High-yield overview

Deltopectoral Approach | Tenotomy vs Peel vs Lesser-Tuberosity Osteotomy | Bone-to-Bone Healing Wins

3Established takedown techniques

Bone-to-boneStrongest healing (LTO)

Axillary n.At risk at the inferior border

6 weeksRepair protection period

Critical Must-Knows

Deltopectoral interval is the internervous plane (deltoid = axillary nerve; pectoralis major = pectoral nerves)
Axillary nerve lies at the inferior border of the subscapularis - protect during capsular release and inferior retraction
Lesser-tuberosity osteotomy gives bone-to-bone healing - the most reliable subscapularis restoration
Subscapularis failure causes anterior instability, internal-rotation weakness and a positive belly-press
Restore tension and version - an overtight subscapularis limits external rotation; a loose one fails

When & Why

What it is. Subscapularis management in shoulder arthroplasty is the controlled detachment and repair of the subscapularis tendon from the lesser tuberosity during anatomic glenohumeral arthroplasty through the deltopectoral approach. The subscapularis arises from the subscapular fossa of the scapula, crosses the anterior glenohumeral joint, and inserts on the lesser tuberosity; the bicipital groove separates this insertion from the greater-tuberosity insertions of supraspinatus, infraspinatus and teres minor. The tendon must be taken down to enter the joint and deliver the humeral head, and the chosen takedown-and-repair technique directly governs postoperative internal-rotation strength, the belly-press and lift-off examination, and anterior stability. Three established techniques exist: tenotomy, subscapularis peel and lesser-tuberosity osteotomy. Indications. - Anatomic total shoulder arthroplasty for glenohumeral osteoarthritis with an intact, repairable rotator cuff

Shoulder hemiarthroplasty for arthritis or avascular necrosis when the glenoid is preserved
Selected proximal humeral fractures managed through the deltopectoral approach (the tuberosity is already fractured, so a separate osteotomy is not performed)
Revision shoulder arthroplasty requiring re-exposure of the glenohumeral joint Contraindications to anatomic arthroplasty (a different strategy is needed): - Irreparable massive rotator cuff tear with cuff-tear arthropathy - reverse total shoulder arthroplasty is preferred, and a deficient subscapularis cannot be managed in the standard way
Severe subscapularis fatty infiltration or tear at the index operation - peel or osteotomy may not be feasible
Active infection Alternative exposure. The anterosuperior (deltoid-on) approach is used by some surgeons for anatomic arthroplasty and leaves the subscapularis largely undisturbed, but the deltopectoral approach remains the workhorse exposure taught in examinations and is the focus of this page.

Why the technique matters

The subscapularis is the only anterior rotator cuff muscle and the primary internal rotator, a dynamic anterior stabiliser and a depressor of the humeral head. Its integrity drives the belly-press and lift-off tests and anterior stability. Subscapularis failure produces anterior instability, weakness and a poor outcome - and is largely preventable with a sound repair.

Why not always tenotomy?

Tendon-to-tendon healing (tenotomy) is the least reliable interface. A peel restores tendon-to-bone healing, and a lesser-tuberosity osteotomy restores bone-to-bone healing - the strongest of the three. The healing hierarchy is the core biomechanical reason to move from a simple tenotomy toward a peel or an osteotomy.

Comparing the three techniques. The three options differ in how the tendon is separated from bone and, crucially, in the healing interface they create.

Tenotomy vs Subscapularis Peel vs Lesser-Tuberosity Osteotomy
Technique	How the tendon is taken down	Healing interface	Repair construct	Relative strength
Tenotomy	Tendon cut about 1 cm medial to the lesser tuberosity	Tendon-to-tendon (or tendon-to-bone)	End-to-end sutures, bone tunnels or suture anchors	Weakest
Subscapularis peel	Tendon elevated sharply off the lesser-tuberosity footprint	Tendon-to-bone	Suture anchors or transosseous tunnels at the footprint	Intermediate
Lesser-tuberosity osteotomy	A bone fragment of the lesser tuberosity raised with the tendon	Bone-to-bone	Cerclage sutures around the humeral stem and neck, plus figure-of-eight	Strongest

Healing hierarchy. Reliability follows a clear order: bone-to-bone (osteotomy) is stronger than tendon-to-bone (peel), which is stronger than tendon-to-tendon (tenotomy). This single fact is the rationale for choosing a peel or an osteotomy over a simple tenotomy, and it is the most commonly asked viva point on the topic. How to choose. A peel or lesser-tuberosity osteotomy is preferred when subscapularis integrity is critical - typically a younger, higher-demand patient - because of superior healing. A tenotomy remains acceptable in lower-demand patients and is the simplest and fastest option; Z-lengthening is added to a tenotomy only when the subscapularis is tight and limits external rotation. An osteotomy is avoided in fracture arthroplasty, where the tuberosity is already fractured and should be repaired directly. A deficient or irreparable subscapularis shifts the decision toward a reverse total shoulder arthroplasty rather than an anatomic design.

The Exposure

Work down through the deltopectoral interval, protect the axillary nerve at the inferior border, take the subscapularis down by the chosen technique, deliver and prepare the joint, then repair the tendon with a construct matched to the takedown and close loosely.

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Image Needed: Clinical PhotoHigh Priority

Intra-operative diagram of the deltopectoral approach to the anterior shoulder showing the internervous interval between deltoid (retracted laterally) and pectoralis major (retracted medially), the cephalic vein in the groove, the conjoined tendon retracted medially, and the subscapularis exposed over the lesser tuberosity with the axillary nerve marked at its inferior border.

Context: A verified image is being sourced for this exposure.

Pending image generation or sourcing

Exposure sequence

Step 1Position, landmarks and incision

Beach-chair (semi-upright) position with the arm draped free so an assistant can rotate and traction the humerus; interscalene block plus general anaesthesia
Pad all pressure points (sacrum, heels, contralateral elbow), secure the head neutral with eyes protected, and plan C-arm access if imaging is needed
Palpate and mark the coracoid (medial border of the dissection), the acromion and anterolateral corner (superior extent), the deltopectoral groove, and the bicipital groove and lesser tuberosity
A longitudinal deltopectoral incision from just below the coracoid toward the deltoid insertion, 10 to 15 cm long, placed slightly lateral to the coracoid so the deep interval opens directly into the groove

Step 2Develop the deltopectoral interval

Deepen through subcutaneous fat to fascia and develop the interval between deltoid (laterally, axillary nerve) and pectoralis major (medially, pectoral nerves) - a true internervous plane
Identify the cephalic vein in the groove and either preserve and retract it laterally with the deltoid or ligate it cleanly
Open down to the clavipectoral fascia and incise it lateral to the conjoined tendon

Step 3Expose the anterior shoulder

Retract the conjoined tendon (short head of biceps and coracobrachialis) medially with the coracoid
Ligate the anterior humeral circumflex vessels as they are encountered inferiorly
The subscapularis and anterior capsule are now exposed over the front of the joint; identify the biceps tendon in its groove as a landmark
Externally rotate the arm to put the subscapularis under tension and bring the lesser tuberosity into view

Step 4Find and protect the axillary nerve (critical)

Before any takedown, palpate the axillary nerve along the inferior capsule where it wraps around the surgical neck, at the inferior border of the subscapularis
Keep all retractors on bone; never place a retractor blindly deep to the inferior subscapularis
Perform any inferior capsular release under direct vision

Step 5Take down the subscapularis (the key step)

Detach the tendon from the lesser tuberosity using the chosen technique: tenotomy (cut about 1 cm medial to the insertion), subscapularis peel (elevate sharply off the footprint), or lesser-tuberosity osteotomy (raise a bone fragment with the tendon)
Incise the capsule in line with, or separately from, the subscapularis and enter the glenohumeral joint
Deliver the humeral head into the wound by extension and external rotation so preparation can proceed

Step 6Prepare the humerus and the glenoid

Use the bicipital groove and native retroversion to plan the humeral head osteotomy, cut in about 20 to 30 degrees of retroversion relative to the epicondylar axis so the prosthetic head sits anatomically and the subscapularis repair is tensioned correctly; prepare the canal and trial the stem and head
Retract the humeral head posteriorly to expose the glenoid; address the labrum, biceps anchor and osteophytes, then prepare and trial the glenoid
Assess soft-tissue tension, version and stability with the trials in place before final fixation

Step 7Repair the subscapularis (the construct)

Repair using the construct matching the takedown: transosseous bone tunnels or suture anchors for tenotomy or peel, or cerclage sutures (typically two heavy non-absorbable sutures around the humeral stem and neck, plus figure-of-eight) for a lesser-tuberosity osteotomy
Set the tension so the arm rests in slight external rotation without strain on the repair and without slack
Re-check tension and humeral version after fixation

Step 8Closure and immobilisation

Close the deltopectoral interval loosely (a tight closure can constrain motion)
Close the subcutaneous layer with absorbable suture and the skin with sutures or a subcuticular absorbable monofilament
Apply a sterile dressing and a sling or shoulder immobiliser with the arm in neutral to slight external rotation to off-load the repair

Protect the axillary nerve at the inferior border

The axillary nerve runs along the inferior border of the subscapularis and then wraps around the surgical neck of the humerus. It is the single most important structure at risk during subscapularis takedown, inferior capsular release and inferior retraction. Protect it by staying on bone, by palpating it along the inferior capsule, by never placing a retractor blindly deep to the inferior subscapularis, and by performing any inferior release under direct vision. Injury weakens deltoid abduction and teres minor external rotation.

Internervous plane nuance

The deltopectoral approach uses the deltoid (axillary nerve) / pectoralis major (pectoral nerves) internervous plane. The subscapularis (upper and lower subscapular nerves) is then the structure deliberately taken down - it is not itself an internervous interval. Examiners commonly ask for the internervous plane (deltoid versus pectoralis major) and then for the structure that must be divided to enter the joint (the subscapularis).

Dangers & Extensions

Structures at risk, by layer

Danger structures and how to protect them
Layer	Structure at risk	Protection
Superficial	Cephalic vein in the deltopectoral groove	Identify in the groove; retract laterally with the deltoid or ligate cleanly
Deep medial	Musculocutaneous nerve (enters coracobrachialis 3 to 8 cm distal to the coracoid)	Gentle retraction of the conjoined tendon; stay on its lateral aspect
Deep inferior	Axillary nerve (inferior border of the subscapularis, around the surgical neck)	Stay on bone; palpate during inferior release; no blind inferior retractors
Capsular inferior	Anterior humeral circumflex artery and veins	Controlled coagulation or ligation as encountered inferiorly
Bony landmark	Biceps tendon in the bicipital groove	Identify and protect, or tenodese as planned

Extensile options. Extend proximally along the groove toward the coracoid and clavicle to reach the rotator interval, the coracoid, the conjoined tendon and the acromioclavicular joint (useful for combined rotator-cuff repair or coracoplasty). Extend distally along the humeral shaft toward the deltoid insertion to reach the proximal humeral diaphysis (rarely needed for arthroplasty, but useful in fracture or revision with stem extension). The posterior cuff and posterior glenoid are not addressed by this approach alone and may require adjunct windows or repositioning in complex revisions. Postoperative protection of the repair (approximately 6 weeks). - Sling or shoulder immobiliser, with the arm in neutral to slight external rotation

Passive and active-assisted forward flexion as prescribed, with pendulums
Limit passive external rotation beyond the safe intra-operative range
Avoid active internal rotation against resistance (for example, pushing up from a chair) for 6 weeks Rehabilitation phases. - Phase 1 (0 to 6 weeks): protection and passive or active-assisted motion; pendulums; no resisted internal rotation
Phase 2 (6 to 12 weeks): progressive active motion and gentle strengthening; restore rotation
Phase 3 (3 months and beyond): progressive resistance and return to function Complications | Complication | Prevention | Management | |--------------|------------|------------| | Subscapularis failure / anterior instability | Sound repair, correct tension and version, 6-week protection | Bracing; revision repair; pectoralis major transfer for chronic insufficiency | | Axillary nerve injury | Stay on bone, palpate the nerve, no blind inferior retractors | Observe for neurapraxia; explore if no recovery; rehabilitation | | Musculocutaneous nerve injury | Gentle medial retraction of the conjoined tendon | Observe; most recover; rehabilitation | | Stiffness | Early controlled motion within limits | Physiotherapy; manipulation under anaesthesia or release if persistent | | Infection | Aseptic technique, prophylactic antibiotics | Irrigation and debridement; component retention or revision as indicated | | Osteotomy nonunion or migration (LTO) | Precise technique, secure cerclage | Revision fixation if symptomatic |

Procedures Through This Approach

Anatomic total shoulder arthroplasty - the principal operation done through this exposure
Shoulder hemiarthroplasty for arthritis or avascular necrosis with the glenoid preserved
Selected proximal humeral fracture fixation or arthroplasty (the tuberosity is already fractured, so no separate osteotomy)
Revision shoulder arthroplasty - re-exposure of the glenohumeral joint
Not addressed by this approach alone: the posterior cuff and posterior glenoid (may require adjunct windows or repositioning in complex revisions)

Viva & Exam Focus

During anatomic shoulder arthroplasty through the deltopectoral approach, the subscapularis must be taken down from the lesser tuberosity to enter the glenohumeral joint, and the chosen repair governs postoperative internal-rotation strength, the belly-press examination and anterior stability. Three established techniques exist. Tenotomy cuts the tendon and repairs it tendon-to-tendon or tendon-to-bone; it is simple but has the weakest healing. A subscapularis peel elevates the tendon off its footprint and repairs it tendon-to-bone with anchors or transosseous tunnels. A lesser-tuberosity osteotomy (Gerber) raises bone with the tendon and fixes it with cerclage, healing bone-to-bone - the strongest interface. The healing hierarchy is bone-to-bone stronger than tendon-to-bone stronger than tendon-to-tendon. The axillary nerve at the inferior border of the subscapularis is the critical at-risk structure and is protected by staying on bone and avoiding blind inferior retractors.

Mnemonic

SUBSCAPSUBSCAP - the three techniques and healing

Subscapularis

the only anterior cuff muscle

Under the deltoid

through the deltopectoral interval

Bone-to-bone healing

the goal of a lesser-tuberosity osteotomy

Stay on bone

to protect the axillary nerve

Cerclage fixation

for the lesser-tuberosity osteotomy

Anchors or tunnels

for the subscapularis peel

Protect the repair

for 6 weeks

Mnemonic

DANGERDANGER - structures at risk

Deltoid

retracted laterally; axillary nerve deep to it

Axillary nerve

at the inferior border of the subscapularis

Musculocutaneous nerve

enters coracobrachialis 3 to 8 cm distal to the coracoid

Cephalic vein

in the deltopectoral groove; preserve or ligate

Biceps tendon

identified in the bicipital groove

Retractors on bone

never placed blindly deep to the inferior subscapularis

Exam Viva Scenarios

Practise clinical reasoning and management decisions out loud

Viva scenarioAdvanced

Clinical prompt

“During an anatomic total shoulder arthroplasty through the deltopectoral approach, describe how you would manage the subscapularis, the techniques available, and how you decide between them.”

Practical approach

The subscapularis must be taken down from the lesser tuberosity to enter the glenohumeral joint, and three established techniques are available: tenotomy, subscapularis peel, and lesser-tuberosity osteotomy. After exposing the tendon and protecting the axillary nerve at the inferior border, I take it down according to the chosen technique. A tenotomy divides the tendon about 1 cm medial to its insertion and repairs it tendon-to-tendon or back to bone; it is the simplest and fastest but has the weakest healing, because tendon-to-tendon healing is the least reliable. A subscapularis peel elevates the tendon sharply off its footprint and repairs it back to the lesser tuberosity with suture anchors or transosseous tunnels, giving tendon-to-bone healing. A lesser-tuberosity osteotomy, described by Gerber, raises a bone fragment with the tendon and fixes it with cerclage sutures, giving bone-to-bone healing, the strongest of the three. My decision depends on the patient and the tissue. The healing hierarchy is bone-to-bone stronger than tendon-to-bone stronger than tendon-to-tendon, so for a younger, higher-demand patient I favour a peel or a lesser-tuberosity osteotomy to maximise the chance of durable function; a tenotomy is acceptable in a lower-demand patient and is the simplest. I avoid an osteotomy in fracture arthroplasty, where the tuberosity is already fractured and should be repaired directly. Throughout, I protect the axillary nerve by staying on bone and never placing a retractor blindly inferior to the subscapularis, I restore correct tension and humeral version, and I protect the repair for about 6 weeks, limiting passive external rotation and resisted internal rotation.

Key clinical points

Three techniques: tenotomy, subscapularis peel, lesser-tuberosity osteotomy

Healing hierarchy: bone-to-bone stronger than tendon-to-bone stronger than tendon-to-tendon

Lesser-tuberosity osteotomy gives the strongest repair but is most demanding

Axillary nerve is protected at the inferior border by staying on bone

Restore tension and humeral version; re-check after repair

Protect the repair for 6 weeks (limit passive external rotation and resisted internal rotation)

Common pitfalls

Saying tenotomy has the strongest healing (it has the weakest)

Not mentioning the axillary nerve at the inferior border

Confusing the internervous plane with the subscapularis itself

Choosing an osteotomy in a fracture case where the tuberosity is already fractured

Further questions

“What is the internervous plane of the deltopectoral approach?”

“How would you protect the axillary nerve during the inferior capsular release?”

“How would you manage a patient with symptomatic subscapularis failure after this operation?”

Viva scenarioStandard

Clinical prompt

“What is the internervous plane of the deltopectoral approach, which structure must be divided to enter the joint, and which nerves are at risk?”

Practical approach

The superficial internervous plane of the deltopectoral approach is between deltoid, supplied by the axillary nerve, laterally, and pectoralis major, supplied by the medial and lateral pectoral nerves, medially. This is a true internervous plane between two muscles supplied by different nerves. To enter the glenohumeral joint, the subscapularis, supplied by the upper and lower subscapular nerves, must be taken down from the lesser tuberosity; the subscapularis is the structure deliberately divided and is not itself an internervous interval. The nerves at risk are the axillary nerve, which runs at the inferior border of the subscapularis and around the surgical neck of the humerus, and the musculocutaneous nerve, which enters coracobrachialis 3 to 8 cm distal to the coracoid and is at risk with retraction of the conjoined tendon. The axillary nerve is the most important: it is protected by staying on bone, palpating it during inferior capsular release, and never placing a retractor blindly deep to the inferior subscapularis.

Key clinical points

Internervous plane: deltoid (axillary nerve) and pectoralis major (pectoral nerves)

The subscapularis is divided to enter the joint

Axillary nerve at risk at the inferior border of the subscapularis

Musculocutaneous nerve enters coracobrachialis 3 to 8 cm distal to the coracoid

Protect nerves by staying on bone and using gentle, vision-guided retraction

Common pitfalls

Saying the subscapularis is the internervous plane (it is the structure divided)

Forgetting the musculocutaneous nerve with the conjoined tendon

Not specifying the axillary nerve as the most important at-risk structure

Further questions

“How does the deltopectoral internervous plane differ from that of the anterolateral (deltoid-splitting) approach?”

“What functional loss follows an axillary nerve injury here?”

“Where exactly is the cephalic vein found and how do you handle it?”

Viva scenarioChallenging

Clinical prompt

“A patient returns 4 months after an anatomic total shoulder arthroplasty with anterior shoulder instability and a positive belly-press test. What has happened and how do you manage it?”

Practical approach

The combination of anterior instability and a positive belly-press after anatomic shoulder arthroplasty points to subscapularis failure. The subscapularis is the primary internal rotator and a key anterior stabiliser, so its loss produces weakness of internal rotation and anterior instability. On assessment I take a detailed history (onset, trauma, function), examine the shoulder for instability and the rotator cuff with the belly-press and lift-off tests, and image with plain radiographs to confirm component position and version and to look for anterior subluxation, with CT to assess component version and cuff integrity if needed. Causes include technical repair failure, devitalisation of the tendon at surgery, overtensioning or under-protection, poor tissue quality, or component malversion that altered cuff tension. For management, if the subscapularis is irreparable and symptomatic the established salvage is a pectoralis major transfer to restore anterior soft-tissue support and function; if component malversion or loosening is contributing, revision of the component is required; and if the soft tissues are not reconstructable, conversion to a reverse total shoulder arthroplasty is considered for stability. This complication is the rationale for choosing a sound repair construct - ideally a peel or lesser-tuberosity osteotomy for bone-to-bone or tendon-to-bone healing - restoring tension and version, and protecting the repair for 6 weeks.

Key clinical points

Anterior instability plus positive belly-press indicates subscapularis failure

Subscapularis is the primary internal rotator and an anterior stabiliser

Image to assess component version and cuff integrity

Salvage is pectoralis major transfer, or component revision, or conversion to reverse arthroplasty

Prevention: sound construct, correct tension and version, 6-week protection

Common pitfalls

Attributing instability purely to glenoid wear without assessing the subscapularis

Promising that a pectoralis major transfer fully restores normal function

Forgetting to assess component version before deciding on salvage

Not counselling the patient about the limited outcomes of salvage surgery

Further questions

“What are the belly-press and lift-off tests and what do they assess?”

“Describe how you would perform a pectoralis major transfer.”

“When would you convert to a reverse total shoulder arthroplasty instead?”

Exam day cheat sheet

SUBSCAPULARIS MANAGEMENT IN SHOULDER ARTHROPLASTY

Position & approach

Beach-chair position with the arm free for rotation
Deltopectoral incision from the coracoid toward the deltoid insertion
Internervous plane: deltoid (axillary nerve) and pectoralis major (pectoral nerves)
Cephalic vein in the groove - preserve or ligate
Conjoined tendon retracted medially with the coracoid

The three techniques

Tenotomy: tendon cut 1 cm medial to insertion; tendon-to-tendon or tendon-to-bone; weakest healing
Subscapularis peel: tendon off the footprint; tendon-to-bone; anchors or tunnels
Lesser-tuberosity osteotomy: bone with tendon; cerclage; bone-to-bone; strongest
Z-lengthening added to tenotomy when the subscapularis is tight
Avoid osteotomy in fracture arthroplasty (tuberosity already fractured)

Healing hierarchy & biomechanics

Bone-to-bone stronger than tendon-to-bone stronger than tendon-to-tendon
Rationale for choosing peel or osteotomy over tenotomy
Restore tension: overtight limits external rotation, loose fails
Humeral version sets cuff tension - match native retroversion
Re-check tension and version after the repair

Axillary nerve & danger structures

Axillary nerve at the inferior border of the subscapularis - most important
Protect by staying on bone and palpating during inferior release
Never place a retractor blindly deep to the inferior subscapularis
Musculocutaneous nerve 3 to 8 cm distal to the coracoid - protect conjoined tendon
Anterior humeral circumflex vessels inferiorly - ligate as needed

Closure & postoperative care

Repair subscapularis per the chosen construct
Close the deltopectoral interval loosely
Sling with arm in neutral to slight external rotation
Limit passive external rotation for 6 weeks
Avoid resisted internal rotation (pushing up from a chair) for 6 weeks

Function, failure & salvage

Subscapularis is the primary internal rotator and anterior stabiliser
Integrity assessed by belly-press and lift-off tests
Failure causes anterior instability and internal-rotation weakness
Salvage: pectoralis major transfer for irreparable insufficiency
Reverse arthroplasty if soft tissues not reconstructable

References

Guidelines, Registries & Global Practice Management of the subscapularis in anatomic shoulder arthroplasty is governed by surgical-biomechanical principles that converge across examination systems. The deltopectoral approach, protection of the axillary nerve at the inferior border, and the healing hierarchy (bone-to-bone stronger than tendon-to-bone stronger than tendon-to-tendon) are universally taught. Arthroplasty registry evidence (for example the National Joint Registry and the Australian Orthopaedic Association National Joint Replacement Registry) principally reports survivorship and revision rather than subscapularis-specific technique, but revision for instability is captured and is relevant to subscapularis failure. Side-by-side principles (where guidance converges): | Body | Position on subscapularis management |

|------|--------------------------------------| | AAOS (US) | Secure subscapularis repair and protection are essential to anterior stability after anatomic arthroplasty; technique is surgeon-dependent but bone-to-bone/tendon-to-bone constructs are favoured for higher-demand patients | | BESS / BOA / EFORT | The deltopectoral approach is standard; the axillary nerve at the inferior border must be protected; lesser-tuberosity osteotomy or peel preferred when subscapularis integrity is critical | | AO Foundation | Restoration of soft-tissue tension and version is part of balanced arthroplasty; protect the repair and limit early external rotation and resisted internal rotation | Registry / population evidence: - Arthroplasty registries report shoulder arthroplasty revision rates broadly in the single-digit percent range at mid-term follow-up, with instability a recognised mode of failure after anatomic designs

Subscapularis failure is a contributor to instability-related revision, which underlines the preventive value of a sound repair Global practice variation. In well-resourced settings, suture anchors, anatomic implants and lesser-tuberosity osteotomy are widely available. In resource-limited settings, the same biomechanical principles are applied with transosseous bone tunnels and standard implants; a simple tenotomy with a meticulous repair remains a reasonable, lower-cost option. Consent (globally applicable). Discuss subscapularis dysfunction or failure with possible anterior instability, axillary nerve injury with deltoid weakness, stiffness, infection, and the potential need for revision (including pectoralis major transfer or conversion to a reverse design) if the subscapularis fails.

Orthopaedic relevance

For the Operative Surgery station, be able to describe subscapularis management systematically: the deltopectoral internervous plane, the three takedown techniques and their healing interfaces, the axillary nerve at the inferior border, restoration of tension and version, and postoperative protection. Know the healing hierarchy and the salvage options for subscapularis failure.

Evidence

Lesser Tuberosity Osteotomy for Total Shoulder Arthroplasty

Gerber C, Pennington SD, Yian EH, Pfirrmann CAW, Correll S • Journal of Bone and Joint Surgery (Am) (2007)

Key Findings:

Introduced lesser-tuberosity osteotomy for anatomic total shoulder arthroplasty, elevating the subscapularis with a bone fragment to achieve bone-to-bone healing
Clinical and imaging assessment showed preserved subscapularis integrity and strength at follow-up, supporting bone-to-bone healing as a reliable restoration
Described fixation of the osteotomy fragment with cerclage sutures around the humeral stem
Established lesser-tuberosity osteotomy as an alternative to tenotomy and peel for preserving subscapularis function

Clinical implication: The landmark description that made bone-to-bone healing of the subscapularis feasible in arthroplasty, underpinning the modern preference for an osteotomy in patients where subscapularis integrity is critical

Evidence

Instability of the Shoulder After Arthroplasty

Moeckel BH, Altchek DW, Warren RF, Wickiewicz TL, Dines DM • Journal of Bone and Joint Surgery (Am) (1993)

Key Findings:

Identified instability as a recognised complication of total shoulder arthroplasty
Attributed most cases of anterior instability to subscapularis failure or devitalisation at the time of surgery
Emphasised that a secure, well-vascularised subscapularis repair and postoperative protection are essential to prevent instability
Established the principle that subscapularis integrity is central to anterior stability after shoulder arthroplasty

Clinical implication: The classic paper linking subscapularis failure to anterior instability, and the reason a sound repair and 6-week protection are mandatory

Evidence

Loss of Subscapularis Function After Total Shoulder Replacement: A Seldom Recognized Problem

Miller SL, Hazrati Y, Klepps S, Chiang A, Flatow EL • Journal of Shoulder and Elbow Surgery (2003)

Key Findings:

Showed that subscapularis dysfunction after total shoulder replacement is under-recognised, even when the tendon appears intact
Used the belly-press and lift-off tests to detect objective subscapularis weakness following tenotomy repair
A meaningful subset of patients had abnormal subscapularis function despite a presumed satisfactory tendon repair
Highlighted that tenotomy repair does not reliably restore full subscapularis strength

Clinical implication: Explains why subscapularis strength is often reduced after a simple tenotomy and supports the move toward peel or osteotomy for better function

Evidence

A Biomechanical Comparison of Three Surgical Techniques for Subscapularis Repair

Van den Berghe GR, Nguyen B, Patil S, D'Lima DD, Mahar A, Hoenecke HR • Journal of Shoulder and Elbow Surgery (2008)

Key Findings:

Compared the biomechanical strength of three subscapularis takedown-and-repair constructs used in shoulder arthroplasty
Tendon-to-bone and bone-to-bone repairs (peel and osteotomy) generally resisted cyclic loading and load-to-failure better than a simple tendon-to-tendon tenotomy repair
Provided the mechanical justification that bone-to-bone and tendon-to-bone constructs are sturdier than tendon-to-tendon
Supported the modern biomechanical rationale for preferring a peel or lesser-tuberosity osteotomy over tenotomy

Clinical implication: The biomechanical evidence behind the healing hierarchy taught in examinations: bone-to-bone stronger than tendon-to-bone stronger than tendon-to-tendon

Evidence

Outcome of Pectoralis Major Transfer for the Treatment of Subscapularis Insufficiency Secondary to Anterior Shoulder Surgery

Jost B, Puskas GJ, Lustenberger A, Gerber C • Journal of Bone and Joint Surgery (Am) (2003)

Key Findings:

Reported the outcome of pectoralis major transfer for symptomatic subscapularis insufficiency following prior anterior shoulder surgery
Showed that pectoralis major transfer can improve pain and anterior stability in selected patients with irreparable subscapularis failure
Underscored the significant functional morbidity of subscapularis insufficiency, which is why prevention via a sound repair is paramount
Serves as the salvage benchmark when subscapularis repair fails after arthroplasty

Clinical implication: Defines the salvage option for subscapularis insufficiency and reinforces why preventing failure with a sound construct and protection is preferable to rescuing it