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Fractures of the forearm bones and distal radius
ORTHOPAEDICS III: UPPER LIMB
Fractures of the forearm bones and distal radius
proximal ulna, and held in place by the annular ligament. The interosseous membrane is a fibrous sheet with a thickened central band. The central band contributes to the majority of stability of the forearm and maintains the intricate articular relationship between the forearm bones.2
Joby John Tim Cresswell
Classification The classification of forearm fractures is anatomical. The need for awareness of associated joint subluxations of the proximal and distal radioulnar joints cannot be overemphasized.
Abstract Fractures of the radius and ulna should be treated as a single unit rather than separate bony entities due to the intricate relationship of both bones in the forearm. Injuries can be divided into fractures of both bones, fracture of a single bone, and fracture of single bone associated with joint injuries. Distal radius fractures have been dealt with separately, as they are most common. The aim of treatment is to restore anatomy, and achieve stability to allow early mobilization to achieve good function. In diaphyseal fractures of the forearm, restoration of the relative lengths of both bones to maintain the integrity of the joints is vital and often requires operative intervention. In fractures of distal radius restoration of volar tilt, radial inclination and length should be achieved and maintained during healing by appropriate methods. Stable fixation allows early return to function.
Treatment Cast immobilization: in adult forearm fractures cast immobilization is very rarely used as any effect on the curvature of the radius will affect the range of pronation and supination. In paediatric fractures, especially in younger children, manipulation and cast stabilization are the preferred methods. Internal fixation modalities: the internal fixation modalities available for treatment are intramedullary nails and dynamic compression plates. Intramedullary nailing: this technique preserves the advantages of closed fracture treatment as the fracture haematoma is not interfered with and insertion of the nails is done at a point distant from the fracture. It also gives the fracture enough stability to allow healing with callus formation. Although a variety of intramedullary fixation devices are available, elastic titanium nails are used commonly in children.
Keywords Distal radius; fracture of both bones of forearm; volar locked plate
Fractures of forearm bones Fractures of the forearm bones (radius and ulna) behave differently to diaphyseal fractures of other long bones because of the surgical anatomy peculiar to the forearm. Although the radius and ulna come into contact with each other only at the ends, namely the proximal and distal radioulnar joints, they function as a single unit. 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 disc. The ulna is a straight bone around which the radius pronates and supinates. The radius of curvature of the radius is complex and should be maintained while treating fractures, as alterations can result in restriction of supination and pronation.1 The interosseous membrane between the radius and ulna is a complex structure, and has prompted some surgeons to treat fractures of the radius and ulna as intra-articular injuries requiring anatomical reduction, absolute stability and early movement.1 The interosseous joint between the radius and ulna is formed at the elbow by the proximal radioulnar joint, which comprises the articulation of the radial head with the notch of the
Dynamic compression plating: this is the preferred method in adults, as it allows accurate reduction of the fracture, maintains the bow of the radius and achieves rigid stability to allow early mobilization of the forearm. Associated injuries Proximal radioulnar joint subluxation (Monteggia fracture): this is a fracture of the proximal ulna with subluxation of the proximal radioulnar joint (Figure 1). The eponym was suggested by Bado in 1967.3 Classification of monteggia injuries Type I: Fracture of the ulnar diaphysis at any level with anterior angulation at the fracture site and an associated anterior dislocation of the radial head. Type II: Fracture of the ulnar diaphysis with posterior angulation at the fracture site and a posterolateral dislocation of the radial head. Type III: Fracture of the ulnar metaphysis with a lateral or anterolateral dislocation of the radial head. Type IV: Fracture of the proximal third of the radius and ulna at the same level with an anterior dislocation of the radial head.
Joby John MS MRCS is a Specialist Registrar in Orthopaedics at the Pulvertaft Hand Centre, Derby Royal Hospital, Derby, UK. Conflicts of interest: none.
Clinical findings In addition to the usual findings associated with a fracture, the dislocated radial head can be palpable at the elbow. More important is the neurological examination for posterior interosseous nerve, which may be injured especially in Bado type II injuries.
Tim Cresswell BM FRCS.Ed (Trauma and Orth) Dip. Orth. Eng is a Consultant Upper Limb and Hand Surgeon at the Pulvertaft Hand Centre, Royal Derby Hospital, Derby, UK. Conflicts of interest: none.
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ORTHOPAEDICS III: UPPER LIMB
Monteggia fracture (with proximal radioulnar dislocation). Figure 1
Fractures of the distal radius
Treatment of monteggia injuries Good outcomes following Monteggia fractures depend on early accurate diagnosis, accurate reduction of the radial head, rigid fixation of the ulna, and postoperative immobilization to allow ligamentous healing about the dislocated radial head. Rigid fixation of the ulna is achieved by using a 3.5 mm dynamic compression plating system applied in static mode to maintain the length of the ulna and hence the reduction of the radial head.
The distal radius is the most common site of fracture in the forearm. The radiocarpal articulation and distal radioulnar articulation support the carpus. These joints comprise three separate articular surfaces that are of concern in treatment of fractures of the distal radius. The scaphoid fossa and lunate fossa are two concave articular surfaces separated by a dorsalevolar ridge, which define clear articulations for the lunate and scaphoid; and the DRUJ that occurs at the sigmoid notch on the radius and accepts the head of the ulna. The distal articular surface of the radius is aligned to the longitudinal axis of the radius at approximately 11 of volar tilt and 22 of ulnar inclination. The ulnar side of the wrist is supported in addition by the triangular fibro-cartilage (TFCC), which articulates with both the lunate and triquetrum. Fractures of the distal radius that extend into these joints are treated as intra-articular fractures. Those fractures limited to the metaphysis of the distal radius, but not involving the joints, may affect the distal radioulnar articulation and hence its biomechanical properties due to alteration of the relative lengths of the radius and ulna. These factors in the surgical anatomy make it imperative that distal radius fractures are treated carefully so that the anatomical parameters and integrity of the articulations are maintained to achieve the best results.
Distal radioulnar joint injuries (Galleazzi fractures) This injury consists of a solitary fracture of the radius at the junction of the middle and distal third with subluxation of the distal radioulnar joint (DRUJ). The insertion of the pronator quadratus on the palmar surface of the distal fragment, the brachioradialis attachment to the styloid of the distal radius and the abductors and extensors of the thumb cause significant deforming forces to the distal fragment and the DRUJ. These deforming forces make it very difficult to maintain a reduced position in cast. These fractures require accurate reduction of the fracture and DRUJ along with stabilization of the radius fracture.4 Clinical features The features of fracture will be accompanied by deformity and tenderness at the DRUJ.
Mechanism of injury of distal radius fractures Facture of the distal radius most commonly arises due to a fall on the outstretched hand. This results in an axial load on a wrist that is dorsiflexed. The non-comminuted fracture on the palmar aspect of the radial metaphyseal area, compared with the dorsal comminuted fragments, suggests that the radius fractures in tension on its palmar surface, subsequently propagating dorsally
Treatment of galleazzi injuries Fractures at the junction of the middle and distal thirds of the radius are best managed with plate fixation, ensuring accurate reduction of the fracture and the DRUJ (Figure 2). Very rarely proximal radioulnar joint subluxation can be associated with fracture of the radial shaft.5
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ORTHOPAEDICS III: UPPER LIMB
Comminuted Galleazzi fracture treated with open reduction and internal fixation. Figure 2
Die-punch fracture:10 Die-punch fracture is an intra-articular fracture with depression of the dorsal aspect of the lunate fossa. Various classification systems have been proposed to describe the injury and help formulate a treatment plan. Broadly they tend to be anatomical classifications that group fracture patterns, biomechanical that describe the mechanism of injury and fracture stability or a combination of both.
where bending moment forces lead to compression stresses. This results in crushing of the cancellous bone and shortening of the distal radius relative to the ulna. Transmission of these forces onto the radial cortex requires intact ligaments. In the elderly where these fractures are common the metaphyseal bone is the weakest. In younger patients, where greater forces are involved, concomitant ligamentous injuries may occur and have particular relevance to the choice of treatment modalities. Classification The eponymous descriptions associated with distal radius fractures have traditionally been good indicators of the type of injury and treatment.
Universal classification system11 A fracture may be defined as either extra-articular or intraarticular. Extra-articular fractures maybe: Type I nondisplaced and stable. Type II displaced.
Colle’s fracture:6 Colle’s fracture is an extra-articular distal radius fracture with dorsal comminution, dorsal angulation, dorsal displacement, and radial shortening.
Intra-articular fractures, are either: Type III nondisplaced or Type IV displaced. Further, displaced articular or nonarticular fractures may be: reducible, stable reducible, unstable complex irreducible. Indicators of instability are (i) shortening of greater than 5 mm, (ii) dorsal angulation greater than 20 , (iii) marked dorsal comminution and (iv) displacement in a plaster of Paris cast. Classification systems proposed for intra-articular fractures include:
Smith’s fracture:7 Smith’s fracture is a fracture of the distal radius with volar displacement. Barton’s fracture:8 Barton’s fracture is a displaced, unstable articular fracture-subluxation of the distal radius with displacement of the carpus along with the articular fracture fragment. These may be either dorsal or volar. Chauffeur’s fracture:9 Chauffeur’s fracture is a fracture of the radial styloid. It may be associated with displacement of the carpus and may be the only bony component of perilunate injury.
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Mayo classification12 This classification describes the scaphoid, lunate, and sigmoid notch fossae of the distal radius as separate articulations.
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Type I fractures are intra-articular but nondisplaced. Type II fractures are displaced involving the radioscaphoid joint. This may be associated with scapholunate injuries. Type III fractures are displaced involving the radiolunate joint. These are die-punch fractures which may not reduce with traction alone. Type IV fractures are displaced involving the radioscaphoid, lunate joints and the sigmoid fossa of the distal radius. This is a significantly comminuted fracture.
Type V: High-velocity injuries that involve combinations of bending, compression, shearing and avulsion mechanisms or bone loss. Clinical features The dorsal aspect of the hand and wrist is usually quite swollen, and ecchymosis may be present, especially in the elderly. The wrist should be examined for tenderness, not only about the radial fracture site, but also at the distal ulna, elbow and shoulder. Median nerve function and flexor and extensor tendon action should be tested.
Fragment-specific classification13 In this classification system intra-articular fractures of the radius are divided into five major fragments, including the radial styloid, ulnar corner, dorsal wall, articular surface, and volar lip fragments. This classification is useful for treatment using fragment-specific fixation.
Investigations Standard posterior-anterior and lateral radiographs are obtained to assess displacement, shortening and comminution. A computed tomography scan may be useful in assessing intraarticular extension and other associated fractures or injuries.
Fernandez classification14 This classification system is based on the mechanism of injury. This system is advantageous because the associated ligamentous lesions, subluxations, and fractures of the neighbouring carpal bones, and soft tissue damage, are directly related to the quality and degree of violence sustained. It also helps in reduction of the fractures by reversing the mechanism. Type I: Bending fractures of the metaphysis in which one cortex fails to tensile stresses and the opposite one undergoes a certain degree of comminution. These are extra-articular fractures (Colle’s & Smith’s fracture). Type II: Shearing fractures. These are intra-articular fractures (Barton’s, reversed Barton’s, and radial styloid fractures). Type III: Compression fractures. These are intra-articular comminuted fractures, complex articular fractures, and pilon radial fractures. These intra-articular fractures are associated with impaction of the subchondral and metaphyseal cancellous bone. Type IV: Avulsion fractures of ligament attachments, includes ulnar and radial styloid fractures associated with radiocarpal fracture-dislocations.
Treatment strategies The aim of treatment is to achieve and maintain reduction until bony union, and to promote rehabilitation to prevent the consequences of immobilization of the wrist and adjacent joints. In intra-articular fractures, anatomical reduction, absolute stability and early mobilization should be achieved. Reduction may be achieved using open or closed means. Closed reduction is achieved by traction through the fingers to disimpact the fragments and correction of the deformity. Reduction of articular fractures may be done by direct visualization using arthroscopy. Indirect reduction is the preferred method and is achieved through the fracture site, where the fractured articular fragments are reduced onto the carpus which serves as a template. Intraoperative radiographs are useful for the assessment of reduction. Maintenance of reduction can be achieved by a variety of methods. Moulded plaster of Paris cast: this is traditionally the most popular method of immobilization (Figure 3). A proper technique
Sequential radiographs showing displacement in a plaster cast after good reduction was obtained in theatre. Three-point moulding of the cast is of paramount importance. Figure 3
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ORTHOPAEDICS III: UPPER LIMB
with three-point moulding is vital. Extremes of palmar flexion and ulnar deviation are to be avoided to prevent median nerve compression and difficulty in mobilizing fingers. This method has the advantage of being non-invasive and avoids risk of surgery. However reduction may be imprecise, and the immobilization is not rigid and therefore best suited to minimally comminuted, stable injuries.
with threads on the head of the screw or smooth peg, allows the head to be fixed onto the plate. This functions as a fixed-angle device preventing instability at the screw plate interface. These pegs or screws can be placed in such a manner that they act as a buttress to the articular surface at the subchondral bone. Locked plating systems allow early mobilization and quicker rehabilitation after injury. They carry the risks associated with all surgical procedures. The choice of treatment modality is governed by many factors and should be reached after careful informed consent from the patient, keeping in mind the fracture configuration and the patient expectations.
Intraosseous Kirschner (K) wire fixation: in this method the distal fragment is fixed onto the proximal shaft fragment using smooth or threaded K wires. Adequate care must be taken to prevent injury to cutaneous nerves and tendons. As a fixation modality this method does not provide sufficient stability and needs supplemental orthotic support. K wires do not maintain length of radius over a period of time in fractures with metaphyseal compaction.
Treatment algorithm according to mechanism of injury Type I: Bending fractures. These fractures are treated by exerting a tension force on the concave side of the angulation. In fractures with adequate bone quality and in the absence of metaphyseal comminution, this can be achieved with a three-point moulded cast. Type II: Shearing fractures. They are usually intra-articular. They are extremely unstable due to the obliquity of the fracture line. They are best treated by internal fixation with plates due to the intra-articular nature and inherent instability (Figure 4). Type III: Compression fractures. Reduction can be achieved in most cases by applying traction. In many cases, disimpaction of cartilage-bearing fragments may require limited or extensile open reduction and fixation. Type IV: Avulsion fractures are a constant component of radiocarpal dislocations in which rotational forces were part of the mechanism of injury. If such fractures remain displaced screw fixation is the method of choice.
External fixation: this method relies on indirect reduction by ligamentotaxis. Supplemental K wire stabilization may be used to stabilize individual fragments. This method suffers from the problems associated with pin site infections. External fixators are useful in those cases where severe comminution prevents internal fixation. Adequate care should be taken to prevent injury to cutaneous nerves and tendons. An open technique where a mini-incision is made to prevent injury is preferred by the authors. Internal fixation: a variety of internal fixation modalities are available. Broadly depending on the site of application on the distal radius they may be categorized as volar devices, dorsal devices or fragment-specific fixation devices. The locking plate,
Radiographs illustrate restoration of length and articular congruity a with locked plate. Note the lateral view is not articular and hence gives the impression of articular penetration with distal pegs. Figure 4
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ORTHOPAEDICS III: UPPER LIMB
Distal radioulnar joint (DRUJ) injuries e Type II (unstable DRUJ lesions): These are clinical and radiographic evidences of subluxation of the ulnar head because of a massive tear of the TFCC and secondary DRUJ stabilizers or an avulsion fracture of the base of the ulnar styloid. Distal radioulnar joint (DRUJ) injuries e Type III (potentially unstable lesions): These are associated with skeletal disruption of the joint surface at the sigmoid notch or the ulnar head. Carpal ligament injuries: The incidence of scapholunate ligament tears in conjunction with distal radius fractures is approximately 30%, and for lunotriquetral ligament tears it is approximately 15%. Open repair of the lesion is recommended after reduction and fixation of the distal radial fracture. Complications of distal radius fractures Nearly 30% of all distal radius fractures in a series of 565 fractures had complications.15
Figure 5 Non-union after distal radius fractures.
Type V: High-velocity injury with combination of fracture patterns. A combination of fixation methods should be selected for treatment.
CRPS I (reflex sympathetic dystrophy): This is treated by elevation of an oedematous hand, and intensive hand therapy is frequently very helpful in preventing the development of full reflex sympathetic dystrophy.
Author’s guide to decision-making Undisplaced fractures: These are generally stable and are unlikely to displace in a moulded cast. They are placed in a well-moulded below-elbow cast, allowing mobilization of the fingers. Good plaster technique with three-point moulding is vital. Radiographic review is done at the end of the first week to assess displacement and loosening of the cast secondary to reduction of swelling. Internal fixation in order to mobilize early is an option that needs to be weighed up against the risks of surgery.
Non-union: Non-unions of distal radius fractures (Figure 5) are extremely rare while non-unions of ulnar styloid process fractures in conjunction with distal radius fractures are quite common. Ulnar styloid non-unions are rarely symptomatic. Treatment of distal radius non-unions must be to achieve union with rigid internal fixation and iliac crest bone grafting. Malunion: Malunions result in wrist pain (radiocarpal, radioulnar and/or ulnocarpal), decreased range of motion, and/or midcarpal instability. If symptomatic, depending on whether the malunion is extra-articular, intra-articular (affecting both the radiocarpal and radioulnar joints), or complex (metaphyseal and articular deformity), post-traumatic wrist deformity can be corrected with extra-articular osteotomies, intra-articular osteotomies, or a combination of both. A
Displaced extra-articular fractures: Closed reduction under appropriate local anaesthetic block is done to realign the fracture and allow soft tissues to heal. The radiographic indicators of instability are looked for and in the presence of significant shortening (>5 mm), angulation (20 dorsal or volar angulation) and displacement, early open reduction and internal fixation is planned. In fractures that are within the acceptable parameters after reduction, namely <5 mm shortening, 0e10 of volar tilt, operative intervention is instituted only when the fractures redisplace in the cast.
REFERENCES 1 Schemitsch EM, Richards RR. The effect of malunion on the functional outcome after plate fixation of fractures of both bones of forearm in adults. J Bone Joint Surg 1992; 74A: 1068e78. 2 Hotchkiss RN, An K, Sowa DT, Basta S, Weiland AJ. An anatomic and mechanical study of interosseous membrane of forearm. Pathomechanics of proximal migration of the radius. J Hand Surg 1989; 14A: 256e61. 3 Bado JL. The monteggia lesion. Clin Orthop 1967; 50: 71e86. 4 Hughston JL. Fractures of the distal radius shaft; mistakes in management. J Bone Joint Surg 1957; 39A. 249e64. 5 Simpson JM, Andreshak TG, Patel A, Jackson WT. Ipsilateral radial head dislocation and radial shaft fracture. A case report. Clin Orthop 1991; 266: 205e8. 6 Colles A. The classic: on the fracture of the carpal extremity of the radius (reprinted from the original 1814 article). Clin Orthop 1972; 83: 3e5.
Displaced intra-articular fractures: In the presence of significant intra-articular step (>3 mm) or gap, early open reduction and internal fixation are done. Injuries associated with distal radius fractures Median nerve injury: If satisfactory reduction is obtained, the symptoms will improve. If the neurological symptoms show no sign of improvement over the first 24e48 hours after closed reduction, an open reduction, internal fixation and carpal tunnel release should be performed. Distal radioulnar joint (DRUJ) injuries e Type I (stable DRUJ lesions): The DRUJ is clinically stable with minimally displaced avulsion fractures of the tip of the ulnar styloid and stable fractures of the neck of the ulna.
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7 Peltier LF. Fractures of the distal end of the radius: an historical account. Clin Orthop 1984; 187: 18e22. 8 Barton JR. Views and treatment of an important injury to the wrist. Med Examiner 1838; 1: 365. Cross reference: Green’s Operative Hand Surgery. 9 Edwards HC. The mechanism and treatment of backfire fracture. J Bone Joint Surg 1926; 8: 701e17. Cross reference: Green’s Operative Hand Surgery. 10 Brindley HH. Wrist injuries. Clin Orthop 1972; 83: 17e23. 11 Cooney WP. Fractures of the distal radius: a modern treatment based classification. Orthop Clin North Am 1993; 24: 211e6.
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12 Bradway JK, Amadio PC, Cooney WP. Open reduction and internal fixation of displaced, comminuted intra-articular fractures of the distal end of the radius. J Bone Joint Surg Am 1989; 71: 839e47. 13 Swigart CR, Wolfe SW. Limited incision open techniques for distal radius fracture management. Orthop Clin North Am 2001; 32: 317e27. 14 Fernandez DL, Jupiter JB. Fractures of the distal radius. New York: Springer Verlag, 1995: 26e52. 15 Cooney WP, Dobyns JH, Linscheid RL. Complications of Colles’ fractures. J Bone Joint Surg Am 1980; 62: 613e9.
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Fractures of the forearm bones and distal radius
proximal ulna, and held in place by the annular ligament. The interosseous membrane is a fibrous sheet with a thickened central band. The central band contributes to the majority of stability of the forearm and maintains the intricate articular relationship between the forearm bones.2
Joby John Tim Cresswell
Classification The classification of forearm fractures is anatomical. The need for awareness of associated joint subluxations of the proximal and distal radioulnar joints cannot be overemphasized.
Abstract Fractures of the radius and ulna should be treated as a single unit rather than separate bony entities due to the intricate relationship of both bones in the forearm. Injuries can be divided into fractures of both bones, fracture of a single bone, and fracture of single bone associated with joint injuries. Distal radius fractures have been dealt with separately, as they are most common. The aim of treatment is to restore anatomy, and achieve stability to allow early mobilization to achieve good function. In diaphyseal fractures of the forearm, restoration of the relative lengths of both bones to maintain the integrity of the joints is vital and often requires operative intervention. In fractures of distal radius restoration of volar tilt, radial inclination and length should be achieved and maintained during healing by appropriate methods. Stable fixation allows early return to function.
Treatment Cast immobilization: in adult forearm fractures cast immobilization is very rarely used as any effect on the curvature of the radius will affect the range of pronation and supination. In paediatric fractures, especially in younger children, manipulation and cast stabilization are the preferred methods. Internal fixation modalities: the internal fixation modalities available for treatment are intramedullary nails and dynamic compression plates. Intramedullary nailing: this technique preserves the advantages of closed fracture treatment as the fracture haematoma is not interfered with and insertion of the nails is done at a point distant from the fracture. It also gives the fracture enough stability to allow healing with callus formation. Although a variety of intramedullary fixation devices are available, elastic titanium nails are used commonly in children.
Keywords Distal radius; fracture of both bones of forearm; volar locked plate
Fractures of forearm bones Fractures of the forearm bones (radius and ulna) behave differently to diaphyseal fractures of other long bones because of the surgical anatomy peculiar to the forearm. Although the radius and ulna come into contact with each other only at the ends, namely the proximal and distal radioulnar joints, they function as a single unit. 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 disc. The ulna is a straight bone around which the radius pronates and supinates. The radius of curvature of the radius is complex and should be maintained while treating fractures, as alterations can result in restriction of supination and pronation.1 The interosseous membrane between the radius and ulna is a complex structure, and has prompted some surgeons to treat fractures of the radius and ulna as intra-articular injuries requiring anatomical reduction, absolute stability and early movement.1 The interosseous joint between the radius and ulna is formed at the elbow by the proximal radioulnar joint, which comprises the articulation of the radial head with the notch of the
Dynamic compression plating: this is the preferred method in adults, as it allows accurate reduction of the fracture, maintains the bow of the radius and achieves rigid stability to allow early mobilization of the forearm. Associated injuries Proximal radioulnar joint subluxation (Monteggia fracture): this is a fracture of the proximal ulna with subluxation of the proximal radioulnar joint (Figure 1). The eponym was suggested by Bado in 1967.3 Classification of monteggia injuries Type I: Fracture of the ulnar diaphysis at any level with anterior angulation at the fracture site and an associated anterior dislocation of the radial head. Type II: Fracture of the ulnar diaphysis with posterior angulation at the fracture site and a posterolateral dislocation of the radial head. Type III: Fracture of the ulnar metaphysis with a lateral or anterolateral dislocation of the radial head. Type IV: Fracture of the proximal third of the radius and ulna at the same level with an anterior dislocation of the radial head.
Joby John MS MRCS is a Specialist Registrar in Orthopaedics at the Pulvertaft Hand Centre, Derby Royal Hospital, Derby, UK. Conflicts of interest: none.
Clinical findings In addition to the usual findings associated with a fracture, the dislocated radial head can be palpable at the elbow. More important is the neurological examination for posterior interosseous nerve, which may be injured especially in Bado type II injuries.
Tim Cresswell BM FRCS.Ed (Trauma and Orth) Dip. Orth. Eng is a Consultant Upper Limb and Hand Surgeon at the Pulvertaft Hand Centre, Royal Derby Hospital, Derby, UK. Conflicts of interest: none.
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ORTHOPAEDICS III: UPPER LIMB
Monteggia fracture (with proximal radioulnar dislocation). Figure 1
Fractures of the distal radius
Treatment of monteggia injuries Good outcomes following Monteggia fractures depend on early accurate diagnosis, accurate reduction of the radial head, rigid fixation of the ulna, and postoperative immobilization to allow ligamentous healing about the dislocated radial head. Rigid fixation of the ulna is achieved by using a 3.5 mm dynamic compression plating system applied in static mode to maintain the length of the ulna and hence the reduction of the radial head.
The distal radius is the most common site of fracture in the forearm. The radiocarpal articulation and distal radioulnar articulation support the carpus. These joints comprise three separate articular surfaces that are of concern in treatment of fractures of the distal radius. The scaphoid fossa and lunate fossa are two concave articular surfaces separated by a dorsalevolar ridge, which define clear articulations for the lunate and scaphoid; and the DRUJ that occurs at the sigmoid notch on the radius and accepts the head of the ulna. The distal articular surface of the radius is aligned to the longitudinal axis of the radius at approximately 11 of volar tilt and 22 of ulnar inclination. The ulnar side of the wrist is supported in addition by the triangular fibro-cartilage (TFCC), which articulates with both the lunate and triquetrum. Fractures of the distal radius that extend into these joints are treated as intra-articular fractures. Those fractures limited to the metaphysis of the distal radius, but not involving the joints, may affect the distal radioulnar articulation and hence its biomechanical properties due to alteration of the relative lengths of the radius and ulna. These factors in the surgical anatomy make it imperative that distal radius fractures are treated carefully so that the anatomical parameters and integrity of the articulations are maintained to achieve the best results.
Distal radioulnar joint injuries (Galleazzi fractures) This injury consists of a solitary fracture of the radius at the junction of the middle and distal third with subluxation of the distal radioulnar joint (DRUJ). The insertion of the pronator quadratus on the palmar surface of the distal fragment, the brachioradialis attachment to the styloid of the distal radius and the abductors and extensors of the thumb cause significant deforming forces to the distal fragment and the DRUJ. These deforming forces make it very difficult to maintain a reduced position in cast. These fractures require accurate reduction of the fracture and DRUJ along with stabilization of the radius fracture.4 Clinical features The features of fracture will be accompanied by deformity and tenderness at the DRUJ.
Mechanism of injury of distal radius fractures Facture of the distal radius most commonly arises due to a fall on the outstretched hand. This results in an axial load on a wrist that is dorsiflexed. The non-comminuted fracture on the palmar aspect of the radial metaphyseal area, compared with the dorsal comminuted fragments, suggests that the radius fractures in tension on its palmar surface, subsequently propagating dorsally
Treatment of galleazzi injuries Fractures at the junction of the middle and distal thirds of the radius are best managed with plate fixation, ensuring accurate reduction of the fracture and the DRUJ (Figure 2). Very rarely proximal radioulnar joint subluxation can be associated with fracture of the radial shaft.5
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ORTHOPAEDICS III: UPPER LIMB
Comminuted Galleazzi fracture treated with open reduction and internal fixation. Figure 2
Die-punch fracture:10 Die-punch fracture is an intra-articular fracture with depression of the dorsal aspect of the lunate fossa. Various classification systems have been proposed to describe the injury and help formulate a treatment plan. Broadly they tend to be anatomical classifications that group fracture patterns, biomechanical that describe the mechanism of injury and fracture stability or a combination of both.
where bending moment forces lead to compression stresses. This results in crushing of the cancellous bone and shortening of the distal radius relative to the ulna. Transmission of these forces onto the radial cortex requires intact ligaments. In the elderly where these fractures are common the metaphyseal bone is the weakest. In younger patients, where greater forces are involved, concomitant ligamentous injuries may occur and have particular relevance to the choice of treatment modalities. Classification The eponymous descriptions associated with distal radius fractures have traditionally been good indicators of the type of injury and treatment.
Universal classification system11 A fracture may be defined as either extra-articular or intraarticular. Extra-articular fractures maybe: Type I nondisplaced and stable. Type II displaced.
Colle’s fracture:6 Colle’s fracture is an extra-articular distal radius fracture with dorsal comminution, dorsal angulation, dorsal displacement, and radial shortening.
Intra-articular fractures, are either: Type III nondisplaced or Type IV displaced. Further, displaced articular or nonarticular fractures may be: reducible, stable reducible, unstable complex irreducible. Indicators of instability are (i) shortening of greater than 5 mm, (ii) dorsal angulation greater than 20 , (iii) marked dorsal comminution and (iv) displacement in a plaster of Paris cast. Classification systems proposed for intra-articular fractures include:
Smith’s fracture:7 Smith’s fracture is a fracture of the distal radius with volar displacement. Barton’s fracture:8 Barton’s fracture is a displaced, unstable articular fracture-subluxation of the distal radius with displacement of the carpus along with the articular fracture fragment. These may be either dorsal or volar. Chauffeur’s fracture:9 Chauffeur’s fracture is a fracture of the radial styloid. It may be associated with displacement of the carpus and may be the only bony component of perilunate injury.
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Mayo classification12 This classification describes the scaphoid, lunate, and sigmoid notch fossae of the distal radius as separate articulations.
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ORTHOPAEDICS III: UPPER LIMB
Type I fractures are intra-articular but nondisplaced. Type II fractures are displaced involving the radioscaphoid joint. This may be associated with scapholunate injuries. Type III fractures are displaced involving the radiolunate joint. These are die-punch fractures which may not reduce with traction alone. Type IV fractures are displaced involving the radioscaphoid, lunate joints and the sigmoid fossa of the distal radius. This is a significantly comminuted fracture.
Type V: High-velocity injuries that involve combinations of bending, compression, shearing and avulsion mechanisms or bone loss. Clinical features The dorsal aspect of the hand and wrist is usually quite swollen, and ecchymosis may be present, especially in the elderly. The wrist should be examined for tenderness, not only about the radial fracture site, but also at the distal ulna, elbow and shoulder. Median nerve function and flexor and extensor tendon action should be tested.
Fragment-specific classification13 In this classification system intra-articular fractures of the radius are divided into five major fragments, including the radial styloid, ulnar corner, dorsal wall, articular surface, and volar lip fragments. This classification is useful for treatment using fragment-specific fixation.
Investigations Standard posterior-anterior and lateral radiographs are obtained to assess displacement, shortening and comminution. A computed tomography scan may be useful in assessing intraarticular extension and other associated fractures or injuries.
Fernandez classification14 This classification system is based on the mechanism of injury. This system is advantageous because the associated ligamentous lesions, subluxations, and fractures of the neighbouring carpal bones, and soft tissue damage, are directly related to the quality and degree of violence sustained. It also helps in reduction of the fractures by reversing the mechanism. Type I: Bending fractures of the metaphysis in which one cortex fails to tensile stresses and the opposite one undergoes a certain degree of comminution. These are extra-articular fractures (Colle’s & Smith’s fracture). Type II: Shearing fractures. These are intra-articular fractures (Barton’s, reversed Barton’s, and radial styloid fractures). Type III: Compression fractures. These are intra-articular comminuted fractures, complex articular fractures, and pilon radial fractures. These intra-articular fractures are associated with impaction of the subchondral and metaphyseal cancellous bone. Type IV: Avulsion fractures of ligament attachments, includes ulnar and radial styloid fractures associated with radiocarpal fracture-dislocations.
Treatment strategies The aim of treatment is to achieve and maintain reduction until bony union, and to promote rehabilitation to prevent the consequences of immobilization of the wrist and adjacent joints. In intra-articular fractures, anatomical reduction, absolute stability and early mobilization should be achieved. Reduction may be achieved using open or closed means. Closed reduction is achieved by traction through the fingers to disimpact the fragments and correction of the deformity. Reduction of articular fractures may be done by direct visualization using arthroscopy. Indirect reduction is the preferred method and is achieved through the fracture site, where the fractured articular fragments are reduced onto the carpus which serves as a template. Intraoperative radiographs are useful for the assessment of reduction. Maintenance of reduction can be achieved by a variety of methods. Moulded plaster of Paris cast: this is traditionally the most popular method of immobilization (Figure 3). A proper technique
Sequential radiographs showing displacement in a plaster cast after good reduction was obtained in theatre. Three-point moulding of the cast is of paramount importance. Figure 3
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ORTHOPAEDICS III: UPPER LIMB
with three-point moulding is vital. Extremes of palmar flexion and ulnar deviation are to be avoided to prevent median nerve compression and difficulty in mobilizing fingers. This method has the advantage of being non-invasive and avoids risk of surgery. However reduction may be imprecise, and the immobilization is not rigid and therefore best suited to minimally comminuted, stable injuries.
with threads on the head of the screw or smooth peg, allows the head to be fixed onto the plate. This functions as a fixed-angle device preventing instability at the screw plate interface. These pegs or screws can be placed in such a manner that they act as a buttress to the articular surface at the subchondral bone. Locked plating systems allow early mobilization and quicker rehabilitation after injury. They carry the risks associated with all surgical procedures. The choice of treatment modality is governed by many factors and should be reached after careful informed consent from the patient, keeping in mind the fracture configuration and the patient expectations.
Intraosseous Kirschner (K) wire fixation: in this method the distal fragment is fixed onto the proximal shaft fragment using smooth or threaded K wires. Adequate care must be taken to prevent injury to cutaneous nerves and tendons. As a fixation modality this method does not provide sufficient stability and needs supplemental orthotic support. K wires do not maintain length of radius over a period of time in fractures with metaphyseal compaction.
Treatment algorithm according to mechanism of injury Type I: Bending fractures. These fractures are treated by exerting a tension force on the concave side of the angulation. In fractures with adequate bone quality and in the absence of metaphyseal comminution, this can be achieved with a three-point moulded cast. Type II: Shearing fractures. They are usually intra-articular. They are extremely unstable due to the obliquity of the fracture line. They are best treated by internal fixation with plates due to the intra-articular nature and inherent instability (Figure 4). Type III: Compression fractures. Reduction can be achieved in most cases by applying traction. In many cases, disimpaction of cartilage-bearing fragments may require limited or extensile open reduction and fixation. Type IV: Avulsion fractures are a constant component of radiocarpal dislocations in which rotational forces were part of the mechanism of injury. If such fractures remain displaced screw fixation is the method of choice.
External fixation: this method relies on indirect reduction by ligamentotaxis. Supplemental K wire stabilization may be used to stabilize individual fragments. This method suffers from the problems associated with pin site infections. External fixators are useful in those cases where severe comminution prevents internal fixation. Adequate care should be taken to prevent injury to cutaneous nerves and tendons. An open technique where a mini-incision is made to prevent injury is preferred by the authors. Internal fixation: a variety of internal fixation modalities are available. Broadly depending on the site of application on the distal radius they may be categorized as volar devices, dorsal devices or fragment-specific fixation devices. The locking plate,
Radiographs illustrate restoration of length and articular congruity a with locked plate. Note the lateral view is not articular and hence gives the impression of articular penetration with distal pegs. Figure 4
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Distal radioulnar joint (DRUJ) injuries e Type II (unstable DRUJ lesions): These are clinical and radiographic evidences of subluxation of the ulnar head because of a massive tear of the TFCC and secondary DRUJ stabilizers or an avulsion fracture of the base of the ulnar styloid. Distal radioulnar joint (DRUJ) injuries e Type III (potentially unstable lesions): These are associated with skeletal disruption of the joint surface at the sigmoid notch or the ulnar head. Carpal ligament injuries: The incidence of scapholunate ligament tears in conjunction with distal radius fractures is approximately 30%, and for lunotriquetral ligament tears it is approximately 15%. Open repair of the lesion is recommended after reduction and fixation of the distal radial fracture. Complications of distal radius fractures Nearly 30% of all distal radius fractures in a series of 565 fractures had complications.15
Figure 5 Non-union after distal radius fractures.
Type V: High-velocity injury with combination of fracture patterns. A combination of fixation methods should be selected for treatment.
CRPS I (reflex sympathetic dystrophy): This is treated by elevation of an oedematous hand, and intensive hand therapy is frequently very helpful in preventing the development of full reflex sympathetic dystrophy.
Author’s guide to decision-making Undisplaced fractures: These are generally stable and are unlikely to displace in a moulded cast. They are placed in a well-moulded below-elbow cast, allowing mobilization of the fingers. Good plaster technique with three-point moulding is vital. Radiographic review is done at the end of the first week to assess displacement and loosening of the cast secondary to reduction of swelling. Internal fixation in order to mobilize early is an option that needs to be weighed up against the risks of surgery.
Non-union: Non-unions of distal radius fractures (Figure 5) are extremely rare while non-unions of ulnar styloid process fractures in conjunction with distal radius fractures are quite common. Ulnar styloid non-unions are rarely symptomatic. Treatment of distal radius non-unions must be to achieve union with rigid internal fixation and iliac crest bone grafting. Malunion: Malunions result in wrist pain (radiocarpal, radioulnar and/or ulnocarpal), decreased range of motion, and/or midcarpal instability. If symptomatic, depending on whether the malunion is extra-articular, intra-articular (affecting both the radiocarpal and radioulnar joints), or complex (metaphyseal and articular deformity), post-traumatic wrist deformity can be corrected with extra-articular osteotomies, intra-articular osteotomies, or a combination of both. A
Displaced extra-articular fractures: Closed reduction under appropriate local anaesthetic block is done to realign the fracture and allow soft tissues to heal. The radiographic indicators of instability are looked for and in the presence of significant shortening (>5 mm), angulation (20 dorsal or volar angulation) and displacement, early open reduction and internal fixation is planned. In fractures that are within the acceptable parameters after reduction, namely <5 mm shortening, 0e10 of volar tilt, operative intervention is instituted only when the fractures redisplace in the cast.
REFERENCES 1 Schemitsch EM, Richards RR. The effect of malunion on the functional outcome after plate fixation of fractures of both bones of forearm in adults. J Bone Joint Surg 1992; 74A: 1068e78. 2 Hotchkiss RN, An K, Sowa DT, Basta S, Weiland AJ. An anatomic and mechanical study of interosseous membrane of forearm. Pathomechanics of proximal migration of the radius. J Hand Surg 1989; 14A: 256e61. 3 Bado JL. The monteggia lesion. Clin Orthop 1967; 50: 71e86. 4 Hughston JL. Fractures of the distal radius shaft; mistakes in management. J Bone Joint Surg 1957; 39A. 249e64. 5 Simpson JM, Andreshak TG, Patel A, Jackson WT. Ipsilateral radial head dislocation and radial shaft fracture. A case report. Clin Orthop 1991; 266: 205e8. 6 Colles A. The classic: on the fracture of the carpal extremity of the radius (reprinted from the original 1814 article). Clin Orthop 1972; 83: 3e5.
Displaced intra-articular fractures: In the presence of significant intra-articular step (>3 mm) or gap, early open reduction and internal fixation are done. Injuries associated with distal radius fractures Median nerve injury: If satisfactory reduction is obtained, the symptoms will improve. If the neurological symptoms show no sign of improvement over the first 24e48 hours after closed reduction, an open reduction, internal fixation and carpal tunnel release should be performed. Distal radioulnar joint (DRUJ) injuries e Type I (stable DRUJ lesions): The DRUJ is clinically stable with minimally displaced avulsion fractures of the tip of the ulnar styloid and stable fractures of the neck of the ulna.
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7 Peltier LF. Fractures of the distal end of the radius: an historical account. Clin Orthop 1984; 187: 18e22. 8 Barton JR. Views and treatment of an important injury to the wrist. Med Examiner 1838; 1: 365. Cross reference: Green’s Operative Hand Surgery. 9 Edwards HC. The mechanism and treatment of backfire fracture. J Bone Joint Surg 1926; 8: 701e17. Cross reference: Green’s Operative Hand Surgery. 10 Brindley HH. Wrist injuries. Clin Orthop 1972; 83: 17e23. 11 Cooney WP. Fractures of the distal radius: a modern treatment based classification. Orthop Clin North Am 1993; 24: 211e6.
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12 Bradway JK, Amadio PC, Cooney WP. Open reduction and internal fixation of displaced, comminuted intra-articular fractures of the distal end of the radius. J Bone Joint Surg Am 1989; 71: 839e47. 13 Swigart CR, Wolfe SW. Limited incision open techniques for distal radius fracture management. Orthop Clin North Am 2001; 32: 317e27. 14 Fernandez DL, Jupiter JB. Fractures of the distal radius. New York: Springer Verlag, 1995: 26e52. 15 Cooney WP, Dobyns JH, Linscheid RL. Complications of Colles’ fractures. J Bone Joint Surg Am 1980; 62: 613e9.
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