Subscapularis Management in Open Shoulder Surgery

Subscapularis Management in Open Shoulder Surgery, subscapularis, from gray’s anatomy
Subscapularis, from Gray’s Anatomy. Image by Henry Vandyke Carter, Wikimedia Commons, Public domain.

Overview

  • Deltopectoral arthroplasty and open stabilisation need subscapularis takedown and repair
  • Options are tenotomy, lesser tuberosity peel or lesser tuberosity osteotomy
  • Failure causes weakness, anterior instability and poorer outcomes, most after anatomic TSR
  • Test with lift off, belly press and bear hug
  • Subscapularis sparing approaches in selected cases
  • Protocols limit external rotation for about six weeks

Western Health Orthopaedic Registrar presentation – Subscapularis Management in Open Shoulder Surgery by Dr Marc-James Friso

Anatomy

  • Largest rotator cuff muscle, inserting on the lesser tuberosity
  • Upper two thirds of the insertion tendinous, lower third muscular
  • Upper and lower subscapular nerves (C5 and C6)
  • Anterior humeral circumflex vessels (three sisters) mark the inferior border

Management

  • Tenotomy about 1 cm medial to the insertion relies on tendon to tendon healing
  • Peel off the lesser tuberosity allows a medialised repair to gain external rotation
  • Lesser tuberosity osteotomy (LTO) gives bone to bone healing visible on radiographs
  • LTO heals more often than tenotomy, with small differences in patient-reported outcomes
  • A randomised trial of peel versus LTO found no functional difference
  • In reverse arthroplasty, medialised designs dislocated more without repair, lateralised designs less so
  • Sling for about 6 weeks, with external rotation limited to the safe range, around 30 degrees
  • No active or resisted internal rotation or pushing up from a chair for 6 weeks

Complications

  • Failure presents with anterior pain, weak internal rotation and increased passive external rotation
  • Positive lift-off, belly press and bear hug tests
  • Axillary radiograph shows anterior subluxation or LTO displacement
  • Ultrasound, CT or MRI for tendon continuity
  • Chronic irreparable deficiency may need pectoralis major or latissimus dorsi transfer
  • Instability with an anatomical prosthesis is often revised to reverse arthroplasty

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.