What would cause "power surge" feeling thru r hand & fingers, after c4-7 d&fusion? then numbness along r side of middle finger?

Nerve irritation: Compression of nerves or the spinal cord can cause the symptoms you describe. This compression may be residual, related to your preoperative condition, or new, possibly from disc protrusion or bone spurs. Finally, even after adequate decompression there may be residual nerve irritation. A ct or MRI scan should help with this diagnosis.