COMPLICATIONS OF INJURY

Complications of fractures and joint injuries

Missed fractures and joint injuries

Scaphoid and hook of hamate fractures are commonly missed, and are discussed below.

Reversed Bennett's fracture is an intra-articular fracture of the base of the small finger metacarpal, usually associated with dorsal and proximal subluxation of the metacarpal shaft due to the unresisted action of the extensor carpi ulnaris tendon. In contrast to intra-articular fractures of the thumb metacarpal base (Bennett's and Rolando's fractures) which have a similar pathologic anatomy (bennett.htm) and good outcome with a variety of treatment techniques (CP), reversed Bennett's fractures are prone to chronic symptoms from posttraumatic arthritis. These fractures are easily missed on plain anteroposterior and lateral x-rays, and presentation is frequently delayed when they are sustained in a boxing injury mechanism.

Phalangeal neck fractures may go unrecognized despite rotation or dorsal translation of the distal fracture fragments, because alignment may look deceptively normal with routine posteroanterior x-rays. The rotated phalangeal neck fracture is unstable, prone to nonunion (CM), and is sometimes referred to as "hangman's fracture" (hangman.htm) because it is easy to miss in children and difficult to treat late.

Missed ligament injuries are usually missed because the patient downplays the extent of injury, only to seek evaluation later because of persistent symptoms.  The most common missed ligament injuries are gamekeeper's thumb and scapholunate ligament injuries, both discussed below.

Intraarticular fractures of the fingers frequently result and stiffness and functional impairment, particularly when sustained during childhood (BZ). Displaced articular fractures should have anatomic reduction and fixation whenever possible.  Even minor degrees of malalignment are usually unacceptable.  Long term problems including degenerative arthritis are common even with optimum initial care.

Pathologic fractures in the hand are most commonly due to enchondroma involving one of the tubular bones. Complications of treatment are more likely with immediate compared to the delayed treatment of the tumor (AB), and the preferred management of pathologic fracture through a benign and tumor is to let the the fracture heal, then return for definitive treatment of the tumor.

Phalangeal  fracture complications: Distal phalanx fractures carry all of the complications previously discussed for fingertip injuries. Displaced distal phalanx fractures (1121100s.htm) may give rise to nonunion if not reduced and provided adequate internal fixation. Phalangeal neck fractures are discussed above. Phalangeal shaft fractures are affected to a much greater degree by associated soft tissue damage and have an overall worse outcome than metacarpal fractures of similar magnitude.  Poor functional outcome is common with phalangeal fractures which are open, comminuted, or associated with either significant soft tissue injury or periosteal stripping - including periosteal stripping performed during open reduction (DX, CG), when there is associated nerve or tendon injury. Only about one in six displaced phalangeal fractures are stable after closed reduction (CG), and redisplacement may occur following temporary Kirschner wire fixation. Angulation results in a zig zag posture due to tendon in balance, resulting in joint contractors to a degree similar to the degree of proximal angulation (0063106S.htm). Outcome is not improved with the use of plate and screw fixation compared to Kirschner wire fixation (CE). Based on outcome studies, a strong argument can be made to refer all finger fractures to a surgeon with specialty training in hand surgery (CF).

Phalangeal joint injuries prone to complications include essentially all interphalangeal joint injuries, because the precision nature of the interphalangeal joints.  It is common for the sprained proximal interphalangeal joint to be stiff, tender, painful and swollen for six to twelve months after injury.  Permanent joint enlargement and flexion contractures are common consequences of even a minor sprain or "jammed finger". Mallet fracture dislocations (mallet.htm) of the distal interphalangeal joint should be distinguished from simple stable displaced mallet fractures, because outcome following conservative management is poor due to joint incongruity. Pure dislocations of the proximal interphalangeal joint (PIPDIS.htm) are most commonly dorsal, usually stable after reduction, and carry about the same outlook has a bad sprain of this joint.  In contrast, palmar dislocations or dislocations with a lateral component are frequently unstable after reduction and are more prone to progressive contractures, angulation, and degenerative joint changes. Fracture dislocations of the proximal interphalangeal joint are usually dorsal with a small volar plate avulsion fracture. These are usually stable if the volar fracture fragment comprises less than one third of the articular surface.  In contrast, dorsal fracture dislocations in which the palmar fragment involves more than one third of the joint surface, palmar fracture dislocations,  and combined dorsal and palmar fractures ("pilon fractures") are intrinsically unstable, and have persistent subluxation (PIPFD.htm).  These extremely difficult injuries may require internal and external fixation, cancellous or osteochondral grafting, and may be unsalvageable.

Metacarpal fractures prone to complications: Metacarpal fractures have fairly predictable healing, but nonunion is more likely in injuries sustained with a crush or blast mechanism. Gunshot injuries of the fingers frequently result in amputation, but similar injuries in the metacarpal area may produce surprisingly little nerve and tendon damage despite severe skeletal injury and risk of nonunion (gsw.htm). Multiple metacarpal fractures are often sustained in crush injury, and the decision must be made between the need for compartment decompression, wide exposure for open reduction and internal fixation versus the use of percutaneous fixation to minimize additional injury (percmeta.htm).

Metacarpal joint injuries prone to complications: Complex dislocations are dislocations in which intraarticular soft tissue interposition provides a block to reduction, also referred to as irreducible dislocations. These most often involve the metacarpophalangeal joints, the home most often involved, and are usually associated with sesamoid interposition (1437308x.htm).  These must be recognized to avoid additional injury from overzealous attempts at closed reduction, and usually require open reduction. Rupture of the thumb metacarpophalangeal joint ulnar collateral ligament, also known as ski pole thumb or gamekeeper's thumb occurs when the thumb is forced into radial deviation.  The extent of injury is frequently not appreciated by the patient and delayed presentation is common.  Results of acute ligament repairs are better than those of late reconstruction (CD), and arthrodesis may be indicated.

Carpal injuries prone to complications

Scaphoid fractures  (scaphfx.htm) Scaphoid fractures are prone to healing problems because of the combination of poor perfusion of the proximal fracture fragment and strong forces across the fracture site from normal wrist mechanics.  Scaphoid fractures may heal in malunion ("humpback deformity"), but delayed union and nonunion are much more common and difficult problems. Left untreated, scaphoid nonunions have a natural progression to a characteristic pattern of wrist arthritis, initially involving the radioscaphoid and capitolunate joints, referred to as scaphoid nonunion advanced collapse, or "SNAC wrist" Unstable, displaced, or proximal fractures are prone to nonunion even with prolonged casting, and should be considered for early open reduction, because the outcome of surgery is more likely to be satisfactory for acute unstable or displaced fractures than for unstable or displaced nonunions. Open reduction, bone graft and screw fixation has as high as a forty percent failure for unstable or displaced nonunions (BW).

Scapholunate ligament injuries occur from the same mechanism of injury as scaphoid fractures. Like scaphoid fractures, these injuries may not be apparent on initial x-rays. Dynamic scapholunate dissociation may be obvious only on kinematic or stress deviation radiographs. Conversely, bilateral benign congenital scapholunate diastasis may be confused with an acute injury if both sides are not compared (0049102s.htm).  Left untreated, scapholunate dissociation has a natural progression to a characteristic pattern of wrist arthritis, initially involving the radioscaphoid and capitolunate joints, referred to as scapholunate advanced collapse, or "SLAC wrist" (sldis.htm) (DW). Treatment options include partial wrist fusion, proximal row carpectomy, and a variety of soft tissue ligament reconstruction procedures. Capsulodesis procedures appear to be more successful than tendon graft procedures, although no current soft tissue procedure reliably corrects scapholunate diastasis visible on x-ray (BY). Injuries associated with scapholunate dissociation or in partial ligament disruption have a better outcome following surgery than those resulting in complete disruption with a static instability pattern (BY).

Perilunate dislocations and fracture dislocations (lunatedis.htm, plfd.htm)are severe wrist injuries which usually result in some degree of permanent wrist stiffness even with ideal management.  These injuries may not be appreciated on casual inspection, the most common report of inadequate evaluation being "something just isn't right".  These injuries require open reduction and internal fixation and frequently require carpal tunnel release for acute traumatic neuritis.

Hook of hamate fractures are often difficult to demonstrate with plain Xrays, and additional evaluation and management may be indicated based on clinical suspicion (1113201xs.htm, hook.htm). Fractures of the hook of the hamate rarely heal with conservative treatment. The problem may mimic a variety of other problems, including carpometacarpal or capitohamate joint disorders. Problems with this fracture include flexor tendon rupture from abrasion against the fractured hook area. Tendon rupture is a significant complication, often resulting in permanent disability despite multiple operations and extensive therapy. Surgery to remove the fractured hook and inspect the tendons and nerves is indicated to minimize these risks.

Forearm fractures prone to complications:

Distal radius fractures account for about one out of every six of fractures seen in the emergency room and three out of four forearm fractures. They are most common in both sexes between 6 and 10 years and in women between 60 and 69 years old. They may be classified by a number of schemes, but no existing scheme correlates well with final functional outcome (CZ). A large number of operative and nonoperative treatment options have been recommended, many of which appear to give comparable results. Operative treatments include external fixation, percutaneous pinning, open reduction, and any combination of these. Poor final outcome is more likely when the fracture is initially very displaced, when the distal radioulnar joint is involved, when the radiocarpal joint is comminuted, when there is residual shortening greater than 2 mm or dorsal angulation greater than 15 degrees. Closed reduction of intra-articular distal radius fractures has a satisfactory outcome in about four out of five cases (BX). However, about one out of three closed reductions redisplace, and only one out of three of fractures which redisplace and require repeated closed manipulation have a good or excellent final outcome (BX). There are conflicting reports regarding the importance of final fracture alignment on function, but one can make the argument to avoid malunion (radmalun.htm) because secondary surgery for distal radius malunion is successful in only three out of four patients (CX). Nonunion (rnonunion.htm, 1441107x.htm) is uncommon, but is more likely following severely displaced fractures because of the possibility of pronator quadratus or other soft tissue interposition. Complex regional pain syndrome (rsd.htm) and finger stiffness occur to some degree in as many as one out of three patients. Loss of motion is also common, but unpredictable. Tendon rupture (AV), early or late, open or closed, relating to fracture displacement, hardware irritation (1441107x.htm) (AP) or ulnar head prominence. Median or ulnar nerve compression may develop early or late following this fracture.  Posttraumatic arthritis is most common in young adults, seen in radiographs of two out of three young patients evaluated years after injury. Fortunately, radiographs do not correlate well with the degree of symptoms, and many of these patients are asymptomatic. Compartment syndrome of the forearm may develop in association with emergency reduction and stabilization of a distal radius fracture with a circumferential cast.  However, compartment syndrome of the forearm may develop after high energy injury distal radius fracture even in the absence of circumferential cast or bandages (BC), and may develop up to 48 hours after the initial injury (AZ). Distal radius fractures in males under 50 years old are at particular risk (BH), probably because these represent a subset of high energy injuries. If clinical examination is unreliable, as in patients who are obtunded or whose symptoms may be masked by narcotics, in hospital observation and or repeated measurement of compartment pressures may be indicated during the first two days after injury. Carpal instability may develop, either as a discrete ligament injury or as a result of changes in the radiocarpal joint angle. Nonunion of associated ulnar styloid fractures is common and usually painless. Prolonged recovery (six to twelve months) is typical, as are long term subjective symptoms, such as pain, fatigue, and loss of grip strength. Such symptoms are reported by about half of patients with a non-compensation related injury; in about four out of five adult patients under the age of 45, and in essentially all patients with compensation related injury. Despite this, three out of four patients on the average have a satisfactory functional result following distal radius fracture.

Both bone forearm fractures in an adult may result in a variety of problems. Complications are more common and prognosis is worse for displaced fractures and for open fractures. On the average, nondisplaced fractures take six to eight weeks to heal, and displaced fractures take three to five months. Satisfactory functional end results may be expected in about eight out of ten patients with nondisplaced fractures and about one half of those with displaced fractures. As many as one half of patients will have obvious loss of forearm pronation, which may or may not be functionally significant. Loss of forearm rotation is most likely when fractures occur in the middle third of the forearm. Synostosis may lock the forearm in a fixed position of rotation. Nonunion occurs in as many as one out of ten patients (1360603x.htm). Nonunion related to technique is more likely when semitubular plates are used, or when less than six cortices are engaged on each side of the fracture. Early protected motion appears to improve the odds of satisfactory final motion. Internal or external fixation is usually indicated for open or very unstable fractures, accepting the risk that postsurgical infection may occur in as many as one out of twenty patients. Proximal forearm fractures are associated with a variety of problems, including nonunion, nerve and tendon injuries and synostosis. One fifth to one half of patients can be expected to have significant permanent loss of forearm rotation. Open treatment of acute fracture or nonunion may be complicated by additional nerve injury or synostosis, more likely when injuries are open or classified as high energy. Synostosis, or cross union between the radius and ulna is much more common in proximal than in distal forearm fractures, occurring in about one out of fifteen patients with proximal fractures. Synostosis is more likely in children, with open fractures, with single incision access to both forearm bones, and following high energy injuries. Results of surgery for correction of synostosis are poor when surgery is performed less than one year or more than three years after injury, and even under ideal conditions, only one in five patients can be expected to regain as much as 50 degrees of forearm rotation.

Longitudinal forearm fracture dislocations (1185902.htm) include three special combinations of injury: Galeazzi fracture-dislocation, Monteggia fracture-dislocation, and the Essex-Lopresti lesion (CC). Galeazzi fracture-dislocation refers to a fracture of the shaft of the radius associated with dislocation of the distal radioulnar joint. Monteggia fracture-dislocation refers to fracture of the ulna with dislocation of the radial head. Each of these fracture-dislocation patterns is best treated with open fracture reduction and closed treatment of the dislocation. Essex-Lopresti lesion refers to longitudinal disruption of the radioulnar interosseous membrane and proximal migration of the radius associated with fractures involving the proximal radioulnar joint, the distal radioulnar joint, or both sites. The most common presentation of Essex-Lopresti is associated with radial head excision for fracture, resulting in ulnocarpal impingement syndrome. Treatment is controversial. When diagnosed acutely in the context of an unreconstructable radial head fracture, Essex-Lopresti justifies use of a temporary radial head implant. Late surgical options include ulnar shortening osteotomy or the developing technique of ligament reconstruction with a tendon graft.

Radial head fractures often appear to be an isolated injury, but are associated with distal radial ulnar joint pathology due to proximal migration of the radius as well as elbow arthritis and loss of elbow motion. Early excision of radial head fractures has a significant complication rate, including proximal migration of the radius, which occurs to some degree in the majority of patients (AC). Efforts should be made to reconstruct rather than excise a fractured radial head.

Skeletally immature forearm fractures and dislocations: "Isolated" radial head fractures in children are often associated with some degree of plastic deformation of the ulna, or "plastic" Monteggia fracture. Chronic pediatric radial head dislocation associated with plastic deformation of the ulna is frequently unrecognized, and requires open reduction and ulna osteotomy in late cases (DA).