High-yield overview

Lateral or Prone | Triceps Left Intact | Medial and Lateral Windows

Triceps intactExtensor mechanism preserved

Lateral or PronePositioning options

Radial nerveKey at-risk structure in spiral groove

21 cmNerve proximal to medial epicondyle (Gerwin)

Critical Must-Knows

The triceps is left intact - mobilised off the septa, never split or detached
Two windows are developed, medial and lateral to the intact triceps
The radial nerve lies in the spiral groove on bone - identify it in the lateral (proximal) window
The ulnar nerve runs behind the medial epicondyle - identify and protect it medially
It is not for complex intra-articular fractures needing articular visualisation - use an olecranon osteotomy

When & Why

What it exposes. The posterior paratricipital approach gives direct access to the posterior humeral shaft, both distal humeral columns (medial and lateral), and the elbow, by developing medial and lateral windows on either side of an intact triceps. It reaches the posterior cortex, the olecranon fossa and the proximal ulna without ever dividing the extensor mechanism. Why this approach is chosen. It works around the triceps rather than through it. Because the extensor mechanism is never divided, the triceps remains attached to the olecranon, which preserves active elbow extension and avoids the principal complication of triceps-reflecting and triceps-splitting exposures: triceps insufficiency. This is why it is the favoured approach for total elbow arthroplasty and for extra-articular distal humeral fractures. Primary indications:

Extra-articular distal humeral shaft fractures (distal third of the shaft)
Selected simple intra-articular distal humerus fractures (low transcolumnar, low T or Y patterns) where the articular block can be reduced without wide direct visualisation
Total elbow arthroplasty - the triceps-sparing variant is a standard exposure for primary and fracture arthroplasty
Acute, non-reconstructable distal humerus fractures in elderly, low-demand patients managed with acute total elbow replacement
Non-union or malunion of the distal humeral shaft, selected hardware removal, and contracture release where the articular surface does not need wide exposure Contraindications:
Complex intra-articular (bicolumnar) fractures requiring anatomic articular reconstruction - the intact triceps blocks anterior articular visualisation; use an olecranon osteotomy
Any need to visualise the anterior trochlea and capitellum directly
Local posterior soft-tissue compromise (previous flaps, infection, severe blistering)
When a triceps-splitting shaft exposure is genuinely required for a proximal shaft fracture Position & landmarks. Most often performed lateral decubitus (affected side up, an axillary roll under the dependent arm, the operative arm over a padded bolster with the forearm hanging free) or prone (chest rolls, arm forward over a support). Both let the forearm hang free so the elbow flexes, which relaxes the triceps and opens the posterior distal humerus. Pad all pressure points, apply a well-padded (often sterile) tourniquet, and confirm a radiolucent table with C-arm access from the opposite side. Bony landmarks to mark are the olecranon tip (around which the incision curves), the medial epicondyle (guides the medial window and ulnar nerve), the lateral epicondyle (guides the lateral window and radial column), and the posterior midline of the arm.

Position pearl

A common exam question is the position for a posterior distal humerus approach. Lateral decubitus (arm uppermost over a bolster) and prone are both correct. The key is that the forearm hangs free so the elbow flexes, which relaxes the triceps and opens the posterior aspect of the distal humerus.

How the posterior exposures compare

Posterior Exposures of the Distal Humerus and Elbow
Approach	Triceps Handling	Articular View	Best Use
Paratricipital (Alonso-Llames)	Intact - mobilised off septa	Limited	Extra-articular, TEA
Olecranon osteotomy	Reflected with olecranon	Excellent (best)	Complex intra-articular
Triceps-splitting	Midline split and repaired	Moderate	Humeral shaft
Bryan-Morrey (reflecting)	Reflected medial to lateral	Good	TEA, reconstruction

The key decision. The single most important question is whether the articular surface needs direct, wide visualisation. If yes (complex bicolumnar fractures), the paratricipital approach is inadequate and an olecranon osteotomy is chosen. If no (extra-articular, or arthroplasty), the triceps-sparing approach is ideal.

The Exposure

Work down through the layers in the lateral or prone position, raising full-thickness flaps, then identify the ulnar nerve medially and the radial nerve laterally before sweeping the intact triceps off the septa to open the two windows onto the posterior cortex.

🦴

Image Needed: AnatomyHigh Priority

Posterior surgical approach to the distal humerus showing the straight posterior midline incision curving around the olecranon tip, full-thickness fasciocutaneous flaps raised, the triceps left intact and retracted to reveal the medial and lateral windows, with the radial nerve protected by a vessel loop in the spiral groove on the lateral side and the ulnar nerve protected behind the medial epicondyle.

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

Pending image generation or sourcing

Exposure sequence

Step 1Position the patient

Place the patient lateral decubitus (affected side up) or prone, with a well-padded tourniquet.
Support the arm so the forearm hangs free and the elbow flexes, which opens the posterior aspect of the distal humerus and relaxes the triceps.

Step 2Skin incision

Make a straight posterior midline incision over the humeral shaft, curving gently around the olecranon tip (usually just medial to it) and onto the proximal forearm.
Length is tailored to the pathology - long enough to expose the fracture or the joint and to raise full-thickness medial and lateral fasciocutaneous flaps.

Step 3Raise full-thickness flaps

Elevate full-thickness fasciocutaneous flaps medially and laterally, staying deep to the subcutaneous tissues to protect the posterior cutaneous nerves.
The triceps aponeurosis and olecranon are now exposed in the midline, with the medial and lateral intermuscular septa visible on each side.

Step 4Medial window - identify the ulnar nerve first

Begin medially. Identify the ulnar nerve in its groove behind the medial epicondyle.
Mobilise it gently and protect it with a vessel loop; do not skeletonise it. This nerve is the key medial structure and must be found before any medial-column work.

Step 5Lateral window - identify the radial nerve

Move laterally. Develop the plane between the lateral head of triceps (and the anconeus distally) and the lateral intermuscular septum.
For any proximal work, identify the radial nerve in the spiral groove where it lies on bone between the lateral and medial heads; protect it with a vessel loop before any proximal retraction.

Step 6Mobilise the intact triceps

The triceps is now mobilised off both intermuscular septa but remains attached to the olecranon.
Retract it medially or laterally to create the two windows onto the posterior humeral shaft and the distal columns.

Step 7Expose the posterior cortex

Through the medial and lateral windows, sweep the deep surface of the triceps off the posterior humeral cortex subperiosteally.
The flat posterior surface of the distal shaft proximal to the olecranon fossa is the safe zone - the radial nerve lies on the bone only more proximally in the groove.

Step 8Access the columns and joint

For distal humeral fixation, expose the medial and lateral columns. The olecranon fossa and posterior trochlea can be reached.
The intact triceps limits how far anteriorly the articular surface can be seen - this is the fundamental limitation of the approach.

Step 9For total elbow arthroplasty

Continue the windows distally onto the olecranon and proximal ulna, retracting the intact triceps to allow resection of the fractured articular block and preparation of the humeral and ulnar canals.
Because the triceps is never detached, reattachment is not required - a major advantage over reflecting approaches.

Step 10Closure

Because the triceps was never divided or detached, closure is straightforward: reapproximate the triceps fascia over the septa if the planes were opened.
Restore the ulnar nerve to its groove, or transpose it anteriorly if medial column hardware threatens it or it was unstable; close the fasciocutaneous flaps and skin over a drain.

There is no true internervous plane. The paratricipital approach is an intermuscular, subperiosteal-on-bone exposure. The triceps (radial nerve) is elevated off the medial and lateral intermuscular septa and retracted as a single intact unit. The medial window is developed between the medial head of triceps (radial nerve) and the medial intermuscular septum; the lateral window between the lateral head of triceps and anconeus (radial nerve) and the lateral intermuscular septum.

No true internervous plane - stay on bone

Like the Bryan-Morrey triceps-reflecting approach, the paratricipital approach has no true internervous plane. The dissection stays on bone, sweeping the intact triceps off the intermuscular septa medially and laterally. The unifying principles are: identify the ulnar nerve medially first, identify the radial nerve in the lateral window before any proximal retraction, and stay strictly on the posterior humeral cortex.

Muscular layers encountered

Anatomy that governs the exposure
Layer	Structure	Nerve Supply	Role in Approach
Superficial	Long head of triceps	Radial nerve	Forms medial border of approach
Superficial	Lateral head of triceps	Radial nerve	Forms lateral border of approach
Deep	Medial head of triceps	Radial nerve	Underlies the radial nerve in the groove
Distal	Anconeus	Radial nerve	Lateral window distal landmark
Floor	Posterior humeral cortex	—	Target of the exposure

Dangers & Extensions

Structures at risk, by layer

Danger structures and how to protect them
Layer	Structure at Risk	Protection
Superficial	Posterior cutaneous nerves (inferior lateral cutaneous nerve of arm, posterior antebrachial cutaneous nerve)	Full-thickness fasciocutaneous flaps deep to the fascia; avoid splitting subcutaneous tissue
Lateral window	Radial nerve and profunda brachii artery in the spiral groove	Identify on bone in the groove, vessel loop, smooth non-crushing retractors, no proximal retraction until identified
Medial window	Ulnar nerve behind the medial epicondyle	Identify first, mobilise gently, protect with a loop; consider anterior transposition if medial column hardware threatens it
Deep	Posterior humeral cortex	Stay subperiosteal, avoid anterior perforation of the shaft

Radial Nerve

THE key structure at risk in the lateral window. Lies in the spiral groove directly on the posterior humeral cortex, accompanied by the profunda brachii artery. At risk during retraction and from the fracture itself. Identify it on bone before any proximal retraction, protect with a vessel loop, and use smooth retractors without pressure.

Ulnar Nerve

Runs behind the medial epicondyle through the cubital tunnel into the forearm. Must be identified first in the medial window and protected throughout. Post-operative ulnar neuropathy is a recognised complication; consider anterior transposition when medial column hardware is used.

Profunda Brachii Artery

Travels with the radial nerve in the spiral groove. Small branches may bleed during lateral dissection; achieve meticulous haemostasis. Major injury is rare but requires repair.

Posterior Cutaneous Nerves

The inferior lateral cutaneous nerve of the arm and the posterior antebrachial cutaneous nerve run in the subcutaneous plane. Protected by raising full-thickness flaps deep to the fascia.

Extensile options. Extend proximally along the humeral shaft for more proximal fractures - the critical constraint is the radial nerve, which crosses the posterior shaft in the spiral groove, so as dissection moves proximally the nerve must be identified on bone and protected. Extend distally onto the olecranon and proximal ulna (routine for total elbow arthroplasty, giving access to the proximal ulna and olecranon fossa). If, intra-operatively, articular visualisation proves inadequate for a complex fracture, convert to an olecranon osteotomy through the same skin incision - a chevron cut through the bare area of the olecranon, reflecting the triceps with the osteotomised fragment proximally to expose the entire articular surface. Closure. Simple because the triceps was never divided: reapproximate the triceps fascia over the septa if opened, restore the ulnar nerve to its groove (or transpose anteriorly if medial column hardware threatens it), and close the fasciocutaneous flaps and skin over a drain. Confirm fixation or component position on AP and lateral radiographs. Complications

Intra-operative complications
Complication	Prevention	Management
Radial nerve injury	Identify on bone in groove, vessel loop, no crush retractors	Document, examine, EMG at 3 weeks, explore if no recovery
Ulnar nerve injury	Identify first medially, mobilise gently	Observe; transposition if symptomatic post-op
Inadequate articular view	Confirm pattern on CT pre-operatively	Convert to olecranon osteotomy

Post-operative complications
Complication	Notes	Prevention / Treatment
Ulnar neuropathy	Commonest nerve complication	Careful handling, transposition if threatened
Radial nerve palsy	Usually traction neuropraxia	Most recover; observe, then EMG
Infection	Wound and deep	Antibiotics, soft-tissue care
Stiffness / heterotopic bone	Loss of motion	Early controlled mobilisation
Triceps weakness	Rare with intact triceps (major advantage)	Rehabilitate

The triceps advantage

The defining benefit of the triceps-sparing approach is that the triceps is never detached, so extensor-mechanism insufficiency - the signature complication of triceps-reflecting (Bryan-Morrey) and olecranon-osteotomy approaches - is avoided. This is why it is the preferred exposure for total elbow arthroplasty, where early active extension and rehabilitation matter most.

Procedures Through This Approach

ORIF of extra-articular distal humeral shaft fractures and selected low intra-articular distal humerus fractures (medial and posterolateral column plating through the two windows)
Total elbow arthroplasty - primary and for acute non-reconstructable fractures (the workhorse exposure)
Distal humeral non-union and malunion repair
Selected hardware removal and posterior elbow contracture release where the articular surface does not need wide exposure Contrast with the triceps-splitting approach. The triceps-splitting approach divides the triceps in the midline to reach the humeral shaft directly. It gives excellent shaft exposure but divides the extensor mechanism (which must be repaired) and is better suited to diaphyseal fractures. The paratricipital approach never divides the triceps, making it the better choice whenever the joint or the distal columns are the target and the articular surface does not need wide exposure.

Viva & Exam Focus

Mnemonic

TRICEPSTRICEPS — the paratricipital steps

Triceps intact

Mobilised off the septa, never split or detached

Radial nerve

Identified in the spiral groove (lateral window)

Internervous plane

None — stay on bone

Care with ulnar nerve

Behind the medial epicondyle

Expose shaft and columns

Through two windows either side of the triceps

Position

Lateral or prone with the forearm free

Splitting avoided

The key contrast with the shaft approach

Mnemonic

RADIALRADIAL — nerve safe zones (Gerwin)

Runs in spiral groove

On the posterior cortex

About 21 cm

Proximal to the medial epicondyle (mean)

Distal septum crossing

About 10 cm proximal to the lateral epicondyle

Identify on bone

Before any proximal retraction

Always smooth retractors

With a vessel loop

Lateral window

Where the nerve is found

Name question

Q: By what other name is the triceps-sparing posterior approach to the distal humerus known? A: The paratricipital approach, also called the Alonso-Llames approach after its original description.

Internervous plane question

Q: What is the internervous plane of the paratricipital approach? A: There is no true internervous plane. The dissection is intermuscular and subperiosteal: the intact triceps (radial nerve) is mobilised off the medial and lateral intermuscular septa and retracted as a single unit. The unifying principles are identification of the ulnar nerve medially, identification of the radial nerve in the lateral window, and staying on bone.

Nerves at risk question

Q: What are the key structures at risk? A: The radial nerve in the spiral groove (lateral window) and the ulnar nerve behind the medial epicondyle (medial window). The radial nerve lies directly on the posterior humeral cortex and must be identified before proximal retraction; the ulnar nerve must be identified first medially.

Indication question

Q: When is this the approach of choice? A: For total elbow arthroplasty (because the intact triceps avoids extensor-mechanism insufficiency) and for extra-articular distal humeral fractures or selected low intra-articular patterns. It is not suitable for complex intra-articular fractures needing anatomic articular reconstruction.

Radial nerve distance question

Q: Where does the radial nerve lie on the posterior humerus? A: On the posterior cortex in the spiral groove, at a mean of roughly 21 cm proximal to the medial epicondyle and about 14 cm proximal to the lateral epicondyle (Gerwin). It pierces the lateral intermuscular septum about 10 cm proximal to the lateral epicondyle to enter the anterior compartment.

Contrast question

Q: How does it differ from the olecranon osteotomy approach? A: The olecranon osteotomy gives the best articular visualisation for complex intra-articular fractures but risks osteotomy non-union and symptomatic hardware. The paratricipital approach preserves the triceps and avoids those problems but gives limited articular view - so it is chosen when articular exposure is not needed.

Exam Viva Scenarios

Practise clinical reasoning and management decisions out loud

Viva scenarioStandard

Clinical prompt

“A 40-year-old sustains an extra-articular distal third humeral shaft fracture in a fall. How would you approach this surgically?”

Practical approach

Begin with a full trauma survey, then focused assessment documenting baseline radial, ulnar, median and anterior interosseous nerve function and the brachial, radial and ulnar pulses, with radiographs of the humerus and elbow and a CT to confirm the fracture is genuinely extra-articular. Because the articular surface does not need direct visualisation, the posterior paratricipital (Alonso-Llames) triceps-sparing approach is ideal, exposing the posterior shaft and columns while keeping the triceps intact. Position lateral decubitus with the arm uppermost over a padded support and the forearm hanging free, then make a straight posterior midline incision curving around the olecranon tip and raise full-thickness fasciocutaneous flaps. Identify the ulnar nerve behind the medial epicondyle first and protect it, then develop the lateral window between the lateral head of triceps and the lateral intermuscular septum, identifying the radial nerve in the spiral groove if working proximally. Mobilise the intact triceps off both septa to create medial and lateral windows, reduce the fracture, and apply medial and posterolateral column plates under fluoroscopy. Close in layers over a drain - the intact triceps makes closure straightforward - document nerve function, and begin early controlled mobilisation once the skin is stable.

Key clinical points

Confirm the fracture is extra-articular on CT

Paratricipital approach preserves the triceps - correct choice here

Identify the ulnar nerve medially first

Identify the radial nerve in the spiral groove if working proximally

Mobilise the intact triceps off both septa

Column plating through medial and lateral windows

Intact triceps means simple closure and preserved extension

Common pitfalls

Choosing this approach for a complex intra-articular fracture that needs an osteotomy

Not identifying the ulnar nerve first in the medial window

Failing to protect the radial nerve during proximal retraction

Forgetting that there is no true internervous plane - stay on bone

Further questions

“How would your approach change if CT showed articular comminution, what is the significance of the radial nerve being on bone in the spiral groove, and when would you prefer an olecranon osteotomy instead?”

Viva scenarioChallenging

Clinical prompt

“A 78-year-old low-demand woman with osteoporosis sustains a comminuted, non-reconstructable distal humerus fracture. Discuss your management and the role of this approach.”

Practical approach

This is a low-demand elderly patient with poor bone stock and a fracture that cannot be stably reconstructed, so the classic teaching - supported by the Morrey group data - is that primary total elbow arthroplasty gives better functional outcomes than attempted ORIF for acute non-reconstructable distal humerus fractures in elderly, low-demand patients. Examine the skin and ulnar nerve and confirm medical fitness. The paratricipital (triceps-sparing) approach is preferred for the arthroplasty: because the triceps is never detached, extensor-mechanism insufficiency is avoided and rehabilitation is simplified, and an olecranon osteotomy is relatively avoided because it compromises the olecranon needed for the ulnar component and risks non-union in poor bone. Through the triceps-sparing exposure, resect the comminuted articular block as dictated by the prosthesis, prepare the humeral and ulnar canals, and cement a linked semiconstrained total elbow prosthesis, retracting the intact triceps for access. Closure is straightforward because the triceps is intact; begin protected motion per the prosthesis protocol and counsel the patient on lifelong lifting restrictions after a total elbow replacement.

Key clinical points

Non-reconstructable distal humerus in a low-demand elderly patient favours primary total elbow arthroplasty

Triceps-sparing approach is the preferred exposure for TEA

Avoid olecranon osteotomy here - compromises the olecranon and risks non-union

Intact triceps avoids extensor-mechanism insufficiency

Cement a linked semiconstrained prosthesis

Lifelong lifting restrictions after TEA

Common pitfalls

Attempting ORIF in bone that cannot hold fixation

Using an olecranon osteotomy when arthroplasty is planned

Not counselling about lifelong weight limits

Detaching the triceps unnecessarily when a sparing approach is available

Further questions

“What are the long-term complications of total elbow arthroplasty, how would you manage this fracture in a younger high-demand patient, and why is the triceps-sparing approach specifically favoured for TEA?”

Viva scenarioChallenging

Clinical prompt

“After a paratricipital approach to the distal humerus, the patient has weak wrist and finger extension post-operatively. What is your assessment and management?”

Practical approach

Examine the radial nerve territory - wrist and finger extension and first web space sensation - and compare with the documented pre-operative baseline, also checking the ulnar and median nerves and excluding a tight dressing or splint as a compressive cause. Loosen any constricting dressing and review the operative note for whether the radial nerve was identified and protected and whether traction or difficulty was recorded, considering whether the original fracture injured the nerve since a pre-operative deficit changes interpretation. The most likely diagnosis is radial nerve neuropraxia from traction or retractor compression during the lateral window dissection, the nerve being vulnerable because it lies directly on bone in the spiral groove with limited mobility. Remove any constriction, splint the wrist in extension to prevent a drop-wrist contracture, and counsel the patient that most neuropraxias recover, documenting the deficit and discussion thoroughly. Arrange electrophysiology at around three weeks to characterise the injury; if there is no clinical or electrical recovery by about three months and the nerve was known to be at risk, consider exploration, as most traction neuropraxias recover fully within three to six months.

Key clinical points

Compare with the pre-operative baseline radial nerve exam

Exclude a tight dressing or splint first

Most likely a traction neuropraxia from the lateral window

Radial nerve is on bone in the spiral groove - limited mobility

Splint the wrist in extension to prevent contracture

Electrophysiology at around 3 weeks

Consider exploration if no recovery by about 3 months

Common pitfalls

Assuming it will resolve without documenting the baseline deficit

Missing a correctable compressive cause such as a tight dressing

Not counselling the patient about prognosis

Rushing to exploration when most neuropraxias recover

Further questions

“What would electrophysiology show in neuropraxia versus axonotmesis, when would you re-explore the radial nerve, and how does the Gerwin radial nerve anatomy explain the risk?”

Exam day cheat sheet

Posterior triceps-sparing (paratricipital) approach — exam-day essentials

Names and concept

Also called the paratricipital approach or the Alonso-Llames approach
Works AROUND the triceps - never splits or reflects it
Medial and lateral windows to an intact triceps
No true internervous plane - intermuscular, subperiosteal on bone

Position and incision

Lateral decubitus (arm uppermost) or prone
Forearm hangs free so the elbow flexes - relaxes the triceps
Straight posterior midline incision curving around the olecranon tip
Full-thickness medial and lateral fasciocutaneous flaps

Ulnar nerve (medial window)

Identify FIRST behind the medial epicondyle
Mobilise gently, protect with a vessel loop
Consider anterior transposition if medial column hardware threatens it
Post-operative ulnar neuropathy is a recognised complication

Radial nerve (lateral window)

Lies directly on bone in the spiral groove
Mean roughly 21 cm proximal to the medial epicondyle (Gerwin)
Pierces the lateral septum about 10 cm proximal to the lateral epicondyle
Identify before any proximal retraction - protect with a loop

Indications and limits

Workhorse exposure for total elbow arthroplasty
Extra-articular distal humeral shaft fractures and selected low patterns
Acute non-reconstructable fractures in elderly - primary TEA
NOT for complex intra-articular fractures - use olecranon osteotomy

Advantage and closure

Triceps intact - avoids extensor-mechanism insufficiency
Simple closure - triceps was never divided or detached
Convert to olecranon osteotomy if articular view proves inadequate
Document radial and ulnar nerve function before and after

References

Guidelines, registries and global practice. Posterior approaches to the distal humerus are taught and practised worldwide, with convergent principles across examination systems. The triceps-sparing (paratricipital) exposure is recognised as the standard approach for total elbow arthroplasty and for extra-articular distal humeral fractures, while olecranon osteotomy remains the reference for complex intra-articular reconstruction. In high-resource settings, pre-contoured column plates, total elbow systems and routine CT are standard; in resource-limited settings, the same posterior exposure principles are applied with small-fragment reconstruction plates and external fixation as needed. The approach itself - and the radial and ulnar nerve anatomy that govern it - is universal.

Convergent guidance on posterior distal humerus approaches
Body	Position on posterior distal humerus approaches
AO Foundation	Choose the exposure by the articular demand: triceps-sparing for extra-articular patterns and arthroplasty, olecranon osteotomy when anatomic articular visualisation is required
BOA / BOAST	Soft-tissue-aware surgery, nerve documentation, and staged management for high-energy open injuries
AAOS / OTA	Anatomic restoration where the articular surface is involved; functional prioritisation in elderly low-demand patients, supporting arthroplasty

Consent (globally applicable): discuss radial and ulnar nerve injury (mostly transient), infection, stiffness and heterotopic bone, and - for arthroplasty - lifelong lifting restrictions and the possibility of future revision.

Evidence

Alternative Operative Exposures of the Posterior Aspect of the Humeral Diaphysis With Reference to the Radial Nerve

LoE 4

Gerwin M, Hotchkiss RN, Weiland AJ • Journal of Shoulder and Elbow Surgery (1996)

Key Findings:

The landmark anatomical study that mapped the radial nerve in the posterior arm
The radial nerve lies on the posterior humeral cortex in the spiral groove at a mean of roughly 21 cm proximal to the medial epicondyle and about 14 cm proximal to the lateral epicondyle
The nerve pierces the lateral intermuscular septum about 10 cm proximal to the lateral epicondyle to enter the anterior compartment
Defined the safe posterior window on bone that underpins the paratricipital exposure

Clinical implication: Established the radial nerve safe-zone distances that govern every posterior humeral exposure, including the paratricipital approach

Evidence

Functional Outcome Following Surgical Treatment of Intra-Articular Distal Humeral Fractures Through a Posterior Approach

LoE 3

McKee MD, Wilson TL, Winston L, Schemitsch EH, Richards RR • Journal of Bone and Joint Surgery (Am) (2000)

Key Findings:

Compared posterior approaches for intra-articular distal humerus fractures
Olecranon osteotomy was associated with symptomatic hardware and re-operation for hardware removal
Triceps-reflecting and triceps-sparing approaches avoided osteotomy-related complications but gave less articular visualisation
Functional outcome was broadly comparable across the posterior approaches studied

Clinical implication: Frames the trade-off between articular visualisation and approach-related morbidity that governs the choice between olecranon osteotomy and triceps-sparing exposures

Evidence

Distal Humeral Fractures Treated With Noncustom Total Elbow Replacement

LoE 4

Kamineni S, Morrey BF • Journal of Bone and Joint Surgery (Am) (2004)

Key Findings:

Reported total elbow arthroplasty for acute, non-reconstructable distal humeral fractures in elderly patients
Supported a triceps-sparing or triceps-reflecting posterior exposure for the arthroplasty
Favoured arthroplasty over ORIF when the articular fragments are too comminuted to reconstruct in low-demand patients
Showed durable, predictable results in this carefully selected group

Clinical implication: The key evidence supporting primary total elbow arthroplasty - via a triceps-sparing approach - for non-reconstructable distal humerus fractures in elderly low-demand patients

Evidence

Total Elbow Arthroplasty: A Systematic Review of the Literature in the English Language Until the End of 2003

LoE 3

Little CP, Graham AJ, Carr AJ • Journal of Bone and Joint Surgery (Br) (2005)

Key Findings:

Systematic review of the total elbow arthroplasty literature
Triceps-sparing and triceps-reflecting approaches are both widely used for the exposure
Triceps-mechanism insufficiency is a recognised complication of triceps-reflecting techniques
Reported pooled rates of loosening, instability and infection across implant designs

Clinical implication: Explains why the triceps-sparing approach - which avoids detaching the extensor mechanism - is favoured for total elbow arthroplasty

Evidence

Surgical Exposures in Orthopaedics: The Anatomic Approach

LoE 5

Hoppenfeld S, deBoer P, Buckley R • Lippincott Williams and Wilkins (textbook) (2009)

Key Findings:

The canonical anatomical reference for orthopaedic surgical exposures
Describes the posterior and lateral approaches to the humerus and the course of the radial nerve
Details the triceps-splitting shaft exposure and the distal lateral approach between brachialis and brachioradialis
Defines the internervous planes and at-risk structures for each humeral exposure

Clinical implication: The foundational anatomical reference underlying the description of the paratricipital and related posterior humeral approaches