Overview
This lecture covers the assessment and diagnosis of the painful or injured shoulder. It works from the fundamentals of shoulder assessment (history, pain mapping, examination) and functional shoulder anatomy (why a joint built for extreme mobility has so little bony stability), then uses age at presentation as a diagnostic filter, and finally works through five common pathologies: instability, cuff impingement, cuff tear, frozen shoulder and arthritis. Fracture is listed but explicitly not covered. It closes with five clinical scenarios applying the framework.
Fundamentals of shoulder assessment
History structure:
- Presenting complaint: pain, stiffness, instability, weakness.
- History of presenting complaint: was there an injury, or was onset insidious?
- Impact: activities of daily living, sleep, driving, work, leisure.
- Treatment so far, past medical history, family history, social history.
Pain is characterised with S.O.C.R.A.T.E.S: Site, Onset, Character, Radiation, Alleviating factors, Timing, Exacerbating factors, Severity.
Examination follows Look, Feel, Move, Special tests, Neurology, Circulation.
Shoulder pain mapping
Pain distribution differs by diagnosis (Bayam et al., Am J Orthop 2011;40(7):353-358):
- Impingement syndrome: lateral shoulder and upper arm, plus a small area at the elbow.
- Rotator cuff tear: lateral shoulder only.
- Glenohumeral OA: broad area over the whole shoulder and upper arm.
- Instability: posterior/lateral upper arm.
- AC joint OA: small patch at the top of the shoulder.
- Calcific tendinitis: lateral upper arm.
Differential diagnosis: thinking beyond the shoulder
A surgical sieve is applied with the mnemonic CDTINMENHIR: Congenital, Degenerative, Traumatic, Inflammatory/Infective, Neoplastic, Metabolic, Endocrine, Nutritional, Haematologic, Iatrogenic, Radiation. For the shoulder, Degenerative, Traumatic and Inflammatory/Infective are the commonest categories, but keep an open mind.
Shoulder presentations can also arise from outside the shoulder:
- Neoplasia (bone lesion)
- Cervical spine pathology
- Diaphragmatic irritation
- Cholecystitis
- Cardiac ischaemia
The summary slide deliberately repeats these referred-pain causes alongside the five common pathologies: both sets should be considered together.
Functional shoulder anatomy
What the shoulder has to do: place the hand “in space” and then hold it there in a very stable fashion. It is also a weight-bearing joint (rugby tackle impact loading, gymnast on rings taking full body weight, overhead lifting, javelin throwing), so it needs a very high degree of stability as well as mobility.
Facts about the shoulder girdle:
- Most mobile joint in the body
- Made up of 4 joints
- Very little bony stability
- 17 muscles attach to the scapula
The glenoid and labrum
The glenoid is a shallow socket. The labrum increases the effective depth of the glenoid concavity, deepening the socket for the humeral head and contributing to glenohumeral joint stability alongside the capsule and the surrounding rotator cuff attachments.
Muscle groups, from proximal to distal
- Stable core: abdominals anteriorly, lumbar and gluteal muscles posteriorly. Shoulder function depends on a stable core as its base.
- Scapular stabiliser muscles: trapezius, levator scapulae, rhomboids (cervical/thoracic spine to medial scapular border), serratus anterior (ribs to scapula).
- Primary GHJ movers: deltoid (clavicle/acromion/scapular spine to humerus), pectoralis major, latissimus dorsi. These large muscles produce gross shoulder movement, as distinct from the smaller rotator cuff muscles.
- Rotator cuff muscles: supraspinatus, infraspinatus, teres minor, subscapularis. Subscapularis lies anteriorly and infraspinatus posteriorly, wrapping around the humeral head. They envelop the head and centre it in the glenoid, acting as dynamic stabilisers.
Shoulder capsule
The capsule provides stability at extremes of motion while allowing range of motion. Structures shown: biceps tendon, superior and middle glenohumeral ligaments, anterior and posterior bands, axillary pouch and the inferior glenohumeral ligament complex (IGHL). In throwing, the IGHL tightens to stabilise at the extreme of external rotation and abduction, during both the cocking phase and the throw.
Range of motion assessed: forward flexion, extension, abduction, external rotation, internal rotation.
Relating age to diagnosis
Data from the University of Washington Shoulder Service, an elective tertiary referral service, 272 patients with a definite diagnosis (fractures and neurological problems excluded).
Age 13 to 30 years: traumatic instability 61%, atraumatic instability 31%, then small slices of RA, partial thickness cuff tear, calcific tendinitis and AVN. Instability dominates.
Age 31 to 45 years: partial thickness cuff tear 24%, frozen shoulder 20%, traumatic instability 16%, atraumatic instability 13%, full thickness cuff tear 13%, DJD 7%, RA 4%, calcific tendinitis 3%. A more even spread across cuff pathology, frozen shoulder and instability.
Over 45 years: full thickness cuff tear 40%, degenerative joint disease 29%, frozen shoulder 22%, partial thickness cuff tear 4%, traumatic instability 2%, plus small calcific tendinitis and AVN slices. Degenerative pathology dominates and instability is now rare.
A second age ladder is given within cuff disease: RC tendonitis/subacromial bursitis under 30s; calcific tendonitis 30-40s; tendinosis/partial cuff tears 40-50s; cuff tear 50-60s; cuff arthropathy 70s.
Instability
Presentation types
- Anterior dislocation: traumatic, sports-related, teenagers to 30s, and common at 95% of dislocations.
- Posterior dislocation: infrequent at 5%, caused by an epileptic fit or electrocution.
Two clinical settings:
- Acute, in trauma clinic: reduced in the Emergency Department, painful, arm in a sling. The capsule/ligament injury is the damaged area anteriorly.
- Chronic, in shoulder clinic: atraumatic laxity and subluxations, not painful, no support used. The posterior band and inferior glenohumeral ligament complex are implicated.
Examination
- Look: abnormal shoulder contour, muscle wasting
- Feel: tenderness, muscle spasm
- Move: good range of motion, scapular winging/dyskinesia
- Tests: rotator cuff strength, apprehension, relocation, general laxity
Acute management of anterior dislocation
In the Emergency Department: assess, document, analgesia IV, oxygen, sedation IV, then reduction by manipulation using the Kocher method, in four steps:
- Traction on the flexed elbow with adduction
- External rotation of the arm
- Adduction and forward flexion of the shoulder, bringing the elbow across the body
- Internal rotation to complete relocation of the humeral head into the glenoid
Post-reduction: sling for 2-3 weeks, analgesia, gradual early mobilisation, physiotherapy.
Chronic symptoms: investigations
X-rays, arthrogram, MR arthrogram.
Associated injuries
- Labral lesion (Bankart lesion): defect of the anteroinferior labrum.
- Fracture of the humeral head (Hill-Sachs lesion): posterolateral humeral head impaction fracture, which engages against the glenoid rim in external rotation.
- Fracture of the glenoid (bony Bankart): a fracture fragment off the anteroinferior glenoid rim, causing glenoid bone loss.
- Rotator cuff tear: in older patients over 40. In this group, dislocation is more often associated with a cuff tear than with a Bankart lesion.
Management
Initially all patients are managed non-operatively with physiotherapy: rotator cuff and core strengthening, scapula stabilising. The younger the patient, the higher the risk of recurrent dislocation.
If non-operative management fails, surgical management (arthroscopic anchor-suture repair of the anteroinferior labrum, i.e. Bankart repair, with preparation of the glenoid rim). Post-operative milestones:
- 6 week sling
- 8-10 weeks no driving
- 12 weeks no heavy lifting
- Return to sport: 12 weeks non-contact, 6 months contact
Cuff disease: impingement syndrome
Pain originating from the sub-acromial space. Common and mostly transient. The subacromial space is reduced and the supraspinatus tendon and bursa become inflamed and impinged.
Causes are divided into intrinsic and extrinsic:
- Intrinsic: tendon vascularity, watershed area, tendon degeneration, cuff dysfunction.
- Extrinsic (external “pressure”): type of acromion, coraco-acromial ligament, clavicular spur/osteophyte.
History and examination
History: age; dominance and occupation; pain (onset, location, radiation, night pain); reach and stretch; painful arc; neurology; neck pain; what analgesia, physiotherapy and injections have been tried.
Examination:
- Look: contour, wasting, scapula position
- Feel: tenderness over the bursa and ACJ
- Move: active and passive range of motion, painful arc, rotator cuff strength
- Tests: Hawkins, Jobe’s
Investigations
Radiographs: AP shoulder and Garth view (apical oblique) or outlet view, to assess acromial shape and the subacromial region. Then ultrasound or MRI depending on shoulder mobility.
Treatment
Non-operative first, for a minimum of 6 months: rest with activity modification, pain relief, physiotherapy exercises, and corticosteroid injections into the subacromial space (up to two).
Operative: arthroscopic or open subacromial decompression, comprising subacromial/subdeltoid bursectomy, acromioplasty (removal of the acromial spur), release of the coraco-acromial ligament, release of calcific deposits, and excision of an infraclavicular spur.
Cuff disease: cuff tear
Presentation
Age 50-60s. “Grey hair = cuff tear”. Either acute traumatic or chronic attritional. Weakness and pain.
Examination:
- Look: contour, wasting
- Feel: tenderness in the subdeltoid region
- Move: active range of motion much less than passive, weak rotator cuff (supraspinatus, infraspinatus, teres minor, subscapularis)
- Tests: supraspinatus test, Gerber’s lift-off, Horn blower’s
Important
Active range of motion much less than passive range of motion is the discriminating finding for a cuff tear, and separates it from frozen shoulder and glenohumeral OA, where the restriction is global and affects passive movement too.
Investigations
Radiographs; ultrasound if good range of motion; MRI if very stiff.
Treatment
- Acute: urgent investigation, early physiotherapy, early reassessment, early intervention; plus rest, analgesia and a sling.
- Chronic: physiotherapy with anterior deltoid strengthening, steroid injections, wait-and-see approach.
Surgery: arthroscopic or open repair of the rotator cuff using suture anchors. Re-tear rate is 20-40% at 1 year.
Frozen shoulder
Presentation
40-50s, more females at a ratio of 1:2, and not uncommonly bilateral (often not simultaneously). Gradual severe pain. Associated with diabetes, lipid and endocrine disease, and Dupuytren’s.
Pathology
Contracture and thickening of:
- the coraco-humeral ligament
- the rotator interval (between supraspinatus and subscapularis)
- the axillary fold (inferior glenohumeral ligament)
This produces a decrease in joint volume. It is not adhesion.
Stages: freezing, frozen, thawing. It is a self-limiting disease but the process can take 3-4 years. Nearly all patients have residual stiffness and 15% have residual pain.
History and examination
History: pain at rest, pain at night, anterior pain, stiffness, and normal radiographs.
Examination: global restriction in range of motion, with external rotation less than 50% of normal.
Lack of passive external rotation has a differential diagnosis of:
- Locked posterior dislocation
- Glenohumeral arthritis
Treatment
Non-operative: gentle movements, analgesia, physiotherapy, glenohumeral steroid injections, fluoroscopic distension.
Operative: manipulation under anaesthetic, or arthroscopic capsular release (arthrolysis), which addresses synovitis in the rotator interval and the thickened middle glenohumeral ligament. Aftercare is a short period in a sling, excellent pain control, aggressive physiotherapy, and “mind over matter”.
Glenohumeral osteoarthritis
Presentation
Over 60s. An uncommon location for OA. Covers osteoarthritis, rheumatoid arthritis and post-traumatic arthritis. Gradual onset with intermittent exacerbations.
History: gradual onset, pain at rest and at night, stiffness, intermittent exacerbations, functional difficulties.
Examination: asymmetry, wasting, limitation of external rotation, global restriction in movement, pain throughout the range of motion.
Investigation
Radiographs, looking for OA features.
Treatment
Non-operative: analgesia, physiotherapy, glenohumeral steroid injection.
Operative: shoulder replacement (arthroplasty), in increasing order of extent:
- Resurfacing (humeral head cap)
- Total shoulder arthroplasty (humeral stem plus glenoid component)
- Reverse polarity shoulder arthroplasty, where the ball-and-socket geometry is reversed and the centre of rotation moves medially and inferiorly, used when the rotator cuff is deficient
Clinical scenarios
Five cases apply the framework. Each is followed by a five-option diagnosis slide (instability, cuff impingement, cuff tear, frozen shoulder, arthritis) with boxes marked X.
Warning
On the diagnosis slides it is not stated whether an X denotes the correct answer or an excluded option. The marks are recorded below exactly as they appear; interpretation was left to the lecture discussion.
Case 1: 56y man, 2 month history of right shoulder and arm pain. Pain anterolateral shoulder radiating down the anterolateral arm almost to the elbow. Wakes several times every night. Managing ADLs but pain with the arm away from the side. Managing work but a lot of painful driving. Not managing biking and gym. Hurt the shoulder at the gym lifting a 20kg kettlebell from the ground to overhead, with sudden pain and a feeling that “something happened”, then gradual increase in pain over the next few days. Marks: X against cuff impingement, cuff tear and frozen shoulder.
Case 2: 34y man, 3 week history of left shoulder and arm pain. Pain anterolateral shoulder radiating to the upper anterolateral arm, constant and disturbing sleep. Managing ADLs but with difficulty. A builder, only managing the admin aspects of his work. Not managing hunting and fishing. Pain started after heavy work pulling down a fence, with gradual increase in intensity, now pretty miserable. Past medical history: Crohn’s disease on pentasa. Mark: X against cuff impingement.
Case 3: 63y man with marked weakness of the left shoulder after a fall 2 weeks ago. Unable to lift the arm away from the side because of weakness. Some pain over the lateral shoulder and proximal third of the arm, wakes if he lies on the right side, but pain manageable. Was changing a caravan tyre, tripped over the damaged tyre and fell onto an outstretched arm, with immediate pain, then bruising extending down the arm a few days later, and since then cannot use the arm away from the side. Otherwise well, no prior shoulder problems, right hand dominant, largely admin work in his landscaping business. Mark: X against cuff tear.
Case 4: 48y woman, 4 month history of pain and stiffness in the right shoulder. Pain lateral shoulder and arm, at times into the forearm. Wakes several times every night. Has to do her bra up in front and cannot undo it, cannot hang washing, does everything she can with the left hand. Difficult to drive. Managing computer work, not involved in sports. Slipped and fell on ice onto the outstretched right hand, pain right away with gradual increase over subsequent weeks, and progressive stiffness. Mark: X against frozen shoulder.
Case 5: 56y male with left shoulder pain and stiffness. Involved in a motor vehicle accident with significant head injury, intubated and ventilated in ICU for 3 weeks, with several grand mal seizures over that time. Made a good recovery, now 8 weeks post injury. Reasonably comfortable with the arm at the side, but pain on moving the arm away from the side, felt generally around the shoulder with some radiation into the lateral proximal arm. No other health problems, continues anti-epileptic medication. Mark: X against instability. The transcript notes that this mechanism (prolonged seizures and immobility post-MVA) is classically associated with posterior dislocation, consistent with instability being marked.
Summary points
The 5 common pathologies are instability, cuff impingement, cuff tear, frozen shoulder and OA. Remember the differential diagnosis (including the referred causes) and the age correlation.
Self-test
- List the four presenting complaints the history framework uses for the shoulder, and state what SOCRATES stands for.
- Distinguish the pain distribution of impingement syndrome from that of a rotator cuff tear on pain mapping.
- List the three categories of the CDTINMENHIR surgical sieve that are commonest for shoulder pathology.
- List five causes of shoulder pain arising from outside the shoulder.
- State the four facts given about the shoulder girdle, and explain the functional problem they create.
- Explain how the labrum contributes to glenohumeral stability.
- Name the four rotator cuff muscles and explain their stabilising role in one sentence.
- Explain what the inferior glenohumeral ligament complex does during throwing.
- Predict the two most likely diagnoses in a 20 year old presenting to a shoulder clinic, with the approximate proportions given.
- State the single commonest diagnosis in the over-45 age band and its proportion.
- List the age ladder for cuff disease from tendonitis through to cuff arthropathy.
- Distinguish anterior from posterior shoulder dislocation by frequency and mechanism.
- Describe the four steps of the Kocher method of reduction.
- List the four injuries associated with shoulder instability, and say which one becomes more likely in patients over 40.
- Distinguish the intrinsic from the extrinsic causes of impingement syndrome, giving the items in each group.
- State the minimum duration of non-operative treatment for impingement, and list what that non-operative treatment involves.
- Explain why active range of motion is much less than passive range of motion in a cuff tear, and state what this finding helps you exclude.
- Describe the pathology of frozen shoulder, including the three structures involved and why it is explicitly not called adhesion.
- Describe the natural history of frozen shoulder, including the stages, the time course and the residual deficits.
- A patient has lost passive external rotation. Give the two differential diagnoses to consider besides frozen shoulder.
- Distinguish the three types of shoulder arthroplasty, and state when the reverse polarity design is used.
- Integrative: a 63 year old falls onto an outstretched arm and two weeks later cannot lift the arm away from his side, with bruising down the arm. Using age, mechanism and examination findings, explain which of the five pathologies this points to and how you would investigate it.
Answers
Reveal answers
- Pain, stiffness, instability and weakness. SOCRATES: Site, Onset, Character, Radiation, Alleviating factors, Timing, Exacerbating factors, Severity.
- Impingement gives pain over the lateral shoulder and upper arm plus a small area at the elbow; a cuff tear gives pain over the lateral shoulder only.
- Degenerative, Traumatic and Inflammatory/Infective.
- Neoplasia, cervical spine pathology, diaphragmatic irritation, cholecystitis and cardiac ischaemia.
- It is the most mobile joint in the body, made up of 4 joints, has very little bony stability, and has 17 muscles attaching to the scapula. It must place the hand in space and then hold it there stably, and also act as a weight-bearing joint, so it must deliver a very high degree of stability despite minimal bony constraint, which falls to the soft tissues and muscles.
- The glenoid is a shallow socket; the labrum increases the effective depth of the glenoid concavity, deepening the socket the humeral head sits in.
- Supraspinatus, infraspinatus, teres minor and subscapularis. They envelop the humeral head (subscapularis anteriorly, infraspinatus posteriorly) and centre it in the glenoid, acting as dynamic stabilisers.
- It tightens at the extreme of external rotation and abduction, during both the cocking phase and the throw, providing stability at the extreme of motion.
- Traumatic instability (about 61%) and atraumatic instability (about 31%) in the 13 to 30 year band.
- Full thickness cuff tear, 40%.
- RC tendonitis/subacromial bursitis under 30s; calcific tendonitis 30-40s; tendinosis/partial cuff tears 40-50s; cuff tear 50-60s; cuff arthropathy 70s.
- Anterior dislocation is common (95%), traumatic, sports-related, and occurs in teenagers to 30s. Posterior dislocation is infrequent (5%) and occurs with an epileptic fit or electrocution.
- (1) Traction on the flexed elbow with adduction; (2) external rotation of the arm; (3) adduction and forward flexion of the shoulder, bringing the elbow across the body; (4) internal rotation to complete relocation of the head into the glenoid.
- Labral lesion (Bankart), humeral head fracture (Hill-Sachs), glenoid fracture (bony Bankart), and rotator cuff tear. Cuff tear becomes more likely over 40, where dislocation is more often associated with a cuff tear than with a Bankart lesion.
- Intrinsic: tendon vascularity, watershed area, tendon degeneration, cuff dysfunction. Extrinsic (external pressure): type of acromion, coraco-acromial ligament, clavicular spur/osteophyte.
- Minimum 6 months. Rest with activity modification, pain relief, physiotherapy exercises, and up to two corticosteroid injections into the subacromial space.
- The cuff is torn and weak, so the patient cannot generate active elevation, while the examiner can still move the joint through range passively. A global restriction affecting passive movement too would instead point to frozen shoulder or glenohumeral arthritis.
- Contracture and thickening of the coraco-humeral ligament, the rotator interval (between supraspinatus and subscapularis) and the axillary fold (inferior glenohumeral ligament), producing a decrease in joint volume. The slide states explicitly that it is not adhesion: the problem is capsular contracture and reduced joint volume.
- Stages are freezing, frozen and thawing. It is self limiting but the process can take 3-4 years. Nearly all patients have residual stiffness and 15% have residual pain.
- Locked posterior dislocation and glenohumeral arthritis.
- Resurfacing (a humeral head cap), total shoulder arthroplasty (humeral stem plus glenoid component), and reverse polarity shoulder arthroplasty, in which the ball-and-socket geometry is reversed and the centre of rotation is moved medially and inferiorly. The reverse design is used when the rotator cuff is deficient.
- Age 50-60s plus a traumatic fall onto an outstretched arm, bruising, and marked weakness with inability to lift the arm away from the side, points to an acute rotator cuff tear (this is Case 3, marked as cuff tear). Examination would be expected to show subdeltoid tenderness and active range of motion much less than passive, with weak cuff testing (supraspinatus test, Gerber’s lift-off, Horn blower’s). Investigate with radiographs, then ultrasound if range of motion is good or MRI if very stiff. Acute tears warrant urgent investigation, early physiotherapy, early reassessment and early intervention.