Symptoms associated with rotator cuff degeneration (subacromial pain) are the most common shoulder problems with non-traumatic onset.
Rotator cuff tendinosis may cause symptoms regardless of whether the tendon is intact or ruptured.
It is important to distinguish symptoms related to non-traumatic rotator cuff rupture from acute symptoms caused by traumatic rupture that can in some cases require even urgent surgical treatment (see Traumatic Tendon Problems of the Shoulder).
The treatment of shoulder tendon problems usually takes several months regardless of the type of treatment chosen.
Incidence
In patients under the age of 50, non-traumatic rotator cuff tendon rupture is rare. In this age group, subacromial pain is often due to changes caused by tendinosis/tendinitis.
The prevalence of degenerative rotator cuff tendon rupture starts to increase after the age of 50: 30% of people aged 60 and as many as 50% of those aged 80 have been found to have a degenerative rotator cuff tendon rupture 6.
Symptoms and findings
Ruptures are often asymptomatic, and it is not yet fully known why they start causing symptoms 35.
Symptoms often develop gradually. A symptom may appear in association with strain but it is often impossible to find a clear predisposing factor.
It may be difficult to assess based on symptoms whether the patient has rotator cuff degeneration or a tendon rupture due to such degeneration.
In either case, there is most often pain in the lateral shoulder and upper arm (subacromial pain) often getting worse when lying down, causing nocturnal discomfort and difficulty sleeping.
In addition to pain, there may be weakness of the infraspinatus or supraspinatus muscles due to pain and/or rotator cuff tendon rupture.
Workup
Clinical assessment
Patients with shoulder symptoms should always be examined with their upper body naked.
If a shoulder tendon problem is suspected, it is essential to pay attention to posture and to any atrophy of the supraspinatus or infraspinatus muscles.
The ranges of active shoulder motion (flexion, abduction, internal and external rotation) should be examined, as well as ranges of passive motion if active motion is restricted.
Testing of rotator cuff muscle strength means testing the strength against resistance, not pain. The strength of the infraspinatus and supraspinatus muscles (picture 1) should be examined separately (picture 2).
The most typical differential diagnostic alternatives include incipient shoulder osteoarthritis and incipient frozen shoulder (in both cases, passive ranges of motion are unaffected in the early stages).
Radiological examination
Shoulder x-ray is the primary radiological examination in patients with shoulder pain. It should be done no later than one month from the onset of symptoms. In patients with rotator cuff degeneration, x-ray findings may be perfectly normal (picture 3).
In prolonged rotator cuff degeneration, x-rays often show sclerosis on the inferior surface of the acromion, degenerative bone cysts in the area of the greater tubercle of the humerus and tendon calcification.
A high riding humerus and decreased subacromial space (cuff arthropathy, picture 4) suggest extensive rotator cuff rupture unsuitable for surgical treatment.
Imaging can subsequently be supplemented by shoulder MRI, as necessary (see Treatment and criteria for referral).
Ultrasonography will provide little added value for diagnosis or for choosing the line of treatment. If the decision is made nevertheless to perform ultrasonography due to regional factors or local guidelines, an x-ray should be taken first, anyway.
Treatment and criteria for referral
The first-line treatment is conservative regardless of whether the patient has rotator cuff degeneration or a resulting tendon rupture 1.
Conservative treatment consists of analgesics and physiotherapy (to control the position and movements of the shoulder girdle) and of paying attention to any contributing ergonomic factors.
Subacromial injection of a glucocorticoid + local anaesthetic can be tried a few times at intervals of 1-2 months.
If there is no response to appropriate conservative treatment in 3-6 months, passive ranges of shoulder motion are unaffected, and x-ray does not show any significant osteoarthritis of the shoulder (picture 5) or decreased subacromial space (picture 4), further diagnostic information on rotator cuff tendon can be obtained by performing MRI of the shoulder, in specialized care, as necessary.
If the rotator cuff tendon shows as intact on MRI, and the long head of the biceps tendon lies intact in its groove or is completely severed, there is no surgical treatment available for the tendon disorder 24.
Surgical treatment can be considered after conservative treatment if MRI shows rupture of the rotator cuff tendon, and no significant fatty degeneration can be seen in the infraspinatus or supraspinatus muscle.
Surgical treatment can also be considered after conservative treatment if the rotator cuff tendon is intact but the long head of the biceps tendon is ruptured or the finding is consistent with its instability (the tendon is situated outside its groove).
If the shoulder x-ray is normal and clinical examination shows restricted passive movement, the patient usually has frozen shoulder Frozen Shoulder. If so, further imaging or assessment for surgery of suspected tendon symptoms is not necessary.
Record in the referral any willingness of the patient to have surgery.
Shoulder surgery requires good cooperation and commitment to treatment after surgery.
The patient should be informed that the treatment of shoulder tendinopathies usually takes several months regardless of the type of treatment chosen.
References
Olkapään jännevaivat [Tendon problems of the shoulder]. A Current Care Guideline. Working group appointed by the Finnish Medical Society Duodecim, the Finnish Society of Physical and Rehabilitation Medicine, and the Finnish Orthopaedic Association. Helsinki: the Finnish Medical Society Duodecim, 2022. (in Finnish) http://www.kaypahoito.fi/hoi50099
Paavola M, Kanto K, Ranstam J et al. Subacromial decompression versus diagnostic arthroscopy for shoulder impingement: a 5-year follow-up of a randomised, placebo surgery controlled clinical trial. Br J Sports Med 2021;55(2):99-107. [PubMed]
Lawrence RL, Moutzouros V, Bey MJ. Asymptomatic Rotator Cuff Tears. JBJS Rev 2019;7(6):e9. [PubMed]
Karjalainen TV, Jain NB, Page CM et al. Subacromial decompression surgery for rotator cuff disease. Cochrane Database Syst Rev 2019;1(1):CD005619. [PubMed]
Minagawa H, Yamamoto N, Abe H et al. Prevalence of symptomatic and asymptomatic rotator cuff tears in the general population: From mass-screening in one village. J Orthop 2013;10(1):8-12. [PubMed]
Yamamoto A, Takagishi K, Osawa T et al. Prevalence and risk factors of a rotator cuff tear in the general population. J Shoulder Elbow Surg 2010;19(1):116-20. [PubMed]