Description of the condition
The distal end of the radius, which is the end nearest the wrist, is one of the most common places for fractures or broken bones in adults (Chung 2001). Often termed wrist fractures, distal radius fractures are commonly defined as fractures occurring within three centimetres (approximately one inch) of the distal end of the radius (Chung 2001).
In the developed world, the incidence of distal radius fracture appears to be increasing (De Putter 2011; Hagino 1999; Melton 1998; Thompson 2004). A UK-based multicentre study of patients aged 35 years and above with distal radius fractures reported an annual incidence of 9 per 10,000 men and 37 per 10,000 women (O'Neill 2001). Before the age of 40, the incidence is higher in men (Singer 1998). In women, the incidence increases with age, especially after the age of 40 years (Broadbent 2003). It has been estimated that at 50 years of age a white woman in the USA or Northern Europe has a 15% lifetime risk of a distal radius fracture, whereas a man has a lifetime risk of just over 2% (Cummings 1985). In the USA, distal radius fractures account for up to 18% of all fractures in the over-65 age group (Baron 1996).
While young adults usually sustain distal radius fractures following high-energy trauma, the injury usually results from low-energy trauma in older people, especially women. A fall from standing height onto an outstretched hand is the leading cause of this injury (Flinkkilä 2011; Sigurdardottir 2011).
Following injury, people present with immediate pain around the distal radius, swelling, bruising, crepitus (crackling, grating or popping sounds and sensations), as well as wrist deformity if the fracture is displaced. In the majority of cases, the fracture is closed (the skin surrounding the fracture is not breached), but a small proportion of people have an open wound exposing the fracture. This is termed an 'open fracture'. Some people with distal radius fractures may present with alteration in finger sensation if there has been compression of the median nerve due to soft tissue swelling or haematoma (bleeding from the fracture) or an associated nerve injury. Radiographs (X-rays) are generally used to confirm the diagnosis and plan the management. In complex fracture cases, a computerised tomography (CT) or magnetic resonance imaging (MRI) may be used to clearly delineate the fracture and associated injuries.
It is difficult to quantify precisely the impact of distal radius fractures in terms of lost work hours and short and long term disability for the population studied. A review by Polinder 2013 of the costs of upper extremity injuries in adults estimated the direct costs, adjusted to 2007 values, of wrist fractures to be 1890 Euro per case. This study also showed higher costs for women (2440 Euro) than men (1150 Euro). People with distal radius fractures are usually managed as outpatients, but it has been estimated that around 20% of patients (mainly older people) require hospital admission (Cummings 1985; O'Neill 2001).
Surgeons have classified fractures by anatomical configuration and fracture pattern to aid communication, research and guide management. Simple classifications were based on clinical appearance and often named after those who described them (eponyms). A 'Colles’ fracture' is one of the common distal radius fractures, typically occurring following a fall on the outstretched hand. Patients present with the characteristic distal forearm 'dinner fork deformity', which indicates a dorsally displaced, dorsally angulated, dorsally comminuted (multiple fragments) and radially shortened distal radius fracture. Others, such as Barton and Smith, added their descriptive classifications for specific fracture patterns. Distal radius fractures can be simply classified as either displaced or undisplaced, extra-articular (not involving the wrist joint) or intra-articular (fractures involving the wrist joint), dorsal and volar displaced fractures and distal radius fractures with or without fracture of ulnar styloid.
There has been a move towards using structured classification systems to define distal radial fractures instead of eponyms or simple descriptors. Ideally, a fracture classification system enables consistent description of the fracture, helps with communication between doctors and aids in the management of the fracture (Fernandez 2001). Jupiter 1997 presented a comprehensive review of the many available fracture classification systems used for these fractures. Brief descriptions of six of the most commonly cited classification systems are in Table 1 (Cooney 1993; Fernández 1993; Frykman 1967; Melone 1993; Müller 1991; Older 1965).
|Name (reference ID)||Brief outline||Comment|
|AO (Arbeitsgemeinschaft für Osteosynthesefragen) (Müller 1991)|
This system is organised in order of increasing fracture severity. It divides the fractures into three major groups:
These three groups are then subdivided, yielding 27 different fracture types.
|There is no assessment of the extent of fracture displacement|
|Fernández (Fernández 1993)|
This system is based on the mechanisms of injury. There are five main groups:
These groups are further categorised by stability, displacement pattern, number of fragments (or comminuted) and associated lesions.
|The injury mechanism is not always apparent. There is no consideration of the extent of displacement|
|Frykman (Frykman 1967)||This system distinguishes between extra-articular fractures and intra-articular fractures of the radiocarpal and radio-ulnar joints, and the presence or absence of an associated distal ulnar (ulnar styloid) fracture.|
There are eight types labelled I to VIII (1 to 8): the higher the number, the greater complexity of the fracture.
|There is no assessment of the extent or direction of fracture displacement, or of comminution|
|Melone (Melone 1993)||This system identifies five fracture types, based on 4 major fracture components: the radial shaft, the radial styloid, and the dorsal- medial and volar-medial fragments.||This is for intra-articular fractures only|
|Older (Older 1965)||This system divides fractures into four types, labelled I to VI (1 to 4) of increasing severity. The types are defined according to extent of displacement (angulation and radial shortening) and comminution.||There is no consideration of radio-ulnar joint involvement|
|Universal Classification (Cooney 1993)||This system divides fractures into four main types, labelled I to VI (1 to 4), distinguishing between extra-articular and intra-articular fractures and displaced and non-displaced fractures. Displaced fracture types II and IV are further subdivided based on reducibility (whether the fracture can be reduced; that is whether the bone fragments can be put back in place) and stability (whether, once reduced, the fragments will remain so).||This does not distinguish between the radiocarpal and radio-ulnar joints. Additionally, there is a 'trial by treatment'|
Complications from distal radius fractures are not uncommon and can arise from either the injury itself or following the treatment provided. Immediate complications following the fracture include associated ligament injury (Geissler 1996), the triangular fibrocartilagenous complex (TFCC) injury (Lindau 2000) and acute carpal tunnel syndrome (compression of median nerve from fracture haematoma) (Belsole 1993). Attrition rupture of extensor pollicis longus (thumb extensor tendon) has been associated with minimally displaced distal radius fractures (Bonatz 1996 ; Helal 1982). Complex regional pain syndrome type 1 (a constellation of symptoms such as swelling, excessive pain, skin colour changes and stiffness) occurs in 1% of patients with non-operative treatment and up to 5% of patients who have an operation (Atkins 2003). Malunion, which may result from redisplacement of an initially reduced fracture, can result in midcarpal instability (dynamic instability resulting from malaligned bones in the midcarpal joint). These changes in the radiocarpal, midcarpal and radioulnar joints can lead to pain (Patton 2004), loss of motion (Kazuki 1993) and reduction in grip strength (Patton 2004), along with the development of later degenerative changes (Park 2002; Taleisnik 1984). In addition, arthritis of the wrist can result from the malunion of intra-articular distal radius fractures. Although a strong correlation has been noted between maximum step displacement in articular fragments and the development of arthritis, no significant correlation has been found between the patients' radiological and functional status (Catalano 1997; Forward 2008; Goldfarb 2006).
Complications resulting from surgical treatment rather than the injury itself are diverse and frequent. They include infection, tenosynovitis (inflammation of the synovial lining of the tendon), rupture of flexor and extensor tendons from prominent metalware, complex regional pain syndrome type 1, iatrogenic nerve or blood vessel injury, delayed union or malunion, screw loosening and intra-articular screw positioning or displacement (Arora 2007).
Description of the intervention
Non-surgical (conservative) treatment of distal radial fractures typically comprises manipulation of the displaced fractures (closed reduction) and wrist or forearm immobilisation for several weeks in an external cast or brace. However, the results of non-operative management, particularly in older people with bones weakened by osteoporosis, are not consistently satisfactory (Handoll 2003). This has resulted in the development of other strategies involving surgery, which are aimed at more accurate reduction and more reliable stabilisation.
The four main strategies for surgical treatment are internal fixation, percutaneous pinning, external fixation and use of bone grafts and substitutes (Fernandez 1996). These methods may be used alone or in a combination with each other. For example, in cases of comminution or bone loss, the distal radius fixation may need to be supplemented with bone grafts or bone graft substitutes to fill the bone defects. Cochrane Reviews examining the evidence for fixation using percutaneous pins (Handoll 2007a), external fixation (Handoll 2007b; Handoll 2008a) and bone grafts and substitutes (Handoll 2008b) are already available. A separate Cochrane Review that aims to compare internal fixation versus conservative treatment and different methods of internal fixation is underway (Hoare 2014). Descriptions of the three main methods of fixation are given below.
Internal fixation generally requires an open approach to directly visualise the fracture. Either a volar (palm side of the forearm) or dorsal approach (back of the forearm) is used for the surgery. Intra-operative imaging in the form of X-rays is commonly used to aid visual assessment of reduction and placement of devices. Stabilisation with plates is the most common type of internal fixation and there are many different types on the market. The reduction of the fracture can be achieved manually before applying a plate or can be assisted by applying a plate on distal end of the fracture and then reducing the plate on to the shaft of the radius. Plates can be applied on the volar, dorsal or radial surfaces of the distal radius (Orbay 2004; Rikli 1996) and can be used singly or in combination according to the fracture pattern and fragments involved. More recently designed plates are generally anatomically pre-contoured for their specific position on the bone. Plates may be either locking (the screw heads themselves screw into the plate to act share the load) or non-locking. A rarer method on internal fixation is intramedullary nailing, where a nail is inserted into the canal in the centre of the radius and usually secured by screws. These devices are usually inserted through a minimally invasive approach (Brooks 2006) and their use is usually limited to extra-articular fractures or intra-articular fractures with fragments large enough to be reduced anatomically by closed means.
In percutaneous pinning, pins or Kirschner wires (K-wires) are inserted percutaneously (through the skin) into the distal radius fracture to help reduce and hold the fracture. K-wires can be used in a myriad of ways (Rayhack 1993). The two main ways are intra-focal (Kapandji 1988) or intra-fragmentary. The former uses the K-wire as a joystick (reduction tool), placing the tip of the wire in the fracture then levering the fracture fragments into a satisfactory position. The other more commonly used method is to reduce the fracture by closed means and then stabilise the reduced fracture with K-wires holding (fixing) the fracture fragments together. Following the percutaneous pinning, the wrist is usually immobilised in a plaster cast for additional stability. The K-wires are generally left in for about four to six weeks but may be removed early if causing any problems such as infection.
When using external fixation, fractures are generally reduced without the need for an open approach to visualise the fragments. Percutaneouly inserted K-wires may be used to augment the reduction. Threaded pins are inserted into the bone either sides of the fracture and secured onto a frame or incorporated into a plaster of Paris cast to maintain the reduction. The threaded pins are inserted through small skin incisions. There are many external fixator systems available. Uniplanar or multiplanar designs allow the fracture to be manipulated and stabilised in one or many planes. The threaded pins can be placed either side of the wrist joint in a "bridging" mode with threaded pins in the metacarpals distally and the radius more proximally. In a "non-bridging" mode, threaded pins are inserted either side of the fracture without spanning the wrist joint. Some external fixation designs incorporate a hinge at the level of the wrist joint to enable early wrist movement whilst maintaining fracture reduction (Capo 2006; Fernandez 1999).
How the intervention might work
In this Cochrane Review, we plan to compare internal fixation with the two other main surgical methods of fixation, namely percutaneous pinning and external fixation. All three methods aim to restore anatomy and stabilise the fractured parts to enable healing to take place. It is widely supposed that open reduction and internal fixation will provide superior anatomical restoration and fixation than either of the other methods that use closed reduction methods. However, internal fixation is more invasive, more complex to perform and more costly, particularly in comparison with percutaneous pinning, which is minimally invasive, versatile and relatively simple and quick to perform and is considerably less expensive (Shyamalan 2009).
All three approaches share the common risk of surgery-related complications, such as of infection and risk of injury to neurovascular structures and tendons but to varying extents. For example, pin track infection is common for both percutaneous pinning and external fixation and careful management of the pin tracks is required to avoid this. Rupture of flexor and extensor tendons from prominent metalware is a well documented complication of plate fixation. Fixation failure, especially in osteoporotic bone, is of concern for all three methods but the development of angular stable plating systems, using locking screw technology has reduced the risk of collapse of already weakened bone as the load is transmitted through the screws and plate (McFadyen 2011). There is also a greater risk of fixation failure in osteoporotic bone for pinning and external fixation as pins, or external fixation, or both, can lose hold in the thin cortices (Trader 1979). For both percutaneous pinning and external fixation, the pins and wires are removed after fracture stabilisation or earlier where there are complications. These are relatively straightforward procedures but the removal or adjustment of a plate is more involved and invasive.
The increased stability attained by internal fixation with locking plates has the anticipated advantage of earlier mobilisation, which can translate into better function (McFadyen 2011). However, many patients usually have a period of wrist immobilisation after internal fixation in order to lower the risk of fixation failure. Moreover, superior anatomical results do not necessarily produce better function and quality of life: there is a poor correlation between radiological findings and functional or clinical outcome (Bentohami 2013; Finsen 2013).
Why it is important to do this review
Distal radius fractures are one of the most common injuries in adults. While there is a lack of consensus on their management (Lichtman 2010), there has been a significant increase in the use of internal fixation; for example, a 13-fold increase was reported between 1998 and 2008 in Finland (Mattila 2011). In particular, there has been a trend to treat older patients presenting with osteoporotic fractures with internal fixation using locking plates (Chung 2009). There is a need to compare internal fixation with the other commonly used surgical methods for treating distal radius fractures, namely percutaneous pinning and external fixation, either alone or in combination with each other, in order to identify which surgical method for treating these fractures gives the best clinical and patient-rated outcomes.