Supracondylar Fractures (Adult)

An adult supracondylar humerus fracture is an extra-articular fracture of the distal humeral metaphysis, proximal to the condyles, lying between the supracondylar ridges and the olecranon fossa. It accounts for approximately 10% of adult distal humerus fractures.

The definition is the exam point. Any articular involvement makes the fracture intercondylar (AO/OTA 13-C), and examiners test the distinction because it changes the classification, the approach and the prognosis.

Who. The peak is at 50-60 years, in osteoporotic bone, but the distribution is bimodal:

• Young adults (20-40) - high-energy trauma: motor vehicle accidents, falls from height, sports injuries and industrial accidents
• Elderly (50+) - low-energy falls from standing on osteoporotic bone, sometimes with minimal trauma

Not a big child's fracture. In children the injury follows a fall on the outstretched hand at 5-7 years, and the long-term cost is cubitus varus. In adults the mechanism is an axial load or a direct blow, the bone is often osteoporotic, and the long-term cost is stiffness rather than deformity. The aim of treatment is therefore fixation stable enough to move the elbow early, which in adults means dual-column plating.

Differential diagnosis. The key task is to distinguish a true extra-articular supracondylar fracture from the intra-articular and adjacent injuries around it.

Two columns. The distal humerus has a triangular architecture: a medial and a lateral column, joined distally by the trochlear-capitellar articular arch. Forces across the elbow are transmitted through both columns.

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Why the supracondylar region breaks. It is the weakest point of the distal humerus. The cylindrical diaphysis changes to a flat metaphysis, thin cortical bone bridges the columns, and the olecranon and coronoid fossae act as stress risers; the supracondylar ridges mark the proximal extent of the region.

What stability needs. Stability requires restoration of both columns, and single-column fixation is insufficient. Fixation also has to be rigid enough for early range of motion.

Nerves and vessels. Management of the ulnar nerve at surgery is discussed under Complications.

The median nerve and brachial artery are less commonly injured than in paediatric fractures. Collateral circulation is usually adequate, and a pulseless but perfused limb may be observed.

AO/OTA 13-A. Adult supracondylar fractures sit in the extra-articular distal humerus group. A2 is the true adult supracondylar pattern.

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Extension and flexion types. The type is named by the direction in which the distal fragment displaces.

Fracture pattern. The shape of the line decides what the fixation has to do.

History. Establish the mechanism and the energy behind it, then the answers that shape the plan:

• Hand dominance - functional importance
• Occupation - manual labour or sedentary
• Pre-injury function - baseline ROM, arthritis
• Previous elbow surgery - may affect the approach
• Medical comorbidities - surgical fitness, bone quality
• Anticoagulation - bleeding risk, haematoma
• Smoking - wound healing, union

Inspection. Expect significant periarticular swelling. An extension-type fracture gives an S-shaped deformity with anterior ecchymosis; a flexion-type fracture gives a reverse S-shaped deformity with posterior ecchymosis. Check the skin for open wounds, tenting and blisters.

Palpation and movement. Assess column integrity, point tenderness over the fracture and crepitus with gentle movement. The Triangle of Hueter stays a normal equilateral triangle, because the fracture is extra-articular. Do not force the examination acutely: document pre-injury ROM if possible, and assess elbow movement and forearm rotation, which tests the DRUJ and PRUJ and is normally full. Ligamentous stability is not testable acutely.

Neurovascular examination. Examine each nerve in turn:

For the circulation, feel the radial and ulnar pulses, check capillary refill and compare with the other side; use a Doppler if the pulses are not palpable.

Radiographs. AP and lateral views of the elbow, and a full-length humerus.

• AP - column integrity, the fracture angle, medial or lateral displacement, and any articular involvement, which would make the fracture intercondylar
• Lateral - confirms the fracture is extra-articular, shows the direction of displacement that defines the type, and shows whether the coronoid and olecranon fossae are involved
• Full-length humerus - required to plan plate length, exclude proximal extension and look for a pathological fracture

A fat pad sign indicates haemarthrosis, though there may be less effusion if the capsule is torn. Intact columns carry a good prognosis; column comminution makes fixation more challenging.

CT. The 3D reconstruction is the gold standard for surgical planning, and it helps confirm that the fracture is truly extra-articular and not an intercondylar pattern requiring intra-articular reconstruction. Obtain thin-cut axial images (1-2 mm) through the full distal humerus, with coronal and sagittal reformats. The indications:

• A fracture pattern that is unclear on plain films
• Assessing the degree of comminution
• Confirming extra-articular versus intercondylar
• Preoperative planning for complex patterns

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Other studies. MRI has a limited role in acute fracture management but may assess ligament integrity, soft tissue interposition and occult pathology. Consider DEXA after a low-energy fracture in the elderly, for fragility fracture pathway planning and to inform the fixation strategy (locking plates, cement). Nerve conduction studies are not typically performed acutely, but may document a pre-existing neuropathy, evaluate post-operative nerve dysfunction, and serve medicolegal documentation.

Angiography is indicated for:

• Hard signs of vascular injury (a pulseless, cold limb)
• An expanding haematoma
• A bruit or thrill
• Active haemorrhage

Most need surgery. Operate for:

• Displacement over 5 mm
• Any angulation
• Unstable patterns
• Polytrauma requiring mobilisation
• Open fractures
• Vascular injury requiring repair

Non-operative treatment. Appropriate for minimally displaced fractures (under 5 mm), patterns stable on stress views, non-ambulatory patients with minimal functional demands, and patients whose comorbidities preclude surgery or who prefer it after informed consent. It often results in poor ROM recovery with high rates of stiffness, so it is reserved for truly stable patterns or poor surgical candidates.

• Weeks 0-2 - long arm splint at 90° flexion, ice and elevation; begin hand and shoulder exercises
• Weeks 2-4 - convert to a hinged brace; gentle ROM within it, targeting full extension to 90° flexion
• Weeks 4-6 - increase ROM progressively, begin strengthening, wean from the brace
• Week 6 onwards - full ROM exercises, progressive strengthening and return to activities

Bone quality decides the construct. Good bone allows standard plate fixation. Osteoporotic bone brings poor screw purchase, comminution and a risk of implant cutout: locking plates are mandatory, longer plates distribute the load, selected screws can be cement-augmented, and in severe osteoporosis with low demand primary TEA is considered.

High-energy injuries. Consider associated injuries and the soft tissue status, and apply damage-control principles. The staged approach is a temporary spanning external fixator, soft tissue recovery over 7-14 days, then definitive ORIF.

Open fractures. Management follows the Gustilo grade.

Primary total elbow arthroplasty. In the elderly, low-demand patient, consider primary TEA with:

• Age over 65-70 with a comminuted fracture
• Severe osteoporosis
• Low functional demands
• Rheumatoid arthritis
• Pre-existing arthritis

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Posterior approach. The most common approach, used for complex fracture patterns, when both columns need access, or when an olecranon osteotomy is planned. It gives excellent exposure, allows dual plating and can be extended proximally and distally; the price is an extensile dissection, a risk of triceps dysfunction and higher stiffness rates.

1. Lateral decubitus or prone
2. Midline posterior incision
3. Full-thickness flaps
4. Identify and protect the ulnar nerve
5. Reach the columns by triceps-splitting, triceps-reflecting (Bryan-Morrey) or olecranon osteotomy

Lateral (Kocher) approach. For simple lateral column fractures and less comminuted patterns. A lateral skin incision is carried through the interval between anconeus and ECU to the lateral column, protecting the radial nerve.

Medial approach. For isolated medial column fractures, or when the ulnar nerve needs exploring. Through a medial skin incision the ulnar nerve is identified first and protected or transposed, and only then is the medial column exposed.

Olecranon osteotomy. Used for complex fracture patterns, when the articular surface needs to be seen (if there is concern for articular extension), and as the approach for TEA. A chevron cut, V-shaped with the apex proximal, gives rotational stability; a transverse cut is simpler and faster. The osteotomy is marked at the non-articular bare area, scored with a saw and completed with an osteotome, and the olecranon is elevated with the triceps attached, giving excellent articular and column exposure.

Osteotomy non-union is quoted at 5-10%, and hardware prominence and the need for removal are the other complications. In the Coles series (see Evidence Base) every chevron osteotomy with adequate follow-up united, and the main downside was hardware prominence requiring removal.

Dual plating, the gold standard. Even for an extra-articular fracture, both columns are plated, each stabilised independently. AO accepts either configuration.

Say this carefully in a viva. The biomechanical edge belongs to parallel plating, but it is cadaveric, paired-specimen, osteoporotic AO C2 bone, and both constructs allowed early mobilisation, which is the outcome that matters. No clinical trial has shown one configuration to be superior in patients. The defensible position is that the configuration matters less than the principles below, and that the surgeon should use whichever lets them get maximum screw purchase in the distal fragments.

The principles. Whatever the configuration:

• Minimum 6 cortices proximal to the fracture in each column; long plates are preferred
• Maximum screw density in the distal fragments
• Locking screws in osteoporotic bone
• Anatomic plates that match the distal humerus contour

The sequence. Reduce and fix in this order:

1. Reduce the articular surface first, if there is any involvement
2. Provisional K-wire fixation
3. Plate one column, reduce the other, plate the second
4. Check for impingement through a range of motion
5. Confirm position with intraoperative imaging

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Stiffness. The number one complication: up to 50% of patients lose functional ROM, which is why stable fixation enabling early ROM is paramount. Risk factors are prolonged immobilisation, heterotopic ossification, intra-articular adhesions, a complex fracture pattern and poor compliance with rehabilitation. Prevention is stable fixation (dual plating), early ROM within 2 weeks, indomethacin prophylaxis against HO and aggressive physiotherapy.

Heterotopic ossification. Occurs in 5-25%, with head injury, burns and delayed surgery as risk factors. Prevent it with indomethacin 75 mg daily for 6 weeks or single-dose radiation. Excise it when mature (12-18 months) and symptomatic.

Nerve injury. The ulnar nerve is the most commonly injured, with neurapraxia in 15-20% from the initial injury, surgical manipulation or hardware. The radial nerve is injured in 5-10%, from proximal fracture extension or the lateral approach. Both are observed for 3 months, then explored if there is no recovery.

Transposing the ulnar nerve. Routine transposition is debated, and the evidence does not support it as protective. In 69 bicolumnar fractures (OTA 13A and 13C) with no pre-operative deficit, ulnar nerve dysfunction was present in 10.1% immediately after surgery and 16% at final follow-up, and no treatment factor, transposition included, was associated with the risk (Vazquez); the authors state plainly that transposition was not protective, and that a retrospective design probably underestimates the true rate. A later review reported late ulnar neuropathy in 38% after this operation, again with no significant difference between in-situ release and anterior transposition.

What follows for practice and for consent. Identify and protect the nerve in every case. Decide on transposition by what the plate actually does to the cubital tunnel rather than by routine; that applies at the index operation, and irritation from a medial plate or screws later may also require it. Warn the patient before surgery that some ulnar symptoms are common: this is one of the few complications where the honest quoted figure is well into double digits, and a patient told nothing will reasonably attribute it to a technical error.

Infection and the wound. Infection is higher with extensile approaches. Wound problems are skin necrosis (especially after the posterior approach), dehiscence and haematoma, and the risk is higher with diabetes, smoking and anticoagulation. Triceps weakness follows the approach or scarring.

Malunion. The direction of the malunion decides its consequence.

Nonunion. Occurs in 2-5%, more commonly than in children. Smoking, diabetes, infection and inadequate fixation are the risk factors, and management is revision ORIF with bone graft, or TEA.

Hardware. Fixation failure is a particular risk in osteoporotic bone.

Prominent hardware is common posteriorly and may need removal after union; use low-profile plates when possible. Implants are removed for prominence, nerve irritation, infection, or at the patient's request after union, at a minimum of 12-18 months after fixation and with confirmed radiographic union.

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Rehabilitation. Four phases, from protection to return to activity.

Follow-up. Radiographs are also taken whenever there is concern for nonunion or hardware failure.

Expected range. After ORIF or TEA:

Scoring a good result. A good outcome is an MEPS over 80 points, a DASH under 20 points and grip strength over 75% of the other side.

Predictors. Young age, a simple fracture pattern, good bone quality, early ROM and a compliant patient favour a good result. Older age, comminution, osteoporosis, delayed treatment, smoking and diabetes count against it.

In the long term. Stiffness is the most common permanent sequela. Symptomatic post-traumatic arthritis develops in 10-20%, hardware removal may be needed in 10-20%, and secondary TEA is the salvage for failed ORIF or severe stiffness.

Global Epidemiology

Adult distal humerus fractures show a consistent bimodal distribution worldwide: high-energy injuries in young men and low-energy fragility fractures in older women. Nationwide Finnish registry data (Palvanen et al., Bone 2009) recorded an age-adjusted incidence of low-trauma distal humerus fractures in women aged 60 and over rising from 12 to 34 per 100,000 between 1970 and 1998, then stabilising/declining to roughly 25 per 100,000 by 2007 — a pattern attributed to cohort and fall-prevention effects (DOI). Extra-articular supracondylar (AO/OTA 13-A) patterns make up roughly 10% of distal humerus fractures; the majority are intra-articular (13-C) in elderly cohorts.

Guidance Compared Side by Side

The single highest-level evidence point shared across bodies: in elderly patients with comminuted, non-reconstructable intra-articular fractures, primary semiconstrained TEA gave better 2-year Mayo Elbow Performance Scores than ORIF (McKee et al., Level I RCT — DOI), with a quarter of ORIF-allocated patients converted intraoperatively because stable fixation could not be achieved.

Registry & Implant Evidence

No joint registry tracks plate-fixation outcomes for supracondylar fractures, but national elbow-arthroplasty data inform the TEA-as-primary-treatment decision. Registries including the NJR (England & Wales), AOANJRR (Australia), AJRR (USA), SHAR/Swedish and NZJR report total elbow replacement as a low-volume procedure with higher revision rates than hip or knee arthroplasty and meaningful early failure when used for acute trauma — reinforcing that primary TEA is reserved for genuinely low-demand patients who can accept a lifelong lifting restriction.

Practice Variation

• High-resource settings: routine CT, precontoured anatomic locking plates, and selective primary TEA; early supervised physiotherapy to combat stiffness.
• Limited-resource settings: conventional reconstruction/one-third tubular plates or non-operative management of stable patterns are more common; TEA and revision capacity are scarce, raising the threshold for arthroplasty.
• Ulnar nerve handling (in-situ decompression vs routine anterior transposition) varies between surgeons and regions without consistent evidence of superiority for routine transposition.