Ipsilateral Fractures Above & Below the Elbow
- A 'floating elbow' is the combination of IPSILATERAL fractures ABOVE and BELOW the elbow on the same limb, so the elbow joint is left flail/'floating' between them - classically a displaced SUPRACONDYLAR humerus fracture with an ipsilateral FOREARM fracture in CHILDREN, or a humeral (shaft/distal) plus forearm fracture in ADULTS.
- It is an indicator of HIGH-ENERGY trauma and carries a HIGHER incidence of OPEN fractures, NEUROVASCULAR injury (e.g. with supracondylar fractures - brachial artery, median/anterior interosseous and radial nerves) and the NEED for open reduction than isolated fractures.
- COMPARTMENT SYNDROME is a key risk - the high-energy mechanism, swelling, and combined fractures (and potential vascular injury) put the forearm at risk - so maintain a high index of suspicion and monitor closely.
- Management requires OPERATIVE STABILISATION of BOTH fractures: a flail elbow cannot be managed in a cast, and rigid fixation of both fractures allows early motion and protects against the complications. In children this is emergency reduction and percutaneous K-wire stabilisation of the supracondylar fracture plus reduction/fixation of the forearm; in adults, plate or nail fixation of the humerus and (usually plate) fixation of the forearm.
- Thorough NEUROVASCULAR assessment (before and after reduction) and treatment of any OPEN wounds (debridement, antibiotics) are essential; outcomes are good with prompt aggressive operative management, though they are worse than for isolated fractures because of the associated injuries.
- The take-home: a floating elbow is a high-energy, complication-prone injury that mandates aggressive operative treatment of both fractures and vigilance for neurovascular injury and compartment syndrome.
- “Floating elbow = ipsilateral fractures above AND below the elbow - a marker of HIGH-ENERGY trauma.
- “Expect (and look for) open fractures, neurovascular injury and COMPARTMENT SYNDROME - higher than isolated fractures.
- “Treat by stabilising BOTH fractures operatively (you cannot cast a flail elbow); early motion follows rigid fixation.
Fractures above and below the same elbow signal a high-energy injury, with higher rates of open fractures, neurovascular injury (brachial artery, median/AIN, radial, ulnar nerves) and the need for open reduction than isolated fractures.
The combination of high energy, swelling, two fractures and possible vascular injury makes forearm compartment syndrome a real risk - monitor closely, have a low threshold for pressure measurement, and beware the obtunded/young child who cannot report symptoms.
Definition & Patterns
The term 'floating elbow' describes ipsilateral fractures on both sides of the elbow - one above (humerus) and one below (forearm) - so the elbow joint is rendered flail / 'floating' between the two fractures. The classic paediatric pattern is a completely displaced supracondylar humerus fracture combined with an ipsilateral forearm fracture (distal radius or both-bone). In adults, the analogous injury is an ipsilateral humeral (shaft or distal) fracture with a forearm fracture. Whatever the exact bones, the injury reflects substantial energy transmitted through the limb.
Associated Injuries & Assessment
- Open fractures (higher incidence than isolated injuries)
- Neurovascular injury - brachial artery, median/anterior interosseous, radial and ulnar nerves (especially with displaced supracondylar fractures)
- Forearm compartment syndrome
- Other high-energy injuries (this is often a polytrauma limb)
- Full neurovascular examination before and after any reduction (pulses, perfusion, all nerves)
- Inspect for open wounds; assess soft-tissue swelling and compartments
- Radiographs of the whole limb (humerus, elbow, forearm, wrist) - do not miss the second fracture
- Treat as a high-energy / potential polytrauma patient (ATLS principles where relevant)
Maintain a high index of suspicion for forearm compartment syndrome - increasing analgesia requirement, pain on passive stretch and a tense forearm are key signs; in a child or obtunded patient, clinical signs are unreliable, so monitor closely and measure compartment pressures if in doubt. With a displaced supracondylar component, also assess the vascular status carefully - a pulseless hand (whether pale or the 'pink pulseless hand') after a high-energy elbow injury demands urgent reduction and reassessment, and vascular exploration if perfusion does not return.
Management
A floating elbow requires operative stabilisation of BOTH fractures - a flail elbow between two fractures cannot be controlled in a cast, and rigid fixation of both allows early motion and reduces complications.
- Children: emergency closed (or open) reduction and percutaneous K-wire stabilisation of the supracondylar fracture, plus reduction and fixation (K-wires/plating as appropriate) of the forearm fracture. Higher rates of open reduction and nerve injury than isolated supracondylar fractures are expected.
- Adults: plate or nail fixation of the humeral fracture and (usually) plate fixation of the forearm fracture, restoring length, alignment and rotation to allow early rehabilitation.
- Always: treat open wounds (debridement, antibiotics, tetanus), monitor compartments, and perform/repeat neurovascular assessment; have a plan for fasciotomy and vascular repair if needed.
With prompt, aggressive operative management, outcomes are generally good - in a paediatric series, most children achieved good or excellent results after emergency reduction and K-wire stabilisation of both fractures. However, because of the associated injuries (open fractures, nerve injury, compartment syndrome), results are less predictable than for isolated fractures, and early recognition and treatment of those complications drives the outcome.
Evidence & Key Studies
Management of the floating elbow injury in children: simultaneous ipsilateral fractures of the elbow and forearm
- In 12 children with a completely displaced supracondylar humerus fracture plus an ipsilateral forearm fracture, all underwent emergency operative reduction and percutaneous K-wire stabilisation; 10 had good/excellent and 2 fair results.
- The incidence of open fractures, nerve injury and the need for open reduction was higher than for isolated supracondylar fractures.
- The floating elbow is an indicator of a high-energy injury and requires aggressive operative management.
Paediatric bilateral 'floating elbow'
- Reports a rare bilateral floating elbow (ipsilateral supracondylar + distal forearm fractures bilaterally) managed by closed reduction and pinning, with uneventful union and no functional limitation.
- Emphasises vigilance for compartment syndrome in floating-elbow injuries.
- Concludes that early surgical fixation may give better results.
According to PubMed, the high-energy nature, the higher rates of open fractures/nerve injury/open reduction, and the good results of emergency operative stabilisation come from the cited Harrington paediatric series, and the compartment-syndrome vigilance and early-fixation message from the cited Rangasamy report. The adult patterns and fixation principles are standard, well-established trauma teaching. (See also our Supracondylar Humerus Fracture, Both-Bone Forearm Fracture and Compartment Syndrome material.)
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A child falls from a height and has a displaced supracondylar humerus fracture and an ipsilateral distal forearm fracture. What is this injury, why does it concern you, and how would you manage it?”
“How does the floating elbow differ in adults, and what general principles guide its treatment?”
Mnemonics & Memory Aids
FLOAT
Hook:A FLOATing elbow: fractures both sides, look for nerve/vessel injury, fix both, watch compartments, high-energy.
BOTH
Hook:Fix BOTH, beware Open injury, the Tense forearm, and the Hand's perfusion.
Definition
- Ipsilateral fractures above AND below the elbow (elbow flail/'floating')
- Children: displaced supracondylar + forearm fracture (classic)
- Adults: humeral (shaft/distal) + forearm fracture
Why it matters
- Marker of high-energy trauma
- Higher rates of open fractures, neurovascular injury, need for open reduction
- Forearm compartment syndrome risk
Assessment
- Neurovascular exam before/after reduction; inspect for open wounds
- Radiograph the whole limb (don't miss the 2nd fracture)
- Assess compartments; treat as high-energy/polytrauma
Management
- Operative stabilisation of BOTH fractures (can't cast a flail elbow)
- Children: CRPP supracondylar + forearm reduction/fixation; Adults: plate/nail humerus + plate forearm
- Treat open wounds; monitor compartments (low threshold for fasciotomy); repair vascular injury; early motion