You are in: eMedicine Specialties > Orthopedic Surgery > HAND AND UPPER EXTREMITY Forearm FracturesArticle Last Updated: Jul 17, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Gopikrishna Kakarala, MBBS, MS (Ortho), MRCSEd, Fellow, Department of Orthopedics, New Cross Hospital, UK Coauthor(s): Adrian W Simons, MBBS, FRCS(Orth), Consulting Staff, Department of Orthopedic Surgery - Hand Surgery, New Cross Hospital, UK Editors: Michael S Clarke, MD, Clinical Associate Professor, Department of Orthopedic Surgery, University of Missouri-Columbia School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Thomas R Hunt III, MD, John D Sherrill Professor and Director of Orthopaedic Surgery, Surgeon in Chief of UAB Highlands Hospital, Director of Hand and Upper Extremity Fellowship, University of Alabama at Birmingham; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine Author and Editor Disclosure Synonyms and related keywords: fractures of the radius and ulna, ulna fracture, radius fracture, radial fracture, ulnar fracture, broken arm, broken ulna, broken radius, broken forearm, fracture of both bones of the forearm INTRODUCTIONSection 2 of 11
  The forearm is a complex anatomic structure serving an integral role in upper extremity function. The dexterity of the upper limb is dependent on a combination of hand and wrist function and forearm rotation. The forearm bones can be considered struts linking 2 halves of a condylar joint formed by the proximal and distal radioulnar joints. Thus, any change in the geometry of the radius or ulna alters the congruency and range of motion of this condylar joint. Malunion, especially shortening and angulation of the radius or ulna, may cause functional problems at the wrist or elbow. If functional disability is to be avoided following fracture, precise anatomic reduction is necessary. Due to the complex arrangement of neurovascular structures surrounding the radius and ulna, surgical approaches to the forearm for fracture fixation require particular care in planning and execution. This article addresses injury to the diaphyseal radius and ulna, as well as associated injury to the distal and proximal radioulnar joints. ProblemTo restore the functional dynamics of the upper limb, very careful attention must be paid to accurate reconstruction of injured structures. In children, rapid bone-healing times and the possibility of remodeling with growth allow conservative treatment much of the time. In adults, nonoperative treatment in the form of plaster casting is often inadequate to ensure anatomic reduction and healing. Achieving anatomic reduction by closed methods is difficult; and often, maintaining a reduction is impossible. For an optimal result, the basic rule is that a stable anatomic reduction with preservation of mobility must be achieved. Operative treatment is therefore the rule, rather than the exception, in adults, The treatment principles of the AO group (Arbeitsgemeinschaft für Osteosynthese, or Association for the Study of Osteosynthesis) have revolutionized treatment of radius and ulna fractures. FrequencyThe literature provides few detail in regard to the incidence of fractures of the radius and ulna in adults. McQueen et al have comprehensively analyzed the incidence of forearm fractures seen at the trauma unit of the Royal Infirmary of Edinburgh over a 3-year period. This unit caters exclusively to adult trauma cases in a specified area and population and thus is a very good guide to the epidemiology of forearm fractures in a westernized country. The causes of injury included direct trauma, fall from a height, road traffic accidents, and sporting injuries. Unlike in other regions, injuries related to gunshots and firearms are not prevalent as a cause of injury in this region. Of the 2812 fractures, just 5% were diaphyseal forearm fractures, and an overwhelming majority of 76% were distal radius fractures. Data from the National Hospital Ambulatory Medical Care Survey show that radius and/or ulna fractures account for 44% of all forearm and hand fractures in the United States.1 EtiologyThe mechanism of injury is variable. The most common cause is a direct blow to the forearm, producing a single (nightstick) fracture of the ulna, radius, or both. The next most likely mechanism is a fall on an outstretched hand with the forearm pronated. Other mechanisms of injury include road traffic accidents and athletic injuries. The force generated is usually much greater than that required to cause a Colles fracture. Most forearm shaft fractures resulting from falls occur in athletes or in persons who fall from heights. Gunshot wounds can result in fracture of both bones of the forearm. These injuries are commonly associated with nerve or soft-tissue deficits and frequently have significant bone loss. Severely debilitating and mutilating injuries are caused by accidents involving farmyard machines and industrial machinery. These severely mangled extremities pose a challenge from the time the decision is made to salvage the limb until the final result. PathophysiologyFractures of both bones of the forearm are usually classified according to the level of fracture, the pattern of the fracture, the degree of displacement, the presence or absence of comminution or segment bone loss, and whether they are open or closed. Each of these factors may have some bearing on the type of treatment to be selected and the ultimate prognosis. Disruption of the proximal or distal radioulnar joints is of great significance to treatment and prognosis. Determining whether the fracture is associated with joint injury is imperative because effective treatment demands that both the fracture and the joint injury be treated in an integrated fashion. ClinicalNondisplaced diaphyseal fractures of the shafts of both bones of the forearm are rare, and the deformity is often obvious, with the patient supporting the deformed and injured limb with the other hand. The symptoms include pain, deformity, and loss of function of the forearm. In these cases, excessive manipulation of the arm should be avoided to prevent further damage to the soft tissues. Clinical examination should include a careful neurologic evaluation of the motor and sensory functions of the radial, median, and ulnar nerves. Check the vascular status and amount of swelling in the forearm. A tense compartment with neurological signs or stretch pain should arouse the suspicion of compartment syndrome (see Image 1), and compartment pressures should be measured and monitored. This may be of significance in polytrauma patients or in comatose or obtunded patients. A low threshold should be maintained when deciding whether a fasciotomy is needed in patients with impending compartment syndrome (see Image 2). Open fractures, especially those resulting from gunshot wounds, frequently have associated nerve and major blood vessel involvement. This involvement must be carefully evaluated. Urgent treatment is required for open fractures. A sterile dressing should be placed over the wound, and formal debridement should be reserved for the operating room. The presence of ipsilateral fractures should be excluded, and a preliminary secondary survey should be performed to rule out other skeletal injuries. INDICATIONSSection 3 of 11
All displaced adult forearm fractures should be stabilized because no other means of management is available that provides a comparable result. The following are specific indications for operative treatment:
RELEVANT ANATOMYSection 4 of 11
The radius and ulna function as a unit, but they come into contact with each other only at the ends. They are bound proximally by the capsule of the elbow joint and the annular ligament and distally by the capsule of the wrist joint, the dorsal and volar radioulnar ligaments, and the fibrocartilaginous articular disk. The ulna is relatively straight, has stable articulation with the distal humerus at the elbow, and runs virtually subcutaneously distally to the ulnar styloid at the wrist. The radius is bowed along its length and thus angles at least 13° opposite to the bow to articulate with the capitellum. The radius and ulna form a joint at the distal end, where the strutlike radius sweeps and rotates around the relatively fixed ulna with pronation and supination. Between the shafts of the radius and ulna is the interosseous space. The fibers of the interosseous membrane run obliquely across the interosseous space from their distal insertion on the ulna to their proximal origin on the radius. The central portion of the interosseous membrane is thickened and is approximately 3.5 cm wide. Hotchkiss et al showed that making an incision on the central band reduces stability by 71%, while making an incision of the triangular fibrocartilage complex and the interosseous membrane proximal to the central band decreases stability by only 11%.2 In the treatment of fractures of the forearm, the radial bow and proper interosseous space must be maintained for normal motion to be achieved. Schemitsch and Richards reported that restoration of the radial bow is related in a linear fashion to the quality of the outcome.3 The normal maximal radial bow, measured from the area between the radius and the ulna across the interosseous membrane, is 15 mm. To achieve 80% of the normal range of movement, this bow must be within 1.5 mm of normal. The same relationship also applies to grip strength. Both the amount and the location of radial bow are crucial correlates to functional outcome. CONTRAINDICATIONSSection 5 of 11
A medically fit patient has few contraindications to operative fixation of a forearm fracture. Highly contaminated compound fractures, particularly with bone loss, may be managed with temporary external fixation followed by debridement and delayed internal fixation. WORKUPSection 6 of 11
Lab Studies
Imaging Studies
Other Tests
Diagnostic Procedures
TREATMENTSection 7 of 11
Medical therapyIn children, the usual plan is to attempt closed reduction followed by cast immobilization. In adults, treatment with immobilization in a molded long arm cast can be used in those rare occasions of a nondisplaced fracture of both bones of the forearm. The cast should be applied with the elbow in 90° flexion. The stable position of pronation or supination can be found by screening on the image intensifier, but in general, fractures of the proximal third are stable in supination, fractures of the middle third are stable in neutral position, and fractures of the distal third are stable in pronation. Follow-up of these patients with radiography in both planes at weekly intervals for the first 4 weeks is mandatory to detect early displacement of the fracture. Sarmiento et al reported the results of a closed method of treatment for nondisplaced fractures of one or both bones of the forearm.4 Only in children does the salubrious effect of growth and remodeling offer an alternative to the otherwise mandatory surgical treatment of displaced or unstable forearm fractures, assuming that adequate alignment and proper rotation of the fragments can be obtained and maintained by closed methods. Angulation in the plane of joint movement is most likely to improve with growth and remodeling. However, rotational deformity and loss of normal interosseous space cannot be expected to improve with growth and remodeling, even in very young patients. The cutoff ages are in the range of 10-12 years in girls and 12-14 years in boys. At these ages, surgical treatment must be strongly considered for displaced fractures of the forearm. Surgical therapyOpen reduction and internal fixation When both bones of the forearm are fractured, they are both exposed and provisionally reduced before fixation of either bone is completed. The fracture with the least comminution (usually the ulna) is fixed first. After reduction and provisional fixation of both bones, pronation and supination are examined; if normal, definitive fixation is performed. The plate must be accurately centered over the reduced fracture and must be of sufficient length to permit, preferably, 6 cortices to be secured by screws on each side of the fracture (see Image 3). The plates should be contoured to fit the bone, especially the radius, to maintain the normal bow of the radius for restoration of normal function. The general rule is that bone grafting is recommended when more than one third of the circumference of the bone is comminuted. If this is instituted, it should be performed away from the interosseous membrane to decrease the risk of synostosis. In their review of 198 forearm fractures, Wright et al reported comparable results in union in comminuted forearm fractures treated with bone grafting and without bone grafting.5 Intramedullary nailing The first widely used and successful medullary forearm nail system was developed by Sage in 1959. The prebent radial nail maintains the radial bow, and the triangular cross-sectional shape prevents rotational instability (see Image 3). When intramedullary devices are used in persons with fracture of both bones, fixation of the radius must be stable enough to prevent collapse of the radial bow; otherwise, elongation of the radius and distraction of the ulnar fracture can occur, resulting in nonunion in either or both bones. The entry point for intramedullary nailing of the ulna is made in the proximal ulna. The radial portal is usually into the radial styloid process between the extensor carpi radialis longus and extensor pollicis brevis. All radial nails should be well seated to avoid fraying of the tendon and possible rupture. The indications for intramedullary nailing are as follows:
Open fractures of the forearm The traditional theory was to not use internal fixation initially in open fractures of the forearm; initial management was with irrigation and debridement. Current treatment trends are to initiate immediate open reduction and internal fixation of all open forearm fractures. Immediate open reduction and internal fixation of Gustilo type I and type II open diaphyseal forearm fractures is appropriate provided thorough debridement is performed. Duncan et al reported 90% acceptable results in persons with Gustilo type I, type II, or type IIIA open diaphyseal fractures treated in this manner; however, their results with IIIB and IIIC injuries were poor.6 Preoperative detailsFractures are best internally fixed as soon after the injury as practical, preferably before the onset of swelling. With delayed fracture presentation, blisters secondary to swelling can develop. Ruptured fracture blisters or abrasions older than 6-8 hours may be a contraindication for surgery. At least 7-10 days may be required for abraded skin and fracture blisters to heal and for swelling to subside. Intraoperative detailsUlnar approach An interneural approach between the extensor carpi ulnaris and flexor carpi ulnaris is used. The plate can be used on the posterior or anterior surface, although the posterior surface is preferred because it is the tension side of the ulna. Care should be taken to avoid damage to the dorsal sensory branch of the ulnar nerve in the distal part of the incision. Palmar approach of Henry The palmar approach of Henry is the most common approach for fixation of the shaft of the radius. It uses the interneural interval between the brachioradialis (radial nerve) and the pronator teres (or flexor carpi radialis distally, innervated by the median nerve). For deep dissection, the arterial branches of the radial artery supplying the brachioradialis muscle are carefully ligated. Rotation of the forearm enhances the view during this approach. Dorsolateral approach Access to the radial shaft runs in the septum between the extensor carpi radialis brevis and the extensor digitorum muscles. It can be useful for fractures of the proximal and middle thirds of the radius and to address injuries to the proximal radioulnar joint. The dorsolateral approach (also called the Thompson approach) potentially involves less soft-tissue stripping than the palmar approach, and patients may experience a more rapid return of wrist and hand function. The 2 nerves vulnerable to injury with this approach are (1) the superficial radial nerve in the distal part of the incision along the brachioradialis muscle crossing the abductor pollicis longus in the subcutaneous layer and (2) the posterior interosseous nerve running through the supinator in the proximal exposure. Reduction techniques Periosteal stripping should be limited to a minimum, and circumferential stripping is to be strictly avoided. Plates of 3.5 mm have been proven to be the ideal size for the forearm bones. The purpose of the plate is to neutralize the torsional forces, and purchase should be obtained at no fewer than 6 cortices in each main fragment in order to achieve this objective. Interfragmentary lag screws, either independently or through a plate hole, should be used to strengthen the fixation if the fracture configuration allows it. Closure Of utmost importance is to close only the subcutaneous tissue and skin. If the deep fascia is sutured tightly, edema and hemorrhage may cause increased pressure in the forearm compartments, which can lead to ischemic contracture. A suction drain can be used to decrease the hematoma and resultant swelling. The drain is removed in 12-24 hours. Postoperative detailsIf the rigidity of the fixation is sufficient, limited postoperative cast immobilization is used. A posterior splint can be applied for 1-2 weeks for comfort. Patients are encouraged to perform both active and active-assisted range-of-motion exercises of the shoulder and hand. Elbow range-of-motion and pronation/supination exercises should begin as soon as remission of pain and swelling of the forearm permits after the plaster splint is removed. However, in the case of a noncompliant patient, external immobilization (usually an above-elbow cast) is essential, along with supervised physiotherapy until the fracture is deemed united based on radiographic findings. Follow-upFollow-up radiographs are taken regularly during the postoperative phase until progressive healing is documented. Determining when a rigidly plated fracture of the forearm has healed based on radiographic findings is difficult partly because very little external callus results when fractures are stabilized in a rigid manner as is the case for plate-and-screw fixation of radius and ulnar fractures. Strenuous activity must be prohibited until bone trabeculae cross the fracture. COMPLICATIONSSection 8 of 11
Nonunion and malunion Nonunion of fractures of the shafts of the radius and ulna is relatively uncommon. Anderson's series of forearm fractures treated with compression plates included 9 nonunions (2.7%) and 4 delayed unions (1.2%) in 330 fractures.7 Almost all of the nonunions and delayed unions appeared to have been caused by infection or errors in surgical technique (see Images 5-6). Accurate open reduction and rigid internal fixation prevent most of these complications. Infection Stern and Drury reported a 3.1% rate of osteomyelitis in forearm fractures; both instances occurred in patients with massive crush injuries (see Image 7).8 With good technique and a contemporary operating environment, the rate is currently much lower. Superficial infections respond well to appropriate antibiotics. The general principles of surgical debridement and copious irrigation are key in treating deep infections. The internal fixation can be left in situ while the infection is being treated, and most fractures proceed to union. The metal can be removed after union of the fracture. Aggressive treatment is required for late infections, when fixation has been lost and nonunion has developed. Metal should be removed along with any nonviable bone. The wound can be left open for dressing changes, or an irrigation-suction system can be instituted. If an intercalary defect results, it can be spanned with a long plate and bone grafting when the wound is healthy and after a period of dressing changes. Serial examinations of the wound are required to determine the appropriate timing for the bone-grafting procedure. If the intercalary defect is large (>6cm), a vascularized fibular bone graft should be considered to bridge the defect (see Image 8). Compartment syndrome Compartment syndromes can occur in the forearm either after trauma (see Image 1) or after surgery. Eaton and Green reported 19 patients with Volkmann ischemia, resulting from a volar compartment syndrome of the forearm.9 An important early sign is pain out of proportion to the injury and pain upon passive extension of the fingers. The presence of the radial pulse is not a reliable diagnostic indicator; the radial pulse was absent in only 5 of their 19 patients. Be aware that the presence of a palpable radial pulse does not rule out the presence of a compartment syndrome. In conscious patients, the diagnosis of compartment syndrome is made on the basis of clinical findings. Compartment pressures can be measured to confirm the diagnosis of compartment syndrome, provided treatment is not delayed. Measurement is especially valuable when making the diagnosis of compartment syndrome in unconscious or obtunded patients. Surgical treatment should be performed early and should include fasciotomy from the elbow to the wrist, including division of the lacertus fibrosis proximally and the transverse carpal ligament distally. Delayed closure of the wound is performed later. A residual defect may require split-thickness skin grafting. Closed compartment syndromes that follow operations in the forearm are usually due to inadequate hemostasis or closure of the deep fascia. They can usually be avoided by releasing the tourniquet before wound closure to make sure hemostasis is adequate and by closing only the subcutaneous tissue and skin. Implant removal and refractures after implant removal Removal of implants is not mandatory and is rarely indicated in an asymptomatic patient because of the risk of complications, including neurovascular injury and refracture. If indicated, implants should not be removed for at least 18 months to 2 years after internal fixation—and even then, only after careful consideration by an experienced surgeon. Removal of forearm fracture plates after healing is not a benign procedure. The rate of refracture is 3.5-25. Evidence indicates that the use of the 3.5-mm plate has considerably reduced the rate of refracture. Comminuted fractures, open fractures, bone defects, technical failure (excessive stripping, inadequate compression), and early plate removal within 1 year after internal fixation increase the risk of refracture. Once a plate has been removed, the forearm should be protected by a splint for 6 weeks. It should then be protected from severe stress and torsion for 6 months. Patients undergoing elective removal of implants should be warned of the potential for refracture even later than 6 months. Mih et al reported an 11% refracture rate in 62 patients, with a mean time to refracture of 6 months.10 Synostosis Bauer et al reported that the highest risk of synostosis is associated with internal fixation of fractures involving the proximal third of both the radius and the ulna.11 Extensive soft-tissue dissection during exposure, the development of a radioulnar hematoma, the risk of interosseous damage, and occasional malpositioning of the dorsal plate if the Boyd approach is used also contribute to an enhanced risk of postosteosynthetic synostosis (see Image 9). In cases in which both bones are fractured, separate surgical approaches for the radius and the ulna have been shown to minimize the risk of radioulnar synostosis. OUTCOME AND PROGNOSISSection 9 of 11
The prognosis for adults with fractures of the radius and ulna depends on many factors. However, the factors under the surgeon's control include choice of treatment method, timing of internal fixation in open fractures, soft-tissue handling, and restoration of osseous anatomy. Anderson reported a union rate of 97.3% for fractures treated with open reduction and internal fixation using compression plates.7 Of these patients, 90% had satisfactory or excellent function, and only 10% had unsatisfactory or poor function. Sage reported a union rate of 93.8% for fractures treated with triangular nails.12 The important feature common to these studies, in which a union rate of more than 90% was reported, was the rigidity of the fixation. If intramedullary nails are used, they must control rotation of the fragments and be sturdy enough to resist angulatory forces. If plates and screws are used, they must be long enough and strong enough to resist loosening and breakage. The prognosis is more guarded for open fractures of the shaft of the radius and ulna with major skin and soft-tissue loss. In these cases, several operative procedures may be necessary, including the initial debridement and stabilization, skin grafting, pedicle or free-flap applications, late reconstruction of the bones, and, frequently, tendon transfers. MULTIMEDIASection 10 of 11
REFERENCESSection 11 of 11
Article Last Updated: Jul 17, 2007 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
