Prolonged use of oral corticosteroids (such as prednisone) can be associated with some of the problems you are describing. Epidural injections for spinal pain and trigger point injections (which often do not use steroids) are rarely a cause for these issues because of the lower dosage and limited exposure. Is it possible that the weight did not come from the injections, but from lack of exercise due to the injury? And even if it is due to injections, if you lose the weight and the cholesterol decreases, the Zocor can always be stopped.