Shares of AxoGen (NASDAQ: AXGN) fell nearly 19% today after the company reported second-quarter 2018 earnings. The healthcare company, which develops and markets surgical solutions for peripheral nerves, actually reported a solid quarter of sales growth compared to the year-ago period. Revenue increased 36% compared to the second quarter of 2017.However, the top-line growth was overshadowed by a huge increase in expenses and overhead, which led to a larger net loss in the second quarter of 2018 compared to the year-ago period.