There are various books that consider both non-surgical and surgical treatments. One of the questions is if you should look at surgical books but I think that knowledge of surgical conditions would put you far ahead of your colleagues.
I think that White and Punjabi’s Clinical Biomechanics and Related Research book is a great start. Bridwell and DeWald’s Textbook of Spinal Surgery is a classic and would give you a great understanding of conditions that need treatment both surgical and non. You could consider “Rehabilitation of the Spine: A Patient-Centered Approach”. Not a bad book but somewhat incomplete.
Dr. Corenman