Richard A. Bernstein, MD
Distal radius fractures are some of the most common fractures (the medical term for "broken bone"). The radius is the bone in the forearm on the thumb side (in the x - ray below, it is the one on the right). Distal radius fractures are generally caused by a fall on an outstretched hand. The fracture is almost always within an inch of the wrist joint, and may extend into the joint. The radius above is fractured at this location: about one inch from the wrist joint.
Fracture types can be described as "extra - articular" (which means the fracture line does not extend into the joint) or "intra - articular" ( which means the fracture line does extend into the joint; this is the more serious type of fracture). They can also be described as "comminuted" (which means the bone is broken into several or many small pieces) or not comminuted. The most serious type of fracture is the comminuted, intra - articular fracture.
The treatment options are quite varied, depending on the exact nature of your fracture, your age, and your activity level. The treatment options include a cast, internal fixation with a plate, percutaneous pin fixation, external fixation, or a combination of these modalities. It is an area of very vigorous research which I have been actively involved in distal radius research since 1993. The treatments, both surgical and non - surgical, have changed greatly in the last few years.
The treatment decision is very complex. As noted above, the factors that are important are the exact nature of your fracture, your age, and your activity level. The nature of the fracture relates to the current alignment of your bones (what position they are in) and whether or not that alignment is acceptable. If it is acceptable, then you will probably get a cast. If it is not acceptable, I may need to reduce the fracture (put the bones in a better position). Sometimes the fracture is of the sort that can be pushed into place without surgery (called a "closed reduction"), and sometimes the fracture needs surgery to push the bones into place (called an "open reduction", because the skin needs to be "opened" for surgery). Usually, if the broken bones need surgery (in medical terms, the fracture needs open reduction), some kind of metal implant will be needed to hold the bones in the proper place while they heal. Most of the time, the metal implant (often called a "plate", but it does not look like a dinner plate!)
This is a great and simple question, but the answer is not simple. It depends on many factors: the nature of your fracture, its treatment, your response to treatment, your age, and your activity level, among many other factors. But it is an important question, and needs to be answered. Most patients need narcotic pain medication for only a few (less than 5) days, or never. Many times, just prescription - strength, non - narcotic medication is all that is needed.
If you have a cast, it is usually on for six weeks, then hand therapy is started. If you have internal fixation surgery, you get a splint for five days and then hand therapy starts to get your wrist joint moving. No splint is usually needed three days after surgery. Casts must be kept dry (use a plastic bag while showering), and surgical incisions need to be kept dry only for five days. No matter what kind treatment you get, you should be actively exercising your fingers, elbow, and shoulder, so they don't get stiff. I will decide, based on your exact fracture, when you can start strengthening exercises; until then, just work on motion.
Everyone wants to know, "Can I return to all my former activities?" This also is a great and simple question, but without a simple answer. Everyone has some stiffness in their wrist after treatment (remember, you fell on your hand hard enough to break the bone, so the joint and all the soft tissues around it are mad at you!). This is why almost everyone is referred to hand therapy as soon as your broken bone can tolerate it safely.
Everyone wants to know, "How much will it hurt?" Most patients will need to take some pain medication for a few days (see above), and some may need it for 10 or so days. Few patients need any pain medication other than aspirin, Tylenol, or Motrin after 10 days. Almost everyone will have some discomfort in their wrist as it heals over a period of three to six months. If you do not develop arthritis, you will not have pain after this. You will still experience some minor discomfort for a year or so.
Almost everyone ends up with some stiffness that is permanent; how much depends on your injury, your age, if you already have some stiffness and arthritis, and how hard you work in hand therapy. The forearm motion that is usually the stiffest is turning your palm up (called "supination") in the position as if you were trying to hold some water in your cupped hand. There is also some limitation in flexion and extension, which are the motions bending your hand toward your palm or toward the back side of your hand.
Most patients return to normal recreation and work activities, and most do not have permanent pain. The most limiting fracture type is a comminuted, intra - articular fracture, and these patients will have the greatest amount of stiffness, may have pain, and are at risk for developing arthritis. Extra - articular fractures usually do not develop arthritis.
The amount of stiffness is largely what determines what activities you can return to. Most patients, who are active playing non - contact and non - impact sports such as bike riding, swimming, etc., can return to those activities, starting at about 3 months after the fracture. Most patients who are active playing contact sports or sports that involve impact, such as tennis, golf, baseball, football, etc, can return to those activities, starting at about 4 months. Most patients who do heavy labor, such as carpentry, plumbing, etc, can return to work at 2 months with restrictions, and regular work without restrictions at 4 months. Most patients who do lighter labor such as painting, or office work activities such as handwriting, keyboards, telephone, etc, can return to work at 1 to 2 months. I do not allow people to do activities where they are at risk for falling for about four months. These are only general guidelines so you have some idea of what to expect, and your specific restrictions will be determined by your individual circumstances.
Dr. Bernstein has a particular interest in distal radius fractures. He has spoken at many national as well as international courses exclusively on distal radius fractures. He is actively involved with developing newer methods of distal radius fracture treatment and with teaching surgeons from around the world about how to treat distal radius fractures.
Dr. Bernstein's lectures and presentation of treating wrist fractures (distal radius fractures)
Current Concepts in Treating Comminuted Distal Radius Fractures, DaVinci Learning Center, Miami, FL.
Treatment of Distal Radius Fractures, Glens Falls, NY
Treatment of Distal Radius Fractures, Providence, RI
Treatment of Distal Radius Fractures, AAOS, San Diego, CA
Treatment of Distal Radius Fractures, Baltimore, MD
Treatment of Distal Radius Fractures, Boston, MA
Treatment of Distal Radius Fractures, AAOS Learning Center, Chicago, IL
Treatment of Distal Radius Fractures, Key Largo, Florida
Treatment of Distal Radius Fractures, Evolution or Revolution, Orthopaedic Grand Rounds, Dartmouth Medical School, Hanover, NH
Treatment of Distal Radius Fracture and Small Bone Fixation of the Hand, Vail, CO
Treatment of Distal Radius Fracture using the Dorsal Nail Plate, Combined American and Japanese Societies for Surgery of the Hand Meeting, Honolulu, HI
Treatment of Distal Radius Fracture using the DVR Volar Fixed Angle Plated, Combined American and Japanese Societies for Surgery of the Hand Meeting, Honolulu, HI
Treatment of Distal Radius Fractures, Evolution or Revolution, Maine Orthopaedic Society Annual Meeting, Sugarbush, ME
Current Techniques in Radius Fracture Fixation, Doral Country Club, Miami, FL
Copyright © 2010, TOG All rights reserved.
Richard A. Bernstein, MD
Our skeleton is a marvelous thing. It grows as we grow! And it does this without shutting down or closing for remodeling. A great thing, or we would be in real trouble!
The skeleton grows due to the presence of a region of the bone called (surprise!)the growth plate. The medical term for this is the physis (adjective form is physeal), and I mention it only so you can understand the term if you run into it and so that you can understand the names of the other parts of the bone.
Here are the parts of a growing bone. The example is of a wrist, partly because about 50% of growth plate injures are at the wrist and partly because that is themost likely growth plate injury my patients will have. In this x-ray, the wrist bonesare at the top and the forearm bones at the bottom; the radius is the bone on the right, it is the one on the thumb side of the hand:
The epiphysis is the end of the bone, with the cartilage that makes up your joint("epi" means "upon", so an epiphysis is the part of the bone that is on the physis).The physis is the growth plate, the part of the bone that has the cells that allows the bone to grow longer. The metaphysis is the broad region of bone right next to the physis. The diaphysis is the narrow center part of the bone.
The growth plate is made up of a special kind of cartilage called (surprise!)growth plate cartilage.
Growth plate injuries occur in children, up until about age 16 for girls and 18 for boys. The growth plate is the weakest area of the growing bone, weaker than the metaphysis or the diaphysis, and weaker than the ligaments of the adjacent joint.In a growing child, a serious injury to a joint is more likely to damage a growth plate than the ligaments that stabilize the joint. Interestingly, each age bracket has a different response to a similar injury of falling on the outstretched arm: little children get a fracture (break) to the bone that only bends it ("greenstickfracture"), older grammar school children get a growth plate injury, young adults will often get a fracture into the joint or a wrist dislocation, and an elderly personwill fracture through the metaphysis. An injury that might cause a sprain in an adult may cause a growth plate injury in a child.
Growth plate injuries are actually a broken bone, which is the same thing as a fracture. They represent about 15 percent of all childhood fractures. They occur twice as often in boys as in girls, with the greatest incidence among 14- to 16-year-old boys and 11- to 13-year-old girls. Older girls experience these fractures less often because their growth plates stop growing and change into solid bone at an earlier age than boys. Boys have a higher rate of fractures due to their more aggressive form of play. In my practice, if you exclude the fractures in girls from falling off horses, boys outnumber the girls probably 4 to1! And all of my"high volume" patients (4 or more fractures) are boys.
The fractures of the growth plate are classified according to the system of Drs. Salter and Harris. This diagram is from their text Disorders and Injuries of the Musculoskeletal System, 3rd Edition. Robert B. Salter, Baltimore, Williams and Wilkins, 1999, and is from the National Institutes of Health website, which has permission to use this image. I added the red color, to show where the fracture is in each case.
I mention this classification system because you will almost certainly hear about it. Unfortunately, it does not actually tell us much about how the fracture should be treated or what the outcome will be.
The main concern about growth plate injuries is that the growing cells can be injured by the fall, which must have been rather forceful, or the growth plate would not have broken. (Most falls don't result in a fracture, do they?) They can also be injured by the doctor, when he or she is trying to help correct the problem by straightening out the broken bone, which is why we try to do it very, very gently. Almost all of growth plate injuries of the forearm heal without any problem(the main problem occurs in knee and hip growth plate injuries, which fact you should bear in mind when you are reading generalized statistics about growth plate injuries). The challenge is that we cannot see the growing cells on the x-ray(see the photo at the top, and note that the growing cartilage cells are within the physis, which is the clear section between the epiphysis and the metaphysis) and we cannot tell if they are injured enough to stop growing or not. Even CT scans and MRI's cannot tell if they are injured enough to stop growing. The only way to tell is to treat the fracture gently and watch how the bone grows by taking x-rays over a period of about 12 months. The diagnosis is always made with the 20-20 of hindsight (what the doctors call a "retrospective diagnosis".)
The incidence of growth plate closure (what happens if the growing cells are injured enough to stop growing) is very rare. A well-respected, published paper cites a rate of 1 case in 547 distal radius (forearm) fractures (Davis and Green,Forearm Fractures in Children, 1976); Dr. David Green is the author of the most respected hand surgery textbook. The rate of growth plate closure varies with the amount of trauma that the forearm was subjected to, among other factors, many of which are still undefined.
The reason I am bringing this up, even though growth plate injuries are very rare,is that if the growth plate is injured enough and it closes, the bone does not grow properly. It can stop growing entirely, which may not be a problem in an older child. It can stop growing only on one side, which in children with a large amount of growth left can cause the bone to grow crooked. These problems are even more rare than growth plate injuries (that is, most growth plate injuries heal without any problems), and usually is not even noticed by the patient. In one long-term study of growth plate injures (157 fractures followed for an average of25 years, a remarkable study, indeed), only 7 had shortening or angulation of the radius, and only 2 were noticed by the patients, and only 3 needed surgery(Cannata, et al. Physeal Fractures of the Distal Radius and Ulna: Long-Term Prognosis, 2003). The majority of the growth plate injuries resulting in bone growth problems had very special kinds of injuries, such an open fractures (bone sticking out of the skin or similar "compound" fractures) that got infected, injuries in which the growth plate of both the radius and the ulna were present, or other rather unusual kinds of injuries. Growth plate injuries and growth disturbances are very rare in the typical, simple fall on an outstretched arm. I recommend follow-up x-rays just to be sure there is NO growth plate and bone abnormalities present, not because I expect them to be present.
In general, we like to straighten out (reduce) fractures, which includes growth plate injuries. We straighten them out (reduce them) as gently as possible. The mild deformity left after a growth plate fracture almost always remodels and growth plate injuries resulting in closure are rare. If your child has sustained a growth plate injury, we will discuss it when you are in the office and will take xrays over time (sometimes over a period of a year) to see how the bone is doing.Remember, growth plate injuries that do not heal properly are rare. If the accident was caused by something like a simple fall on an outstretched arm, in Dr. Green's study, only 1 in 547 forearm fractures resulted in a growth disturbance.
Copyright © 2010, TOG All rights reserved.
Revised 12/21/10 / updated 1/28/2016
Richard A. Bernstein, MD
Forearm fractures in children are common and are managed differently than similar injuries in adults. Historically, the results of nonoperative treatment of adult forearm fractures have been poor, with reports of nonunion, malalignment, and stiffness due to the lengthy immobilization required for union. Currently, most adults with both-bone forearm fractures are treated by open reduction and internal fixation. In pediatric patients, treatment is primarily nonoperative because of uniformly rapid healing and the potential for remodeling of residual deformity.
Although the outcomes in children are usually good, treatment of individual patients and education of families can be challenging. Beyond the sometimes difficult mechanics of fracture reduction and maintenance, the clinician is faced with controversies regarding techniques of reduction, position of immobilization, and definition of an acceptable reduction.
The purpose of this article is to critically summarize available information and present treatment recommendations based on a literature review and the previous experience of the senior author (C.T.P.). The scope of this discussion will be limited to the more common entities, such as pediatric forearm and distal radius fractures, and will not include articular fractures, plastic deformation, and fracture-dislocations, such as Monteggia lesions.
The ulna is a relatively straight bone around which the curved radius rotates during pronation and supination. The axis of rotation passes obliquely from the distal ulnar head to the proximal radial head. The two bones are stabilized distally and proximally by the triangular fibrocartilage complex and the annular ligament, respectively. Further stabilization is provided by the interosseous membrane, with oblique fibers passing distally from the radius to the ulna; these fibers are somewhat relaxed in supination and tighter in pronation.
The pronator quadratus (distally) and pronator teres (inserting on the middle portion of the radius) actively pronate the forearm, while the biceps and supinator (proximal insertions) provide supination. The insertions of these four muscles can partially account for fragment position in complete fractures. In distal-third fractures, the proximal fragment will be in neutral to slight supination, and the weight of the hand combined with the pronator quadratus tends to pronate the distal fragment. In proximal-third fractures, the distal fragment is pronated, and the proximal fragment is supinated. Mid-shaft fractures tend to leave both fragments in a neutral position with the distal fragment slightly pronated and the proximal fragment slightly supinated.
Several anatomic differences distinguish pediatric forearms from those of adults. The pediatric radial and ulnar shafts are proportionately smaller, with narrow medullary canals, and the metaphysis contains more trabecular bone. In addition, the periosteum in children is much thicker than that in adults; this feature can both hinder and help in the management of pediatric fractures.
The proximal and distal physes provide longitudinal growth, which contributes to remodeling after fracture healing. The distal radial and ulnar growth plates are responsible for 75% and 81% of the longitudinal growth of each bone, respectively. 1 This is consistent with the oft-made observation that distal forearm fractures have greater potential for remodeling than do more proximal fractures. 2-4 Additional remodeling can also be attributed to elevation of the thick osteogenic periosteum after fracture (Fig. 1). Intramembranous ossification by the periosteum will assist in rapid healing and subsequent remodeling of residual diaphyseal deformity. Normal Function and Treatment Objectives. The goal of treatment of forearm and distal radius injuries is to facilitate union of the fracture in a position that restores functional range of motion to the elbow and forearm. The predominant motions affected by malunion are pronation and supination, which are a function of skeletal length and axial and rotational alignment. Normal supination from neutral is 80 to 120 degrees; normal pronation from neutral is 50 to 80 degrees. 5 It is important to realize that .normal" motion may not be what is needed for normal function Biomechanical testing has revealed that common activities of daily living require 100 degrees of forearm rotation, equally split between pronation and supination. 6 Limited pronation is more easily compensated for by shoulder abduction. Secondary concerns include cosmetic alignment; however, acceptable reduction usually precludes gross malalignment. Ulnar alignment is the most important cosmetic determinant.
Fig. I In completely displaced pediatric forearm fractures; the periosteum is tom and elevated. In cases of reversed fracture obliquity, it becomes difficult to reduce the bone end to end with longitudinal traction, as the periosteum tightens around the buttonholed proximal end. However, the elevated periosteum does provide a framework for rapid cortical remodeling as bone and cous form along the elevated margin.
Specific classification schemes have not been developed, but fractures are generally categorized according to location, amount of cortical disruption, displacement, angulation, and malrotation. As mentioned previously, we will not address articular fractures, physeal fractures, or fracture-dislocations in this article. Three main types of forearm fractures will be discussed: greenstick fractures, complete fractures, and distal radial metaphyseal fractures. Greenstick fractures are incomplete fractures with an intact cortex and periosteum on the concave surface. These are usually the result of excessive rotational force. Complete fractures of both bones of the forearm are classified by location as being in the proximal, middle, or distal third. Proper treatment depends on differentiating greenstick and complete fractures. Completely displaced distal metaphyseal fractures of the radius will be discussed separately because of the differences in reduction and outcome.
It is important to have a basic understanding of the forces leading to forearm fracture, as reductions are often performed in the direction opposite to that of the initial injury. Pediatric forearm fractures typically follow indirect trauma, such as a fall on an outstretched hand. Direct trauma may additionally account for open fractures, severely displaced fractures, and those in the proximal forearm.9 Evans described an indirect mechanism of axial compression force in varying directions and degrees of rotation, the latter accounting for different patterns of fragment angulation. The final degree of fragment displacement due to indirect trauma varies between greenstick and complete fractures, but the initial mechanism of injury is usually the same. In some cases, the force is not sufficient to completely displace the fracture, and therefore a greenstick fracture results. A greenstick fracture in one forearm bone may coexist with a complete fracture in the other.
Radiographically, greenstick fractures demonstrate angulation due to rotational deformity. 7,10 Fractures with apex-volar angulation are the result of an axial force applied with the forearm in supination; fractures with the less common apex-dorsal angulation are the result of an axial force applied in pronation. 10 Reducing a greenstick fracture usually involves rotation in the direction opposite to the deforming force. When indirect or direct trauma exceeds the resistance of the forearm, complete fractures of both bones will follow. In severe falls, the bones may initially angulate according to the rotation of the wrist.
However, when completely broken by either indirect or direct forces, the bones shorten, angulate, and rotate within the confines of the surrounding periosteum, interosseous membrane, and muscle attachments. Because the final positioning in complete fractures depends to some degree on the relationship of fracture location and the insertions of the pronating and supinating muscles, reduction is more complex than for simple greensick fractures.
Distal radius fractures usually follow a fall on an outstretched hand. The resultant angulation may also be accompanied by rotational deformity. Apex-volar angulation (the most common deformity) is accompanied by supination and apex-dorsal angulation with pronation. In our experience, solely ulnar fractures are less common, and probably result from direct trauma.
The diagnosis of forearm fractures is usually self-evident from the history and the obvious deformity. Child abuse must always be considered in patients less than 3 years of age. Inspection and palpation should be carefully performed; occasionally, soft-tissue swelling will obscure gross malalignment. The wrist and elbow should be examined for swelling, tenderness, and unusual prominences that may signify a Monteggia or Galeazzi fracture. Cursory examination of the humerus and clavicle may detect fractures that have also resulted from a fall on an outstretched hand. Detailed neurovascular examination is necessary before and after reduction; median, ulnar, and posterior interosseous neurapraxias have been documented. Such deficits usually resolve with observation in 2 to 3 weeks.
Radiographic evaluation should include anteroposterior (AP) and lateral views of the forearm. If the elbow and wrist are not adequately visualized, corresponding views should be obtained to eliminate radial head dislocation, supracondylar fracture, and distal radioulnar joint injury. Forearm radiographs are examined to determine fracture pattern (complete or greenstick), location (proximal, middle, or distal third), displacement, angulation, and rotation.
Displacement and angulation are fairly easy to document on AP and lateral views. Although deformities can often be quantified and described on these standard views, it is important to remember that fracture angulation and displacement are always in a single plane, between those obtained on orthogonal radiographs. The magnitude of the deformity is at least as great as or greater than that seen on each view. Malrotation in complete fractures can be difficult to detect and assess, but can be suspected when the cortical, medullary, or bone diameters of both fragments are not equal. Malrotation can be gauged from deviations of normal orientation of proximal and distal bony prominences.
On a standard AP view, the radial tuberosity is seen in profile on the medial side, while the radial styloid and thumb are seen 180 degrees opposite on the lateral side. On this same view, ulnar styloid and coronoid process are not seen. Lateral views reveal the ulnar styloid pointing posterior and the coronoid process pointing directly anterior; the aforementioned radial prominences will not be seen. Another useful method for determining rotation of the proximal fragment utilizes the tuberosity view described by Evans. This technique allows a quantitative assessment of proximal fragment rotation. The distal fragment can then be manipulated and rotated into a corresponding position.
In many centers, a large proportion of forearm and distal radius fractures are treated outside the surgical suite, requiring the treating surgeon to consider and administer appropriate anesthesia. Strict guidelines for conscious sedation have been established by the American Academy of Pediatries.14 A survey of orthopaedic surgeons completed in 1993 indicated that as many as one third of orthopaedic surgeons were not in compliance with these guidelines during fracture reduction. 15
The chosen method should be as safe as possible, induce the least trauma, including fracture reduction. As no one method completely meets these criteria, several different choices exist, each with its own advantages and disadvantages.
Options include quick reduction without anesthesia, hematoma block which involves an injection of the anesthetic in the area of the fracture or going to the hospital for either a block type or a general anesthetic. Intravenous sedation entails the potential for overdosage and cardiopulmonary depression.
Regional intravenous blocks have the advantages of rapid onset of effect, simple administration, and good muscle relaxation. Disadvantages include pain when the injured limb is exsanguinated by wrapping or elevation. Premature cuff deflation may lead to major neurologic and cardiac complications when high doses are used.
Use of general anesthesia relieves the surgeon of the burden of providing safe and effective anesthesia. This allows the surgeon to concentrate on reduction and stabilization unencumbered by the proximity of anxious parents. In addition, if several reduction attempts are required, general anesthesia provides total relaxation with minimal constraints. Furthermore, if reduction is inadequate or unstable, it easy to convert to operative stabilization.
Anatomic reduction is usually not required for pediatric forearm fractures due to the potential for growth and remodeling. However, the treating physician must be able to define reasonable residual malalignment by answering several important questions: What are the acceptable limits of displacement at healing, and to what degree do the deformities remodel over time? How is remodeling potential affected by variables such as age and location of the fracture? Does malalignment at healing and follow-up correlate with loss of motion? What degree of documented motion loss is associated with poor function and patient dissatisfaction?
It is uniformly agreed that post-traumatic angular deformities in children have variable remodeling potential; however, it has not been consistently proved that deformities characterized by rotational malalignment will also remodel. Many studies have documented better radiographic remodeling of distal fracture and fractures in patients less than 9 or 10 years of age. It is important to realize that fracture location and age may not be independent variables. Creasman et al 22 documented better results in distal fractures; however, their patients were on average 3 years younger than patients with proximal fractures. Whether anatomic alignment correlates with final range of motion is controversial. Fuller and McCullough4 demonstrated a positive relationship with residual angulation and eventual range of motion. However, there are certainly examples of excessive malunion with good motion.
Conversely, cases of "anatomic" healing with documented motion loss have been reported. Carey et al 24 reported the follow-up data on 33 patients with bothbone forearm fractures and demonstrated average angulation of 12 degrees in patients aged 6 to 10 years and 9 degrees in patients aged 11 to 15 years. While almost all patients in the former group had full motion, those in the latter group had a small loss of rotation averaging 20 to 30 degrees. This disparity suggests that factors other than alignment may affect range of motion. Perhaps motion loss in such cases is due to contracture of the interosseous membrane from the injury and/or immobilization.
However, it is clear from in vitro studies that fracture malrotation proportionally decreases forearm rotation.27 Published discrepancies between residual angular deformity and final forearm rotation may be due to inability to accurately document and record radiographic malrotation. Finally, what is the subjective outcome in pediatric patients with fractures of both forearm bones, and does residual deformity or motion loss correlate with decreased function? Although several authors have demonstrated decreased remodeling potential in proximal fractures, Holdsworth and Sloan found that only 3 of 51 proximal forearm malunions showed marked loss of function, with a mean attendant loss of 65 degrees of forearm rotation. Studies of documented malunions demonstrate that good function can be obtained in all patients with motion loss up to 50 degrees, and that more symptomatic losses of 90 degrees can be partially compensated for with shoulder abduction. Other authors have demonstrated little functional loss with decreases in forearm rotation of 35 to 40 degrees. Higgstrom et al 3 found that some patients with a limitation of 60 degrees or less in the range of pronation and supination appeared to be unaware of their incapacity. In addition, it is conceivable that patients with initially unsatisfactory motion may have improvement with time. Although differing definitions of acceptable alignment have been delineated in the literature, many patients with residual deformity have good functional results.
Our recommendations are based on previous studies of malunion in children with relatively good function. In fractures at any level in children less than 9 years of age, we accept complete displacement, 15 degrees of angulation, and 45 degrees of malrotation. In children 9 years of age and older, we continue to accept bayonet apposition but only 30 degrees of malrotation; acceptable angulation is 10 degrees in proximal fractures and 15 degrees in more distal fractures. In distal radial metaphyseal fractures, we accept complete displacement and up to 20 degrees of angulation. In cases of completely displaced and slightly angulated distal radius fractures, it is important to inform the family that cosmetic deformity may be noted initially after fracture healing; however, remodeling can be expected to improve the appearance as long as 2 years of growth remains.
Historically, incomplete fractures were treated by completing the fracture and then manipulating the bones into an acceptable position. This approach has the theoretical advantage of increasing the size of the fracture callus and decreasing the risk of refracture. Currently, it is recognized that residual angulation is a result of malrotation and that the fracture should be reduced by rotating in the direction opposite to the deforming force. Traction and manipulation of the apex while rotating will often assist in the reduction. Most greenstick fractures are supination injuries with apex-volar angulation, which can be reduced with varying degrees of pronation. It can be difficult to remember whether to pronate or supinate the hand. Most fractures can be reduced by rotating the palm toward the deformity. Fractures with apex-volar angulation are a result of axial load in supination; there- fore, the palm should be rotated volarly (pronation). Fractures with apexdorsal angulation are a result of pronation force; therefore, the palm should be rotated dorsally (supination). It is not uncommon to see a greenstick fracture of one bone and a complete fracture of the other. in these cases, we use the same principles of reduction by rotation.
After reduction, the forearm should be immobilized in the same position that reduced the fracture. Studies have documented 10% to 16% rates of redisplacement when greenstick fractures were not adequately rotated in the cast. Complete Fractures Complete both-bone forearm fractures are reduced with a combination of sustained traction and manipulation. The fingers are taped to prevent sores and placed in fingertraps with the elbow at 90 degrees of flexion. Countertraction is provided by 10 to 15 lb of weight suspended from a sling over the distal humerus. The fracture and soft tissues are slowly brought out to length for 10 to 15 minutes, and the arm is allowed to find its own rotation.12 End-toend apposition is then attempted with deformity exaggeration and direct manipulation. If attempts to achieve bone apposition are unsuccessful, complete overriding of fracture fragments is accepted as long as rotation and angulation are reduced (Fig. 2). Fracture alignment in traction is assessed with fluoroscopy or plain radiography. If alignment is adequate, the distal part of the long arm cast is applied and molded while the arm is still in traction. Residual malrotation is addressed before cast application by rotating the forearm. It was traditionally taught that the hand should be casted in a position dictated by the relationship of fracture location with the insertions of the pronators and supinators. This principle is used to direct distal forearm positioning when residual malrotation is present. Because most displaced both-bone fractures are in the middle region, the hand is placed in a neutral or slightly supinated position, which usually accommodates rotation and angulation. Pronation is rarely employed for complete fractures and may result in a functional loss of supination due to soft-tissue contracture.
Fig. 2A, Displaced midshaft fracture of the radius and ulna in a girl aged 9 years I month. 2B, The fracture was reduced in neutral position. Bayonet apposition with minimal angulation and no rotational malalignment was accepted. The fracture united in this position. 2C, Radiographs obtained 6 years later demonstrate complete remodeling. Clinical examination demonstrated full range of motion in pronation and supination.
Distal radius fractures are reduced with a combination of traction, angulation, and rotation of the palm in the direction of the angulation. In the case of completely displaced and bayoneted fractures, sustained longitudinal traction is used with fingertraps, as previously described. After the fracture has been brought out to length, deformity exaggeration and rotation may produce end-to-end contact. It may be difficult to obtain apposition, as torn periosteum tightens around the buttonholed proximal fragments (Fig. 1). In these cases, it is acceptable to leave the fragments overlapped as long as rotation and angulation are reduced (Fig. 3). Typically, these fractures are immobilized in casts. Sugar-tong splinting is another form of immobilization commonly used immediately after reduction. If this method is selected, it is important to tighten the splint or convert to a cast when the initial swelling resolves in 2 or 3 days; high rates of reangulation in distal radius fractures have been reported. Distal radius fractures without ulnar fracture are immobilized in a lesser degree of pronation or supination depending on the apex direction. As these fractures are the result of an angulatory force as well as rotation, the position of the wrist is less critical. There is some suggestion that distal radius fractures are more stable in supination because of the action of the brachioradialis.
Fig. 3A, Distal radius fracture and intact ulna in an 8-year-old girl. Preliminary reduction failed to reduce bayonet apposition. B, After initial immobilization in a sugar-tong splint, a change was made to a long arm fiberglass cast. Early callus formation is noted along the dorsally elevated periosteum. C, Continued remodeling was noted 3 months after fracture. D, The fracture was almost completely remodeled 2 years after injury.
All fractures are eventually placed in either fiberglass or plaster long arm casts with the elbow at 90 degrees. Plaster may be easier to mold, but fiberglass permits better radiographic visualization. Casts are molded with anterior and posterior pressure applied over the interosseous membrane (Fig. 4, A). This tends to separate the bones and increase stability in the cast, and a straight ulnar border is produced. Medial and lateral molding above the humeral condyles will prevent the cast from sliding distally and angulating the fracture after swelling resolves (Fig. 4, B). Meticulous casting is critical as several studies have documented reangulation in approximately 8% to 14% of cases. 11,12,28,29 Some have blamed poor casting technique,11,28 while others have attributed the reangulation to residual rotational malalignment.7,12,30 Forearm AP and lateral radiographs are taken after reduction and immobilization, and improvements of residual angulation can then be corrected by wedging the cast. 23
After adequate reduction and immobilization, patients typically return for a followup radiograph 1 to 2 weeks after injury. Several studies have documented reangulation during the first 2 weeks. If reangulation is documented, cast removal and re-reduction under general anesthesia are recommended. Good results of re-reduction have been documented if performed within a few weeks of the initial fracture. If no reangulation is appreciated, the cast is continued for 6 to 8 weeks or until there is radiographic evidence of healing. Patients cannot participate in contact sports for 4 to 6 months, but all other activities are permitted. Refractures are uncommon; when they do occur, it is usually within several months of cast removal.