Bipolar Z-plasty operation for torticollis. A, Skin incisions. B, Clavicular and mastoid attachments of sternocleidomastoid muscle are cut, and Z-plasty is performed on sternal origin. C, Completed operation; note preservation of medial portion of sternal attachment.(Redrawn from Ferkel RD, Westin GW, Dawson EG, et al: Muscular torticollis: a modified surgical approach, J Bone Joint Surg 65A:894, 1983.) SEE TECHNIQUE 31.4.