Primary reverse TSA in elderly low-demand patients with comminuted 3- or 4-part fractures, head-split patterns or fracture-dislocations | advanced
Surgical Imaging
Location: The axillary nerve exits the quadrilateral space and lies on the deep surface of the deltoid approximately 5-7 cm distal to the acromion. It is vulnerable during deltoid retraction and during humeral preparation.
Risk: Excessive or prolonged retraction of the deltoid or aggressive inferior capsular release can stretch or lacerate the nerve. Nerve injury presents as deltoid weakness and sensory loss over the lateral shoulder.
Fix: Identify the nerve early by palpation or direct visualisation, limit retraction time, and protect it with a Penrose drain or vessel loop during humeral work.
The trap: Placing the baseplate in excessive retroversion or superior tilt leads to scapular notching, reduced range of motion, and early loosening.
The fix: Use preoperative CT to measure glenoid version. Correct retroversion to less than 10 degrees with eccentric reaming or augmented baseplate. Place the baseplate low on the glenoid with 5-10 degrees of inferior tilt. Confirm with image intensifier or navigation.
The trap: Setting the stem too proud prevents anatomic tuberosity reduction; setting it too low reduces deltoid tension and risks instability. Malrotation affects tuberosity healing and rotation recovery.
The fix: Use the pectoralis major tendon insertion as a landmark for stem height (approximately 5.5 cm from the top of the humeral head prosthesis in most systems). Set version to 20-30 degrees retroversion relative to the epicondylar axis or the bicipital groove. Trial reduction of the greater tuberosity must be anatomic before final implantation.
Mechanism: Impingement of the humeral socket on the inferior scapular neck during adduction and external rotation causes progressive bone loss and can lead to baseplate loosening.
Prevention: Inferior placement of the glenosphere (inferior overhang of 2-4 mm), inferior tilt of the baseplate, and use of a lateralised or inferior-offset glenosphere design. Avoid superior placement at all costs.
Risk factors: Excessive deltoid tension from over-lengthening the humerus, poor bone quality in elderly patients, and aggressive postoperative physiotherapy.
Recognition: Sudden onset of pain over the acromion 4-12 weeks postoperatively with loss of active elevation. Radiographs may show a transverse fracture line; CT confirms if plain films are equivocal.
Prevention: Avoid over-tensioning (humeral length should restore but not exceed native length). Protect the acromion with a sling for 4-6 weeks and delay aggressive deltoid strengthening.
Consequence: Failure of tuberosity healing eliminates external and internal rotation recovery and converts the reverse TSA into a pure deltoid-powered elevation device with limited rotation.
Prevention: Anatomic reduction of both tuberosities around the prosthesis, robust autograft from the humeral head packed between tuberosity and shaft/prosthesis, and secure fixation with heavy non-absorbable sutures through bone tunnels and around the prosthesis. Avoid overstuffing the joint.
I.N.D.I.C.A.T.EINDICATE — Indications for Primary Reverse TSA in Proximal Humerus Fracture
D.E.L.T.O.P.E.C.T.O.R.A.LDELTOPECTORAL — Operative Steps for Reverse TSA in Fracture
N.O.T.C.HNOTCH — Prevention of Scapular Notching and Key Complications
Surgical Indications
Absolute Indications
- Comminuted 3- or 4-part proximal humerus fracture in a patient older than 70 years with low functional demand
- Head-split fracture patterns where anatomic reconstruction is impossible
- Fracture-dislocation with rotator cuff tear or tuberosity comminution precluding ORIF
- Pre-existing rotator cuff deficiency or massive irreparable tear with fracture
- Failed ORIF or hemiarthroplasty with tuberosity nonunion or cuff failure in an elderly patient
Relative Indications
- 4-part fracture with poor bone quality where surgeon judges ORIF fixation unreliable
- Valgus-impacted 4-part fracture with greater tuberosity comminution greater than 50%
- Patient preference for single definitive procedure over staged reconstruction
Contraindications
Absolute:
- Active infection
- Severe glenoid bone loss precluding baseplate fixation
- Non-functional deltoid (axillary nerve palsy)
- High-demand younger patient where joint preservation or ORIF is feasible
Relative:
- Moderate glenoid retroversion greater than 20 degrees without augmentation capability
- Poor medical optimisation (uncontrolled diabetes, anticoagulation)
- Cognitive impairment limiting rehabilitation compliance
Evidence for Primary Reverse TSA versus Hemiarthroplasty and ORIF
Functional Outcomes
Primary reverse TSA in selected elderly patients provides reliable elevation (typically 120-140 degrees) even when tuberosities do not heal. Hemiarthroplasty outcomes are highly dependent on tuberosity healing; nonunion rates of 30-50% lead to poor elevation and rotation. ORIF in osteoporotic 4-part fractures carries high reoperation rates for screw cut-out and avascular necrosis.
Key Comparative Evidence
- Primary reverse TSA shows lower reoperation rates than ORIF in patients older than 70 years with complex fracture patterns.
- Elevation is superior to hemiarthroplasty when tuberosity healing is unreliable.
- Rotation recovery remains inferior to anatomic reconstruction when tuberosities heal, but patient satisfaction is high because elevation is functional for activities of daily living.
Decision Threshold
Age greater than 70 years, low demand, and fracture patterns with greater than 50% tuberosity comminution or head-split morphology shift the balance toward primary reverse TSA. In younger or higher-demand patients, ORIF with modern locking-plate constructs or hemiarthroplasty with meticulous tuberosity repair remains preferred when bone quality permits.
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A 78-year-old woman with low functional demand presents with a comminuted 4-part proximal humerus fracture after a fall. CT shows greater tuberosity comminution involving greater than 60% of the fragment and a head-split component. The rotator cuff appears intact on imaging. What is your recommended treatment and why?”
“Six weeks after reverse TSA for a 4-part fracture, a 75-year-old man reports sudden onset of pain over the acromion and loss of active elevation. Radiographs show a transverse acromial fracture. How do you manage this complication?”
“You are planning reverse TSA for a 72-year-old woman with a 4-part proximal humerus fracture. Preoperative CT shows 25 degrees of glenoid retroversion. How do you address glenoid version during surgery and what are the consequences of leaving it uncorrected?”