Posterior Surgical Treatment of Cervical Spondylotic Myelopathy: Review Article

Background

Cervical spondylosis is now recognised as the leading cause of myelopathy and spinal cord dysfunction worldwide. Chronic spinal cord compression results in chronic inflammation, cellular apoptosis, and microvacular insufficiency, which are thought to the biologic basis for cervical spondylotic myelopathy (CSM).

Questions/Purposes

Our purpose was to address the key principles of CSM, including natural history and presentation, pathogenesis, optimal surgical approach, results and complication rates of posterior surgical approaches for CSM so that the rationale for addressing CSM by a posterior approach can be fully understood.

Methods

We conducted a systematic search of PubMed/MEDLINE and the Cochrane Collaboration Library for literature published through February 2014 to identify articles that evaluated CSM and its management. Reasons for exclusion included patients with ossification of the posterior longitudinal ligament (OPLL), patients with degenerative disc disease without CSM, and patients with spine tumor, trauma and infection. Meeting abstracts/proceedings, white articles and editorials were additionally excluded.

Results

The search strategy yielded 1,292 articles, which was reduced to 52 articles, after our exclusion criteria were introduced. CSM is considered to be a surgical disorder due to its progressive nature. There is currently no consensus in the literature whether multilevel spondylotic compression is best treated via an anterior or posterior surgical approach.

Conclusion

Multilevel CSM may be safely and effectively treated using a posterior approach, either by laminoplasty or with a laminectomy and fusion technique.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9425-5) contains supplementary material, which is available to authorized users.     

Limited intercarpal fusion as a salvage procedure for advanced Kienbock disease

Background

With progressive lunate collapse, salvage procedures in advanced Kienbock disease attempt to provide pain relief and maintain motion. Scaphocapitate arthrodesis may provide a durable option with comparable outcomes to proximal row carpectomy in the well-selected patient.

Methods

We performed a retrospective chart review of all consecutive patients with Lichtman stage IIIA or IIIB Kienbock’s disease who underwent either scaphocapitate or scaphotrapeziotrapezoid-capitate arthrodesis from January 2004 to December 2013.

Results

Twelve patients were included with a mean age of 41.6 years. Ten patients underwent scaphocapitate arthrodesis, while two patients underwent scaphotrapezio-trapezoid-capitate arthrodesis with an average clinical follow-up of 13.1 months. All patients achieved fusion. The average postoperative flexion-extension arc was 53° (range 20–110°). The average ulnar deviation was 9° (range 5–15°), and the average radial deviation was 13° (range 5–25°). Postoperative pain scores were significantly improved, having changed from an average of 6.6 preoperatively to 2.8 on a 10-point scale (W = 18, P < 0.05).

Conclusions

Despite a mean flexion-extension arc that is reduced from that of a normal individual, the postoperative range of motion following a midcarpal arthrodesis was not significantly different than that reported in a recent systematic review of proximal row carpectomy (73.5° compared with 53°, respectively) (P = 0.05). Additionally, given the significant postoperative reduction in associated pain symptoms at the time of follow-up, scaphocapitate arthrodesis should be considered as a treatment option for wrist salvage in the patient with advanced Kienbock’s disease.     

Change in Body Mass Index after Simultaneous Bilateral Total Knee Arthroplasty: Risk Factors and Its Influence on Functional Outcomes

BackgroundPrevious studies evaluating weight changes following total knee arthroplasty (TKA) were performed on heterogenous cohorts. However, no study has evaluated weight changes in a cohort of simultaneous-bilateral TKA (SB-TKA) patients. This study aimed to evaluate the prevalence of patients who lost or gained weight, determine if postoperative weight change influences functional outcome, and identify predictors of weight change after SB-TKA.MethodsProspectively collected registry data of 560 patients who underwent SB-TKA were reviewed. Patients were assessed preoperatively, at 6 months, and 2 years using the Knee Society Score, Oxford Knee Score, Short-Form 36, and range of motion. Change in body mass index (BMI) >5% was used to categorize patients into 3 groups: lost, maintained, or gained weight. Analysis of variance, Kruskal-Wallis test, and chi-squared test were used to compare functional outcomes between groups. Multivariable logistic regression evaluated predictors for postoperative weight changes.ResultsAt 2 years, 59% of patients maintained weight, 28% of patients gained weight, and 13% of patients lost weight. All groups experienced similar improvements in functional outcomes, rates of minimal clinically important difference attainment, and patient satisfaction (P > .05). Older patients were more likely to gain weight (P < .05). Patients with higher preoperative BMI were more likely to gain weight (P < .05) and less likely to lose weight (P < .05). Patients with greater preoperative comorbidities were less likely to lose weight (P < .05).ConclusionUp to 41% of patients experience significant weight changes after SB-TKA. Older patients with higher preoperative BMI were more likely to gain weight, while higher preoperative BMI with more comorbidities were less likely to lose weight following SB-TKA; however, postoperative weight changes do not appear to affect functional outcomes.Level of EvidenceIII, therapeutic study.     

STAG2 as a prognostic biomarker in low-grade non-muscle invasive bladder cancer

ObjectiveImprovements to bladder cancer risk stratification guidelines are needed to better tailor post-operative surveillance and adjuvant therapy to individual patients. We previously identified STAG2 as a commonly mutated tumor suppressor gene in bladder cancer and an independent predictor of progression in NMIBC. Here we test the value of combining STAG2 immunostaining with other risk stratification biomarkers in NMIBC, and as an individual biomarker in MIBC.Materials and MethodsSTAG2 immunohistochemistry was performed on a progressor-enriched cohort of tumors from 297 patients with NMIBC, and on tumors from 406 patients with MIBC from Aarhus University Hospital in Denmark. Survival analysis was performed using Kaplan-Meier survival analysis, the log rank test, and Cox proportional hazards models.ResultsSTAG2-negative low-grade NMIBC tumors were 2.5 times less likely to progress to muscle invasion than STAG2-positive low-grade NMIBC tumors (Log-rank test, P = 0.008). In a composite group of patients with AUA intermediate and high-risk NMIBC tumors, STAG2-negative tumors were less likely to progress (Log-rank test, P = 0.02). In contrast to NMIBC, we show that STAG2 is not useful as a prognostic biomarker in MIBC.ConclusionsSTAG2 immunostaining can be used to subdivide low-grade NMIBC tumors into two groups with substantially different risks of disease progression. Furthermore, STAG2 immunostaining may be useful to enhance NMIBC risk stratification guidelines, though larger cohorts are needed to solidify this conclusion in individual risk groups. STAG2 is not useful as a biomarker in MIBC. Further study of the use of STAG2 immunostaining as a biomarker for predicting the clinical behavior in NMIBC is warranted.     

Using the internet to assess and teach medical students in dermatology

Background and Objectives: We wish to develop and evaluate a user-friendly online interactive teaching and examination model as an adjunct to traditional bedside teaching of medical students during a clinical rotation in dermatology. Methods: Following completion of an online examination, senior medical students at the University of British Columbia (n = 178) were asked to complete an online survey to evaluate their acceptance of this new method. The online examination model was evaluated through students' responses to the questionnaire-based evaluation they were asked to complete following their examination. Responses were evaluated on a standardized 5-point scale. Results: A high response rate was achieved (98.9%). Overall, 93% of senior medical students felt that the Internet was a useful and effective way to administer a dermatology examination. Most (90%) preferred the online examination to a traditional paper-and-pencil examination and the majority (88%) felt that the quality of digital images presented was sufficient to make an accurate diagnosis. In addition, students strongly supported the further development of teaching resources on the web and would use these resources in learning dermatology (93%). Conclusions: The development of an online interactive examination tool for dermatology is technically feasible with current technology. Senior medical students are not only accepting of this new technology but also prefer it to more traditional formats and indicate enthusiasm for the development of further online teaching resources in dermatology.     

β-Amyloid of Alzheimer's Disease Induces Reactive Gliosis That Inhibits Axonal Outgrowth

Pathological lesions in the brains of patients with Alzheimer's disease (AD) are characterized by dense deposits of the protein β-amyloid. The link between the deposition of β-amyloid in senile plaques and AD-associated pathology is, at present, controversial since there have been conflicting reports on whether the 39-43 amino acid β-amyloid sequence is toxic or trophic to neurons. In this report, we show that β-amyloid peptide when presented as an insoluble substrate which mimics its conformation in vivo can induce cortical glial cells in vitro and in vivo to locally deposit chondroitin sulfate containing proteoglycan. In vitro the proteoglycan-containing matrix deposited by gila on β-amyloid blocks the usual ability of the peptide to allow cortical neurons to adhere and grow. Chondroitin sulfate-containing proteoglycan was also found in senile plaques of human AD tissue. We suggest that an additional effect of β-amyloid in the brain, which compounds the direct effects of βamyloid on neurons, is mediated by the stimulation of astroglia to become reactive. Once in the reactive state, glial cells deposit large amounts of growth-inhibitory molecules within the neuropil which could impair neuronal process survival and regeneration leading to neurite retraction and/or dystrophy around senile plaques in AD.