COMPARISON OF OUTCOMES OF ENDOSCOPIC MICRODISCECTOMY VERSUS CONVENTIONAL DISCECTOMY FOR LUMBER DISC DISEASES

Introduction: Chronic lumbosacral pain is a communal and difficult clinical condition at the center of pain management. The most common surgical indication is back pain or intractable and severe functional impairment that does not respond to conservative measures. In this study we have compared the results of endoscopic d microdiscectomy and conventional discectomy procedure. Material and Methods: We included 54 patients with severe lower back pain who did not improve after long-term conservative treatment and who had level 3 disc prolapse, radiating to one or both lower limbs. Oswestry Disability Index (For Low Back Pain) was documented with questionnaire comeback and applied as a clinical tool for valuation. Results: The average age of the 54 patients was 46 years and 75% of patients have paracentral disc protrusion. The mean endoscopic microdiscectomy surgery time was 110 minutes; was longer than conventional discectomy (82 minutes). However, blood loss was very small compared to conventional discectomy. According to the ODI result, both conventional and endoscopic discectomy gave same outcomes in all classes. Conclusion: Endoscopic microdiscectomy is a new, effective and safe procedure that reduces the invasiveness of the surgical approach. The results obtained by this approach are comparable with those obtained with open discectomy to alleviate symptoms during prolonged observation, and because the tissue has minimal trauma, it is much better in early mobilization and morbidity

Different factors limit early- and late-season windows of opportunity for monarch development.

Seasonal windows of opportunity are intervals within a year that provide improved prospects for growth, survival, or reproduction. However, few studies have sufficient temporal resolution to examine how multiple factors combine to constrain the seasonal timing and extent of developmental opportunities. Here, we document seasonal changes in milkweed (Asclepias fascicularis)-monarch (Danaus plexippus) interactions with high resolution throughout the last three breeding seasons prior to a precipitous single-year decline in the western monarch population. Our results show early- and late-season windows of opportunity for monarch recruitment that were constrained by different combinations of factors. Early-season windows of opportunity were characterized by high egg densities and low survival on a select subset of host plants, consistent with the hypothesis that early-spring migrant female monarchs select earlier-emerging plants to balance a seasonal trade-off between increasing host plant quantity and decreasing host plant quality. Late-season windows of opportunity were coincident with the initiation of host plant senescence, and caterpillar success was negatively correlated with heatwave exposure, consistent with the hypothesis that late-season windows were constrained by plant defense traits and thermal stress. Throughout this study, climatic and microclimatic variations played a foundational role in the timing and success of monarch developmental windows by affecting bottom-up, top-down, and abiotic limitations. More exposed microclimates were associated with higher developmental success during cooler conditions, and more shaded microclimates were associated with higher developmental success during warmer conditions, suggesting that habitat heterogeneity could buffer the effects of climatic variation. Together, these findings show an important dimension of seasonal change in milkweed-monarch interactions and illustrate how different biotic and abiotic factors can limit the developmental success of monarchs across the breeding season. These results also suggest the potential for seasonal sequences of favorable or unfavorable conditions across the breeding range to strongly affect monarch population dynamics

Different factors limit early‐ and late‐season windows of opportunity for monarch development

Abstract Seasonal windows of opportunity are intervals within a year that provide improved prospects for growth, survival, or reproduction. However, few studies have sufficient temporal resolution to examine how multiple factors combine to constrain the seasonal timing and extent of developmental opportunities. Here, we document seasonal changes in milkweed (Asclepias fascicularis)–monarch (Danaus plexippus) interactions with high resolution throughout the last three breeding seasons prior to a precipitous single‐year decline in the western monarch population. Our results show early‐ and late‐season windows of opportunity for monarch recruitment that were constrained by different combinations of factors. Early‐season windows of opportunity were characterized by high egg densities and low survival on a select subset of host plants, consistent with the hypothesis that early‐spring migrant female monarchs select earlier‐emerging plants to balance a seasonal trade‐off between increasing host plant quantity and decreasing host plant quality. Late‐season windows of opportunity were coincident with the initiation of host plant senescence, and caterpillar success was negatively correlated with heatwave exposure, consistent with the hypothesis that late‐season windows were constrained by plant defense traits and thermal stress. Throughout this study, climatic and microclimatic variations played a foundational role in the timing and success of monarch developmental windows by affecting bottom‐up, top‐down, and abiotic limitations. More exposed microclimates were associated with higher developmental success during cooler conditions, and more shaded microclimates were associated with higher developmental success during warmer conditions, suggesting that habitat heterogeneity could buffer the effects of climatic variation. Together, these findings show an important dimension of seasonal change in milkweed–monarch interactions and illustrate how different biotic and abiotic factors can limit the developmental success of monarchs across the breeding season. These results also suggest the potential for seasonal sequences of favorable or unfavorable conditions across the breeding range to strongly affect monarch population dynamics