What could cause a really sharp pain in my spine?

Several possibilitie: If it's directly along the spine, could be disc injury, herniation, torn ligament, tumor (not likely as these tend to be dull aching), or commonly a locked vertebra (higher up, could be rib).A good history & physical, esp. Hands-on osteopathic exam could elucidate cause leading to proper treatment.Simple, sharp pain is frequently easily diagnosed & fixable by osteopathic manipulation right in office.

Depends: On the type of pain and its location. Much more information would be required here.