Impact of instrumentation in lumbar spinal fusion in elderly patients

Background and purpose An increasing number of lumbar fusions are performed using allograft to avoid donor-site pain. In elderly patients, fusion potential is reduced and the patient may need supplementary stability to achieve a solid fusion if allograft is used. We investigated the effect of instrumentation in lumbar spinal fusion performed with fresh frozen allograft in elderly patients

The contribution of RCTs to quality management and their feasibility in practice

The randomized controlled trial (RCT) is generally accepted as the most reliable method of conducting clinical research. To obtain an unbiased evaluation of the effectiveness of spine surgery, patients should be randomly assigned to either new or standard treatment. The aim of the present article is to provide a short overview of the advantages and challenges of RCTs and to present a summary of the conclusions of the Cochrane Reviews in spine surgery and later published trials in order to evaluate their contribution to quality management and feasibility in practice. From the searches, 130 RCTs were included, 95 from Cochrane Reviews and systematic reviews, and 35 from additional search. No study comparing surgery with sham surgery was identified. The first RCT in spine surgery was published in 1974 and compared debridement and ambulatory treatment in tuberculosis of the spine. The contribution of RCTs in spinal surgery has markedly increased over the last 10 years, which indicates that RCTs are feasible in this field. The results demonstrate missing quality specifications. Despite the number of published trials there is conflicting or limited evidence to support various techniques of instrumentation. The only intervention that receives strong evidence is discectomy for faster relief in carefully selected patients due to lumbar disc prolapse with sciatica. For future trials, authors, referees, and editors are recommended to follow the CONSORT statement. RCTs provide evidence to support clinical opinions before implementation of new techniques, but the individual clinical experience is still important for the doctor who has to face the patient

Visual attention and action: How cueing, direct mapping, and social interactions drive orienting

Despite considerable interest in both action perception and social attention over the last 2 decades, there has been surprisingly little investigation concerning how the manual actions of other humans orient visual attention. The present review draws together studies that have measured the orienting of attention, following observation of another’s goal-directed action. Our review proposes that, in line with the literature on eye gaze, action is a particularly strong orienting cue for the visual system. However, we additionally suggest that action may orient visual attention using mechanisms, which gaze direction does not (i.e., neural direct mapping and corepresentation). Finally, we review the implications of these gaze-independent mechanisms for the study of attention to action. We suggest that our understanding of attention to action may benefit from being studied in the context of joint action paradigms, where the role of higher level action goals and social factors can be investigated

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Union versus nonunion after posterolateral lumbar fusion: a comparison of long-term surgical outcomes in patients with degenerative lumbar spondylolisthesis

It has been reported that in patients undergoing posterolateral lumbar fusion (PLF), the fusion status is not related to the short-term operative results. To determine whether the fusion status influences the long-term operative results of PLF, we retrospectively examined the surgical outcomes of uninstrumented PLF for a minimum of 8 years (average, 9.5 years), by comparing cases exhibiting union with those exhibiting nonunion. Uninstrumented PLF was performed for the treatment of lumbar canal stenosis (LCS) with degenerative spondylolisthesis. Since nine patients were lost to final follow-up, the study included 42 patients, and the follow-up rate was 82.4%. The mean age of the patients was 64.1 years (range 46–77 years). Eight patients exhibited fusion at the L3–4 level and 34 patients, at the L4–5 level. The fusion status was assessed using plain radiographs. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scores. Nonunion was noted in 26% (11/42) of the patients. There were no statistically significant differences between the groups exhibiting union and nonunion with respect to age, sex, preoperative JOA score, or preoperative lumbar instability. The union group achieved better operative results than the nonunion group at the 5-year and final follow-up (P = 0.006 and 0.008, respectively) although there was no significant difference in the percent recovery at 1 and 3-year follow-up (P = 0.515 and 0.506, respectively). A stepwise regression analysis revealed that the best combination of predictors for percent recovery at the time of final follow-up included the fusion status and the presence of comorbid disease. The results indicate that the fusion status following PLF is a critical factor influencing the long-term but not short-term operative results in the treatment of LCS with degenerative spondylolisthesis

Estudo prospectivo comparativo entre pseudoartrose e fusão óssea na estenose de canal lombar Prospective-comparative study between pseudarthrosis and bone fusion in lumbar stenosis

OBJETIVO: Estudo prospectivo comparativo entre pseudoartrose e fusão óssea na estenose de canal lombar MÉTODO: 38 pacientes operados de estenose de canal lombar e submetidos à artrodese avaliados por meio de questionários (escala visual analógica - VAS e questionário de incapacidade Rolland Morris). Foram solicitadas radiografias para avaliação da fusão lombar. RESULTADOS: Foi observada uma efetiva melhora entre o momento pré-operatório e após um ano em relação ao VAS, tanto no grupo que obteve fusão óssea como no grupo com pseudartrose. Em relação ao questionário Rolland Morris houve uma tendência de melhora no grupo com fusão óssea e uma significante melhora no grupo com pseudoartrose. CONCLUSÃO: Não houve diferença entre os grupos (fusão óssea e pseudoartrose) em relação à dor e incapacidade. Nível de Evidência: Nível II, estudo prospectivo longitudinal.<br>OBJECTIVE: Prospective-comparative study between pseudarthrosis and bone fusion in lumbar stenosis METHODS: 38 patients operated on for lumbar spinal stenosis and submitted to arthrodesis were evaluated by the Visual Analogue Scale (VAS) and Roland Morris Disability Questionnaire. Radiographs were requested to evaluate spinal fusion. RESULTS: An effective improvement was observed between the preoperative period and one year after the operation, in relation to VAS, both in the group that received a bone fusion and in the group with pseudarthrosis. With regard to the Roland Morris questionnaire, there was a tendency towards an improvement in the bone fusion group and a significant improvement in the pseudarthrosis group. CONCLUSION: There was no difference between the groups (bone fusion and pseudarthrosis) in relation to pain and disability. . Level of Evidence: Level II, longitudinal prospective study