Below is the regulation for the State of Texas. Basically, it says that you can remove the spacer cone for specific surgical applications that would be otherwise prohibited at the SSDs specified by the regulation. If you do remove it, then you must have written operating and safety procedures that provide precautionary measures to be adhered to during the use of the shorter SSD, in accordance with manufacturer’s precautions, if provided. Ideally this means you should use the spacer cone except for those procedures that are not in your category of “specific surgical applications”.  If you remove the spacer device, be sure you defined in your policies and procedures the safe actions you take when the spacer is removed. This typically might be a statement that the operator must ensure that the x-ray tube is kept at the maximum practicable distance from the surface of the patient during the procedure. You should also identify what procedures that entails.

289.227(m)(6)
(6) Source-to-skin distance (SSD).
(A) Means shall be provided to limit the SSD to the following:
(i) not less than 38 cm on stationary fluoroscopic systems; and
(ii) not less than 30 cm on portable fluoroscopic systems.
(B) For image-intensified fluoroscopic systems intended for specific surgical application that would be prohibited at the SSDs specified in subparagraph (A) of this paragraph, provisions may be made for operation at shorter SSDs, but in no case less than 20 cm.
(C) For stationary or portable C-arm fluoroscopic systems manufactured on or after June 10, 2006, having a maximum source-to-image receptor distance of less than 45 cm, the following requirements shall be met.
(i) Means shall be provided to limit the SSD to not less than 19 cm.
(ii) Such systems will be labeled and used for extremity use only.
(iii) For those systems intended for specific surgical applications that would be prohibited at the SSD specified in clause (i) of the subparagraph, provisions may be made for operation at a shorter SSD, but in no case less than 10 cm.
(D) The registrant’s written operating and safety procedures shall provide precautionary measures to be adhered to during the use of the shorter SSD, in accordance with manufacturer’s precautions, if provided.