Fig. 26.1
Cutaneous radiation of pain during irritation of individual structures. (a) Radiation of pain during irritation of intervertebral discs (Modified after Cloward); (b) radiation of pain during irritation of deep musculoligamentous structures in interspinous space (Modified after Feinstein) [6]
As shown by figures, certain sites of cutaneous radiation of pain during irritation overlap. In addition, long-term irritation results in the activation of spinal neurons and diffusion of signal at the spinal cord level, which complicates detection of the exact source of pain based on this single indicator. The given findings can, however, help determine at least approximately the level of involvement, on which clinical examination, imaging methods and ultimately the therapeutic efforts should be focused, without wasting efforts at nonspecific attempts to treat a “painful shoulder”.
26.2.2 Acute and Chronic Pain
A painful condition is regularly associated with a significant limitation of mobility of the affected region, impairment of the quality of life and restriction of self-care activities, which often turn into chronic condition. For clinicians, the concept of chronic pain is rather associated with its duration (pain persisting for more than 4–6 weeks), while physiologists and algesiologists perceive it as a manifestation of inability to control sufficiently and efficiently the respective disorder or pain caused by it, i.e. as a manifestation of central fixation of pain pattern, with unfavourable prognosis.
The opinion supported by algesiologists that chronic pain is a separate entity has not been generally accepted. It is a symptom of a condition which has a certain cause and develops in a certain way. In the authors’ view, it is important to find out the share of the initial, underlying process in long-term pain, as it is closely related to the essential issue, how long it is reasonable to attempt at (using, where appropriate, also non-pharmacological treatment) controlling the underlying process and when and how to combine these procedures with purely analgesic therapy, in order to manage adequately the respective disorder.
Due to close relationship between the neck and shoulder, which is given primarily by common innervation (joint capsule, skin, subcutis and muscles of the shoulder are innervated mainly from C5, C6, and C7 nerve roots – see Fig. 26.2) as well as by muscles connecting the cervical spine and the shoulder girdle, this region is called cervicobrachial, and the pain affecting this region is referred to as cervicobrachial regional syndrome.
Fig. 26.2
Map of radicular innervation of the neck and arm. (Left front view, right rear view)
26.2.3 Defined Entities
Of this “mixed category”, certain well-, or at least better, defined entities may be separated, such as:
Cervical radiculopathy (irritation). It is characterised by radicular radiation of pain, neurological finding of iritation or failure of the given nerve root, with pain culminating at night. Pain caused by damage of C5–C8 radiates into the neck, shoulder and arm (Fig. 26.2).
Lesion or disease of the brachial plexus or spinal cord: requires a detailed neurological assessment, including electrophysiological examination and other supportive methods. Care of this and the previous conditions is the responsibility of neurologists and physiotherapists.
Painful shoulder syndromes “Milwaukee shoulder” and “frozen shoulder” are diagnosed, specified and treated by rheumatologists, orthopaedic surgeons or physiotherapists.
“Milwaukee shoulder” is an entity found almost exclusively in the elderly population. Clinical features include the presence of massive, often hemorrhagic effusions in one or both shoulders which, however, are not inflammatory (confirmed by cytologic examination of joint effusion) and almost do not respond to local application of steroids. Effusion contains hydroxyapatite microcrystals, moving freely in the joint space and tendons (McCarty) (Fig. 26.3), as well as a big amount of enzymes, collagenases and neutral proteases which destruct periarticular soft tissues and often result in tear of the rotator cuff and subchondral osteolysis of the humeral head. The process is relatively painless, and thus the patients seek medical care only in the late stages of the disease when the joint is already severely damaged.
Fig. 26.3
Radiograph of calcification of the supraspinatus tendon
In terms of therapy, this condition is hard to control. We have achieved good results with application of radioisotope (yttrium, rhenium) in the affected joint. The cause of this disorder is unknown.
“Frozen shoulder” is a manifestation of chronic unspecified capsulitis of shoulder, affecting predominantly diabetic patients and patients with disorders of the thyroid gland function. This type of inflammation is initially highly painful and later results in joint capsule fibrosis and more or less limited range of motion.
The disease often heals with a functional handicap [7].
Shoulder arthritis. It is also manifested also by so-called capsular pattern of restriction of movement. It should be examined by rheumatologist for potential borrelia infection developing systemic disease and crystal arthritis and for exclusion of arthritis bacterial in origin. Bacterial infection is usually accompanied by fever and high general inflammation parameters (ESR, CRP) and should be treated by orthopaedic surgeons.
Elderly patients often experience degeneration and spontaneous ruptures of muscles, tendons and bursae in the region of the shoulder (Fig. 26.4). The most frequent is rupture of the long head of the biceps tendon in its intra-articular course (in the bicipital groove on the anterior aspect of the humeral head) or of its part and rupture of the subdeltoid or subacromial bursa. A simple clinical sign of rupture of the biceps tendon is pain on the anterior shoulder and a newly identifiable elastic resistance within the muscle belly. In case of complete rupture, patients are not able to perform arm flexion with hand in supine position. Muscle ruptures are diagnosed by sonography and in case of doubts, MRI is indicated. Elderly patients with this condition are treated predominantly non-operatively; they mostly develop alternative mobility stereotypes.
Fig. 26.4
An 82-year-old woman after spontaneous rupture of the subacromial bursa and rotator cuff
Rupture of the rotator muscles (partial or complete) is quite common in this age group, mostly after a longer period of exacerbating pain of the impingement syndrome nature primarily painful and limited abduction and flexion of the arm with hand in supine position, which signals marked degenerative changes in rotators and failing function of the rotator cuff. Failure of the cuff as a dynamic stabiliser of the humeral head position (Fig. 26.5) is accompanied by cranial subluxation of the humeral head with compression in the subacromial space (impingement syndrome). Long-term impingement causes severe degenerative changes in the glenohumeral and acromioclavicular joints – rotator cuff arthropathy.
