Scapula Fractures

Fractures of the scapula are relatively uncommon, accounting for 3% of all shoulder girdle injuries. These generally occur as the result of high-energy trauma explaining the frequent association with other, often life-threatening, injuries that may be of greater significance than the fracture itself. It is not uncommon for scapular fractures to be overlooked in polytrauma patients and often noticed incidentally on a chest radiograph or CAT scan.

A classification system was developed by Ada and Miller (Table 3), which divided fractures into those involving the acromion, spine and coracoid, type 1, glenoid neck, type 2, intra-articular glenoid fractures, type 3, and isolated scapular body fractures, type 4.

Table 3 Scapular Fracture Classification System

Data from Ada JR, Miller ME: Scapular fractures: analysis of 113 cases. Clin Orthop 269:174–180, 1991.

Associated injuries are quite common due to the high-energy mechanisms in which they usually occur. In one study of 148 fractures in 116 scapulae, 96% had associated injuries with upper thoracic rib fractures being the most common. Pulmonary injuries were also common with an overall incidence of 37%, of which 29% were hemopneumothorax and 8% pulmonary contusion. Head injuries were observed in 34%, ipsilateral clavicle fractures were seen in 25%, and 12% of patients had cervical spine injuries, of which 4% had permanent cord injuries.

Management of these fractures is often nonsurgical as poor healing is an infrequent complication due to the rich blood supply from the investing rotator cuff musculature. Nonoperative management consists of admission for a period of 24 hours to assess pulmonary and cardiac status. A brief period of sling immobilization is initiated for comfort, followed by passive range of motion. Most fractures are united by 6 weeks such that active mobilization and strengthening can ensue safely. Maximal functional recovery can take 6–12 months.

Operative indications include intra-articular glenoid fractures with 5 mm of displacement, coracoid fractures with intra-articular extension and more than 5 mm of step-off, glenoid rim fractures with persistent or recurrent glenohumeral instability.

The injury pattern described as the “floating shoulder” deserves attention. This refers to a “double disruption” of the superior shoulder suspensory complex. This complex consists of a bone and soft tissue ring formed by the glenoid, coracoid process, coracoclavicular ligaments, distal clavicle, acromioclavicular joint, and acromion process. Isolated disruption of one of these components is generally tolerated well; however, when two or more structures are damaged, it is thought to produce an unstable situation. This is commonly seen with ipsilateral clavicle and glenoid neck fractures. The treatment of such injuries is somewhat controversial in that good results have been reported with fixation of both the glenoid and clavicle, clavicle alone, and more recently, nonoperative management. At this time, reasonable indications for operative intervention would include glenoid neck fractures with more than 3 cm of medial displacement in combination with injury to another structure. Each patient, however, must be evaluated individually.

Scapulothoracic Dissociation

Scapulothoracic dissociation is an infrequent injury that can be thought of as an internal forequarter amputation, which is almost always seen in conjunction with severe injuries to the brachial plexus and subclavian vessels. It is the result of a massive traction injury causing significant lateral displacement of the scapula relative to its thoracic articulation. According to the paper by Althausen et al., 88% have associated vascular lesions and 94% presented with severe neurologic injuries. A flail extremity resulted in approximately 52%, early amputation in 21%, and death in 10% of patients.

Diagnosis is made clinically by the presence of massive swelling, weakness, pain, tenderness, and absent or diminished pulses. It is crucial not to attribute pulselessness to a more distal injury when a more proximal, life threatening injury may be the underlying cause. Radiographically an AP film of the chest with the cassette oriented transversely may reveal lateral displacement of the scapula. Measurement from the medial border of the scapula to the spinous processes should alert the physician to the possibility of a scapulothoracic dissociation with a distance of more than 1 cm when compared to the opposite side. This may or may not be seen in conjunction with an acromioclavicular separation or clavicle fracture.

Management is controversial but arterial injuries may warrant immediate exploration and repair. As many as 10% of patients who survive the initial injury may die from exsanguination. Brachial plexus exploration may be carried out at the same time. Bony stabilization may be necessary to protect vascular repairs but the role of internal fixation is otherwise less clear.

Glenohumeral Dislocation

Due to its lack of bony constraint, the shoulder is the most commonly dislocated joint in the body. It is not a true ball and socket joint, but more like a golf ball resting on a golf tee. The static restraints to dislocation are composed of the glenoid labrum, capsule, and glenohumeral ligaments, while the rotator cuff musculature provides additional dynamic stability.

Anterior dislocations are by far the most common type. These are usually the result of an eccentric load applied to the arm while in an outstretched position as would be seen in a volleyball player while spiking the ball. Posterior dislocations occur with a posteriorly directed force on an adducted, flexed arm, and also have been noted to occur in patients who are seizing.

An anteriorly dislocated shoulder will present with the arm at the side or in slight abduction and external rotation. Normal loss of the shoulder contour may be seen with a prominent “sulcus” sign. Adduction and internal rotation are usually limited. A patient with a posterior dislocation will hold the arm in an adducted, internally rotated position.

Evaluation should include a thorough neurologic examination prior to any attempted reduction. Neurologic involvement is not infrequent with the axillary nerve being most commonly affected. Vascular status should likewise be documented, as vascular injuries can occur, although less commonly. Radiographic evaluation should also be completed prior to commencing treatment. A standard trauma series as described earlier is extremely helpful in delineating any associated glenoid rim or humeral head impaction fractures.

Reduction is most easily carried out with some form of sedation and or injection of lidocaine into the joint capsule. Gentle traction–counter traction will reduce most dislocations. Irreducible dislocations and fracture dislocations are best managed in the operating room with general anesthesia.

Postreduction, a period of immobilization in a sling from 10 days to 2 weeks is recommended followed by a supervised physical therapy program. In patients younger than 20 years, recurrence rates up to 90% have been reported most likely due to the violent nature of the dislocation and the very commonly associated anterior-inferior labral tear or “Bankart” lesion that occurs. In contrast, patients aged over 40 years commonly have associated rotator cuff tears. A high index of suspicion should be present at follow-up examination of these patients in the early recovery period.

Proximal Humerus Fractures

Proximal humerus fractures are common injuries, especially with our aging population. The majority of these injuries are minimally displaced or nondisplaced and can be treated conservatively. Factors to take into consideration in the treatment plan are age of the patient, hand dominance, bone quality, fracture type, and fracture displacement. Associated injuries in the multitrauma patient are also important in the decision-making process.

Assessment should consist of a thorough neurovascular examination along with a radiographic trauma series. The presence of an expanding axillary mass and absent distal pulses is concerning for a vascular injury. Nerve injuries occur in as many as one-third of patients and are more common with increasing age. In one study the incidence of nerve injury with proximal humeral fracture-dislocations was greater than 50% after age 50. If present, these injuries may take 9 months or more to recover neurologic function, which is often incomplete.

These fractures are classified according to the description by Neer. He described six variations of displaced proximal humerus fractures, and defined displacement as greater than 1 cm or 45 degrees of angulation. The anatomic “parts” consist of the anatomic neck, surgical neck, and greater and lesser tuberosities. Despite poor interobserver reliability, this is the most frequently used classification system. Figure 2 depicts various fracture patterns that are both considered “two-part fractures.” The portion of the humerus that is displaced has clinical relevance due to the varying blood supply of the proximal humerus. Displacement of the anatomic neck for example, has a high chance of disrupting the blood supply and adversely affecting outcome, regardless of the treatment chosen.

Figure 2 Displaced greater tuberosity fracture on left (white arrow), and displaced anatomic neck fracture on right. Both are considered “two-part fractures” according to the Neer classification.

Treatment varies from a period of immobilization in a sling followed by supervised physical therapy with close radiographic evaluation in nondisplaced or impacted fractures. Open reduction and internal fixation (ORIF) with aggressive therapy to reduce postoperative stiffness is preferable in fractures with greater displacement. The greater tuberosity fracture in Figure 2 was treated with suture fixation to the shaft, whereas the anatomic neck fracture underwent ORIF with a plate and screws as seen in Figure 3. In both cases, rapid aggressive physical therapy was possible postoperatively.

Figure 3 Intraoperative photos of greater tuberosity fracture being repaired with suture anchors (above). Intraoperative fluoroscopy post–open reduction and internal fixation of anatomic neck fracture seen in Figure 2.

(Courtesy of Robin M. Gehrmann, MD.)

Humeral Shaft Fractures

There is a bimodal distribution of diaphyseal humeral shaft fractures, the first occurring in young males involved in high-energy motor vehicle accidents, falls from height, or gunshots. The second peak is seen in elderly women who sustain the fracture during a fall from a standing height. The reported incidence is approximately 14 per 100,000 per year.

Historically, treatment of these fractures has been successful with nonoperative management; initial splinting is followed by placement in a functional brace in the subacute phase. Gravity serves as an important factor in reduction and maintenance of alignment with this method of treatment. The complication rates of nerve injury and delayed union or nonunion have been lower than those reported for operative treatment. In one study of 922 patients treated with functional bracing, only 3% of fractures failed to heal and 98% of patients regained near-full motion of the shoulder and elbow. Even in severely displaced or comminuted fractures such as the one seen in Figure 4, functional bracing may be the treatment of choice to minimize the risks associated with a major surgical procedure.

Figure 4 Clinical photos of a humeral fracture brace. Radiograph on right shows complex fracture being treated in this brace at 6 weeks with acceptable alignment of all components. Greater tuberosity component (dotted arrow), surgical neck (solid arrow), and comminuted shaft with early callus formation.

(Courtesy of Robin M. Gehrmann, MD.)

Treatment of fractures with associated nerve injury remains controversial. The reported incidence of radial nerve palsy varies from 1.8% to 24% with shaft fractures. The nerve is most commonly contused with a neuropraxia that recovers in greater than 70% of reported cases. Transverse fractures of the middle third are more likely to have a neuropraxia than spiral fractures of the distal third, which have a higher incidence of laceration or entrapment of the radial nerve as can be seen in Figure 5.

Figure 5 Intraoperative photograph of radial nerve. Incarcerated between bony spike of fracture fragments in a distal third humerus fracture (left) (white arrow). Post–open reduction internal fixation (ORIF) with radial nerve crossing plate proximally (right).

(Courtesy of Robin M. Gehrmann, MD.)

Low-velocity gunshot injuries to the humeral shaft have been shown to have similar infection and union rates when treated nonoperatively and given a 3-day course of oral ciprofloxacin versus 3 days of intravenous cephalosporin and amino glycoside.

The indications for operative intervention include open fractures, fractures with vascular injury, and injuries that cannot be acceptably aligned in a splint or functional brace as is most commonly seen in obese patients or severely comminuted fractures. Exploration for acute nerve injury cannot be universally recommended at this time.

Distal Humerus Fractures

Distal humerus fractures account for approximately 2% of all adult fractures. Both operative and nonoperative treatments have been reported to have poor outcomes due to pain, deformity, stiffness, nonunion, and ulnar neuropathy. The factors that appear to be most predictable of a good outcome are the ability to achieve an anatomic reduction of the joint surface and the ability to start early active motion.

When there is a displaced intra-articular component, operative treatment is the only way one can restore articular congruity. Nondisplaced or minimally displaced fractures can be treated nonoperatively if they are stable enough to allow for early range-ofmotion (ROM) exercises. If the joint is not restored to its anatomic position, it will become painful as the high joint reactive forces lead to premature arthrosis.

In the case of a badly comminuted joint surface, in a low-demand elderly patient with poor bone quality other options would include early range-of-motion exercises to attempt to re-create some form of joint surface or primary total elbow arthroplasty. With modern fracture treatment principles and fixation devices good results can be achieved most of the time with ORIF.

Extra-articular fractures of the distal humerus occur more frequently in children than adults. They can be difficult to control in a splint or brace due to the muscle forces acting on the distal fragment, as well as the anatomy of the thin flat metaphyseal region, which makes it difficult to get any bony apposition for stability.

In children the more common “extension-type” fracture would require casting with the elbow in a greater-than-100 degrees flexion for maintenance of the reduction. Historically, this has led to the disastrous complications of Volkmann’s ischemic contractures. It is therefore recommended that those fractures that are significantly displaced be closed reduced and pinned allowing the arm to be immobilized in 90 degrees or less, virtually eliminating this complication.

In adults the goals of reconstruction are aimed at re-creating the articular surface, and then re-establishing the medial and lateral columns of the humerus, Figure 6. An olecranon osteotomy is usually necessary in order to provide adequate exposure of the articular surface, after which the ulnar nerve is identified and retracted. Transposition of the nerve at the time of surgery is somewhat controversial at present.

Figure 6 Preoperative anteroposterior (AP) radiograph of comminuted intra-articular distal humerus fracture (left), and postoperative AP film (right) with restoration of the articular surface and the medial and lateral columns.

(Courtesy of Robin M. Gehrmann, MD.)

Complications include ulnar neuropathy, heterotopic ossification, and painful impinging hardware, which can be removed once the fracture has healed, and if necessary ulnar nerve transposition can be carried out at the same time.

In experienced hands, these fractures can be treated operatively with good to excellent results in most patients.

Elbow Dislocation

The elbow is the second most commonly dislocated joint (after the shoulder), accounting for 20% of all dislocations. Fifty percent of elbow stability is due to the highly congruent ulnohumeral joint, with the other 50% being provided by the collateral ligaments. The anterior band of the medial collateral ligament (also known as the anterior oblique ligament) is the primary stabilizer to valgus stress. The lateral collateral ligament complex (particularly the lateral ulnar collateral ligament) provides restraint to posterolateral rotatory subluxation and dislocation.

Elbow dislocation usually occurs in adolescents and young adults, frequently from a fall onto an outstretched arm with the shoulder abducted and elbow extended. Patients present with pain and inability to move the elbow. Gross deformity may be apparent, but can be under appreciated due to swelling. A thorough neurovascular examination and documentation is essential because 20% of cases have associated nerve injuries, usually neuropraxia of the ulnar or median nerves. The shoulder and wrist should be carefully evaluated to rule out concomitant injuries, which can occur in up to 15% of cases. Any forearm tenderness and instability of the distal radioulnar joint should be recognized as signs of disruption of the interosseous membrane (i.e., an Essex-Lopresti injury).

Radiographs of the elbow are used to confirm the clinical diagnosis of dislocation. An elbow dislocation that does not involve a fracture is known as a simple dislocation, and is classified according to the direction of the dislocation. Dislocation with associated fracture(s) of the radial head/neck and/or coronoid process (i.e., complex dislocation) must be determined on imaging studies because they have implications for definitive treatment (Figure 7).

Figure 7 (A) Anteroposterior (AP) and (B) lateral elbow x-rays of a 42-year-old painter who fell off a ladder. The radiographs show a complex posterior dislocation (best seen on the lateral view) with an associated radial head fracture (best seen on the AP view). The patient had prior distal biceps repair with suture anchors. This elbow injury pattern can also be classified as a type IV radial head fracture. (C) A lateral forearm radiograph in the same patient showing an ipsilateral radial shaft fracture that was subtle (and could have been readily missed) on the elbow films.

(Courtesy of Virak Tan, MD.)

An acute elbow dislocation should be initially managed by prompt closed reduction under adequate analgesia and muscle relaxation. This can usually be achieved in the emergency room with intramuscular or intravenous medication(s). Several reduction techniques have been described, but they all involve correcting the medial-lateral displacement, followed by longitudinal traction and flexion of the forearm. A “clunk” is often felt with reduction of the joint.

After reduction, stability is assessed by checking range of motion with valgus-varus stress. Passive motion to within 30 degrees of full extension suggests a stable reduction and mobilization of the elbow can begin within a few days when the patient is more comfortable. If the elbow is unstable after reduction, then it should be immobilized in 90 degrees of flexion for approximately 3 weeks before beginning motion. Alternatively, an overhead rehabilitation protocol can be initiated with proper splinting and supervision. The overhead protocol takes advantage of gravity to maintain reduction during elbow motion.

Posterior elbow dislocation with associated fractures of the radial head and the coronoid process has been referred to as the “terrible triad of the elbow” because of the difficulties encountered in its management. Definitive treatment of these complex elbow dislocations usually involves surgery because they are highly unstable and are prone to numerous complications when inadequately treated. With operative treatment, the surgeon should attempt to restore elbow stability by (1) reestablishing radiocapitellar contact (by either repairing the radial head or replacing it with a prosthesis), (2) repairing the lateral collateral ligament, and (3) performing internal fixation of the coronoid fracture, as needed.

The outcome of nonoperative management of a simple elbow dislocation is highly successful. Poor results can occur with prolonged immobilization (usually greater than 3 weeks) and inadequate rehabilitation. Other complicating sequelae include heterotopic ossification and stiffness. Additionally, complex dislocations can also have recurrent instability, failure of fixation, post-traumatic arthritis, and tardy ulnar nerve palsy.

Radial Head Fractures

Radial head fractures are common injuries accounting for one-third of elbow fractures. Fifty percent to 60% of elbow dislocations have associated radial head and neck fractures. The mechanism of injury is usually an axial load on a pronated forearm. Patients with radial head fractures often present with lateral elbow pain upon extension or forearm rotation. Diagnosis and classification (modified Mason) of these injuries are based on radiographs. Type I is nondisplaced, type II is a displaced single fragment, and type III is a comminuted fracture. Type IV is a radial head fracture with an associated elbow dislocation.

Nondisplaced fractures are well managed with early mobilization. Operative indications for radial head fractures include displacement greater than 3 mm, bony block to elbow motion, Essex-Lopresti lesion (i.e., associated disruption of the interosseous membrane), and an unstable elbow. Surgery for radial head fracture may entail excision, internal fixation or prosthetic replacement. Isolated radial head fractures can be safely excised without compromising elbow stability or function, especially in the elderly patient. Ring et al. have shown that internal fixation is best reserved for radial head fractures with three or fewer fragments. Specialized precontoured radial head plates are available, and should be placed in the “safe zone” to prevent hardware impingement on the radial notch. Metallic prosthetic radial head replacement is performed when fixation of the head is not possible in the setting of an Essex-Lopresti lesion or a type IV fracture. At the time of this writing, there is no role for silicone radial head spacer due to silicone synovitis.

Coronoid Fractures

The coronoid process of the ulna serves as an anterior buttress of the greater sigmoid notch and is the attachment site for the anterior bundle of the medial collateral ligament and anterior capsule. Therefore it has an important role in providing stability to the elbow. Coronoid fractures are common, and are associated with 10% of elbow dislocations. Classically, three types have been identified to occur in the coronal plane and are best seen on a lateral elbow x-ray: type I, tip avulsion; type II, less than 50%; and type II, greater than 50%. More recently, an oblique or vertical fracture line about the anteromedial coronoid is also recognized to cause instability of the ulnohumeral joint (Figure 8). This fragment is best seen on computed tomography scan. In general, types I and II coronoid fractures can be managed without fixation of the fragment itself. Because displaced type III or anteromedial fractures are associated with elbow instability, they should be treated with internal fixation and as part of the overall surgical management of elbow dislocation. Failure to stabilize these fractures will result in recurrent elbow subluxation or dislocation.

Figure 8 (A) Anteroposterior (AP) and (B) lateral elbow radiographs and (C) a three-dimensional computed tomography scan showing an anterior medial coronoid fracture. This patient had an elbow dislocation that was emergently reduced prior to these imaging studies. (D) and (E) The patient subsequently underwent operative fixation of his coronoid fracture and repair of both the lateral and medial collateral ligaments with suture anchors.

(Courtesy of Virak Tan, MD.)

Olecranon Fractures

The greater sigmoid notch of the ulna is formed by the olecranon and coronoid processes. The olecranon makes up the proximal half of the notch, and by definition, isolated fractures involving this portion do not result in ulnohumeral instability. Olecranon fractures can result from direct force or from eccentric loading of the triceps. Minimally displaced fractures (<2-mm gap at 90 degrees of elbow flexion) are uncommon but can be treated with elbow splinting at 30 to 45 degrees of flexion. More commonly, the fractures are displaced and require operative fixation to restore active elbow extension. Several options exist for fixing olecranon fractures including tension band technique with supplemental Kirschner wires or screw(s), bicortical interfragmentary screw(s), and plating. Comminuted fractures are best managed with dorsal plate fixation. In cases of severe comminution, excision of the fragments, and reattachment of the triceps to the remaining portion of the proximal ulna may be required.

Complications of olecranon fixation most commonly involve hardware prominence, which can be managed by removal after the fracture has healed. In addition, elbow stiffness, malunion, nonunion, and post-traumatic arthritis can also occur.

Monteggia Fracture

Monteggia fracture is a fracture of the proximal ulna with dislocation of the radial head. It occurs in 1%–2% of all forearm fractures. Bado described four types of injury patterns: type I, apex anterior ulnar fracture and anterior radial head dislocation; type II, apex posterior ulnar fracture and posterior radial head dislocation; type III, proximal ulnar metaphyseal fracture and lateral radial head dislocation; and type IV, proximal ulnar and radial shaft fractures and anterior radial head dislocation (Figure 9). The key to successful outcome of Monteggia fracture is anatomic reduction and fixation of the ulna fracture. Upon reduction of the ulna, there is typically concomitant stable relocation of the radial head. Irreducible radial head dislocations can be associated with posterior interosseous nerve entrapment. In type IV lesions, open reduction and internal fixation of both the ulna and radius are required.

Figure 9 A single anteroposterior radiograph of the forearm showing a Monteggia type IV variant where there are fractures of the midshaft of the ulna and radial neck, and dislocation of the radial head.

(Courtesy of Virak Tan, MD.)

Complications of Monteggia fractures often result from nonanatomic or loss of fixation of the ulna fracture, leading to recurrent dislocation of the radial head. Poor outcomes can also be due to heterotopic ossification with proximal radioulnar synostosis.

Radial and/or Ulnar Shaft Fractures

Fractures of both the radial and ulnar shafts (“both-bone forearm” fractures) are operative injuries in the adult population. Most surgeons prefer compression plating of both bones using a separate incision for each. The anatomic bow of the radial shaft must be restored to prevent loss of forearm motion. In children, this injury may be treated with closed reduction and casting, provided that nearanatomic alignment of the shafts are established.

Isolated radial shaft fractures are uncommon but can occur from projectile injury such as a gunshot blast. A Galeazzi injury pattern must be ruled out by assessing the distal radioulnar joint (DRUJ) for instability. Even without DRUJ disruption, isolated radial shaft fractures are poorly controlled by casting, and therefore should generally have internal fixation.

Isolated ulnar shaft fractures are commonly referred to as “night stick fractures” because historically they occurred as a result of a direct blow to the ulnar aspect of the forearm from a night stick. In the modern era, motor vehicle accidents can also cause this injury. Fractures with less than 10 degrees of angulation and 50% shaft displacement can be treated by nonoperative means. Surgical treatment with compression plating is indicated for the more displaced fracture. Care should be taken to avoid injury to the dorsal sensory branch of the ulnar nerve during the approach for distal third fractures.

Galeazzi Fractures

A Galeazzi fracture is defined as a fracture of the middle to the distal radial shaft with subluxation or dislocation of the DRUJ. It is an uncommon injury, with incidence varying from 3% to 6% of all forearm fractures. The mechanism is a direct blow to the dorsoradial wrist or a fall onto an outstretched hand with forced pronation of the forearm. Radiographic signs of a Galeazzi fracture include an ulnar styloid fracture, widened DRUJ on the AP view, dorsal dislocation of the distal ulna on the lateral view, and 5 mm or greater of radial shortening through the fracture site.

Operative treatment is essential in all Galeazzi fractures because closed treatment has resulted in a 92% failure rate due to loss of reduction of the radial shaft. After stable anatomic internal fixation of the radius, the distal radioulnar joint stability is assessed. If the joint is stable with forearm rotation, then immobilization is not necessary. However, if the DRUJ is reducible but is unstable, then either the arm must be immobilized in supination or the DRUJ pinned in the reduced position. Failure to reduce the DRJU by closed means necessitates open reduction of the joint.

The major concerns with treatment of Galeazzi fracture is loss of forearm rotation due to malalignment of the radius and incongruity of the DRUJ leading to painful motion.

Distal Radius Fracture

Fractures of the distal radius are common, accounting for approximately 250,000 to 300,000 cases in the United States annually. This injury represents 20% of all fractures leading to emergency room visits and 75% of all forearm fractures. The mechanism is typically either a low-energy mechanism such as a fall onto an outstretched hand or a high-energy impact such as a motor vehicle accident or fall from height. Although in the past distal radius fractures were thought of as a homogeneous group of injuries, it is now widely recognized that there are different and often complex fracture patterns.

The diagnosis of a distal radius fracture is based on the history, examination, and imaging studies. Age, hand dominance, occupation/vocation, and mechanism of injury should be obtained in the history. Associated injuries in other areas of the body should be ruled out when there is a high-energy mechanism. Evaluation of the injured extremity should not just focus on the deformed wrist, but include examination of the elbow and forearm. Careful neurovascular examination must be performed with attention to the median nerve, since acute carpal tunnel syndrome can develop with displaced distal radius fractures.

Closed reduction and splinting of acute displaced fractures should be done in the emergency room to correct the wrist deformity and decrease the risk of traumatic carpal tunnel syndrome. In those cases in which there is minimal comminution and articular step-off, casting with close radiographic follow-up remains a good option. Loss of reduction is the main drawback of nonoperative treatment. Casting has also been associated with wrist/hand stiffness, compressive neuropathies, and complex regional pain syndrome.

For fractures that cannot be adequately reduced or maintained by closed methods, an external fixator with or without Kirschner wires may be indicated. Often times, overdistraction or flexion of the wrist is required to maintain reduction, which may lead to hand stiffness, median nerve compromise, and complex regional pain syndrome. Additionally, the risk of pin tract infection and soft tissue irritation is reported up to 60% of cases.

In light of the limitations of external fixation, open reduction and internal fixation have become a more widely used technique. Exposing the fracture through a dorsal or volar approach allows direct visualization and manipulation of the fracture fragments. A number of plate and screw constructs are available for both dorsal and volar fixation. Dorsally applied hardware has associated complications, such as tendon irritation or rupture and the possible need for removal of the hardware after fracture healing. Thus, the volar approach has recently become more popular. Newer fixed-angle plating systems allow early therapy to regain wrist and finger motion. However, the amount of soft tissue dissection and the extramedullary position of the implant still pose some disadvantages in treating wrist fractures.

Intramedullary devices such as the Micronail (Wright Medical Technology, Inc., Memphis, TN) attempt to counteract some of the disadvantages noted with open reduction and plating. By residing within the medullary canal, these devices minimize or eliminate soft tissue irritation and pin track infection, yet maintaining fracture reduction and alignment (Figure 10).

Figure 10 A single posteroanterior radiograph of the wrist in a patient who underwent distal radius fracture fixation with an intramedullary device. The fracture line is faintly visible just proximal to the distal screws.

(Courtesy of Virak Tan, MD.)

Perilunate Dislocations

Perilunate dislocations are relatively rare but complex injuries involving only 7% of all injuries of the carpus. They most often result from high energy mechanisms, including motor vehicle accidents, falls from height, or contact sports, and thus are often associated with other significant trauma. Mayfield et al. showed that an axial load with hyperextension and ulnar deviation of the wrist, coupled with intercarpal supination, reproduced a spectrum of “progressive perilunate instability.” Four stages of perilunate injuries were described as the carpus is disrupted around the lunate. The pattern of sequential failure begins radially and is transmitted either through the body of the scaphoid (producing a trans-scaphoid fracture) or through the scapholunate (SL) interval (producing a SL dissociation). The force then propagates to the ulnodorsal aspects of the wrist. In stage I, there is disruption of the scapholunate and radioscaphocapitate ligaments. In stage II, the force disrupts the lunocapitate association. In stage III, there is failure of the lunotriquetrial interosseous and ulnotriquetrial ligaments, where the entire carpus separates from the lunate. Finally, stage IV involves palmar lunate dislocation into the carpal tunnel. Mayfield demonstrated that slower application of load produced fractures (radial styloid, scaphoid and/or capitate) prior to the lunate dislocation, termed “greater arc injuries.” Conversely, a more rapidly applied force produced purely ligamentous disruptions, termed “lesser arc injuries.”

Correct diagnosis and treatment of these injuries is imperative in order to restore wrist motion and function. The major pitfall in treating perilunate carpal injuries is delayed or missed diagnosis. The patient may have multiple (even life-threatening) injuries that preclude adequate workup and imaging of extremity injuries. Other times, the dislocation is missed because the radiographs are misread by inexperienced observers.

The typical presentation of an acute perilunate dislocation includes pain and swelling about the wrist. Deformity may be more subtle than expected. The carpus is usually displaced dorsally. In a lunate dislocation, the lunate can come to lie within the carpal tunnel; therefore, thorough neurovascular assessment of the upper extremity is important. A well-taken wrist series is the key to the diagnosis. Posterior-anterior view will show disruption of the normal carpal arcs (Figure 11A). Lateral radiograph will reveal loss of colinearity between the capitate, lunate, and the radius (Figure 11B). Traction radiographs may be indicated to further assess the injury pattern.

Figure 11 (A) Posteroanterior radiograph of a stage III trans-styloid perilunate. The abnormal triangular appearance of the lunate (black dots) has disrupted Gilula’s arcs (black lines). (B) Lateral radiograph of the same patient showing the lunate (outlined) is still articulating with the distal radius; however, there is dislocation of lunocapitate articulation. There is loss of colinearity among the radius, lunate, and capitate. (C) An emergent extended carpal tunnel release is required for irreducible perilunate dislocations. The transverse carpal ligament has been divided longitudinally, and the content of the carpal canal (including the median nerve, bottom arrow) is retracted ulnarly. The lunate (top arrow) is seen dislocated into the carpal canal.

(Courtesy of Virak Tan, MD.)

Once the diagnosis of a perilunate dislocation is made, treatment consists of immediate closed manipulation to achieve reduction and immobilization. Reduction is usually undertaken with the patient under intravenous sedation. The arm is first suspended in longitudinal traction. With the wrist extended and maintaining traction, a thumb is used to push the lunate back into its fossa as the wrist is then flexed to reduce the capitate over and into the concavity of the lunate. Failure to achieve a reduction via closed means often indicates interposed volar capsule and necessitates an urgent open procedure. A patient with an irreducible perilunate dislocation at minimum must undergo an urgent temporizing extended carpal tunnel release to decrease the pressure on the median nerve (Figure 11C). Failure to do so could result in permanent median nerve dysfunction.

Early definitive treatment of perilunate injuries is necessary to minimize the devastating complications of chronic carpal instability and traumatic arthritis associated from missed or inappropriately treated injuries. Despite the overall consensus that open reduction and internal fixation is the treatment of choice for restoring carpal alignment in acute perilunate dislocations, the ideal surgical approach is less explicit. There are three basic surgical approaches that can be used: volar, dorsal, and combined dorsal–volar approach.

The volar or palmar approach is typically used for reduction of the lunate and carpal tunnel release. Additionally, direct repair of the capsular rent at the space of Poirier can be done volarly. The dorsal approach provides exposure of the carpus for restoring alignment and repairing the scapholunate interosseous ligament (SLIL) which is thought to be the key to successful long-term results. Moreover, scaphoid and other carpal bone fractures can also be addressed dorsally. The combined dorsal–volar approach offers the advantages of both and is the preferred choice for the authors since it allows access to all the injured structures.

Carpal Fractures and Ligamentous Injuries

Trauma to the carpus can result in fractures or ligamentous disruptions. The scaphoid is the most common carpal fracture and can occur in isolation or in conjunction with distal radius or perilunate injuries. Emergency room management of isolated scaphoid fracture should include appropriate x-ray views, followed by a long-arm thumb-spica splint immobilization. Ninety percent to 95% of acute nondisplaced scaphoid fractures will heal with proper immobilization; however, it may take 8–12 weeks and several cast changes. Percutaneous headless screw fixation of acute scaphoid fractures has resulted in shorter healing time and less overall disability. Displaced scaphoid fractures require open reduction and fixation; there is no role for closed treatment under normal circumstances. Missed or inadequate treatment of a scaphoid fracture can result in malunion, nonunion, and/or avascular necrosis, which will lead to wrist arthritis in the long run.

Fractures of the other carpal bones are uncommon and are usually a part of a larger injury spectrum. Kienbock’s disease should be ruled out in patients with a lunate fracture but minimal trauma.

Scapholunate dissociation results from disruption of the scapholunate interosseous ligament. Dorsal wrist pain with tenderness over the scapholunate interval is the usual finding. The scaphoid shift test may also be positive. The space between the scaphoid and lunate will be widened on the AP radiograph. Early surgical treatment of this injury is simpler, and has better results than delayed reconstruction.