresponded to a number necessary to treat of 69 patients to prevent one of these infections. There were no significant adverse events attributed to either cefuroxime or placebo. CONCLUSION: A single, preoperative dose of cefuroxime significantly reduces the risk of organ-space infection, most notably spondylodiscitis, after surgery for herniated disc.

La variabilité chirurgicale en Suisse : différences intercantonales observées pour trois interventions

En Suisse, la variabilité géographique de la consommation de soins chirurgicaux est un domaine encore inexploré. Ce rapport examine de manière descriptive trois interventions chirurgicales réalisées en Suisse entre 2003 et 2005 : la prothèse partielle ou totale de hanche, la prothèse de genou et la cure de hernie discale. Il se concentre sur les caractéristiques démographiques des patients opérés, leur diagnostic et les différences des taux d'intervention selon les cantons. Les résultats sont présentés sous forme de taux bruts, de taux standardisés et de cartes géographiques de distribution.

Unilateral optic disc edema following trabeculectomy.

Two cases of a benign form of optic disc edema after successful trabeculectomy are reported. In both patients, optic disc edema was noted 2 to 4 weeks after trabeculectomy. The edema occurred without loss of visual acuity or field. The absolute intraocular pressure and intracranial pressure were normal--that is, the edema was not a syndrome of hypotony or pseudotumor cerebri. However, both patients had intracranial pressure in the high-normal range. The decrease in intraocular pressure into the low normal range after trabeculectomy may have altered the intracranial pressure:intraocular pressure ratio at the lamina cribrosa enough to produce optic disc edema.

Radiographic total disc replacement angle measurement accuracy using the Oxford Cobbometer: precision and bias.

Total disc replacement (TDR) clinical success has been reported to be related to the residual motion of the operated level. Thus, accurate measurement of TDR range of motion (ROM) is of utmost importance. One commonly used tool in measuring ROM is the Oxford Cobbometer. Little is known however on its accuracy (precision and bias) in measuring TDR angles. The aim of this study was to assess the ability of the Cobbometer to accurately measure radiographic TDR angles. An anatomically accurate synthetic L4-L5 motion segment was instrumented with a CHARITE artificial disc. The TDR angle and anatomical position between L4 and L5 was fixed to prohibit motion while the motion segment was radiographically imaged in various degrees of rotation and elevation, representing a sample of possible patient placement positions. An experienced observer made ten readings of the TDR angle using the Cobbometer at each different position. The Cobbometer readings were analyzed to determine measurement accuracy at each position. Furthermore, analysis of variance was used to study rotation and elevation of the motion segment as treatment factors. Cobbometer TDR angle measurements were most accurate (highest precision and lowest bias) at the centered position (95.5%), which placed the TDR directly inline with the x-ray beam source without any rotation. In contrast, the lowest accuracy (75.2%) was observed in the most rotated and off-centered view. A difference as high as 4 degrees between readings at any individual position, and as high as 6 degrees between all the positions was observed. Furthermore, the Cobbometer was unable to detect the expected trend in TDR angle projection with changing position. Although the Cobbometer has been reported to be reliable in different clinical applications, it lacks the needed accuracy to measure TDR angles and ROM. More accurate ROM measurement methods need to be developed to help surgeons and researchers assess radiological success of TDRs.

Idiopathic chiasmal neuritis: clinical features and prognosis.

OBJECTIVES: To describe the clinical features of idiopathic chiasmal neuritis in a large cohort of patients and to report their visual and neurologic outcomes. DESIGN: A retrospective medical record review of consecutive patients with chiasmal neuritis at a single institution. Patients with clinical or radiographic evidence of inflammation involving the intraorbital optic nerve and patients with a systemic inflammatory or neoplastic disorder were excluded. RESULTS: Twenty patients were identified (14 female, 6 male; mean age, 37 years). Visual acuity at initial examination ranged from 20/15 to light perception. Progressive visual loss beyond 1 month was documented in 1 patient. Twelve of 15 patients who underwent magnetic resonance imaging demonstrated chiasmal enlargement and/or enhancement; 6 patients had 1 or more white matter lesions. Follow-up time ranged from 2 weeks to 22 years, with a mean of 5.7 years. The final median visual acuity was 20/20 (range, 20/15-20/50) and visual fields were normal or improved. Of 15 patients with a minimum follow-up interval of 1 year, 6 developed multiple sclerosis. CONCLUSIONS: The demographic and clinical features of idiopathic chiasmal neuritis resemble those of idiopathic optic neuritis. Visual prognosis is excellent. In this series, 40% of patients subsequently developed multiple sclerosis.

Bilateral anterior ischemic optic neuropathy following influenza vaccination.

Optic neuritis is an occasional complication of vaccination. Visual loss can be unilateral or bilateral, and most patients recover substantially without treatment. The presumptive mechanism is an immune-mediated demyelinating injury of the optic nerve. We report two patients who had permanent visual loss following influenza vaccination. Their pattern of visual loss, segmental optic disc changes, and failure of visual recovery were atypical for demyelinating optic neuritis and reminiscent of a primary ischemic injury to the optic nerve. We speculate that an immune complex-mediated vasculopathy following vaccination can cause anterior ischemic optic neuropathy. Clinicians should be aware of this entity because of the less favorable prognosis for visual recovery in these cases.

The role of laparoscopic biopsies in lumbar spondylodiscitis.

Infection of an intervertebral disk is a serious condition. Diagnosis often is elusive and difficult. It is imperative to obtain appropriate microbiological specimens before initiation of treatment. The authors describe a 51-year-old woman with lumbar spondylodiscitis that was because of infection after the placement of an epidural catheter for postoperative analgesia. A spinal magnetic resonance imaging confirmed the diagnosis, but computed tomography-guided fine needle biopsy did not provide adequate material for a microbiologic diagnosis. Laparoscopic biopsies of the involved disk provided good specimens and a diagnosis of Propionibacterium acnes infection. The authors believe that this minimally invasive procedure should be performed when computed tomography-guided fine needle biopsy does not provide a microbiologic diagnosis in spondylodiscitis.

International Society of Urological Pathology (ISUP) Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens. Working group 2: T2 substaging and prostate cancer volume.

The 2009 International Society of Urological Pathology consensus conference in Boston made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. Issues relating to the substaging of pT2 prostate cancers according to the TNM 2002/2010 system, reporting of tumor size/volume and zonal location of prostate cancers were coordinated by working group 2. A survey circulated before the consensus conference demonstrated that 74% of the 157 participants considered pT2 substaging of prostate cancer to be of clinical and/or academic relevance. The survey also revealed a considerable variation in the frequency of reporting of pT2b substage prostate cancer, which was likely a consequence of the variable methodologies used to distinguish pT2a from pT2b tumors. Overview of the literature indicates that current pT2 substaging criteria lack clinical relevance and the majority (65.5%) of conference attendees wished to discontinue pT2 substaging. Therefore, the consensus was that reporting of pT2 substages should, at present, be optional. Several studies have shown that prostate cancer volume is significantly correlated with other clinicopathological features, including Gleason score and extraprostatic extension of tumor; however, most studies fail to demonstrate this to have prognostic significance on multivariate analysis. Consensus was reached with regard to the reporting of some quantitative measure of the volume of tumor in a prostatectomy specimen, without prescribing a specific methodology. Incorporation of the zonal and/or anterior location of the dominant/index tumor in the pathology report was accepted by most participants, but a formal definition of the identifying features of the dominant/index tumor remained undecided.