Anatomy of the Elbow

The projections of the distal humerus (medial epicondyle, lateral epicondyle, trochlea and capitellum) and the olecranon (the prominent bony point at the back of the elbow) provide joint stability. The medial and lateral collateral ligament complexes — particularly the lateral ulnar collateral ligament (LUCL) — form the basis of elbow stability. A healthy elbow allows eating, combing the hair and dressing without pain.

Because the elbow is highly prone to stiffness, the fundamental principle of treatment is anatomical reduction with fixation rigid enough to permit early movement.

Distal Humerus Fractures

These are fractures of the region of the humerus close to the elbow. They usually result from high-energy injuries (in younger patients) or from low-energy falls in older patients with osteoporosis. The AO classification is widely used:

• Supracondylar (extra-articular) fracture: above the joint, proximal to the condyles; particularly common in children
• Transcondylar / intercondylar (T or Y) fracture: involving both the supracondylar region and the joint surface
• Isolated condyle fracture: lateral condyle (the most common, particularly in children) or medial condyle fracture
• Capitellum fracture: the anterior part of the distal humerus that articulates with the radial head
• Medial or lateral epicondyle fracture: usually in adolescents, together with ligament or tendon avulsion

Olecranon Fractures

The olecranon is the prominent bony projection of the ulna at the back of the elbow. It fractures from a direct blow or from sudden contraction of the triceps tendon (avulsion). The Mayo classification is widely used:

• Type I: non-displaced; may be treated non-operatively
• Type II: stable but displaced; surgery is required, with tension band or plate fixation
• Type III: unstable (with associated subluxation or dislocation); plate fixation is standard
• Comminuted fracture: common in older patients with osteoporosis; occasionally excision of the olecranon with reattachment of the triceps tendon, or arthroplasty, may be used

Radial Head Fractures

This is the most common fracture around the elbow. It usually results from a fall on an outstretched hand (FOOSH). The Mason classification is widely used:

• Mason Type I: non-displaced or minimally displaced (<2 mm); treated non-operatively with early movement
• Mason Type II: displaced partial fracture (>2 mm); surgery (screw or mini-plate fixation) is required if it blocks joint movement
• Mason Type III: comminuted, involving the entire radial head; ORIF is used where possible and, rarely, a prosthesis
• Mason Type IV: radial head fracture with elbow dislocation; may be a component of the "terrible triad"

Coronoid Process Fractures

This is a fracture of the small projection on the front of the ulna; it plays a critical role in elbow stability. The Regan–Morrey classification is used:

• Type I: tip fracture only; usually treated non-operatively
• Type II: less than 50% of the coronoid; surgery may be required where there is associated dislocation or instability
• Type III: more than 50% of the coronoid; almost always requires surgery
• Anteromedial fracture: with lateral collateral ligament injury; creates varus instability and requires repair or sometimes reconstruction

Complex Elbow Injuries

These are difficult cases in which more than one structure is injured together. Surgical treatment is required for anatomical reduction and early movement.

• "Terrible triad": elbow dislocation + radial head fracture + coronoid fracture (with lateral collateral ligament rupture)
• Monteggia fracture: proximal ulna fracture + radial head dislocation
• Trans-olecranon fracture–dislocation: an intra-articular olecranon fracture with dislocation of the humeroulnar joint
• Varus posteromedial instability pattern: anteromedial coronoid fracture + LUCL rupture

Classification by Displacement and Joint Involvement

• Non-displaced fracture: the bone fragments have not shifted; some are suitable for non-operative treatment
• Displaced fracture: the fragments have shifted; surgical reduction is required
• Intra-articular fracture: the fracture line extends into the joint surface, increasing the long-term risk of arthritis
• Open fracture: the bone has penetrated the skin; infection risk is high and emergency surgery is required

Symptoms

• Sudden, severe pain: at the moment of injury, prominent around the elbow
• Swelling and bruising: marked bleeding into the joint (haemarthrosis) and oedema within the first hours
• Restricted movement: difficulty bending and straightening the elbow and rotating the forearm
• Deformity: visible in displaced fractures (particularly olecranon and distal humerus fractures)
• Tenderness: pain that increases on palpation of the fracture site
• Crepitus: a grating sensation and sound during movement
• Inability to extend the elbow actively: triceps mechanism insufficiency in olecranon fractures
• Altered sensation or coldness: if there is nerve or vascular injury (particularly the ulnar, median and radial nerves and the brachial artery)
• Open wound: loss of skin integrity in an open fracture
• Loss of joint stability: a feeling of dislocation or of the joint giving way in complex injuries such as the terrible triad

Mechanisms of Injury

• Fall on an outstretched hand (FOOSH): the most common mechanism for radial head and supracondylar fractures
• Direct blow: typical for olecranon fractures (a fall onto the elbow)
• High energy: road traffic accidents, falls from height, motorcycle accidents
• Excessive contraction: sudden triceps contraction (olecranon avulsion fracture)
• Sports injuries: cycling, skiing, motocross, gymnastics
• In children: falls from low height — particularly supracondylar fractures
• Pathological fractures: with minimal trauma in the presence of bone tumour or metastasis

Diagnosis

Diagnosis is based on a detailed history, physical examination and imaging. Examination assesses swelling, haemarthrosis, deformity, points of tenderness, range of motion (flexion–extension and pronation–supination), joint stability (varus/valgus stress tests), neurovascular status (particularly the ulnar nerve — sensation in the little finger and the intrinsic muscles of the hand; the median nerve — thumb flexion; the radial nerve — wrist extension; and the brachial pulse) and skin integrity. Careful monitoring for compartment syndrome is required.

Plain radiographs are the first-line investigation; anteroposterior and lateral elbow views are standard. A "sail sign" (elevation of the anterior fat pad) or a visible posterior fat pad on the lateral view suggests an occult fracture (particularly of the radial head). CT is almost always required for surgical planning in intra-articular fractures (distal humerus, coronoid, comminuted radial head) and complex injuries; three-dimensional CT is critical for assessing fragment displacement. MRI is used to evaluate associated ligament injuries, cartilage damage and occult stress fractures. Angiography or CT angiography may be required where vascular injury is suspected after a high-energy injury.

Non-operative (Conservative) Treatment

Stable, non-displaced fractures that do not disturb the joint surface are suitable for non-operative treatment. Typical candidates are non-displaced Mason Type I radial head fractures, non-displaced olecranon fractures (Mayo Type I) — particularly in lower-demand older patients — non-displaced isolated coronoid tip fractures and some stable distal humerus fractures. Treatment consists of a short period in a splint or cast (10–20 days) followed by graduated active range-of-motion exercises in a purpose-made brace. Prolonged immobilisation markedly increases the risk of elbow stiffness.

Surgical Treatment (ORIF or Arthroplasty)

Open reduction and internal fixation (ORIF) is the standard treatment for displaced or unstable fractures and those that disturb the joint surface. Typical candidates are displaced distal humerus fractures, displaced olecranon fractures, Mason Type II–III radial head fractures (where there is a mechanical block), displaced coronoid fractures, complex elbow injuries (terrible triad, Monteggia, trans-olecranon), open fractures and patients who develop secondary displacement during non-operative treatment. The fundamental aim of treatment is to preserve the patient's own bone and joint surface through anatomical reduction and rigid fixation.

Advantages

The principal advantage is anatomical restoration of the fracture with rigid fixation. This reduces the long-term risk of joint surface incongruity, malunion, non-union and post-traumatic arthritis. Whereas prolonged immobilisation in non-operative treatment can lead to elbow stiffness, surgery allows early movement — which is particularly important in elbow fractures because the elbow is one of the joints most prone to stiffness.

• Anatomical reduction: fragments are restored with millimetre precision and the joint surface is accurately repaired
• Early motion: stable fixation allows elbow range-of-motion exercises to begin within 1–7 days after surgery, markedly reducing the risk of stiffness
• Restoration of stability: ligament injuries and dislocations are repaired, reducing the risk of recurrent dislocation
• Operative time: 60–90 minutes for olecranon and radial head fractures; 120–180 minutes for distal humerus fractures; longer for complex elbow injuries
• Discharge the same day or after 1–2 days (longer in complex cases)
• Elbow function is better preserved in the long term; the risk of post-traumatic arthritis and stiffness is higher after non-operative treatment of displaced intra-articular fractures

Disadvantages

There are surgery-specific risks: wound infection, deep infection, implant failure, nerve injury (particularly the ulnar nerve) and rare vascular injury, together with rare anaesthetic complications.

• Ulnar nerve sensitivity: the ulnar nerve is at risk during distal humerus and olecranon surgery; temporary or permanent numbness may develop. The nerve is protected during surgery or transposed anteriorly.
• Implant irritation: prominence of K-wires and wires beneath the skin at the back of the olecranon is common; implant removal is required in 30–80% of patients. Plates are less irritating.
• Joint stiffness: elbow stiffness may develop despite surgery; additional immobilisation or a late start to movement increases the risk.
• Heterotopic ossification: common in elbow surgery (the risk is three times higher where there is an associated head injury) and may cause loss of movement.
• There is a risk of a poor functional outcome in complex fractures or in patients with significant comorbidity.

Why Surgery?

The elbow is a critical joint for positioning the hand and forearm in space. Even 1–2 mm of joint surface incongruity leads to cartilage wear and post-traumatic arthritis in the long term. Elbow stiffness severely restricts daily activities; the functional range of motion is defined as 30–130° of flexion–extension and 50° of supination to 50° of pronation, and losing this range can prevent a patient from washing their face, combing their hair or eating. In olecranon fractures the integrity of the triceps mechanism is essential for active elbow extension. The surgeon therefore prefers surgical treatment whenever the fracture is displaced and unstable or threatens joint function, and aims for rigid (stable) fixation that permits early movement in order to prevent elbow stiffness.

Who is a Candidate?

Surgery is performed for displaced or unstable elbow fractures and for those that disturb the joint surface.

• Displaced distal humerus fractures
• Mayo Type II–III olecranon fractures
• Mason Type II–III radial head fractures causing a mechanical block or comminuted
• Displaced coronoid fractures (particularly with dislocation)
• Complex elbow injuries (terrible triad, Monteggia, trans-olecranon)
• Open fractures; patients who develop displacement during non-operative treatment
• Patients whose general health is suitable for general anaesthesia and surgery
• Non-operative treatment: stable, non-displaced fractures (Mason Type I radial head, Mayo Type I olecranon, isolated coronoid tip fractures) and selected patients at very high surgical risk

Expected Outcomes

Most patients with a correctly treated elbow fracture achieve a pain-free, functional elbow. Most return to daily activities within 3–6 months; complete recovery may take up to a year in complicated cases. Mild loss of range of motion (particularly 10–20° at the extremes of extension or flexion) is common, but the functional range is preserved in most patients. Recovery may be prolonged after complex elbow injuries and comminuted distal humerus fractures, and a small number of patients are left with persistent stiffness or loss of function. Early surgery, anatomical reduction and disciplined rehabilitation are the principal determinants of success.

Risks Specific to Non-operative (Splint/Cast) Treatment

• Elbow stiffness (contracture): the most common and most important complication; marked loss of range of motion due to prolonged immobilisation
• Inadequate reduction / secondary displacement: fragments shifting within the cast; further surgery may be required
• Skin problems: pressure sores and friction beneath the splint or cast
• Triceps and biceps muscle atrophy
• Sudeck's atrophy (complex regional pain syndrome / CRPS)
• Malunion, non-union and loss of functional range of motion

Risks Specific to Surgery — Common (Under 5%)

• Superficial wound infection (usually treated with antibiotics)
• Postoperative pain, swelling and temporary bruising
• Temporary joint stiffness — resolves with regular physiotherapy
• Transient symptoms related to anaesthesia such as nausea and dizziness
• Temporary numbness of the hand and forearm after a regional block
• Haemarthrosis and prolonged oedema (which may persist for 6–12 months)

Risks Specific to Surgery — Less Common

• Deep infection (osteomyelitis / implant infection): 1–3%; particularly in open fractures; may require revision, implant removal and prolonged antibiotics
• Ulnar nerve injury or late ulnar neuropathy: the ulnar nerve is the nerve most commonly affected in elbow surgery; temporary numbness is common, permanent neuropathy rare
• Median, radial or posterior interosseous nerve injury (with the lateral approach)
• Brachial artery injury (very rare)
• Implant failure: loosening or breakage of screws or plates, particularly with early loading
• Compartment syndrome: rare but very important; increasing pain, tightness and loss of sensation in the forearm; requires emergency fasciotomy
• Heterotopic ossification (bone formation in soft tissue): common in elbow surgery (5–25%), particularly where there is an associated head injury; excision may be required in advanced cases
• Complex regional pain syndrome (CRPS)
• Deep vein thrombosis (DVT) — very rare in the upper limb
• Non-union of an olecranon osteotomy (5–10% in distal humerus surgery)

Long-term Complications

• Elbow stiffness (contracture): the most common long-term complication; marked restriction of movement in 5–20% of patients. Capsular release surgery may be required in advanced cases
• Malunion: mechanical disturbance, pain and an increased risk of arthritis
• Non-union: particularly of the distal humerus and olecranon; increased by smoking and diabetes
• Post-traumatic osteoarthritis: may develop years later after intra-articular fractures
• Chronic instability: a tendency to recurrent dislocation, particularly after complex elbow injuries (terrible triad)
• Chronic pain; late ulnar neuropathy (compression of the ulnar nerve in its groove)
• Loss of strength (particularly grip, gripping and lifting)

Implant-related Problems

• Implant irritation close to the skin: prominence of K-wires and wires beneath the skin at the back of the olecranon; implant removal is required in about 30% of patients (and generally in about 75% after an olecranon tension band)
• Implant migration: displacement of K-wires, which may penetrate the skin
• Plate irritation: a medial distal humerus plate may irritate the ulnar nerve region
• A radial head prosthesis that is too long: disturbance of the joint space and post-traumatic arthritis
• Need for implant removal: usually performed after 9–12 months, once fracture healing is complete

Factors that Increase Risk

• Smoking (markedly increases the risk of wound healing problems, non-union and infection)
• Poorly controlled diabetes (impaired wound healing, risk of infection)
• Osteoporosis (poor implant purchase, secondary displacement)
• Immunosuppressive therapy and rheumatological disease
• Advanced age; high-energy or open fracture
• Associated head injury (increased risk of heterotopic ossification)
• Active or recently treated infection (dental, urinary, skin)
• Prolonged immobilisation (the determining factor for stiffness)

Contact Your Doctor Immediately If You Have

• Sudden increase in pain or swelling
• Fever above 38 °C
• Discharge, malodour or separation of the wound
• Increasing numbness, tingling or weakness in the forearm, hand or fingers
• Bruising, coldness or pallor of the fingers (suspected vascular problem)
• Excessive tightness in the forearm, unbearable pain or pain on straightening the fingers (suspected compartment syndrome)
• Wound edge separation or exposed hardware
• Intense pain or tightness within the splint or cast

Long-term Outcomes

With accurate diagnosis, appropriate treatment and compliant rehabilitation, the great majority of elbow fractures heal without problems. Most patients return to daily activities within 3–6 months, and return to sport is possible within 6–12 months. Complete recovery may take up to a year in some cases; stiffness may persist for 12 months, particularly after complex distal humerus fractures and terrible triad injuries.

There is a risk of post-traumatic arthritis years later after intra-articular fractures; anatomical reduction, early motion and compliant rehabilitation reduce this risk. Stopping smoking, controlling blood glucose and maintaining a healthy weight are critical factors for healing and long-term outcome.