Greater Tuberosity Fractures

Greater tuberosity fractures are a clinically important subset of proximal humerus fractures because of their intimate relationship with rotator cuff function. The tuberosity is the attachment point for three of the four cuff tendons, supraspinatus, infraspinatus and teres minor, so a fragment that moves takes the cuff insertion with it.

Who. They account for 15-20% of all proximal humerus fractures, with a bimodal distribution: young males after high-energy injury and elderly females after low-energy falls. The rate is higher in contact sports and falls, and the risk factors are osteoporosis in the elderly, contact sports participation, seizure disorders and alcohol intoxication.

Mechanism. The direct mechanism is a fall onto the lateral shoulder or a direct blow. The indirect mechanisms are forceful abduction with external rotation, avulsion of the tuberosity by the rotator cuff during a dislocation, and hyperabduction injury.

Associated injuries. Look for the injuries that travel with it:

• Anterior shoulder dislocation, in 15-30%
• Rotator cuff tears
• Hill-Sachs lesion
• Bankart lesion

The greater tuberosity is the landmark that determines rotator cuff function and shoulder biomechanics, and its anatomy explains the displacement patterns the fracture produces.

The bone. The tuberosity lies lateral to the articular surface and forms the lateral margin of the bicipital groove; the lesser tuberosity, where subscapularis inserts, lies medial to the groove. The anatomical neck runs between the tuberosities and the head, the surgical neck below the tuberosities. Its blood supply comes from the ascending branch of the anterior humeral circumflex artery, the posterior humeral circumflex artery and the vessels of the rotator cuff tendons.

The cuff attachments. Three facets, three tendons, and the fourth cuff tendon pointedly elsewhere:

The combined footprint is approximately 6cm², which matters when the cuff has to be reconstructed onto it.

The deforming forces. Supraspinatus pulls the fragment superiorly; infraspinatus and teres minor pull it posteriorly. The combined vector is posterior and superior, and posterior-superior displacement is the most common and the most problematic pattern. How far a fragment moves depends on its size, the bone quality, the associated injuries and the degree of rotator cuff involvement.

Why direction matters. A superiorly displaced fragment sits under the acromion and causes subacromial impingement. A posteriorly displaced fragment limits external rotation. Either malunion leaves a functional deficit and pain, which is the primary reason displaced fractures are treated surgically.

Neer's classification by displacement remains the primary system for clinical decision-making. The morphological classification describes what the fragment looks like and influences the choice of fixation, and the direction of displacement predicts what the patient will lose.

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History. The mechanism predicts the associated injuries, so ask for it precisely:

• Fall onto the outstretched hand or the shoulder
• Direct blow to the lateral shoulder
• A dislocation event, and whether and how it was reduced
• Seizure activity
• Motor vehicle accident

The patient reports lateral shoulder pain, an inability to lift the arm and weakness with external rotation, sometimes with a history of dislocation. Three findings are red flags: numbness over the deltoid, which is the axillary nerve; severe weakness, which suggests a complete cuff avulsion; and any vascular compromise.

Inspection and palpation. Swelling sits over the lateral shoulder, with ecchymosis that may extend down the arm, the arm held in adduction and internal rotation and the normal shoulder contour lost. There is point tenderness over the greater tuberosity and crepitus with gentle rotation; palpate for the associated injuries as well.

Movement. Active abduction is limited and painful and external rotation is weak and painful, while passive range may be preserved. External rotation strength is the critical assessment and must be compared with the contralateral side.

• External rotation lag sign, which indicates cuff avulsion
• Hornblower's sign, for teres minor function
• Resisted external rotation strength

Neurovascular assessment. The axillary nerve is the most commonly injured nerve: test deltoid motor function and sensation over the regimental badge area, and document both before and after any manipulation. A high-energy mechanism may injure the brachial plexus, so complete the motor and sensory examination of the upper limb. The axillary artery is at risk with dislocation: check the distal pulses and capillary refill, and consider angiography if there is concern. Document the complete neurovascular examination before any reduction attempt.

Radiographs. The trauma series is three views, and each answers a different question:

• True AP (Grashey): taken perpendicular to the scapular plane, it shows the glenohumeral joint space and identifies the fracture and its displacement
• Scapular Y: the lateral projection of the scapula; confirms reduction and shows anterior or posterior displacement
• Axillary: shows posterior displacement (the crescent sign), identifies a Hill-Sachs lesion and confirms glenohumeral reduction. It is the most important view for assessing displacement
• Velpeau axillary: the alternative when the arm cannot be abducted; the patient leans back over the cassette, which is useful in the emergency setting

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Why the views matter more than it sounds. The whole management algorithm rests on a millimetre measurement, and the commonest view under-reads it. The fragment is pulled posterosuperiorly by supraspinatus and by infraspinatus and teres minor, so a substantial part of the displacement lies in the plane the AP projects along and is foreshortened out of the image. A fracture measured at 3mm on the AP alone can be well beyond 5mm once the posterior component is seen.

The practical consequence. Never accept a below-threshold measurement made on a single AP: the number that decides operation versus sling has to come from an axillary (or Velpeau) view, and from CT where the plain films disagree or the fragment is comminuted.

CT. CT is for surgical planning of the displaced fracture, for assessing fragment size and comminution, for evaluating an associated glenoid injury and for assessing a failed closed reduction. It gives the exact displacement measurement, the fragment size for fixation planning, the bone quality, any Bankart or bony Bankart lesion and the size of a Hill-Sachs lesion. The 3D reconstruction shows the fracture geometry, helps plan the approach and is useful for patient education; CT with 3D reconstruction is standard for surgical planning.

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MRI. MRI is not usually needed acutely. It is reserved for suspected rotator cuff pathology, the chronic or delayed presentation, persistent weakness despite a healed fracture, and pre-operative assessment of cuff quality; consider it if non-operative treatment fails, and it is useful at 6-8 weeks if symptoms persist. It shows a partial or complete cuff tear, muscle quality and atrophy, associated labral pathology and cartilage injury.

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Algorithm

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The decision. Displacement, its direction, and what the patient needs from the shoulder. The standard surgical threshold is 5mm of displacement, lowered to 3mm for overhead athletes and labourers who need full shoulder function, and in the active patient a posteriorly displaced fragment is a strong indication whatever the number, because it blocks external rotation. Elderly and low-demand patients may accept greater displacement once comorbidities and functional goals are weighed.

The threshold is softer than it looks. "Operate over 5mm" is a useful headline that examiners like to probe. Direction matters more than the absolute number, because the functional consequence of the displacement, impingement or a block to external rotation, is what drives the decision: a small superior or posterior displacement in an active or overhead patient can be more significant than a larger displacement tolerated in a low-demand elderly patient. Measurement is unreliable on a single view, which is why the number comes from a true AP plus an axillary, with CT when in doubt, accounting for the cuff's deforming pull. And the threshold is trending down: because even modest superior displacement causes impingement, many authors now use a lower threshold of around 3mm for active patients and reserve the more lenient 5mm tolerance for the elderly and low-demand.

Know what kind of number 3mm is before you defend it. It is a demand-adjusted threshold from expert recommendation, not a displacement at which harm has been demonstrated, and Platzer's 2005 cohort is the reason the general figure stays at 5mm. In 135 non-operatively treated fractures displaced 1 to 5mm, 97% did well, and those over 3mm did only slightly worse with no statistical significance, so the authors recommended non-operative treatment across that whole range. The honest formulation is that 3mm lowers the bar for patients in whom a small loss of external rotation or a little impingement actually costs them something, not that 3mm is where the shoulder starts to fail.

Screw fixation. Reduce the fragment anatomically, hold it with a provisional K-wire and pass the cannulated screw over the wire, adding a washer if the bone quality is poor. Two screws are typical: they control rotation and prevent the fragment toggling. Aim the screws towards the medial calcar, use a lag technique if the bone allows, and bury the head below the cortical surface, because a proud screw head causes impingement.

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Suture anchor fixation. Place the anchors in the anatomic footprint, in the medial cortex, pass the sutures through the rotator cuff, reduce the fragment with traction and tie the sutures over it in a mattress or simple configuration. The cuff tissue provides the purchase, multiple anchors improve the fixation, and augmentation with transosseous sutures is worth considering.

Tension band. A heavy non-absorbable suture is passed through the rotator cuff tendons and through bone tunnels in the shaft, then tied over a bridge of bone, converting distraction to compression. It works in osteoporotic bone, has a low implant profile and is cost effective.

Plate fixation. The plate must not protrude superiorly, or it will impinge under the acromion. Screws into the tuberosity fragment must capture the rotator cuff tendons through bone, and suture augmentation may be used; the exposure requires more extensive soft tissue dissection than a percutaneous screw technique.

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Malunion. The most common complication of non-operative treatment of a displaced fracture. A superior malunion causes subacromial impingement, a posterior malunion an external rotation block, and a combined malunion both. The patient has pain with overhead activity, weakness of external rotation, catching and clicking, and night pain. Treatment is osteotomy and repositioning, or arthroscopic subacromial decompression in mild cases, and severe cases may require reverse shoulder arthroplasty, which is why achieving an anatomic reduction in the displaced fracture matters so much.

Non-union. Rare with appropriate treatment. The risk factors are large fragment displacement, poor blood supply, osteoporosis and inadequate immobilisation, and it presents with persistent pain, weakness and motion at the fracture site. Treatment is revision fixation with bone graft and a rotator cuff repair if needed; consider arthroplasty if severe.

Stiffness. The most common complication overall. The risk rises with prolonged immobilisation; aggressive early motion protocols prevent it while protecting the repair, and established stiffness may need manipulation or release.

Avascular necrosis. Rare with an isolated greater tuberosity fracture; the risk rises with combined patterns, and it is monitored with serial radiographs.

Hardware prominence. Screw heads may cause impingement and may need removal after healing. Avoid proud hardware at the time of surgery.

Rotator cuff failure. May occur with anchor fixation, related to poor cuff tissue quality, and may require revision repair.

Rehabilitation runs in three phases: protect the fixation, restore motion, then restore strength.

Non-operative treatment of the minimally displaced fracture. Union in over 95%, good to excellent outcomes in 85-90% and return to pre-injury function in 80-85%, with a mean Constant score of 85-90, a mean ASES score of 85-90 and return to sport in 85%. Pain resolves by 6-8 weeks, range of motion recovers by 8-12 weeks, strength by 12-16 weeks and full activity is reached at 3-4 months.

Operative treatment of the displaced fracture. Union in over 95% with adequate fixation, good to excellent outcomes in 85-95% and return to pre-injury function in 80-90%, with a mean Constant score of 80-90, a mean ASES score of 85-92 and return to sport in 80-85%. Union takes 8-12 weeks, full range 12-16 weeks and full activity 4-6 months. The complications to quote are stiffness in 5-10%, hardware removal in 10-15% and revision surgery in under 5%.

Prognosis. Patient factors and fracture characteristics both influence the final outcome.

• Favourable: younger age, good bone quality, an anatomic reduction, early surgery within 2 weeks, and compliance with rehabilitation
• Unfavourable: older age, osteoporosis, a delay in treatment over 3 weeks, an associated rotator cuff tear, a comminuted fracture pattern and posterior displacement

Global Epidemiology

Greater tuberosity fractures are best understood within the wider epidemiology of proximal humeral fractures, which are among the most common osteoporotic fractures worldwide. Court-Brown et al. prospectively studied 1027 proximal humeral fractures and found a unipolar age distribution with peak age-specific incidence in women aged 80-89 years, with roughly half of all fractures minimally displaced (PMID 11580125, DOI). Isolated greater tuberosity fractures account for a minority of this group and show a more bimodal pattern - younger patients sustaining high-energy or sporting injuries (frequently as part of an anterior dislocation) and older patients with low-energy falls on osteoporotic bone (Green and Izzi, PMID 14671536, DOI). Mutch et al. reported a mean age of 58 years across 199 isolated greater tuberosity fractures, with a female predominance (PMID 24788500, DOI).

Guideline & Society Guidance

There is no single high-level (RCT-based) guideline dedicated to isolated greater tuberosity fractures; recommendations are derived from proximal humeral fracture guidance and expert reviews. The table below summarises the position of major bodies and the level of supporting evidence.

Registry & Trial Evidence

No national joint registry captures isolated greater tuberosity fracture fixation, because these are bone-and-soft-tissue procedures rather than arthroplasty; registry data (AOANJRR, NJR, AJRR) are relevant only when displaced fracture-dislocations in the elderly proceed to reverse shoulder arthroplasty, where these registries report implant survivorship and revision rates. The randomised-trial evidence base specific to greater tuberosity fractures is sparse; the strongest comparative data remain cohort studies showing better function after fixation of genuinely displaced fragments versus non-operative treatment (Platzer, PMID 18349710, DOI) and excellent non-operative outcomes for minimally displaced (1-5mm) fractures (Platzer, PMID 15963996).

Practice Variation

Practice variation is driven by patient demand and bone quality rather than geography: screw or plate fixation predominates for large split fragments in good bone, whereas suture-anchor or transosseous suture constructs (including arthroscopic suture-bridge techniques) are favoured for comminuted, avulsion-type or osteoporotic fragments (Li et al., PMID 28401278, DOI). Arthroscopic fixation is concentrated in high-volume shoulder units with the requisite expertise. Imaging and specialist access also vary by setting rather than by country: plain radiography and CT are routinely available, whereas MRI access can be more limited outside major centres but is rarely required acutely; telehealth with image transfer increasingly supports regional and rural management with specialist input. In high-income settings, structured falls-prevention programmes help reduce the low-energy osteoporotic fracture burden in the elderly.

Self-Assessment Questions