Carpal Fractures

Can Somebody Give Me A Hand?

By Jeff Freshour

History of the Procedure

• Wilhelm Conrad Roentgen's discovery of x-rays, for which he was later awarded the Nobel Prize in Physics, was a major turning point in the understanding and categorization of wrist fractures. One year after Roentgen obtained the first radiograph of the hand in 1895, Sir Robert Jones published the first report on the clinical use of a radiograph to locate a bullet in the wrist. By the early 20th century, the radiograph allowed for the description of almost every currently known wrist fracture.

• Radiographs provided insights into fracture fixation that proved particularly valuable by the mid-20th century. Treatment of war injuries has always played a significant role in the development and refinement of surgical principles and procedures. The knowledge obtained from treating casualties during World War I played an important role in the treatment of fracture fixation during World War II, when military surgeons developed a number of fixation procedures with the intent of expediting the return of soldiers to the battlefield.

• Martin Kirschner was a German surgeon known for his fixation methods, particularly the development of the Kirschner wire (K-wire) fixation technique. Contemporary surgeons continue to favor this fixation method in the treatment of unstable fractures. The K-wire fixation method is technically easy to perform and probably the least traumatic method of fixing bones.

• In the years following the war, advances in the treatment of carpal fractures included refinements in surgical techniques and improvements in prosthetic implants available for reconstruction.

Frequency

• Upper-extremity fractures are among the most common fractures of the skeletal system. Carpal bone fractures account for 18% of hand fractures. Of the carpal elements, bones in the proximal row are the most frequently fractured. The scaphoid is by far the most common carpal bone fractured, representing 70% of fractures in the carpal group and 10% of all hand fractures. Triquetral fractures are the second most common, accounting for 14% of wrist injuries. The incidence of isolated fractures of any of the remaining carpal bones is comparatively low, in the range of 0.2-5%.

• Carpal injury is usually a result of direct or indirect trauma. In general, mechanisms that cause carpal fractures are injuries of moderately high energy. If the diagnosis is not established early or if a displaced fracture displacement is not recognized, disability may result.

Mechanisms of Injury• Scaphoid fractures

Two thirds of scaphoid fractures occur at the wrist, an area of the bone that can be impinged upon by the styloid process of the radius during a radial deviation maneuver. This fracture is usually associated with a force applied to the distal pole of the scaphoid, often with the wrist hyperextended. The radiostyloid essentially functions as a fulcrum against the center of the scaphoid, resulting in the predominance of fractures at the wrist level. The mechanism of injury usually consists of a fall on the palm of an outstretched hand. On clinical examination, pain is elicited when pressure is exerted on the distal pole or on the scaphoid at the anatomic snuffbox on the radial aspect of the wrist.

• Triquetral fractures The mechanism of triquetral injury usually consists of either a direct blow to the dorsum of the hand or extreme dorsiflexion of the hand. The fracture is thought to result either from the hamate being forced against the triquetrum or from the ulnar styloid creating a volar compressive force on the dorsal aspect of the triquetrum. On clinical examination, palpation of the triquetrum is facilitated by radial deviation of the hand. This maneuver allows direct palpation of the triquetrum as it moves away from the ulnar styloid process. Point tenderness is usually elicited directly over the triquetrum.

• Lunate fracturesThe mechanism of lunate fracture involves either chronic repetitive trauma leading to multiple microfractures or a direct traumatic blow resulting in a primary fracture. The etiology of avascular necrosis of the lunate or Kienböck disease has long been debated.5,6 The arterial blood supply of the lunate is variable, and it may be predominately derived from a single vessel. Other evidence, however, suggests that venous stasis may be more of an etiologic factor than an inadequate arterial supply. The diagnosis should be suspected in the patient who reports central dorsal wrist pain, loss of motion at the wrist, and diminished grip strength. Tenderness is demonstrated with direct palpation of the dorsal aspect of the lunate.

Mechanisms of Injury• Pisiform fractures

Pisiform fractures usually involve either a direct blow to the ulnar aspect of the wrist or forceful hyperextension, as in a fall on an outstretched hand. On clinical examination, the diagnosis is suggested by pain and tenderness with direct palpation of the pisiform.

• Trapezial fracturesTrapezial fractures usually result from a direct blow to the dorsum of the hand or from a fall on a radially deviated closed fist. Patients usually complain of a painful and weak pinch. On clinical examination, point tenderness is present on direct palpation of the trapezium.

• Hamate fracturesThe mechanism of hamate injury usually involves direct trauma to the volar aspect of the hand. It is not an uncommon injury in athletes who sustain a direct blow against the hamate while gripping the handle of a tennis racquet, golf club, or baseball bat. The end of the handle strikes the hamate during an unorthodox swing, resulting in a fracture. Pain elicited with the gripping of objects is a common complaint. On clinical examination, tenderness is localized to either the volar or dorsal ulnar aspect of the wrist.

• Capitate fracturesBecause of its protected position, isolated fractures of the capitate are rare. Capitate injury usually involves a direct axial load transmitted down the shaft of the third metacarpal with the wrist in dorsiflexion and slight radial deviation. Tenderness is demonstrated with direct palpation immediately proximal to the base of the third metacarpal.

Presentation• A complete history should be obtained from each patient

being evaluated for a potential wrist injury. A thorough physical examination and extensive radiographic evaluation should be complimented with basic knowledge of wrist anatomy and common fracture patterns. This vastly improves the accuracy of the diagnosis and thereby directs the treatment of carpal fractures.

• Once the diagnosis is established, the cardinal objective is to obtain and maintain normal anatomic alignment, because nonanatomic positioning may lead to functionally disabling results. Thereafter, treatment revolves around protective immobilization followed by thorough rehabilitation of the injured hand. These established principles provide clinical guidelines for the management of carpal injuries, and they are critical steps to a successful outcome in the treatment of carpal fractures.

Treatment OptionsScaphoid fractures

• Scaphoid fractures are classified as fractures of the proximal pole, wrist, distal one third, or distal tubercle. Scaphoid fractures are further categorized as stable or unstable. Stable fractures are nondisplaced and have minimal comminution, as seen in the image below, whereas unstable fractures are displaced and have considerable comminution. A standard series of radiographs, including those in the AP, lateral, and oblique views, are necessary to evaluate a scaphoid fracture. A stable scaphoid fracture is usually treated with cast immobilization. On average, 12 weeks are required for union of the scaphoid to occur. If radiographic evidence of scaphoid nonunion persists after 4 months of immobilization, operative intervention may be indicated.Should a strong clinical suspicion be present, even in the presence of apparently normal radiographic findings, a possible scaphoid fracture should be diagnosed based on the history and clinical findings. When a scaphoid fracture is suspected without radiographic confirmation, treatment consists of cast immobilization for 2-3 weeks followed by repeat radiographic examination. If plain radiographic findings are equivocal after 2 weeks, the scaphoid can be evaluated with CT.An unstable scaphoid fracture and scaphoid nonunion should be treated surgically with open reduction and internal fixation. Repair may involve K-wire fixation, screw fixation, bone grafting, or a combination of these techniques.After fixation is achieved, it should be confirmed intraoperatively with fluoroscopy to ensure full reduction. Postoperative immobilization is then provided for 6-12 weeks with application of a thumb spica cast.

• Lunate fracturesLunate fracture patterns are classified into 4 stages based on radiographic findings. Stage I demonstrates no significant radiographic changes. In stage II, some degree of bone fragmentation is present without evidence of collapse. In stage III, fragmentation and collapse are observed. Stage IV demonstrates evidence of fragmentation, collapse, and arthritis.Treatment of lunate fractures varies according to the stage of the disease. Most treatment options revolve around stress reduction, revascularization, or replacement of the lunate. Salvage procedures are reserved for advanced disease. Treatment options for stage I include no treatment or immobilization. The remaining stages are surgically treated with a variety of techniques. In stages II and III, the treatment options are surgical and include stress reduction, revascularization, and lunate replacement. Stage IV is also treated surgically with salvage procedures, such as scaphocapitate arthrodesis, total wrist arthrodesis, or proximal row carpectomy.

• Triquetral fracturesTriquetral fractures are radiologically separated into peripheral chip fractures or body fractures. Standard AP, lateral, and oblique radiographs are usually sufficient for their diagnosis.Triquetral chip fractures are treated symptomatically with 2-3 weeks of immobilization if discomfort becomes significant. Once symptoms resolve or become less significant, range-of-motion exercises can be initiated. Fractures of the body of the triquetrum require more significant attention. If the fracture is minimally displaced, it should be treated with cast immobilization for 4-6 weeks, with range-of-motion exercises beginning after cast removal.Displaced triquetral chip fractures that fail to unite after conservative immobilization are rarely symptomatic enough to warrant surgical excision. On the contrary, displaced fractures involving the body of the triquetrum should be surgically treated with either closed reduction and percutaneous pinning or open reduction and internal fixation.

• Pisiform fracturesThe pisiform fracture patterns commonly include transverse body fractures, comminuted fractures, or avulsion fractures. Standard radiographs, including AP, lateral, and oblique views, are usually sufficient for diagnosis. Pisiform fractures are almost universally treated conservatively with cast immobilization for 6 weeks. Range-of-motion exercises should be initiated after cast removal.

• Trapezial fracturesTrapezial fractures involve either the body or the trapezial ridge. Fractures of the body are either comminuted or vertical in orientation. Trapezial ridge fractures have been separated into 2 types: Type I fractures occur through the base of the trapezial ridge, whereas type II fractures involve the tip of the trapezial ridge. Standard radiographs, including carpal tunnel views, may help in making the diagnosis.Nondisplaced trapezial body fractures are treated conservatively with the application of a thumb spica cast for 6 weeks. Displaced trapezial body fractures require surgical attention.Trapezial ridge fractures have been separated into 2 types: those involving the base and those involving the tip of the trapezial ridge. Both types are treated conservatively with closed reduction in a thumb spica cast for 6 weeks.Displaced trapezial fractures are approached volarly. Trapezial body fractures are treated with operative reduction and internal fixation by using K-wire fixation. If symptoms persist despite conservative treatment, small type II fractures involving the trapezial ridge may be excised.

• Capitate fracturesCapitate fractures are classified as either a fracture pattern known as scaphocapitate syndrome or as an isolated capitate fracture. Scaphocapitate syndrome consists of a scaphoid wrist fracture and a proximal capitate fracture. Plain radiography is usually sufficient to make the diagnosis. Isolated capitate fractures may be difficult to diagnose with standard plain radiographs, and a CT scan is often required to establish the diagnosis. Nondisplaced capitate fractures should be treated with closed reduction and immobilization.Displaced capitate fractures require operative reduction and internal fixation. The capitate is usually approached dorsally. Alignment is typically achieved and maintained by using K-wire or screw fixation. If comminution is extensive, bone grafting may be performed concomitantly.

• Hamate fracturesFractures involving the hamate are separated into either hamate hook fractures or hamate body fractures. AP, lateral, and oblique radiographs usually depict the fracture. Carpal tunnel views are useful in diagnosing hamate hook fractures, but a CT scan may provide the most definitive findings.Nondisplaced hamate hook fractures (see image below) and nondisplaced hamate body fractures are both treated conservatively and immobilized with a cast for 6 weeks. Range-of-motion exercises are started when the cast is removed.

Radiographic Studies

Scaphoid Fracture (non-displaced)

Radiographic Studies

ORIF Scaphoid Fracture

Radiographic Studies

Nondisplaced fracture of the hook of the hamate.

Radiographic Studies

Lunate Fracture Trapezoid Fracture

Radiographic Studies

Trapezial Fracture Triquetrium Fracture

Radiographic Studies

Hamate Fracture Capitate Fracture

Perioperative Care• Preoperative Details

The treating physician must carefully consider the patient's age and occupation and the nature of the injury before selecting the appropriate fixation method. Furthermore, obtaining written informed consent is imperative. This means that the patient understands the complexity of the injury and the estimated time required for healing. The operative risks and potential complications, including nonunion, risk of infection, and the need to later remove hardware (if indicated), should also be discussed. Thorough patient education cannot be overemphasized, because it is critical to the success of treatment.

• Intraoperative DetailsWith the upper extremity anesthetized, the arm is prepared and draped in the standard fashion. A pneumatic tourniquet on the upper arm is inflated to maintain a bloodless operative field. Depending on the nature and location of the fracture, a volar or dorsal approach may be used to expose the injury. Reduction may be achieved by using K-wires as joysticks. Fixation may proceed with either K-wires or a bone screw. Bone grafting may be considered for injuries with extensive comminution. Intraoperative fluoroscopy is used to determine the effectiveness of the reduction. After the wound is closed, a protective cast is then applied for immobilization.

• Postoperative DetailsVarious postoperative management strategies exist. Bone healing after internal fixation may take 6-12 weeks and, in a few cases, longer. Postoperative cast immobilization is maintained until healing is confirmed radiographically or clinically. K-wires can be removed after radiographs show evidence of bony union. Mobilization is initiated once the fixation is deemed stable. Thereafter, range-of-motion and strengthening exercises can be initiated with the supervision and guidance of a physical therapist.

Complications

• Nonunion is the most common complication after scaphoid fracture treatment, and it may occur in 5-10% of cases, despite proper treatment. Over several years or longer, patients may then experience pain, instability, and eventual collapse that leads to intercarpal or radiocarpal arthritis. Observation alone has no role in the treatment of scaphoid nonunion, and all cases should be corrected surgically.

• Most pisiform fractures heal with conservative measures. However, chronic pain at the pisotriquetral joint may persist as a result of pisotriquetral joint degenerative changes. Pisotriquetral arthrosis is suspected when pain symptoms persist after a period of immobilization. Pisiform excision is the accepted treatment for this condition.

• The incidence of nonunion is higher with fractures involving the tip of the trapezial ridge than with fractures of the base of the trapezial ridge. The accepted treatment for painful nonunion of either type is excision, which is generally well tolerated.

• Nonunion of the hamate hook is a potential complication after operative reduction and fixation. Excision is the accepted treatment for symptomatic hamate hook nonunion.

Outcome Studies

• Carpal fractures in athletes.Geissler WB.Department of Orthopaedic Surgery, Division of Hand and Upper Extremity Surgery, University of Missisippi Medical Center, Jackson, Mississippi, USA. 3doghill@msn.com

• AbstractA review of the literature shows that 3% to 9% of all athletic injuries occur to the hand or wrist. Also, hand and wrist injuries are more common in pubescent and adolescent athletes than adults. Although knee and shoulder injuries are more common athletic injuries, an injury to the hand or wrist significantly can impair the athlete's ability to throw or catch a ball, or swing a bat or racquet. A college football player trains year round for just 11 or 12 hours of playing time. An athletic injury that occurs during the season can have profound consequences for the athlete's career and emotions. When defining a management plan for a particular wrist athletic injury, the time to heal the injury and the time to rehabilitate fully must be considered. The athlete must be informed fully of the length of recovery. The continued advancement of fixation methods and techniques are diminishing fracture morbidity considerably. Small-cannulated compression screws that provide rigid fixation can be inserted with decreased surgical dissection, thus preserving critical vascular supply and promoting accelerated healing and earlier rehabilitation. The arthroscope as a valuable adjunct in the management of wrist fractures was virtually unheard of years ago, but is now common. The ability to arthroscopically guide a cannulated compression screw to stabilize a scaphoid fracture without a formal open volar approach can reduce surgical morbidity significantly and allow the athlete to return to competition more quickly. Mechanisms of injury that cause osseous fractures of the wrist are fairly high energy. A high index of suspicion for associated soft tissue injuries should be kept in mind when fractures of the wrist are identified. The wrist is composed of eight carpal bones tightly interwoven with each other by intrinsic and extrinsic wrist ligaments. The management of carpal fractures depends on prompt diagnosis, stable and anatomic alignment of the involved carpal bone, protective immobilization of the injury, and thorough rehabilitation. Displaced fractures of the hook of the hamate, trapezial ridge fractures, and comminuted pisiform fractures are managed best by early excision to promote uncomplicated recovery and early return to sport. For most athletes, return to competition can be expedited safely with the use of padded gloves and custom playing splints or casts. The sports medicine physician always must put the athlete's safety first when deciding the appropriate time for return to competition.

Thank You

Questions/Comments?