The question asks for techniques commonly used to close the raw area after excision of a pilonidal sinus to avoid a midline wound. Let's examine the options provided:

1. Limberg Procedure: This is a type of rhomboid flap, which is known for its application in closing defects like a pilonidal sinus excision. It is designed to avoid a midline wound by transposing tissue.
2. Y-V Plasty: This technique involves incising in a "Y" shape and then bringing the tissue edges together to form a "V". However, it is less commonly used specifically for pilonidal sinus excisions.
3. Z-plasty: Z-plasty is a surgical technique used to improve the functional and cosmetic appearance of scars. It is highly effective in realigning scars and can be used to redirect tension lines away from the midline, making it applicable here.
4. Karydakis Procedure: This technique involves creating an asymmetric elliptical incision to excise the sinus, followed by a lateral skin flap to cover the defect, effectively avoiding a midline wound. It is a well-known procedure for pilonidal sinus treatment.

Based on the above explanations, the techniques that are commonly used for closing a pilonidal sinus excision without leaving a midline wound are:

• I. Limberg Procedure
• III. Z-plasty
• IV. Karydakis Procedure

Thus, the correct answer is I, III, and IV.