Fractures of the distal radius are among the most common fractures, and of these, the most familiar pattern is the Colles’ fracture, first described in 1814. Although Colles considered these to be stable fractures that usually enjoyed satisfactory outcomes, more modern experience has shown that these injuries require careful evaluation and treatment specific to the fracture pattern if they are to have good outcomes. Familiarity with the anatomy and natural history of distal radius fracture patterns is essential to managing or referring these fractures appropriately. Fractures of the radius and ulnar shaft are usually displaced and unstable, and most require operative treatment. Nondisplaced extraarticular fractures of the distal radius and isolated fractures of the ulnar shaft can be managed effectively by primary care providers. Those clinicians with additional experience in fracture reduction can safely manage displaced Colles’ fractures with accurate assessment of fracture alignment and careful attention to follow-up care and rehabilitation. Fractures of the distal radius are common in children and adolescents and heal without difficulty in most cases.
See Appendix for stepwise instructions for a sugar-tong splint and short- and long-arm casts used in the treatment of radius and ulna fractures.
Go to Expert Consult for the electronic version of a patient instruction sheet named “Broken Hand or Wrist or Arm,” which covers the steps of care from pain relief to rehabilitation exercises. This can be copied to hand out to patients to assist them during the treatment period.
Distal Radius Fractures (Adult)
The distal radius has three separate articulations. The distal radial articular surface has two fossae, the scaphoid fossa and the lunate fossa, which articulate with the scaphoid and lunate in the proximal carpal row. The sigmoid notch is a concave groove that articulates with and stabilizes the distal ulna. The medial side of the distal radius is attached to the distal ulna, the triquetrum, and the lunate via the triangular fibrocartilaginous complex (TFCC). This complex is composed of the triangular fibrocartilage, the ulnocarpal meniscus, and the ulnolunate ligament. These attachments are responsible for ulnar styloid fractures that frequently accompany distal radius fractures.
Four anatomic measurements are important in the evaluation of distal radius fractures ( Fig. 6-1 ). On the anteroposterior (AP) view, the slope of the distal radial articular surface, or radial inclination, is approximately 25 degrees, the radial length is approximately 1 cm from the tip of the radial styloid to an imaginary perpendicular line drawn from the distal ulnar articular surface, and the center of the radial joint surface should be 1 to 2 mm distal to the ulnar joint surface. The difference between the center of the radial joint surface and the ulnar joint surface is referred to as the ulnar variance . If the ulnar surface extends distal to the radial joint center, this is called a positive ulnar variance . This is abnormal and may interfere with normal wrist function. On the lateral view, the distal radius has a slight volar tilt of approximately 10 degrees. The median nerve and extensor pollicis longus tendon are in close proximity to the distal radius and may be injured in association with fractures in this location ( Fig. 6-2 ).
Traditionally, the most common classification system of distal radius fractures is that introduced by Frykman in 1967 ( Fig. 6-3 ). Types I and II are extraarticular fractures, types III and IV are intraarticular fractures involving the radiocarpal joint, types V and VI are intraarticular fractures involving the radioulnar joint, and types VII and VIII are intraarticular fractures involving both the radiocarpal and radioulnar joints. Even-numbered types indicate the presence of an ulnar styloid fracture in addition to the distal radius fracture. The Frykman classification is useful in describing fractures of the distal radius and evaluating the outcome of treatment. The higher the Frykman number, the greater the likelihood of poor results.
Signs of fracture instability include more than 20 degrees of dorsal angulation, marked comminution, and more than 10 mm of radial shortening. Stable fractures are usually extraarticular, with minimal to moderate displacement, and do not become redisplaced when reduced.
Mechanism of Injury
By far, the most common cause of distal radius fractures is a fall on an outstretched hand with the wrist in extension. Postmenopausal women incur 60% to 70% of all Colles’ fractures. Another 10% to 15% are caused by violent injuries to younger patients in which the lunate is driven into the radius, causing a higher-force “die-punch” radius fracture.
Patients report the typical cause of injury and complain of pain and swelling in the wrist. During examination, obvious swelling and ecchymosis of the wrist are apparent, especially dorsally. The displacement caused by a Colles’ fracture has been called a “silver fork” deformity because of the gross appearance of the hand and wrist. The patient has point tenderness at the dorsal aspect of the wrist, and pain limits range of motion (ROM). Median nerve function should be tested by checking sensation at the volar aspect of the thumb and second and third fingers. Capillary refill should take less than 2 seconds, and the radial pulse should be full. The scaphoid (anatomic snuff box) and other carpals should be palpated as well to seek evidence of associated carpal bone or ligament injuries.
Three views of the wrist (AP, lateral, and oblique) are necessary in the evaluation of distal radius fractures. The AP view should be examined for the radial inclination, radial length, and ulnar variance ( Fig. 6-1A ), and the lateral view should be examined for the normal volar tilt of the distal radial articular surface ( Fig. 6-1B ). The radiocarpal and distal radioulnar joints should be examined for evidence that the fracture extends into the joint. High-risk features such as comminution, severe displacement, and more than 2 mm of articular surface stepoff should also be sought. Concomitant dislocation may indicate the present of either a Barton’s or Hutchinson’s fracture (discussed separately below). The Colles’ fracture is an extraarticular fracture (Frykman types I and II) and usually occurs within 2 cm of the distal radial articular surface. In this fracture, the volar cortex fails in tension (sharp fracture), and the dorsal cortex fails in compression (dorsal comminution). In a typical Colles’ fracture, the distal fragment is displaced dorsally and proximally. The angle of radial inclination is decreased, the radial length is shortened, and the normal volar tilt is lost or reversed to a dorsal tilt ( Fig. 6-4 ).
The radiographs should also be examined for associated fractures, particularly of the ulnar styloid, scaphoid, or lunate. Occasionally, disruption of the supporting ligaments of the wrist results in scapholunate dissociation, the so-called Terry Thomas sign, seen radiographically as a gap between the scaphoid and lunate (see Fig. 5-12 ).
Indications for Orthopedic Referral
Emergent Referral (Within 30 to 60 Minutes)
Patients with open fractures, acute neuropathy, tenting of the skin, compartment syndrome, or vascular compromise require emergent orthopedic referral. If specialist care is not promptly available, tenting or neurovascular compromise associated with a displaced fracture can generally be corrected by immediate closed reduction after adequate analgesia or local anaesthesia is achieved (discussed below).
Nonemergent Referral (Within 24 to 48 Hours)
If the fracture is displaced and the physician is uncomfortable performing the necessary reduction, the patient should be referred and have reduction performed within 24 hours (preferably). Physicians who are comfortable performing reductions can reduce and manage many distal radius fractures. However, certain distal radius fractures are inherently unstable and likely to lose position even if reduction can be achieved initially. These fractures are best treated by an orthopedic surgeon. There is a paucity of evidence regarding which specific radiographic and clinical features mandate surgical evaluation. Studies have illustrated that available systems tend to underestimate instability and should be used with caution. Fractures with any of the following generally require referral: comminution, intraarticular extension, more than 20 degrees of dorsal angulation, displacement of more than two thirds the width of the radius, more than 5 mm of radial shortening or ulnar variance of more than 5 mm (i.e., ulnar joint surface >5 mm distal to the center of radial joint surface). Other fractures that typically require operative fixation include fracture dislocations, factures with associated injuries to carpal bones or ligaments, displaced intraarticular fractures (i.e., >2 mm stepoff on joint surface), fractures with large displaced ulnar styloid fragments, and fractures with palmar displacement (Smith’s fracture, discussed below). Patient characteristics also influence the choice of operative or conservative treatment. “High-demand patients” (i.e., active patients whose dominant wrist is injured) are more likely to require surgery to obtain a satisfactory result. In elderly patients, particularly those at higher operative risk, it may be preferable to avoid surgery even if surgery would otherwise be strongly preferred for that particular fracture. This common practice has been validated in one small study of low-demand patients over the age of 70 years with unstable radius fractures. After nearly 5 years of follow-up, bony alignment was far better in the operative group, but functional and subjective outcomes were the same in both groups, and cast treatment was significantly less painful.
Table 6-1 summarizes the management guidelines for distal radius (Colles’) fractures.
|Splint type and position|
|Initial follow-up visit|
|Patient instruction||Icing, elevation, ROM of fingers and shoulder|
|follow – up care|
|Cast or splint type and position|
|Length of immobilization|
|Follow-up visit interval|
|Repeat radiography interval|
|Patient instruction||Finger and shoulder ROM exercises while immobilized|
|Aggressive hand, wrist, and elbow rehabilitation after immobilization, especially in elderly adults|
|Indications for orthopedic consult|
The treatment of distal radius fractures should be individualized and modified by several key factors: fracture pattern, bone quality, patient’s functional demands (i.e., age, hand dominance, occupation, hobbies, and activities), and associated injuries (e.g., median nerve compression, carpal fractures, and elbow fractures). Closed reduction and cast immobilization are still the standard treatments for stable fractures.
Nondisplaced Extraarticular Fractures (Frykman Type I or II)
Patients with nondisplaced or minimally displaced extraarticular fractures can be treated initially with one of several splint types. The application of circumferential casts in the acute setting has been associated with an increased risk of ischemia and carpal tunnel syndrome and should not be performed unless the cast is bivalved. For nondisplaced fractures with no unstable features (see above), a well-molded “clamshell” splint should suffice. Indeed, one small study in adults and several studies in children (see below) support use of a splint. A clamshell splint includes two separate components: a volar splint extending from near the elbow to the palmar crease plus a dorsal splint extending from near the elbow to the dorsal metacarpophalangeal (MCP) joints. To provide maximal stability, a well-molded sugar-tong splint could be used instead. It consists of a wrist and forearm splint that extends from the proximal palmar crease to the volar forearm around the elbow and back to the dorsum of the MCP joints. The elbow is flexed to 90 degrees, the forearm is placed in neutral pronation–supination, and the wrist is placed in neutral flexion-extension. See the Appendix for a stepwise description of how to apply this splint. The patient should be advised to keep the arm elevated, begin active ROM at the shoulder and fingers immediately, and return for follow-up evaluation in 3 to 5 days.
Displaced Extraarticular Fractures (Frykman Type I or II)
Closed reduction of displaced extraarticular fractures can be attempted after adequate anesthesia. A hematoma block is adequate for most displaced fractures along with intramuscular or intravenous analgesia for the patient. Some patients require a Bier block or axillary nerve block (see Chapter 4 for a description of the hematoma block and Bier block techniques). Studies have compared different reduction techniques and found no difference in effectiveness.
Reduction Method with Finger Traps
Traction is applied to the thumb and index and middle fingers with the elbow at 90 degrees of flexion and the forearm in neutral rotation. With a stockinette, 5 to 10 lb of traction is applied to the arm for at least 5 minutes before reduction is attempted ( Fig. 6-5, A ). The examiner’s thumbs are placed on the dorsal aspect of the distal fracture fragment while the fingers are placed on the volar forearm just proximal to the fracture line. The distal fracture fragment is then pushed distally, volarly, and ulnarly to reduce the dorsal displacement and radial shortening common in Colles’ fractures ( Fig. 6-5, B ). After reduction, median nerve function should be tested and a sugar-tong splint (described above) applied to hold the reduction. Splinting the wrist in 15 degrees of palmar flexion, 10 to 15 degrees of ulnar deviation, and slight pronation is often recommended to help prevent loss of position. Splints that hold the wrist in greater than 15 degrees of volar flexion increase the risk of acute carpal tunnel syndrome and complex regional pain syndrome (CRPS). Using gently molded three-point control while shaping the splint helps maintain the reduction.
Reduction Method without Finger Traps
If finger traps are not available, closed reduction can be attempted with the help of an assistant ( Fig. 6-6 ). The assistant holds the patient’s elbow and provides countertraction. The forearm is supinated and held with the examiner’s left hand while longitudinal traction is applied with the right hand and thumb to the distal fragment. The fracture is disimpacted by allowing dorsal angulation in the supinated position. Fracture reduction is accomplished by pronating the forearm and wrist. The pronation is done entirely with the right hand while the left hand remains stationary. The wrist is directed into ulnar deviation by this maneuver, which seems to correct radial and dorsal angulation of the distal fragment. After reduction, median nerve function should be tested and the arm splinted as previously described.
After reduction, postreduction radiographs are obtained. The goal of reduction is to restore normal length, alignment, and articular surface congruity. Adequate reduction requires no dorsal tilt to the distal radial articular surface, less than 5 mm of radial shortening, and less than 2 mm of displacement of fracture fragments. If these criteria are not met, a second attempt at closed reduction should be made. The patient should be instructed to keep the arm elevated, begin active ROM at the shoulder and fingers immediately, and return for follow-up evaluation in 2 to 3 days. If adequate reduction cannot be achieved by closed means, the patient should be referred to an orthopedic surgeon after the arm is splinted as previously described.
Intraarticular Fractures (Frykman Types III to VIII)
If median nerve function is intact, the fracture should be stabilized in a sugar-tong splint and the patient referred to an orthopedic surgeon. If median nerve function is impaired, an attempt at closed reduction should be made with finger trap traction, and the patient’s arm should be placed in a sugar-tong splint. The patient should then be referred urgently to an orthopedic surgeon.
Nondisplaced Extraarticular Fractures
Patients should be seen within 3 to 5 days to allow swelling to subside before definitive casting. The splint is removed, and neurovascular status is reconfirmed by checking the radial pulse, capillary refill at the fingers, and median nerve function. Repeat radiographs are obtained with the arm out of the splint to confirm that no loss of position has occurred. If the fracture remains nondisplaced or minimally displaced, a short-arm cast may be applied, extending from the distal palmar crease to within 2 inches of the antecubital fossa. The wrist is placed in neutral position, and the cast should permit full flexion at the MCP joints and at the elbow. Patients are instructed to maintain active ROM at the fingers, elbow, and shoulder, and they should return in 2 weeks for routine follow-up and repeat radiographs to check fracture alignment. Cast immobilization is continued for 4 to 6 weeks and may be discontinued when the patient no longer has tenderness at the fracture site. Repeat radiographs can be obtained at 4 to 6 weeks to document healing.
For patients 60 years of age and older, the period of immobilization should be as brief as possible, and the duration of remobilization (i.e., physical therapy to regain full ROM) should approximate the duration of immobilization. If the fracture is stable (determined by radiographs every 1 to 2 weeks), an acceptable alternative to cast immobilization is a cock-up wrist splint if the older patient is comfortable in this device. Use of the splint rather than a cast is more comfortable for patients and minimizes postimmobilization stiffness, but selecting patients with stable fractures who agree to frequent follow-up is important in using this method of treatment effectively.
Comminution of the dorsal cortex commonly seen in Colles’ fractures predisposes these fractures to loss of position and dorsal displacement of the distal fracture fragment. If displacement develops, the patient should be treated as described for displaced extraarticular fractures, bearing in mind that the fracture is very likely unstable unless loosening of the splint or cast contributed to loss of position.
Extraarticular Fractures After Closed Reduction
After closed reduction, the patient should be seen within 2 to 3 days. If swelling has decreased, the sugar-tong splint can either be wrapped more tightly to help maintain position or else a long-arm cast may be applied with the wrist and forearm in the position described above and the elbow at 90 degrees. The patient is seen again 1 week later, and repeat radiographs are obtained to check the position. If the reduction position has been lost, another reduction should be attempted. The patient should be examined and have radiographs taken every 1 to 2 weeks with the arm out of the cast and with a new, well-molded splint or cast applied. Loss of position should generally lead to orthopedic referral. Repeated closed reduction may be a reasonable alternative if loosening of the splint or cast allowed the displacement.
The total period of immobilization required for healing is usually 6 to 8 weeks. A sugar-tong splint or long-arm cast is used for the first 3 to 4 weeks, and a short-arm cast is used for the last few weeks of immobilization. Use of gently molded three-point control when applying splints and casts may help maintain the reduction. The patient should be converted to the short-arm cast when there is evidence of some radiographic healing and the fracture remains stable in an adequate position. For older patients, immobilization in a sugar-tong splint or long-arm cast should be for as brief a period as possible, usually no more than 2 weeks. Longer immobilization may cause wrist stiffness, and poor function may result.
Fracture site tenderness, swelling, ROM, and median nerve function should be checked during each visit. Radiographs should be examined for signs of dorsal displacement, volar angulation, and radial shortening. The patient should be instructed to maintain finger, elbow, and shoulder ROM daily. Finger exercises include full extension, full flexion, making a fist, opposing the thumb to each fingertip, claw exercises (flexion of the distal interphalangeal [DIP] and proximal interphalangeal [PIP] joints while the MCP joints are held in extension), flexion of the MCP joints with the PIP and DIP joints in extension, and abduction–adduction in the radioulnar plane. Shoulder exercises should include pendulum exercises and active elevation and rotation. When the cast is discontinued, full active ROM exercises are initiated; the duration of mobilization activities should approximate the duration of immobilization.
Return to Work or Sports
Return to work is dictated by the type of duty required and the degree of impaired ROM and strength. Patients returning to light duty and undemanding tasks can return to work immediately and pursue rehabilitation as already outlined. If the patient’s occupation requires heavy labor and extensive use of the wrist and forearm, it is best to delay return to full duties until ROM at the wrist is maximized and strength is near normal. Modification of duties is another option for patients undergoing rehabilitation exercises. Wearing a protective volar splint during contact and collision sports activities may be useful in the first month after the immobilization cast is removed.
Fractures of the distal radius are associated with several complications, including malunion, hand stiffness, post traumatic arthritis, unrecognized associated injuries, tendon or nerve injury, compartment syndrome, and CRPS. Because of the dorsal comminution seen in distal radius fractures, malunion is a common complication. The distal radial fragment tends to be displaced dorsally, leading to limited wrist ROM and arthritis. Stiffness of the wrist is a common complication of distal radius fractures, particularly for patients older than 60 years. For these older patients, prolonged immobilization should be avoided, and cast immobilization should be as brief as symptoms allow.
Unrecognized associated injuries often complicate distal radius fractures. These include injuries to the wrist ligaments and carpal bones. Fractures of the ulnar styloid occur in nearly half of distal radius fractures. Small fractures of the distalmost part of the ulnar styloid are not clinically significant, but fractures across the base of the ulnar styloid may cause instability at the distal radioulnar joint (DRUJ).
Compression neuropathy most commonly affects the median nerve, although the radial and ulnar nerves may also be injured in distal radius fractures. Symptoms of median nerve injury include pain out of proportion to the injury, paresthesias in the volar aspect of the thumb and second and third fingers, and weakness of thumb opposition. Early symptoms of median nerve injury are usually caused by marked fracture displacement, stretching during the fall itself, edema or hematoma in the area of the carpal tunnel, swelling resulting from efforts at reduction, and compression resulting from cast placement and improper splint or cast position (>15 degrees of wrist flexion). Late symptoms of median nerve injury are more likely the result of volar displacement of the fracture fragment or nerve compression by excessive callus formation. Mild nonprogressive paresthesias may be observed, but unrelenting pain or signs of motor loss are indications for urgent carpal tunnel release and exploration of the median nerve.
CRPS after a distal radius fracture is associated with physical inactivity after cast immobilization. In the first few weeks after injury, burning shoulder pain and swelling of the hand and fingers develop. During the next few weeks, swelling decreases, but the pain persists. The severity of the pain prevents joint motion, and during the next 3 to 6 months, a “frozen” hand, shoulder, or both develop. Early skin changes include redness and swelling followed by dystrophic skin changes and mottling. Early recognition of the syndrome and prompt initiation of physical therapy measures may alleviate or reverse CRPS. CRPS can usually be prevented by substantial ROM exercises during the entire treatment period.
Smith’s fracture of the distal radius, sometimes referred to as the reverse Colles’ fracture, is an uncommon and usually unstable fracture in which the distal radial fragment is displaced volarly and proximally (the so-called garden spade deformity). The cause of injury is usually a direct blow to the dorsum of the wrist. Less commonly, cyclists may sustain this fracture if they are thrown over the handlebars. During examination, the patient demonstrates fullness at the volar aspect of the wrist caused by volar displacement of the distal fracture fragment and has a dorsal prominence at the distal end of the proximal fragment. Extension of the wrist accentuates the deformity. Radiographs show a fracture of the distal radius, usually cortex to cortex through the metaphysis, with volar displacement of the distal radial fragment ( Fig. 6-7 ). The fracture may be extraarticular or intraarticular or may be part of a fracture dislocation of the wrist.
Most Smith’s fractures should be referred to an orthopedic surgeon, but a primary care provider skilled in fracture reduction techniques may attempt closed reduction if the fracture is extraarticular (Frykman type I or II). The anesthesia and distraction techniques (finger traps or countertraction) are the same as described for a Colles’ fracture. While maintaining traction, the fingers of both hands support the proximal forearm fragment. The thumbs are placed on the volar aspect of the wrist and are used to push the distal fragment dorsally. The patient is placed in a single or double sugar-tong splint with the elbow flexed to 90 degrees, the forearm in neutral pronation–supination, and the wrist in slight extension. Postreduction radiographs are taken, and the same criteria for acceptable reduction as with the Colles’ fracture are used. Severe comminution, intraarticular extension, and inability to maintain the reduction by closed means are indications for orthopedic referral. The same close follow-up with serial examinations, repeat radiographs, and regular cast changes as outlined earlier in the treatment of reduced Colles’ fractures should be used in the management of Smith’s fractures.
Barton’s fracture is a fracture dislocation of the distal radius in which either the volar or dorsal aspect of the distal radial articular surface is sheared off with disruption of the radiocarpal joint. It is usually caused by violent direct injury to the wrist. Seventy percent of Barton’s fractures occur in young male laborers or motorcyclists. Barton’s fractures are extremely unstable and require open reduction and internal fixation (ORIF). The key to treating these intraarticular fracture dislocations is anatomic reduction by surgical means and stabilization of the wrist joint. Initial treatment should consist of immobilization in a double sugar-tong splint with the wrist in neutral position and prompt referral of the patient to an orthopedic surgeon.
Hutchinson’s fracture (also called chauffeur’s fracture) is an intraarticular fracture dislocation in which the radioscaphocapitate ligament avulses a fragment of the radial styloid. It is often associated with carpal bone and ligament injuries. The most common mechanism involves a firm blow to the radial styloid, which may be achieved by falling backward on an outstretched hand with ulnar deviation. Hutchinson’s fractures require surgical repair.
Distal Radius Fractures (Pediatric)
Fractures of the radius are common among children and adolescents. Fractures of the distal radial metaphysis are the most common and account for approximately 62% of these injuries. Another 14% of radius fractures among children involve the distal radial physis.
The metaphysis is particularly vulnerable because the cortex of the distal radius is thin, and the metaphysis extends more proximally in children than in adults. This anatomy leads to fractures unique to children, including torus fractures and greenstick fractures. Torus fractures are simple buckle fractures of the cortex caused by an axial force applied to the immature bone ( Fig. 6-8 ). A typical greenstick fracture is caused by a severe bending force applied to the distal radius that causes a compression fracture (buckling or plastic bending) at the dorsum of the distal radius; the volar surface (i.e., the tension side) is typically disrupted ( Fig. 6-9 ). Most metaphyseal fractures of the distal radius occur between the months of May and August and affect children between the ages of 9 and 14 years. Most distal radius fractures coincide with peak growing spurts for children (i.e., 11 to 12 years of age in girls and 13 to 14 years of age in boys). The distal metaphysis is at risk because of the relative porosity of the bone during peak periods of growth. The nondominant hand is involved in slightly more than half of all cases, and 70% of cases involve boys.
Mechanism of Injury
The patient usually sustains a fall on the extended wrist, causing tension on the strong volar intercarpal and radiocarpal ligaments. As with most injuries involving children and adolescents, the ligaments remain intact, but the bone fails, leading to fracture. A simple fall may result in a nondisplaced fracture, but a fall in conjunction with forward momentum (e.g., while the patient is riding a bicycle or inline skating) may produce displaced fractures. If the patient sustains a fall from a height, displaced fractures and concomitant fractures (e.g., supracondylar or scaphoid fractures) are more commonly seen.
The patient usually describes a fall on the extended wrist and reports pain and swelling at the wrist. During physical examination, the patient has tenderness at the dorsum of the distal radius. Dorsal displacement of the distal fracture fragment may be disguised by soft tissue swelling. Capillary refill and radial pulses are usually normal, but median or ulnar nerve injury may be present because the nerves have been stretched. Paresthesias in the median nerve distribution are more likely if the fracture is significantly angulated or if significant swelling occurs at the fracture site. A complete examination of the elbow and wrist is essential because distal radius fractures may be associated with ipsilateral supracondylar or scaphoid fractures.
AP and lateral views of the wrist are usually adequate to determine the type of fracture and the amount of displacement. For older children and adolescents, three views of the wrist should be ordered (AP, lateral, and oblique). It is important for the examining physician to distinguish torus-buckle fractures and greenstick fractures from “complete” fractures involving both cortices. Torus fractures of the distal radius metaphysis are nondisplaced because of the strong intact periosteum, which maintains alignment ( Fig. 6-8 ). Greenstick fractures usually show compression of the dorsal cortex and apex volar angulation ( Fig. 6-9 ). The dorsal cortex usually remains intact but may undergo plastic deformation, and the volar cortex is usually disrupted. Less commonly, apex dorsal angulation with compression of the volar cortex is seen. Late displacement or reangulation may occur in greenstick fractures ( Fig. 6-10 ). The most common pattern for a complete fracture is bayonet apposition ( Fig. 6-11 ). Distal radius fractures are usually associated with an ulnar fracture ( Figs. 6-8, 6-9, and 6-11 ). Intraarticular fractures are uncommon.