Dislocation and hypertrophy of the medial head of the clavicle: An unusual late complication of radical neck dissection.
We report three cases of a rare late complication of neck dissection: anterior dislocation and hypertrophy of the sternal head of the clavicle manifesting as a hard lump in the lower neck. We describe the mode of presentation, etiology, and methods of prevention.
In addition to the various medical complications that can occur following any surgical procedure in the head and neck region, a number of surgical complications can occur, as well. The incidence of surgical complications following neck dissection is reported to range from 13 to 54%, depending on the study and the type of surgical technique. [1,2]
Immediate complications include the development of hematoma, seroma, and infection, which can result in necrosis of the wound or flap. Facial lymphedema is often seen during the immediate postoperative period, but it usually begins to regress within several days, especially when the neck dissection has been performed on only one side. 
Delayed complications include flap necrosis, exposure of the carotid, and carotid rupture. Laryngeal lymphedema can also occur, which necessitates a tracheotomy in certain cases. Some degree of scapular drooping is observed following all types of neck dissection, especially when the spinal accessory nerve has been removed. Another late complication is fracture of the clavicle, which is usually precipitated by mechanical stress.
In this paper, we briefly describe three cases of an anterior dislocation and hypertrophy of the sternal head of the clavicle, which manifested as a hard mass in the lower neck.
Case 1. A 57-year-old woman had experienced a mass in her right lower neck 33 years earlier. At that time, she had been diagnosed with a papillary carcinoma of the thyroid gland. She underwent a total thyroidectomy and a right radical neck dissection, which included an en bloc removal of the sternocleidomastoid muscle on the right. She had experienced no problems related to her neck dissection during the intervening 33 years.
When she came to our institution, she said that for several weeks she had noticed a slowly growing, nonpainful mass in her neck. Examination revealed a hard, nonmobile, nontender mass that measured 3 x 4 cm in the medial right lower neck (figure 1A). The entire right clavicle was dislocated anteriorly, and the mass was located at the level of the clavicular sternal head. She reported that prior to the onset of her recent symptoms, she had been carrying heavy objects with her right hand. An x-ray of the right clavicle confirmed the clinical diagnosis (figure 1B). The patient was reassured and advised to minimize weight-bearing with the right arm.
Case 2. A 73-year-old man had undergone a total laryngectomy and left radical neck dissection more than 30 years earlier. He reported that in recent years, a hard, nonpainful mass had developed over the medial aspect of the left clavicle. Throughout its long, insidious onset, the mass had not been problematic, and the patient ignored it. Physical examination revealed a large, hard mass over the sternal head of the left clavicle (figure 2). The entire clavicle on that side had bulged forward. The examination was otherwise negative.
Case 3. A 37-year-old woman had noticed that a continuous and progressive bulging over the lower aspect of the right side of the neck had developed several months after she had undergone a right radical neck dissection. Physical examination revealed a significant anterior dislocation of the entire right clavicle, accompanied by severe scarring of the ipsilateral neck (figure 3).
Crile first described the classic radical neck dissection in 1906.  Since then, many refinements have been advocated to reduce postsurgical functional disability while preserving oncologic safety. These modifications include techniques to preserve various functionally important anatomic structures, particularly the spinal accessory nerve, the jugular vein, the sternocleidomastoid muscle, and the cervical plexus of the sensory nerves. 
Removal of the sternocleidomastoid muscle and accessory nerve can place increased stress on the clavicle, shoulder, and sternoclavicular joint and result in variable degrees of weakness. Weakness is often overcome with physiotherapy. The sternocleidomastoid muscle is important in stabilizing and supporting the medial end of the clavicle. Following standard radical neck dissection, the force of prolonged traction eventually leads to disruption of the sternoclavicular joint capsule.
Despite advancements in surgical skills and techniques, neck dissection still causes a considerable amount of morbidity. Among the most common immediate postoperative complications are the development of hematoma, seroma, and infection, with resultant necrosis of the wound or flap. Although facial lymphedema is frequently seen during the immediate postoperative period, it normally begins to regress within several days. Delayed complications include flap necrosis, exposure of the carotid artery, laryngeal lymphedema, and functional disabilities.
The most disturbing sequela of traditional radical neck dissection is loss of shoulder function as a result of a resection of the spinal accessory nerve and denervation of the trapezius muscle.  Efforts to preserve the spinal accessory nerve have gained widespread approval, as various studies have shown that rates of subsequent nodal recurrence do not differ significantly among the various modified neck dissection techniques. [7,8]
Recent studies have also compared the effect of various types of neck dissection on the function of the trapezius muscle and the range of motion of the shoulder girdle mechanism. Remmler et al reported that patients who underwent supraomohyoid neck dissection experienced significantly better measurable shoulder function than did those who underwent radical and modified radical neck dissection. Moreover, Remmler et al found that modified radical neck dissection caused less shoulder dysfunction than did radical neck dissection.
Other long-term complications of neck dissection involve the clavicle. In addition to dislocation, another complication involving the clavicle is fracture, which is usually precipitated by mechanical stress; seven such cases have been diagnosed at the University of Florida.
In patients with dislocation and hypertrophy of the sternal head of the clavicle, the presenting symptom is a hard mass at the site of the dissection, which can be mistaken for a recurrence of cancer. The mass often enlarges over a period of several weeks or months. Enlargement, which is a sign of hypertrophy of the medial head of the clavicle, seems to be instigated by use of the ipsilateral arm.
Palpation of the mass will reveal it to be fixed and relatively hard. Inspection of the clavicle will demonstrate considerable anterior dislocation compared with the opposite side. Elevation of the shoulder usually results in a reduction of the dislocation.
Resection of the sternocleidomastoid muscle during radical neck dissection appears to eliminate a major source of support for the clavicle, and the bone becomes dislocated as a result of forces exerted on it by motion of the ipsilateral arm. As the medial head of the clavicle continually rubs against the sternum, it becomes considerably hypertrophic. Dislocation occurs because the clavicle is unopposed and unsupported by the sternocleidomastoid muscle. Hypertrophy is a long-term process and often occurs 25 years or more after surgery.
From the Head and Neck Unit, Royal Marsden Hospital, London. Reprint requests: Jamal A. Shreif, MD, 4th Floor, Blue Building, Abdel Aziz St., Beirut, Lebanon.
(1.) Taylor JM, Mendenhall WM, Parsons JT, Lavey RS. The influence of dose and time on wound complications following post-radiation neck dissection. Int J Radiat Oncol Biol Phys 1992;23:41-6.
(2.) Razack MS, Baffi R, Sako K. Bilateral radical neck dissection. Cancer 1981;47:197-9.
(3.) Million RR, Cassisi NJ, Mancuso AA, et al. Management of the neck for squamous cell carcinoma. In: Management of Head and Neck Cancer: A Multidisciplinary Approach. 2nd ed. Philadelphia: J.B. Lippincott, 1994.
(4.) Crile GW. Excision of cancer of the head and neck: With special reference to the plan of dissection based on 132 patients. JAMA 1906;47: 1780-6.
(5.) Sobol S, Jensen C, Sawyer W, et al. Objective comparison of physical dysfunction after neck dissection. Am J Surg 1985; 150:503-9.
(6.) Remmler D, Byers R, Scheetz J, et at. A prospective study of shoulder disability resulting from radical and modified neck dissections. Head Neck Surg 1986;8:280-6.
(7.) Brandenburg JH, Lee CY. The eleventh nerve in radical neck surgery. Laryngoscope 1981;91: 1851-9.
(8.) Jesse RH, Ballantyne AJ, Larson D. Radical or modified neck dissection: A therapeutic dilemma. Am J Surg 1978;136:516-9.
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|Comment:||Dislocation and hypertrophy of the medial head of the clavicle: An unusual late complication of radical neck dissection.|
|Author:||Evans, Peter Rhys|
|Publication:||Ear, Nose and Throat Journal|
|Article Type:||Brief Article|
|Date:||Feb 1, 2000|
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