This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
In this affection the head and the neck are so twisted that the face is turned toward the side opposite the contracted muscle and looks somewhat upward. It is usually caused by some affection of the sternomastoid muscle. It is not always the only muscle involved, as the trapezius and others may likewise be affected. It is congenital or acquired. In the congenital cases it is caused by an injury to the sternomastoid muscle, occurring during childbirth; a swelling or tumor may be present in the course of the muscle. In the acquired form the distortion may be more or less permanent and may be due to caries or other disease of the spine. In such cases it is evident that treatment is to be directed to the diseased spine rather than to the sternomastoid muscle, which will be found to be relaxed.
Fig. 170. - Torticollis or wry-neck.
Inflammation of the lymph-nodes of the neck may cause the patient to hold the head and neck in a distorted position. The wry-neck in this case will disappear as the cause subsides. Rheumatic affections of the neck are a common cause, and the sternomastoid muscle may then become contracted and require division. In rare instances a nervous affection causes a spasmodic torticollis. The persistent movements render this a very distressing affection, and to relieve it not only has the sternomastoid but also the trapezius been divided, and even the spinal accessory and occipital nerves have been excised.
Division of the siernomastoid muscle should be done by open and not by subcutaneous incision. The sternal origin of the sternomastoid muscle is a sharp, distinct cord, but its clavicular origin is a broad, thin band extending outward a third of the length of the clavicle. An incision 2 or 3 cm. or more in length is made over the tendon and the bands are to be carefully isolated before being divided. The structure most important to avoid is the internal jugular vein. It lies close behind the sternal origin of the muscle and great care must be taken to avoid it. In one case in which it was accidentally wounded it was necessary to ligate it. As the deep fascia of the neck splits to enclose the sternomastoid muscle it is opened by the operation and infection has caused in such cases wide-spread phlegmonous inflammation.