Superior (Transacromial / Saber-Cut) Approach to the Shoulder

What it exposes. The superior approach reaches the shoulder joint from above, passing over the top of the acromion and through the deltoid. It gives direct access to the supraspinatus, the superior glenohumeral joint, the subacromial space, and the acromioclavicular region. Primary indications: - Open rotator cuff repair (historical) - particularly large or retracted tears needing direct superior access

• Acromioplasty and subacromial decompression when performed open
• Acromioclavicular joint procedures - distal clavicle excision (Mumford), AC reconstruction
• Selected proximal humeral and superior glenoid exposures where an anterior route is inadequate
• Tumour involving the superolateral shoulder girdle
• Suprascapular nerve decompression at the transverse scapular ligament (more often posterior or arthroscopic) Why the approach is now limited. Arthroscopic cuff repair, arthroscopic subacromial decompression, and mini-open deltoid-sparing techniques now provide equivalent or superior visualization with far less deltoid morbidity. The extensile transacromial approach, once standard for massive cuff tears, is reserved for the uncommon tear that cannot be mobilized or fixed arthroscopically, for selected revision work, or for tumour. Contraindications: - Pre-existing deltoid deficiency or detachment (no working muscle to split or repair)
• Anterior pathology better served by the deltopectoral approach
• Most degenerative cuff tears (arthroscopy is the standard of care) Alternative approaches: - Deltopectoral approach - the workhorse for anterior shoulder pathology (glenohumeral joint, subscapularis, arthroplasty); does not endanger the deltoid origin
• Anterolateral deltoid-split approach - a more limited split for subacromial work and certain proximal humeral fractures
• Posterior approach - for posterior glenoid, the infraspinatus, and the trapezius-deltoid internervous interval
• Arthroscopic repair - the modern default for cuff tears and subacromial decompression Position & landmarks. Beach-chair (semi-recumbent) is the standard position. The patient sits up roughly 60 to 70 degrees, the shoulder is brought off the edge of the table, and the arm is left free so an assistant can apply traction, rotation, and flexion-extension as needed to deliver the cuff into the wound. A padded headrest, secure torso strapping, and protection of all pressure points (especially the contralateral ulnar nerve and the sacrum) are mandatory; a towel or bolster under the scapula can tilt the shoulder forward. Lateral decubitus is an alternative for some posterosuperior work, but the beach-chair set-up gives the best superior access and is the position examiners expect. Beach-chair safety checklist: - Confirm haemodynamic stability - the seated position can precipitate hypotension; communicate with anaesthesia
• Pad all pressure points and secure the torso to prevent sliding
• Protect the head and neck in a neutral, supported position
• Position the contralateral arm carefully to avoid brachial plexus stretch
• Confirm C-arm access if intra-operative imaging is anticipated
• Plan and rehearse cerebral perfusion considerations for prolonged seated surgery Surface landmarks to mark before draping: - Acromion - palpate its anterior, lateral, and posterior borders; the lateral border is the reference for the axillary-nerve measurement
• Acromioclavicular (AC) joint - the step-off between the distal clavicle and the acromion
• Distal clavicle - marks the anterosuperior boundary
• Coracoid process - anteroinferior reference; the saber-cut incision aims toward it
• Scapular spine - posterior boundary, origin of the posterior deltoid Incision planning. Mark the bony landmarks on the skin before draping so the incision can be centred precisely over the pathology. Review plain radiographs for acromial morphology (Bigliani type), acromiohumeral narrowing, proximal migration of the humeral head, and calcific deposits, and an MRI to characterize tear size, retraction, muscle atrophy, and fatty infiltration - the imaging determines whether the cuff is repairable and whether an extensile open route is justified.

The deltoid-split incision is centred over the supraspinatus. The saber-cut incision runs obliquely across the AC region and can be extended into a deltopectoral approach if anterior access is needed. The transacromial incision is placed so the osteotomy can elevate the acromion with its attached deltoid.

Work down through the deltoid over the top of the acromion, splitting the muscle in the line of its fibres to reach the subacromial bursa and the supraspinatus, or - for a massive retracted tear - osteotomizing the acromion and reflecting it with the deltoid. The defining teaching point is the dissection basis, not an internervous plane.

Deltoid anatomy (the muscle you are splitting): | Feature | Detail | |---------|--------| | Origin | Lateral third of the clavicle, acromion, scapular spine | | Parts | Anterior (clavicular), middle (acromial), posterior (spinal) | | Insertion | Deltoid tuberosity of the humerus | | Nerve supply | Axillary nerve (C5, C6) | | Deep relation | Axillary nerve and posterior circumflex humeral artery run on its deep surface |

What lies beneath. Below the deltoid lies the subacromial bursa, then the rotator cuff - chiefly the supraspinatus as it passes under the coracoacromial arch to its greater-tuberosity insertion. The coracoacromial arch (acromion, coracoacromial ligament, and AC joint) forms the roof over which the cuff glides. The suprascapular nerve enters the supraspinatus from its deep, medial surface, tethering the muscle. Coracoacromial arch and impingement. The arch is a primary restraint to superior migration of the humeral head, and its anterior undersurface is the site of mechanical impingement on the cuff. A hooked (type III) acromion, anteroinferior spurs, and AC joint osteophytes narrow this space. Reshaping the arch (acromioplasty) and decompressing the subacromial space are among the procedures the superior approach was built to perform.

Structures at risk, by layer

Two nerves to name. Examiners expect two nerves. The axillary nerve is at risk during the deltoid split and during subdeltoid dissection - it lies on the deep deltoid surface about 5 cm below the lateral acromion. The suprascapular nerve is at risk when the cuff is mobilized - it is tethered roughly 2 cm medial to the glenoid rim and limits how far a retracted supraspinatus can be pulled laterally. Most traction injuries are neurapraxic and recover, but suprascapular nerve injury denervates the supraspinatus and infraspinatus, compounding the very cuff deficiency the operation set out to treat; both are avoided by gentle technique. How to extend the approach: - Distally - continue the deltoid split down the humeral shaft, always respecting the axillary nerve safe zone; the split's distal limit is the nerve.

• Anteriorly - convert to a deltopectoral approach (useful when anterior glenoid or the lower subscapularis must be reached).
• Medially / posteriorly - toward the scapular spine and supraspinous fossa to expose the supraspinatus belly or the suprascapular notch, taking the deltoid origin off the scapular spine (the trapezius-deltoid interval); the suprascapular nerve and artery at the transverse scapular ligament are at risk here. Closure - the critical step. Meticulous repair of the deltoid origin is the single most important step. A dehisced deltoid after acromioplasty or transacromial osteotomy causes persistent weakness, deformity, and is notoriously difficult to salvage.

Closure principles. Close the deltoid fascia, reapproximate subcutaneous tissue, and close skin. Apply a sling or abduction pillow to unload the repair, and restrict active abduction against resistance until healing - typically about six weeks. Post-operative rehabilitation: - 0 to 6 weeks: Sling or abduction pillow; passive and active-assisted motion only; protect the deltoid origin and any cuff repair; no active abduction against gravity.

• 6 to 12 weeks: Progress to active motion and gentle strengthening as the deltoid repair consolidates; confirm radiographic union of any acromial osteotomy.
• 12 weeks and beyond: Progressive resistance and functional rehabilitation; return to demand activity once strength and motion are restored. The rehabilitation timeline is dictated by the integrity of the deltoid repair and the cuff fixation. If an acromial osteotomy was performed, protect against active abduction and resistive loading until radiographic union is confirmed.

• Open rotator cuff repair - supraspinatus and adjacent cuff, especially retracted tears (historical standard)
• Anterior acromioplasty / open subacromial decompression - removal of the anterior acromial prominence and bony spurs
• Distal clavicle excision (Mumford) - for AC joint arthrosis
• AC joint reconstruction - for AC dislocation
• Suprascapular nerve decompression - release of the transverse scapular ligament
• Selected proximal humeral and superior glenoid work, and tumour resection

Guidelines, Registries & Global Practice

Rotator cuff disease is among the most common upper-limb complaints worldwide, and its management is addressed by major orthopaedic bodies across examination systems. The superior and transacromial approaches are taught as historical and selective exposure techniques rather than the workhorse for degenerative cuff tears. Side-by-side principles (where guidance converges): - The AAOS appropriate-use criteria for rotator cuff symptoms acknowledge arthroscopic and mini-open repair as mainstream options, with open transacromial exposure reserved for selected massive or revision tears.

• BOA and BOAST principles emphasize careful patient selection, deltoid-sparing techniques where possible, and the avoidance of deltoid dehiscence.
• Across regions, the trend is the same: arthroscopic cuff repair and subacromial decompression have displaced the extensile open superior approach, reducing deltoid morbidity. Global practice variation. In well-resourced settings, arthroscopy is the default for most cuff pathology; the open transacromial route survives only for the uncommon irreparable-looking tear that proves immobile arthroscopically. In resource-limited settings, an open deltoid-splitting repair remains a reasonable definitive option when arthroscopy is unavailable, with the same emphasis on protecting the axillary nerve and repairing the deltoid. Consent (globally applicable). Discuss deltoid weakness or dehiscence (the defining risk of this approach), axillary and suprascapular nerve injury, infection, stiffness, failure of cuff healing, and the possibility that an irreparable tear may need reconstruction (tendon transfer) or reverse arthroplasty.