Abstract
The anconeus muscle is susceptible to the development of myofascial pain syndrome. Stretch or impact injuries to the anconeus muscle sustained while playing tennis or with overuse such as excessive handshaking and digging have been implicated in the evolution of anconeus syndrome. In addition, repeated microtrauma may result in the development of myofascial pain in the anconeus muscle. Treatment of anconeus syndrome is focused on blocking the myofascial trigger and achieving prolonged relaxation of the affected muscle. Conservative therapy consisting of trigger point injections with local anesthetic or saline solution is the starting point. Because underlying depression and anxiety are present in many patients suffering from anconeus syndrome, the administration of antidepressants is an integral part of most treatment plans. Pregabalin and gabapentin have also been shown to provide some palliation of the symptoms associated with this painful condition.
Keywords
anconeus syndrome, forearm pain, fibromyalgia, myofascial pain, trigger points, trigger point injection, stretch and spray, antidepressants, pregablin, botulinum toxin
ICD-10 CODE M79.7
The Clinical Syndrome
The anconeus muscle is susceptible to the development of myofascial pain syndrome. Such pain is most often the result of repetitive microtrauma to the muscle caused by such activities as prolonged ironing, handshaking, or digging ( Fig. 42.1 ). Tennis injuries caused by an improper one-handed backhand technique have also been implicated as an inciting factor in myofascial pain syndrome, as has blunt trauma to the muscle.
Myofascial pain syndrome is a chronic pain syndrome that affects a focal or regional portion of the body. The sine qua non of myofascial pain syndrome is the finding of myofascial trigger points on physical examination. Although these trigger points are generally localized to the part of the body affected, the pain is often referred to other areas. This referred pain may be misdiagnosed or attributed to other organ systems, thus leading to extensive evaluation and ineffective treatment. Patients with myofascial pain syndrome involving the anconeus muscle often have referred pain in the ipsilateral forearm.
The trigger point is pathognomonic of myofascial pain syndrome and is characterized by a local point of exquisite tenderness in the affected muscle. Mechanical stimulation of the trigger point by palpation or stretching produces not only intense local pain but also referred pain. In addition, involuntary withdrawal of the stimulated muscle, called a jump sign, is often seen and is characteristic of myofascial pain syndrome. Patients with anconeus syndrome have a trigger point over the superior insertion of the muscle ( Fig. 42.2 ).
Taut bands of muscle fibers are often identified when myofascial trigger points are palpated. Despite this consistent physical finding, the pathophysiology of the myofascial trigger point remains elusive, although trigger points are believed to result from microtrauma to the affected muscle. This trauma may result from a single injury, repetitive microtrauma, or chronic deconditioning of the agonist and antagonist muscle unit.
In addition to muscle trauma, various other factors seem to predispose patients to develop myofascial pain syndrome. For instance, a weekend athlete who subjects his or her body to unaccustomed physical activity may develop myofascial pain syndrome. Poor posture while sitting at a computer or while watching television has also been implicated as a predisposing factor. Previous injuries may result in abnormal muscle function and lead to the development of myofascial pain syndrome. All these predisposing factors may be intensified if the patient also suffers from poor nutritional status or coexisting psychological or behavioral abnormalities, including chronic stress and depression. The anconeus muscle seems to be particularly susceptible to stress-induced myofascial pain syndrome.
Stiffness and fatigue often coexist with pain, and they increase the functional disability associated with this disease and complicate its treatment. Myofascial pain syndrome may occur as a primary disease state or in conjunction with other painful conditions, including radiculopathy and chronic regional pain syndromes. Psychological or behavioral abnormalities, including depression, frequently coexist with the muscle abnormalities, and management of these psychological disorders is an integral part of any successful treatment plan.