Scaphoid fractures can be located at the distal pole (10%), waist (70%), or proximal pole (20%). The primary vascular supply to the scaphoid is via the radial artery, two branches of which supply the distal pole and waist of the scaphoid. With no direct arterial supply, the proximal pole depends on fracture union for revascularization. Delayed diagnosis or nonunited fracture may lead to proximal scaphoid avascular necrosis, which appears as sclerosis, fragmentation, and collapse.

Scaphoid waist fracture. Acute, nondisplaced, minimally comminuted, transverse scaphoid waist fracture.

Scaphoid avascular necrosis. Remote, nonunited, scaphoid waist fracture with dense sclerosis and fragmentation of the proximal and distal fragments.

Primary management is nonoperative with wrist immobilization in slight flexion and radial deviation. Time to union can vary based on location of the fracture and may be as long as 24 weeks for proximal scaphoid fractures. Surgical intervention is reserved for nonunited, displaced, or unstable fractures.

Scapholunate dissociation is the most common ligamentous disruption of the carpus and is often associated with scaphoid fracture. In trauma, the scapholunate ligament fails under high-energy loading of the extended, ulnar-deviated wrist. Scapholunate dissociation can also be seen in the setting of chronic arthritis. On PA radiographs, the normal scapholunate interval is less than 2 mm. In scapholunate dissociation it is greater than 3 mm. Pain is localized over the dorsal scapholunate region and exacerbated by dorsiflexion. Scapholunate ligament reconstruction may be required to prevent persistent instability.

Scapholunate dissociation with remote scaphoid fracture and avascular necrosis. The scapholunate interval is 6 mm. The proximal scaphoid pole is sclerotic with slight fragmentation at the scaphoid waist. Marked radiocarpal narrowing and subchondral sclerosis.

Colles fracture (after Abraham Colles, an irish surgeon, 1773-1843) typically results from a fall onto a hyperextended wrist, which clinically appears as a “dinner fork” deformity due to dorsal angulation of the distal radial fragment and hand. Colles fractures may be impacted, extend to the radiocarpal or radioulnar articulations, and are often associated with an ulnar styloid fracture. They are more common in elderly women, as osteoporosis is a predisposing factor. Most are managed with closed reduction and cast immobilization with the wrist held in neutral to slight flexion.

Colles fracture. Comminuted, dorsally angulated distal radial fracture with associated ulnar styloid fracture but without involvement of the radiocarpal or distal radioulnar joints.

The Smith fracture is another type of transverse distal radial fracture (Robert William Smith, Colles’ successor at Trinity college in Dublin, 1807-1873). In contrast to the Colles fracture, it is characterized by volar angulation of the distal fragment. Smith fractures result from either a direct blow to the back of the wrist or a fall onto a flexed wrist with the forearm in supination. The hand and distal radial fragment are displaced towards the palm, causing a “garden spade” deformity on physical examination. Less common than Colles fractures, they are usually seen in younger patients with high-energy trauma. Smith fractures are unstable and often require open reduction and internal fixation. Because of its location, the median nerve is susceptible to injury and should be evaluated before and after closed reduction.

Smith fracture. Transverse distal radius fracture without radiocarpal extension, radioulnar extension, or associated ulnar styloid fracture. Moderate volar angulation of the distal fragment.

Radial styloid fractures are due to axial compression of the scaphoid into the distal radius with associated radial collateral ligament avulsion and are often associated with scapholunate injury and perilunate dislocation. It is an unstable fracture that requires operative fixation and immobilization.

Hutchinson/Chauffeur’s fracture. Nondisplaced, intra-articular, oblique fractures of the radial aspect of the distal radii with extension to the radoiocarpal joint in two patients.

Plain radiographs (AP, lateral, oblique) of the wrist are sufficient for diagnosis. Distal radius fractures are classified according to (1) extension into the radiocarpal joint, (2) extension to the distal radioulnar articulation, and (3) the presence of an associated ulnar styloid fracture. These features should be included in a description to facilitate the orthopedic surgeon’s ability to make optimal management decisions

Most pediatric fractures can be managed by closed reduction. Adult fractures usually require operative fixation.

Monteggia fracture (adult). Midulnar diaphysis fracture with dorsal and ulnar displacement of the distal fragment, override, and associated volar/radial dislocation of the radial head.

Monteggia fracture (pediatric). Midulnar incomplete fracture with apex volar angulation and volar dislocation of the distal radius relative to the capitellum.

The Galeazzi fracture is a distal radial diaphysis fracture with dislocation of the distal radioulnar joint. Galeazzi fractures are three times as common as Monteggia fractures. The mnemonic MUGR ( “Monteggia–Ulna, Galeazzi–Radius,”) aids in recalling which bone is fractured in these injuries.

Galeazzi fractures are usually seen in children between 9 and 12 years of age and result from impact to the dorsolateral wrist or a fall onto an outstretched hand.

Radiographic findings include a transverse or oblique distal radial diaphysis fracture, widened distal radioulnar joint, and distal subluxation of the ulna relative to the radius.

Urgent operative fixation is normally required for adults with Galeazzi fractures. Children younger than 10 years may be treated with closed reduction and splinting, but they should have prompt follow-up orthopedic evaluation.

Galeazzi fracture (adult). Transverse distal radius fracture; dorsal displacement of the distal fragment, override and disruption of the DRUJ with dorsal ulnar dislocation.

The nightstick fracture is an isolated mid-shaft ulnar fracture that results from direct trauma to the ulna. In cases of assault, it is a defensive fracture that occurs when a victim attempts to protect his face from an overhead blow (historically delivered via a police officer’s nightstick). In contrast to the similar-appearing Monteggia fracture, the radiocapitellar relationship is normal.

Nondisplaced fractures are treated with splint immobilization. Open reduction and internal fixation is usually necessary when displacement is greater than 50% or angulation is greater than 10° in any plane

Nightstick fracture. Transverse fracture at the junction of the mid- and distal ulnar thirds with slight ulnar displacement of the distal fragment. Associated forearm soft tissue swelling..

Clinical features include pain, swelling and inability to extend the forearm against gravity. Ulnar nerve injury is possible

Best seen on the lateral elbow radiograph, olecranon fractures appear as a defect extending from the dorsal ulnar cortex to the articular surface of the trochlea. Type A fractures ( AO classification) are extra-articular, Type B fractures are intra-articular, and Type C fractures are associated with radial head fractures.

Nondisplaced olecranon fracture (Type A). Subtle, nondisplaced intra-articular fracture.

Displaced intra-articular olecranon fracture (Type B). Minimally comminuted intra-articular olecranon fracture with extension to the trochlear joint surface. Approximately 8 mm fragment displacement; marked soft tissue swelling.

In most cases, olecranon fractures require open reduction and internal fixa- tion to restore the articular surface and preserve the elbow extensor mechanism. Nondisplaced fractures can be managed conservatively. Post-traumatic arthritis occurs in ~ 20% of patients, particularly if reduction is suboptimal.

Triceps avulsion injuries are unusual and are characterized on radiographs by a small, proximally displaced osseous flake or enthesophyte fragment. Usually the result of a fall on an outstretched hand with the elbow in flexion, triceps avulsion injuries may be seen in weightlifters, patients with renal disease, and patients who receive systemic steroid therapy or local steroid injection.

Triceps avulsion. A fractured enthesophyte at the triceps insertion is proximally displaced with respect to the olecranon.

Intra-articular radial head fracture. Nondisplaced, mildly impacted, intra-articular radial head fracture. Elevation of the anterior and visible posterior elbow fat pads indicate elbow effusion. The ulna and distal humerus are normal.

Associated injuries may include ulnar coronoid process fracture, elbow dislocation, medial collateral ligament injury, interosseous membrane injury, and damage to the wrist triangular fibrocartilage complex.

Radial head fracture classification (Mason)

Type I

Non-displaced fracture

Type II

Partial fracture with  > 2 mm displacement (impaction, depression, angulation)

Type III

Comminuted fracture of entire radial head

Type IV

Comminuted fracture with associated elbow dislocation

Type I fractures are treated conservatively with brief immobilization and analgesia. Type II fractures are treated with open reduction and internal fixation. Type III fractures of-ten require excision of the radial head and prosthetic replacement.

The Essex-Lopresti fracture-dislocation is defined by interosseous ligament disruption, usually accompanied by a fracture of the radial head and disruption of the wrist triangular fibrocartilage. These injuries result in distal radioulnar joint dislocation; associated clinical findings include pain in the wrist and forearm on pronation and supination, and swelling and tenderness over the fractured radial head. Treatment consists of radial head repair or replacement.

Essex-Lopresti fracture-dislocation. Impacted intra-articular radial head fracture with associated widening of the distal radioulnar articulation and subluxation of the distal ulna.

Simple dislocations are treated with closed reduction and brief immobilization. Postreduction images should be carefully evaluated for radial head fracture, coronoid process fracture, or intra-articular bone fragments; CT may be helpful for operative planning in complex dislocations and in cases with comminuted fractures.

The “terrible triad” refers to elbow dislocation with associated fractures of the ulnar coronoid process and radial head. In this injury, the lateral collateral ligament is almost always disrupted, resulting in an unstable elbow. It is generally managed surgically by reattaching the ulnar coronoid process and affixing the radial head fracture (or replacing the radial head).

Posterior elbow dislocation. The ulna is dorsally dislocated with respect to the humerus, and the trochlea contacts the base of the coronoid process. A triangular fragment anterior to the distal humeral metaphysis corresponds to the fractured coronoid process tip. The radial neck is impacted, and the radial head is fractured and volarly angulated. A large joint effusion and marked soft tissue swelling are present. These findings correspond to a “terrible triad injury.”

Complex and unstable elbow fracture/dislocations require operative treatment. They are more likely to be complicated by osteoarthritis, range of motion limitation, instability, and recurrent dislocation.

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Radiographs should be obtained in AP, transscapular, and (if possible) axillary views. Articular surface fractures associated with a hemarthrosis may show inferior humeral head subluxation relative to the scapular glenoid (pseudosubluxation).

Pseudosubluxation. Nondisplaced (one-part) fractures of the humeral neck and greater tuberosity. The humeral head is inferiorly subluxed due to an associated hemarthrosis. Because none of the fragments are separated by more than 1 cm, this is considered a one-part fracture.

The Neer classification system divides the proximal humerus into four parts, which are located between the epiphyseal lines where fractures primarily occur: the anatomic neck, the surgical neck, and the greater and lesser tuberosities. Fragments are considered displaced if separated by more than 1 cm or > 45° angulation. A one-part fracture contains no displaced fragments, regardless of the number of fracture lines. Two-part, three-part, and more severely comminuted fractures are character- ized by progressively greater displacement and angulation of the small fragments.

One-part humeral head fracture. Transverse, slightly impacted surgical humeral neck fracture with minimal displacement of the greater tuberosity. No fragments are separated by more than 1 cm, nor is there significant angulation of any fragment.

Two-part humeral head fracture. Impacted fracture of the surgical humeral neck with ~ 90° angulation of the humeral head with respect to the shaft.

Three-part humeral head fracture. Displaced fractures with separation and displacement of the diaphysis, medial humeral head, and greater tuberosity.

One-part fractures are treated with immobilization and analgesics, but all other proximal humeral fractures require urgent orthopedic consultation in the emergency department because of the high risk of complications. Closed reduction, operative fixation, or a combination of the two may be necessary.

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Anterior shoulder dislocation is the most common type of shoulder dislocation (~ 95%) and occurs with forced arm abduction, external rotation, and extension. The humeral head is displaced anterior, medial, and inferior to its normal location, and its posterolateral surface strikes the anteroinferior surface of the scapular glenoid.

Pain and muscle spasm are the rule, and patients typically hold the affected arm in slight abduction and external rotation.

Anterior shoulder dislocations are well characterized by standard radiographic series consisting of AP views in internal and external rotation, the scapular-y view, and the axillary view. CT or MR may be useful for detection of subtle osteocartilaginous fractures or intra-articular fragments. MR, in particular, is superior for identification of rotator cuff, capsular, and glenoid labral injuries.

Anterior shoulder dislocation. The humeral head is dislocated inferiorly and anteriorly with respect to the scapular glenoid. On the scapular “Y” view the humeral head is normally centered over the “Y" made up of the junction of the scapular body and spine. In this case it is anteriorly displaced. Several small bony fragments adjacent to the glenoid reflect an associated bony Bankart lesion.

In anterior dislocation, impaction fractures of the posterolateral humeral head (Hill-Sachs lesion) and anteroinferior glenoid labrum avulsion (Bankart lesion) commonly occur. An osseous glenoid rim fracture, when present, is referred to as a bony Bankart lesion.

Hill-Sachs lesion. Radiograph and CT after reduction of anterior shoulder dislocation; lateral humeral head impaction fracture.

Luxatio erecta

Luxatio erecta (inferior dislocation) is an uncommon anterior dislocation variant that tends to occur in elderly individuals. It results from forceful hyperabduction with impingement of the humeral neck on the acromion. The humeral head is inferiorly displaced with the humeral shaft directed superolaterally along the glenoid margin. The humeral articular surface is directed inferiorly and is no longer in contact with the inferior glenoid rim.

Luxatio erecta. Anterior-inferior right humeral head dislocation with fixed adduction of the humerus.

Luxatio erecta is almost always accompanied by detachment of the rotator cuff and neurovascular compression. Associated fractures are also common. Early reduction should be attempted in an effort to prevent neurologic or vascular damage.

Posterior shoulder dislocation

Posterior shoulder dislocation is much less common than anterior dislocation (~ 5%) and can be a difficult diagnosis both clinically and radiographically. Injury mechanisms include seizures, electrocution, or a blow to the back of the shoulder with the arm internally rotated and abducted. Patients are usually unable to rotate their arm externally, and these injuries can be missed if axillary or scapular “Y” views are not obtained.

On frontal radiographs, the normal slight superposition of the medial humeral head on the glenoid is lost. Because patients cannot externally rotate the affected arm, only internally rotated AP radiographs are possible; these do not show the greater tuberosity in profile and the humeral head looks like a light bulb. When the AP external rotation view appears identical to the internal rotation view, consider posterior dislocation!

Posterior shoulder dislocation. Frontal radiograph shows lateral displacement of the humeral head with little overlap of the glenoid fossa. The humeral head has a typical “light bulb” appearance with poor visualization of the greater tuberosity. Postreduction radiograph for comparison; the humerus now articulates normally with the glenoid.

Subtle posterior shoulder dislocation. The orientation of the humeral head is unchanged on internal and external rotation radiographs and demonstrates the “lightbulb” sign. A subtle, vertically oriented crescentic lucency is superimposed on the mid-humeral head (trough sign).

A fracture of the anterior humeral head, known as the trough sign or reverse Hill- Sachs lesion, reflects impaction of the anterior humeral head against the posterior glenoid rim. The corresponding fracture of the posterior glenoid (when present) is called a reverse Bankart lesion.

Reverse Hill Sachs and Bankart lesions. Axillary view shows superposition of the humeral head on the posterior glenoid. Postreduction axial CT shows impaction at 10 o’clock, consistent with a reverse Hill-Sachs lesion, and a tiny avulsion of posterior glenoid; a reverse Bankart lesion.

The inferior cortex of the acromion and distal clavicle should normally align on the AP view. The distance between the acromion and distal clavicle is variable but usually less than 8–10 mm. Weight-bearing views with comparison to the uninjured shoulder may be necessary to demonstrate subluxation.

Grade I

Normal or slight acromioclavicular subluxation. Acromioclavicular ligament sprain with intact coracoclavicular ligament.

Grade II

Acromioclavicular ligament tear with acromioclavicular widening or distal clavicular elevation. Coracoclavicular ligament injury without widening of the normal coracoclavicular distance (< 1.3 cm).

Grade II acromioclavicular separation. The distal clavicle is separated from the acromion by 1 shaft’s width and is elevated 1.2 cm with respect to the coracoid.

Grade III

Acromioclavicular and coracoclavicular ligament disruption. Distal clavicle elevation relative to the acromion. Coracoclavicular distance > 1.3 cm or a side-to-side difference of > 5 mm on bilateral AP views. Weight-bearing radiographs may be necessary to reveal these findings.

Grade III acromioclavicular separation. The distal clavicle is displaced from the acromion by 1.5 shafts’ width and is elevated 3 cm with respect to the coracoid.

Grade I and II injuries are usually treated conservatively. Grade III injuries may ben- efit from operative stabilization

Scapular fractures may be difficult to diagnose on conventional radiographs but are easily appreciated on chest CT. They are described as body, spine, acromion, coracoid, scapular neck, and glenoid fractures. Fragment displacement is usually minimal due to the supporting muscles and periosteum. Unless the glenoid fossa is involved, most scapular fractures are managed nonoperatively. Fractures that extend to the articular surface may require operative reconstruction.

Comminuted scapular body fracture with extension to glenoid articular surface. Associated mid- clavicular fracture. Normal glenohumeral, acromioclavicular, and coracoclavicular relationships.

The diagnosis is based on history and clinical examination. Radiographs are obtained to identify and characterize any osseous  avulsion fracture.

Minimally displaced avulsion of the ulnar base of the first proximal phalanx (oblique and PA radiographs).

Nondisplaced avulsion of the ulnar base of the first proximal phalanx, nearly invisible on oblique radiograph. STIR MRI shows increased signal at the avulsion site. T1-weighted image shows the radial and ulnar collateral ligaments at the first carpometacarpal joint.

Ultrasound and MRI can be used to identify a Stener lesion, in which the avulsed ligament is displaced below the adductor pollicis aponeurosis. This is present in most complete tears, prevents normal healing, and normally requires surgical management.

Immobilization is the primary initial treatment for nondisplaced avulsion fractures and ligament strains without major instability; a thumb spica cast or splint should be placed for 6 weeks. Surgery is usually indicated for ligamentous injuries with significant thumb instability and for displaced fractures.