The long head of biceps at the shoulder: a scoping review

BACKGROUND

This review aimed to explore the available literature to update our understanding of the long head of biceps (LHB) at the shoulder. Synthesise our findings to identify emergent themes and knowledge gaps to inform future research and management directions.

METHODS

PubMed, Embase, Cinahl, SportDiscus, CENTRAL, and Web of Science were searched from inception to 31st December 2021. Articles were included if they referenced adult participants > 18 years of age and were written in English.

RESULTS

214 articles were included in the final analysis, and results were categorised into six emergent themes: (1) Anatomy - Normal anatomical variation of the biceps from aberrant origins, third and fourth accessory heads, and an absence of the LHB tendon (LHBT) are not necessarily benign, with shoulder pain and instability a commonly reported theme. (2) Function - Bicep's role in glenohumeral elevation and stability in healthy shoulders is minimal. In contrast, LHB has a more significant role in shoulder stability and humeral head depression in subjects with rotator cuff failure or an absent LHBT. (3) Pathology - There is an association between LHB tendinopathy, rotator cuff disease, LHBT instability and occult rotator cuff tears. Early recruitment and hyperactivity of the LHB in subjects with symptomatic rotator cuff tears and instability suggest a potential compensatory role. (4) Assessment - The limited diagnostic utility of special orthopaedic tests in assessing LHBT pathology was a consistent theme. The utility of magnetic resonance imaging and ultrasound to identify full-thickness tendon tears and instability of the LHBT was moderate to high. However, the utility of clinical tests and imaging may be underestimated due to arthroscopy's limitations in fully visualising the proximal LHBT. (5) Non-Surgical Management - Ultrasound-guided injections into the biceps sheath show greater accuracy and patient outcomes than blinded injections; however, the entry of injectate into the intraarticular glenohumeral joint may have unwanted complications. (6) Surgical management - For the surgical management of biceps pathology with or without rotator cuff pathology, both biceps tenodesis and tenotomy report similar improvements in pain without any significant adverse effect on strength or function. Tenodesis favoured higher overall constant scores and a lower incidence of Popeye deformity and cramping arm pain, with tenotomy trending to be more cost and time effective. For patients with a healthy LHBT, rotator cuff repair with adjunctive tenodesis or tenotomy fails to provide additional clinical improvements compared to rotator cuff repair in isolation.

CONCLUSIONS

The scoping review highlights the variability of biceps anatomy, which is not necessarily benign and suggests a minimal role of the LHB in shoulder elevation and stability in healthy individuals. In contrast, individuals with rotator cuff tears experience proximal humeral migration and demonstrate hyperactivity of the LHB, suggesting a potential compensation role. The observed prevalence of LHBT pathology with rotator cuff tears is well established; however, the cause-and-effect relationship between LHBT pathology and rotator cuff disease is undetermined. The diagnostic utility of clinical tests and imaging to exclude LHBT pathology may be understated due to the limitations of arthroscopy to visualise the proximal LHBT fully. Rehabilitation programs for the LHB are understudied. Similar post-surgical clinical outcomes are observed for tenodesis and tenotomy for biceps and rotator cuff-related shoulder pain. Subjects undergoing biceps tenodesis are less likely to have cramping arm pain and a Popeye deformity than patients undergoing biceps tenotomy. The significance of routine surgical removal of the LHBT and sequelae on rotator cuff tear progression to failure and long-term shoulder function is unknown, and further research is required.

PRE-REGISTRATION

OSF: https://osf.io/erh9m.

Physical tests for shoulder impingements and local lesions of bursa, tendon or labrum that may accompany impingement

BACKGROUND

Impingement is a common cause of shoulder pain. Impingement mechanisms may occur subacromially (under the coraco-acromial arch) or internally (within the shoulder joint), and a number of secondary pathologies may be associated. These include subacromial-subdeltoid bursitis (inflammation of the subacromial portion of the bursa, the subdeltoid portion, or both), tendinopathy or tears affecting the rotator cuff or the long head of biceps tendon, and glenoid labral damage. Accurate diagnosis based on physical tests would facilitate early optimisation of the clinical management approach. Most people with shoulder pain are diagnosed and managed in the primary care setting.

OBJECTIVES

To evaluate the diagnostic accuracy of physical tests for shoulder impingements (subacromial or internal) or local lesions of bursa, rotator cuff or labrum that may accompany impingement, in people whose symptoms and/or history suggest any of these disorders.

SEARCH METHODS

We searched electronic databases for primary studies in two stages. In the first stage, we searched MEDLINE, EMBASE, CINAHL, AMED and DARE (all from inception to November 2005). In the second stage, we searched MEDLINE, EMBASE and AMED (2005 to 15 February 2010). Searches were delimited to articles written in English.

SELECTION CRITERIA

We considered for inclusion diagnostic test accuracy studies that directly compared the accuracy of one or more physical index tests for shoulder impingement against a reference test in any clinical setting. We considered diagnostic test accuracy studies with cross-sectional or cohort designs (retrospective or prospective), case-control studies and randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Two pairs of review authors independently performed study selection, assessed the study quality using QUADAS, and extracted data onto a purpose-designed form, noting patient characteristics (including care setting), study design, index tests and reference standard, and the diagnostic 2 x 2 table. We presented information on sensitivities and specificities with 95% confidence intervals (95% CI) for the index tests. Meta-analysis was not performed.

MAIN RESULTS

We included 33 studies involving 4002 shoulders in 3852 patients. Although 28 studies were prospective, study quality was still generally poor. Mainly reflecting the use of surgery as a reference test in most studies, all but two studies were judged as not meeting the criteria for having a representative spectrum of patients. However, even these two studies only partly recruited from primary care.The target conditions assessed in the 33 studies were grouped under five main categories: subacromial or internal impingement, rotator cuff tendinopathy or tears, long head of biceps tendinopathy or tears, glenoid labral lesions and multiple undifferentiated target conditions. The majority of studies used arthroscopic surgery as the reference standard. Eight studies utilised reference standards which were potentially applicable to primary care (local anaesthesia, one study; ultrasound, three studies) or the hospital outpatient setting (magnetic resonance imaging, four studies). One study used a variety of reference standards, some applicable to primary care or the hospital outpatient setting. In two of these studies the reference standard used was acceptable for identifying the target condition, but in six it was only partially so. The studies evaluated numerous standard, modified, or combination index tests and 14 novel index tests. There were 170 target condition/index test combinations, but only six instances of any index test being performed and interpreted similarly in two studies. Only two studies of a modified empty can test for full thickness tear of the rotator cuff, and two studies of a modified anterior slide test for type II superior labrum anterior to posterior (SLAP) lesions, were clinically homogenous. Due to the limited number of studies, meta-analyses were considered inappropriate. Sensitivity and specificity estimates from each study are presented on forest plots for the 170 target condition/index test combinations grouped according to target condition.

AUTHORS' CONCLUSIONS

There is insufficient evidence upon which to base selection of physical tests for shoulder impingements, and local lesions of bursa, tendon or labrum that may accompany impingement, in primary care. The large body of literature revealed extreme diversity in the performance and interpretation of tests, which hinders synthesis of the evidence and/or clinical applicability.

Protocol for determining the diagnostic validity of physical examination maneuvers for shoulder pathology

BACKGROUND

Shoulder complaints are the third most common musculoskeletal problem in the general population. There are an abundance of physical examination maneuvers for diagnosing shoulder pathology. The validity of these maneuvers has not been adequately addressed. We propose a large Phase III study to investigate the accuracy of these tests in an orthopaedic setting.

METHODS

We will recruit consecutive new shoulder patients who are referred to two tertiary orthopaedic clinics. We will select which physical examination tests to include using a modified Delphi process. The physician will take a thorough history from the patient and indicate their certainty about each possible diagnosis (certain the diagnosis is absent, present or requires further testing). The clinician will only perform the physical examination maneuvers for diagnoses where uncertainty remains. We will consider arthroscopy the reference standard for patients who undergo surgery within 8 months of physical examination and magnetic resonance imaging with arthrogram for patients who do not. We will calculate the sensitivity, specificity and positive and negative likelihood ratios and investigate whether combinations of the top tests provide stronger predictions of the presence or absence of disease.

DISCUSSION

There are several considerations when performing a diagnostic study to ensure that the results are applicable in a clinical setting. These include, 1) including a representative sample, 2) selecting an appropriate reference standard, 3) avoiding verification bias, 4) blinding the interpreters of the physical examination tests to the interpretation of the gold standard and, 5) blinding the interpreters of the gold standard to the interpretation of the physical examination tests. The results of this study will inform clinicians of which tests, or combination of tests, successfully reduce diagnostic uncertainty, which tests are misleading and how physical examination may affect the magnitude of the confidence the clinician feels about their diagnosis. The results of this study may reduce the number of costly and invasive imaging studies (MRI, CT or arthrography) that are requisitioned when uncertainty about diagnosis remains following history and physical exam. We also hope to reduce the variability between specialists in which maneuvers are used during physical examination and how they are used, all of which will assist in improving consistency of care between centres.

A survey of the McKenzie Classification System in the Extremities: prevalence of mechanical syndromes and preferred loading strategies

BACKGROUND

Classification of patients with extremity problems is commonly based on patho-anatomical diagnoses, but problems exist regarding reliability and validity of the tests and diagnostic criteria used. Alternatively, a classification system based on patient response to repeated loading strategies can be used to classify and direct management.

OBJECTIVE

The purpose of this study was to investigate the prevalence of McKenzie's classification categories among patients with extremity problems and the loading strategies used in their management.

DESIGN

This was a prospective, observational study.

METHODS

Thirty therapists among 138 invited (response rate=22%) with a Diploma in Mechanical Diagnosis and Therapy (MDT) were identified from the McKenzie Institute International registry and recruited worldwide to complete an e-mailed questionnaire. They provided data about their age, years qualified, years since gaining a diploma, and practice, and prospectively provided data on anatomical site and categorization for 15 consecutive patients with extremity problems.

RESULTS

Data were gathered on 388 patients; classification categories were as follows: derangement (37%); contractile dysfunction (17%); articular dysfunction (10%); and "other" (36%), of which 20% were postsurgery or posttrauma. Exercise management strategies and syndrome application varied considerably among anatomical sites. Classification categories remained consistent in 85.8% of patients over the treatment episode.

LIMITATIONS

These findings are not generalizable to therapists who are not experienced with use of MDT in the extremities.

CONCLUSIONS

This study demonstrates that trained clinicians can classify patients with extremity problems into MDT classifications and that these classifications remain stable during the treatment episode. Further work is needed to test the efficacy of this system compared with other approaches, but if derangements are as common as this survey suggests, the findings have important prognostic implications because this syndrome is defined by its rapid response to repeated movements.

Testing procedures for SLAP lesions of the shoulder involving contraction and torsion of biceps long head and glenohumeral glides

Testing procedures for SLAP lesions of the shoulder can combine resisted elbow flexion, forearm pronation and supination, and glenohumeral glides. These procedures reproduce symptoms by increasing biceps long head active tension or passive torsion, and by placing the shoulder in an unstable position. We compared activation of biceps long head and pain intensity, between supinated and pronated forearm positions, between different glides, and between individuals with and without shoulder impairment. A case control study. Twelve participants with suspected SLAP lesions and twelve with no history of shoulder injury volunteered. Electromyography measured muscle activity in biceps long head, normalised against maximum voluntary isometric contraction (MVIC). Subjective pain intensity scores were recorded. Biceps long head activity was greater in forearm supination (mean 39% MVIC) than pronation (mean 24% MVIC), but pain was higher in pronation (mean 4.5/10) than supination (3.2/10). Biceps long head activity was greater when testing without a glide, but there was no difference in pain comparing the glide conditions. The impaired group experienced more pain (mean 3.9/10) than controls (mean 0.3/10) but there was no difference in shoulder muscle activity. No one combination of testing procedures appeared to be diagnostic of SLAP lesions in our sample. This study supports the theory that biceps long head acts as a stabiliser of the shoulder, and suggests that clinical testing procedures for SLAP lesions may need to inhibit biceps long head activity. The addition of glides to SLAP testing procedures did not affect the reproduction of pain.

A meta-analysis examining clinical test utility for assessing superior labral anterior posterior lesions

BACKGROUND

The reported accuracy of clinical tests for superior labral anterior posterior lesions is extremely variable. Pooling results from multiple studies of higher quality is necessary to establish the best clinical tests to use.

HYPOTHESIS

Certain clinical tests are superior to others for diagnosing the presence or absence of a superior labral anterior posterior lesion.

STUDY DESIGN

Meta-analysis.

METHODS

A literature search of MEDLINE (1966-2007), CINAHL (1982-2007), and BIOSIS (1995-2007) was performed for (labrum OR labral OR SLAP OR Bankart) AND (shoulder OR shoulder joint OR glenoid) AND (specificity OR sensitivity AND specificity). Identified articles were reviewed for inclusion criteria. Sensitivity and specificity values were recorded from each study and used for meta-analysis.

RESULTS

Six of 198 identified studies satisfied the eligibility criteria. Active compression, anterior slide, crank, and Speed tests were analyzed using receiver operating characteristic curves. The accuracy of the anterior slide test was significantly inferior to that of the active compression, crank, and Speed tests. There was no significant difference in test accuracy found among active compression, crank, and Speed tests. Between studies, methodological scores did not significantly affect sensitivity and specificity values.

CONCLUSION

The anterior slide test is a poor test for detecting the presence of a labral lesion in the shoulder. Active compression, crank, and Speed tests are more optimal choices. Clinicians should choose the active compression test first, crank second, and Speed test third when a labral lesion is suspected.

Diagnostic accuracy of clinical tests for superior labral anterior posterior lesions: a systematic review

STUDY DESIGN

Systematic literature review.

OBJECTIVES

To conduct a systematic review of case series and clinical trials that investigate the diagnostic accuracy of clinical tests for superior labral anterior posterior (SLAP) lesions.

BACKGROUND

Primary contact practitioners are often presented with shoulder problems and use a battery of clinical tests to reach a diagnosis. Early detection of SLAP pathology may lead to more optimal interventions and better outcomes for patients.

METHODS AND MEASURES

The OVID search interface was utilized with MEDLINE, AHMED, CINAHL, and SPORTDiscus databases searched from 1996-2006. Studies were retrieved that included patients with shoulder pain who underwent at least 1 clinical shoulder test for SLAP lesions. For an article to be included in this review, the results of the clinical tests needed to be compared with findings on arthroscopy. Quality of the manuscripts included in this review were rated using the QUADAS appraisal tool, so comparisons could be made across studies.

RESULTS

Seventeen published manuscripts fit the inclusion/exclusion criteria and were used for this review. Eight studies were found to be of high quality. Within these 8 studies, 1 group of authors reported high diagnostic accuracy values for the crank test: sensitivity, 91% (95% confidence interval [CI], 76%-97%); specificity, 93% (95% CI, 79%-88%); positive likelihood ratio, 13.6 (95% CI, 3.6-52.1); and negative likelihood ratio, 0.1 (95% CI, 0.0-0.3). One study on the resisted supination external rotation test also scored high on the QUADAS and reported diagnostic accuracy values of 83% (95% CI, 66-92), 82% (95% CI, 52-95), 4.6 (95% CI, 1.3-16.1), and 0.20 (95% CI, 0.1-0.5), respectively. Of significance is the fact that the majority of papers reporting highly accurate clinical diagnostic tests were of low quality with the results not supported by other authors.

CONCLUSION

It appears that no single test is sensitive or specific enough to determine the presence of a SLAP lesion accurately. Further research is required to determine whether subgrouping of patients by mechanism of injury or the type of SLAP lesion may improve diagnostic accuracy. Determining the diagnostic accuracy of a combination of 2 or more tests is also needed.

An evaluation of the anatomic basis of the O'Brien active compression test for superior labral anterior and posterior (SLAP) lesions

It has been suggested that the positive position of the O'Brien test (shoulder flexion, horizontal adduction, and internal rotation) tensions the bicipital labral complex relative to the negative position (shoulder flexion, horizontal adduction, and external rotation). This study measured active and passive tension in the long head of biceps in the 2 positions of the O'Brien test to validate the proposed anatomic basis of the test. Active tension was measured using surface electromyography of the long head of biceps in 12 healthy young adults. Passive tension was measured using a load cell attached to the intracapsular tendon of the long head of biceps in 5 cadaver specimens. Active and passive tension were higher in the negative position, thus refuting the proposed anatomic basis of the test. Although there may be an alternative basis for the test, the failure to support the proposed anatomic basis may partly explain the variable likelihood ratios obtained in clinical accuracy studies of the O'Brien test. The results of this study reinforce the need for anatomic validation during the development of clinical testing procedures.