This study of congenital muscular torticollis in infancy is continuing. The data obtained so far may be summarized as follows:
1. The tumor in the sternocleidomastoid muscle was discovered at an average age of 3.5 weeks and disappeared at an average age of three and one-half months. The longest period between time of appearance and time of disappearance of the tumor was five months. Hulbert gave the shortest period as two months, the longest as eleven months, and the average as seven months. Chandler gave the average period as five to eight months.
2. Asymmetry of the face and skull, although occasionally present at birth, was usually not evident until two and one-half months of age. Said in another way, facial asymmetry did not usually appear until about one and one-half months after the tumor appeared in the sternoeleidomastoid muscle. The asymmetry tended to disappear for the most part, but as a rule not completely, by the age of six months. We did not detect any appreciable asymmetry in any of the patients with congenital muscular torticollis after one year of age, except in two whose results we have mentioned as poor. Asymmetry secondary to intra-uterine position is observed frequently at birth. This asymmetry is not permanent and has not been related to a subsequent development of a sternocleidomastoid tumor.
3. Two of the thirty-five patients have had residual wryneck. All others had excellent results. The two patients with poor results were among the five treated surgically. We do not infer that all patients will get excellent results, without wryneck deformity, if treated non-surgically; why these two surgically treated patients obtained poor results we can only guess. They were operated upon at six and nineteen and one-half months of age, respectively. No immobilizing cast or dressing in the overcorrected position was used. It is the impression of some that the overcorrected position shiould be mnaintained postoperatively to prevent reattachment of the sectioned muscle and tendon.
4. It is frequently said that no tumor exists in infants with well established wryneck, and it is even said that there may be two entities-one with tumor and one without. More accurately, it shlould be stated that there is no history of tumor in many patients with wryneck. Bianco found the incidence of wryneck without history of tumor to be about 80 per cent-only about 20 per cent of the patients with well developed wryneck deformity had a positive history of sternocleidomastoid tumor. Our studies throw some light on this point. Thus, as we have recorded, a sternocleidomastoid tumor was first found by the mother in 50 per cent of the infants in our study; in the other half it was missed by the mother, but was found by the physician during routine examination. Our study approaches the problem in the neonatal and early infancy periods and is based on examination of unselected infants; it is not a study based on infants brought to the physician because of tumor in the sternocleidomastoid muscle. We believe, therefore, that it presents an index of incidence, natural history, and results.
Statements in the literature imply that as the neck begins to undergo relative lengthening at about the age of three years, the involved sternocleidomastoid fails to grow with corresponding rapidity, so that tile onset of true wryneck occurs. Why does this occur in very few children? Why not in all? Is it a matter of degree of involvement by the tumor, that is, a matter of the ratio of normal muscle remaining to muscle replaced by fibrous tissue? Perhaps if enough normal muscle remains, it can grow, stretch, and otherwise adapt to the environment of growth and development, and no deformity will result.
Hulbert stated that four of every five tumors resolve completely and leave no deformity. In only two of thirty-five patients have we seen the tumor go on to produce deformity. When last examined, fifteen of our patients were one to four years of age, and twenty were four to twelve years of age; none of the twenty had wryneck deformity. It would seem from this number of traced patients that the incidence of development of torticollis after the tumor disappeared may be considerably less than the 20 per cent cited by Hulbert.
It is concluded that there is no justification for operating upon all patients with congenital muscular torticollis in infancy. If there is detectable wryneck deformity with contracture of the sternocleidomastoid muscle after the age of one year, this muscle should be sectioned then because the deformity at that age may be permanent. However, from our experience (Patient 5 after second operation) and that of others there is every indication that an operation at any age up to twelve years will give as good a result as an operation at any earlier age. If the operation is properly carried out, there should be no residual deformity of the neck, except for atrophy of the sectioned muscle, which will occur if an operation is done at any age. The asymmetry of the skull and face will correct itself as long as growth potential is present. The child will grow and these bones will be reshaped in the absence of the deforming pull of a tight sternocleidomastoid muscle.
Copyright 1959 by The Journal of Bone and Joint Surgery, Incorporated