Can a spinal fusion be done if the verabre is fractured l5s1in serious pain low back down leg also 2hdinsted disc?

Yes, a fusion may be: A treatment option for a vertebral fracture if indicated bya spine surgeon for primarily instability reasons or for neurologic or nerve reasons. Disc herniations causing primarily leg pain are generally treated without surgey with 10% going to surgery and rarely is a fusion indicated unless instability is present such as with a condition called a spondylolisthesis.

Depends: The location of the fracture would determine the type of treatment. Other medical conditions would also determine this. Yes, a fractured vertebra can be successfully treated with fusion. However, if severe osteoporosis exists, there would need to be a darned good reason to do this. "you can't nail a custard pie to the wall" as the saying goes. Steel screws don't work well in soft bone.