The first acknowledged description of rotator cuff (RC) tears is attributed to J.G. Smith in the London Medical Gazette¹ who described the occurrence of tendon rupture of the shoulder following injury. The four rotator cuff muscles (supraspinatus, infraspinatus, teres minor and subscapularis) fuse to form a tendon that encompasses the humeral head. The rotator cuff contributes to glenohumeral movement and functions as a dynamic stabiliser of the joint, supporting the capsule and preventing excessive anterior and posterior shearing.^2,3

A commonly held view is that the four rotator cuff tendons are separate entities^4–6 and, as a consequence of this, muscle- and tendon-specific tests have been developed.⁷ However, Clark and Harryman⁸ have shown that all four tendons fuse, with fibres of subscapularis and infraspinatus combining with those of the supraspinatus. The clear implication of the anatomical structure is that it is not possible clinically to differentiate individual tendon pathology selectively.⁹

Of the range of shoulder pathologies, disorders of the periarticular soft tissue, including the rotator cuff, are considered to be the most common.¹⁰ The incidence of structural rotator cuff tendon pathology, including full thickness RC tendon tears, increases with age.^11–13 In a systematic review of the efficacy of clinical rotator cuff tests, Lewis and Tennent⁹ concluded that there does not appear to be a correlation between tears and symptoms as research studies have demonstrated substantial numbers of people with asymptomatic shoulders and full function have partial or full thickness RC tendon tears.^11–15 Additionally, there does not appear to be a significant difference in incidence of tears between groups of people with and without shoulder symptoms.¹³ In the 40–49 year age group both groups demonstrated an equal number of tears (58%), while in the 50–59 year age group the incidence of tears in the symptomatic and asymptomatic groups continued to remain equal, increasing to 78%.¹³ It appears that the presence of pain may be of more relevance than the size of the tear.^16–18 Lewis and Tennent (2007)⁹ concluded that making a diagnosis of rotator cuff disease, including symptomatic full thickness tears of the rotator cuff, and determining the cause of the symptoms are difficult.

The spectrum of hypotheses that have been proposed to explain the aetiology of rotator cuff tendon disease including tears is extensive. It includes: extrinsic mechanisms (acromion, coracoid process, superior aspect of the glenoid fossa), intrinsic degeneration, postural abnormalities, glenohumeral instability, dietary insufficiencies and evolution.⁹ It is probable that the cause of tendon pathology is multifactorial, and current diagnostic classifications and aetiological explanations are inadequate.

Treatment for rotator cuff tendon disease ranges from conservative treatment (including exercise, electrotherapy, acupuncture, manual therapy, injection therapy, taping) to surgery. Rotator cuff tendon surgery is thought to be less successful in an elderly population and when the RC tendon tears have retracted past the glenoid rim.^19–21 In this group of patients, treatment options include exercise therapy, attempts at tendon repair and shoulder joint replacement procedures.

Patients with symptomatic shoulders that have radiological evidence of full thickness tears of the rotator cuff experience pain and reduced functional ability. The reduction in function may be substantial, including an inability to dress, attend to personal hygiene and use utensils to eat. Pain may be so severe that sleep is affected. However, there is considerable uncertainty as to why the presence of a structural full thickness tear of the rotator cuff may be associated with disabling pain and loss of function in some individuals and be asymptomatic in others.^11–13 Answering this pivotal question will substantially advance our understanding of shoulder pathology and will help to guide appropriate management and care strategies for patients with symptomatic full thickness tears of the rotator cuff.

Conservative treatment, including exercise therapy, is often offered as the first management approach for patients with full thickness rotator cuff tears. It is essential that recommendations and management guidelines are based, in part, upon the available research. As such, a systematic review of the literature was conducted to synthesise the available research on the effectiveness of exercise therapy for full thickness tears of the rotator cuff.

METHOD

Identification and selection of trials

A literature search of the MEDLINE (1950 to 31.7.06), AMED (1985 to 31.7.06), PEDro (to 31.7.06), EMBASE (1974 to 31.7.06), the Cochrane Library (to 31.7.06) and CINAHL (1982 to 31.7.06) databases was conducted using the search terms: shoulder, rotator cuff, rotator cuff tears, subacromial impingement syndrome, exercise, rehabilitation, physiotherapy, physical therapy, clinical trials, case studies, systematic reviews. With the exception of PEDro, OVID was used to search all databases. This was supplemented by manual searches of reference lists of articles identified in the electronic searches.

Criteria for inclusion of trials

To be included in this review, studies had to be randomised clinical trials (RCT) and observational studies in any language. Patients were required to be skeletally mature human adults who had a clinical diagnosis of full thickness, or massive, or inoperable rotator cuff tears. Studies were required to mention explicitly that at least one treatment group received exercise therapy for the treatment of this condition. Studies were included if the exercise therapy group was administered in isolation or in conjunction with other treatments. In addition, studies were required to report one or more of the following outcome measures: shoulder impairment, shoulder disability, pain, patient-perceived effect/benefit, impact on quality of life.

Assessment of trial quality

Prior to commencing the review it was determined that the quality of any RCTs identified would be assessed using the PEDro scale (http://www.pedro.fhs.usyd.edu.au),²² and the quality of any observational studies identified would be assessed using guidance from the NHS Centre for Reviews and Dissemination.²³ Each included publication was scored independently by both authors. Any disagreements (n = 2) were resolved by consensus. Consensus was achieved on all publications included in the review without the need to resolve disagreements by a third independent reviewer.

RESULTS

Trials included in the review

The search of the databases identified no appropriate RCTs and 111 observational studies, of which 77 were rejected following review of the abstracts. Full text copies of 34 observational studies were obtained and, following a detailed review of these, 24 were rejected as they did not fulfil the inclusion criteria. The reasons for this were: full thickness rotator cuff tears not specified (15 studies) and exercise therapy not specified (9 studies). Following the literature search, no RCTs and 10 observational studies were reviewed by the authors.

Descriptions of all the observational studies included in this review are detailed in table 1.

Table 2 details the methodological quality of the observational studies included in this review.

Participant information, together with inclusion and exclusion criteria and treatment interventions, are detailed in table 3.

A description of the intervention outcome is detailed in table 4.

RESULTS

The mean age of the patients participating in these investigations ranged from 59 to 78 years (youngest 44, oldest 83). In total, 272 patients were included in the 10 investigations reviewed (116 females, 156 males). Within the investigations, subject numbers ranged from one (2 single case studies^31,32) to 54 (retrospective case series study²⁹).

The mean final outcome measurements were taken from a minimum of 7 weeks to a maximum of 7.6 years. The final measurement in four trials was made less than one year after the final treatment (range 7 weeks to 6 months).

In two studies the time from onset of symptoms to commencement of rehabilitation was not stated. In the eight studies where the duration of symptoms prior to commencement of treatment was stated, the time ranged from 1 week to 30 years. The cause of symptoms (traumatic, non-traumatic) was detailed in five investigations, and in five studies no information was provided regarding the causation of symptoms.

The diagnosis of full thickness rotator cuff tendon tears was made by: ultrasound (3 studies), MRI (2 studies), arthrogram (4 studies) and arthroscope (1 study).

Outcome measures used in the trials

The outcome measures used in these studies included: shoulder impairment (8 trials), shoulder disability (9 trials) and pain (9 trials). Other outcome measurements included: Oxford Shoulder Score (1 trial), Constant–Murley Score (2 trials), Modified Constant–Murley Score (1 trial), Shoulder Pain and Disability Index (1 trial), American Shoulder and Elbow Surgeons Score (1 trial), Simple Shoulder Test (1 trial), UCLA Shoulder Rating Score (1 trial), Japanese Orthopaedic Association Score (1 trial), Modified Wolfgang’s Criteria (1 trial), SF 36 (2 trials), SF-12 (1 trial) and patient’s perception (3 trials).

Trial quality

No RCTs were identified for inclusion in this review. Of the 10 observational trials included, two involved single case studies and eight were case series investigations. Two specifically stated they were prospective and two were retrospective investigations. It is possible that the remaining six investigations were prospective but this was not stated as part of the methods. No study stated that the investigators were blinded to the initial or follow-up outcome measurements.

Exercise therapy

Four trials involved an exercise only programme,^24,26,27,31 and six involved exercise in combination with other treatments (slings, analgesics, NSAIDs, corticosteroid injections, therapeutic modalities such as ultrasound, and education). Nine studies involved land-based exercises and one study involved a water-based programme (hydrotherapy). The quality of information relating to the type of exercise, duration, intensity, repetitions and progression varied substantially in the included studies. On the basis of the information provided, it would be possible to repeat the exercise programme from only five of the included investigations.^{24,28,30–32} One study²⁴ advocated exercises for shoulder flexion (aiming to recruit anterior deltoid) and another³⁰ recommended avoiding this movement entirely, preferring to exercise the humeral head depressors and rehabilitate shoulder elevation in the direction of shoulder abduction only. The rationale for both approaches appeared to be hypothetical and not supported by definitive evidence.

DISCUSSION

Appropriately designed and analysed randomised placebo controlled trials are considered to be the most rigorous study design to assess the effectiveness of a clinical investigation.³⁴ Observational studies provide some limited evidence to guide clinical practice. However, in view of the existence of selection bias and other confounding factors, there is concern relating to the validity of observational studies and the ability to generalise the findings of such studies to inform clinical practice. Although a number of assessment tools have been proposed to score the quality of observational studies, they have not been adequately developed or fully validated.³⁵ Additionally, there is no validated scoring system for observational studies.

The literature review for this investigation failed to identify any randomised clinical trials which had investigated the effectiveness of exercise in the management of full thickness tears of the rotator cuff. Ten observational studies that included exercise as part of the therapeutic intervention for full thickness tears of the rotator cuff (8 English, 1 French and 1 German language) were identified. Of these, eight were case series investigations (ranging from 10 to 54 participants) and two were single case studies.

Due to the diversity of study designs, inclusion criteria, interventions, types of exercise, outcome measurements, follow-up times, and home versus clinic-based programmes, it was considered inappropriate to attempt to pool the results.

Overall, the results suggest that exercise therapy (defined as strengthening and stretching), when included as part of a treatment programme, has a beneficial effect for patients who have symptomatic shoulders and radiological or arthroscopic evidence of full thickness rotator cuff tears. It is not possible at present to determine the potential size of that effect with any certainty and although there appears to be a definite benefit of including exercise, it is arguable that, on the basis of the findings, the effect at present should only be considered as modest. It is also not possible to determine if it is exercise alone or exercise in combination with other interventions that offers the greatest benefit. In addition, guidance as to the most appropriate exercise therapy, including duration, intensity and number of repetitions, remains speculative. There is also uncertainty as to when to start and how to progress the exercise programme. There is also no guidance to follow to inform clinicians whether the exercise needs to be specific or general in nature. Additionally, it is unclear why the exercise may be having a beneficial effect. A non-exhaustive list of possibilities includes: pain modulation, teaching other muscles to perform and co-ordinate movement, an unspecified therapeutic effect on the structurally damaged rotator cuff muscles and tendons, placebo, and reducing kinesiophobia and the patient’s uncertainty if the arm should be moved. In addition, the relationship between outcome and upper limb dominance, as well as outcome and onset (traumatic or non-traumatic event), requires further investigation to determine if differences exist between these important variables. There is also uncertainty over how long to offer conservative care before seeking a surgical opinion. Recommendations have ranged from 3 months to 18 months.^29,36–38

Uncertainty exists regarding the advice a clinician should offer patients concerning the benefit of exercise therapy and the size of the full thickness tear. Hawkins and Dunlop (1995)²⁷ reported that a greater number of patients with large (3–5 cm) and massive (>5 cm) full thickness rotator cuff tears eventually choose surgical management than those with small (<1 m) and moderate (1–3 cm) size tears. However, the presence of a massive tear does not imply that surgery is mandatory, as Picolli and Hasson (2004)³² reported substantial improvement in function and pain after 7 weeks in an individual with a 5 cm tear identified on MRI following a traumatic fall down steps.

Other investigations have reported equivocal results relating to the size of the tear and function. McCabe et al (2005)³⁹ reported that patients with massive rotator cuff tears (identified during arthroscopic surgery) had a significant reduction in strength in comparison to the contralateral asymptomatic side when strength was tested at 10° of shoulder abduction. However, no reduction in strength was reported when the shoulder was tested at 90° of shoulder abduction in the plane of the scapula, external rotation at 90° abduction, or during the ‘full can test’. It is possible that weakness identified during clinical tests may be more attributable to pain inhibition than true weakness.^16–18 Ben-Yishay et al (1994)¹⁶ reported significant increases in range of movement and strength in 14 patients (9 with full thickness RC tears) following a subacromial injection. This finding suggests that the presence and size of a tear may be less important than the presence of pain. This may also help to explain why individuals with full thickness tears but without shoulder pain are able to function normally.^11–13

There is uncertainty as to what constitutes best management and treatment for a patient with a symptomatic shoulder with a structural diagnosis of a full thickness rotator cuff tear. Following a retrospective analysis of 50 patients with rotator cuff tears who had undergone surgical repair, Ellman et al (1986)³⁶ proposed that tears (including massive tears) are best treated surgically and that earlier surgery will result in a better outcome than if the operation is delayed, especially with massive recent tears. Others³⁸ have suggested that conservative management, including exercise therapy, for full thickness rotator cuff tears may also be associated with substantial improvement. Bartolozzi et al (1994)³⁸ reported good to excellent improvement in 76% (n = 68) of patients following non-surgical care for rotator cuff tears. Of note, improvement was found to increase significantly as post-treatment follow-up duration increased. This suggests that there may be an element of natural resolution in some patients with rotator cuff tears, which may or may not be associated with the initial treatment. However, these studies,^36,38 as with the studies included in this systematic review, lack the robustness of a prospective, randomised placebo controlled trial with attention to power, allocation concealment and other features that would strengthen the utility of the conclusions that have been reached.

Appropriately designed randomised clinical investigations that address the areas identified as deficiencies in our knowledge base as a result of this review would help to address this lack of understanding and provide clinicians with better and more appropriate information to present to patients to help inform discussions and decisions regarding management and care pathways. For these studies to provide meaningful information, it is imperative that appropriate and validated impairment and disability outcome measures are incorporated into the design. To be able to pool the results from future randomised controlled trials, these studies should endeavour to use the same validated outcome measures.

CONCLUSION

The findings of this review suggest that the inclusion of exercise therapy, either in isolation or as part of a nonoperative package of care for full thickness tears of the rotator cuff, has some benefit. In addition, the findings suggest that it would be appropriate to recommend exercise therapy as a therapeutic option to patients with a symptomatic shoulder with an imaging diagnosis of a full thickness rotator cuff tear of either traumatic or non-traumatic origin. However, there is no definitive guidance as to when to start the programme, what to include in the programme and when to refer for a surgical opinion. This review draws attention to the fact that many diverse exercise approaches with different levels of supervision have been investigated, but that no definitive clinical guidance is possible. As such, it is essential that appropriately designed randomised clinical investigations, using appropriate validated outcome measurements, are conducted to begin to address the considerable deficiencies in our knowledge base regarding best management practice for this common and disabling condition.