Distal-Third Forearm Fractures Treatment & Management

Updated: Apr 06, 2021
  • Author: Arvind D Nana, MD; Chief Editor: Harris Gellman, MD  more...
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Treatment

Approach Considerations

There are no contraindications for nonsurgical management of a closed distal radius fracture (DRF). Indications for surgical treatment should be based on radiographic findings after initial reduction, expected functional needs, associated medical conditions, and other traumatic injuries (see Surgical Therapy below).

Open fractures necessitate emergency surgical intervention and should be treated according to accepted principles. The decision for initial versus delayed placement of hardware should be based on the level of wound contamination and on the ability to achieve soft-tissue coverage over the implants.

The magnitude and direction of displacement and the type of fragmentation at the fracture site are important factors determining the treatment plan; treatment recommendations are based on these critical parameters as previously presented (see Pathophysiology). Key points can be summarized as follows:

  • An intact volar buttress is the key to a stable reduction; when disrupted, this buttress must be restored
  • All intra-articular fractures have one or more components of the Melone four-part pattern, and each component must be addressed and stabilized
  • Dorsal bone grafting is an important adjunct in promoting stability and healing when dorsal metaphyseal comminution is present
  • External fixation should be used in conjunction with dorsal bone grafting when dorsal comminution is present; the external fixator should be used as a neutralization device and can be removed early (~4 weeks) when used in this fashion
  • Every patient is unique, and the ultimate treatment plan should be based on individual needs and expectations
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Nonoperative Therapy

Stable fractures

Closed treatment methods are indicated for stable fractures. Stability is predicated on accurate reduction and adequate bony integrity to maintain that reduction. Surgical treatment may be necessary for injuries that are identified as unstable. [12]

Nondisplaced extra-articular and intra-articular fractures

For nondisplaced extra-articular and intra-articular DRFs, immobilization without fracture manipulation is recommended. Experience has demonstrated that a circular cast or even a bivalved cast has the potential for complications, such as compartment syndrome and swelling of the digits. A padded sugar-tong plaster splint with 20-30° of wrist palmar flexion and neutral rotation is a safe alternative, and the elastic bandages around the sugar-tong plaster splint can be adjusted later to accommodate decreased swelling, without manipulation of the fracture.

Three-point molding is an important aspect of the sugar-tong plaster splint because this helps maintain reduction of the fracture. Appropriate molding along the dorsal distal radius, volar distal forearm, and dorsal proximal forearm helps achieve adequate three-point molding. The authors have found that a flat surface of the splint along the volar distal forearm is key to achieving three-point molding (see the images below).

Closed reduction, fracture manipulation, and motio Closed reduction, fracture manipulation, and motion arthroplasty of the sigmoid notch were performed under a local hematoma block. Note the flat surface of the splint along the volar distal forearm to achieve 3-point molding of the sugar-tong plaster splint.
Postreduction posteroanterior (PA) view demonstrat Postreduction posteroanterior (PA) view demonstrates an adequate stable reduction of fracture fragments; thus, surgical intervention was not required.

The sugar-tong plaster splint with its U shape around the elbow prevents pronation and supination but allows some elbow motion. Elimination of pronation and supination neutralizes deforming forces (eg, brachioradialis) on the fracture fragments. Wrinkles in the splint must be avoided, especially on the volar side, because such wrinkles can cause local compression of the median nerve, carpal tunnel, and volar skin. Conversion to a short arm circular cast is not always necessary or recommended; however, if it is necessary, it should be done at 2-4 weeks after sugar-tong plaster splint immobilization.

Plain radiographs should always be obtained after splinting to confirm that the fracture fragments are not displaced. Radiographs should be acquired every week for 2-3 weeks after immobilization to ensure stability of the fracture. Maintaining the wrist above the level of the heart and early finger motion facilitate rapid improvement of swelling.

During the period of immobilization, finger motion and "six-pack" finger exercises, as described by Palmer, are important and should be performed at least three times a day (see the image below). These exercises emphasize finger extension, metacarpophalangeal (MCP) joint flexion, proximal interphalangeal (PIP) joint flexion, full finger flexion, finger abduction and adduction, and thumb motion. [28]

"Six-pack" exercises as Palmer describes, are perf "Six-pack" exercises as Palmer describes, are performed during the period of immobilization to encourage and maintain finger motion.

After immobilization for a total of 4-6 weeks, the recovery of pronation and supination and wrist flexion and extension should be emphasized. Occupational therapy may be necessary during or after immobilization if the patient has difficulty with finger motion or wrist motion, respectively. Strenuous activities with the affected wrist should be restricted for the first 3 months after injury.

Displaced extra-articular and intra-articular fractures

All displaced DRFs should initially be treated with closed reduction and fracture manipulation and immobilization in a sugar-tong plaster splint. Even if adequate reduction is not achieved, the initial closed reduction limits injury to the nerves, tendons, and soft tissues as a result of the displaced bone fragments. The use of ultrasonography to guide DRF reduction has been shown to be feasible and safe. [29]  

Manipulation of the fracture can be achieved in the emergency department (ED) or outpatient clinic by using a hematoma block and/or sedation or by using a Bier block. [30] Local hematoma block without sedation is believed to be a safe option in the outpatient setting and can be performed as long as 7-10 days after injury.

Longitudinal traction with finger traps is helpful during closed reduction, and if used, the traction should be maintained for several minutes before fracture manipulation to take full advantage of ligamentotaxis and tissue creep. Plain radiographs and, ideally, fluoroscopic images can be used to assess the fracture reduction with traction. If the reduction is inadequate, the fracture can be easily manipulated again.

Articular congruity of the sigmoid notch of the distal radius is just as essential as that of the radiocarpal joint. If the fracture line involves the sigmoid notch, motion arthroplasty of the sigmoid notch can be achieved by pronating and supinating the forearm during the reduction maneuvers. Adequate reduction of the sigmoid notch must also be evaluated on traction and postreduction views.

If adequate reduction is achieved with fracture manipulation, a sugar-tong plaster splint should be applied, with the longitudinal traction in place. As the splint is setting up, the longitudinal traction can be released, and the dorsal and palmar three-point molding of the sugar-tong plaster splint can carefully be completed with light manual traction. The wrist should be placed in 20° volar flexion, neutral rotation, and 15° ulnar deviation to take advantage of ligamentotaxis and three-point molding.

Once the splint is hard, manual traction is released and plain radiographs ordered. Continue the immobilization if the radiographs demonstrate maintained reduction, but operative treatment should be considered if the fracture becomes displaced in the splint. Scheduled follow-up visits with plain radiography are essential in the treatment of DRFs.

If adequate reduction criteria are not achieved, surgical intervention is necessary (see Surgical Therapy). In the interim before surgery, sugar-tong plaster splinting can be used to immobilize the fracture and limit damage to surrounding structures. High-energy injuries are often associated with extensive swelling, and operative intervention should be performed after swelling has decreased, usually several days after injury. [15]

Unlike a nondisplaced DRF, a displaced DRF implies more injury to the soft-tissue envelope; therefore, splint immobilization should be continued for a minimum of 6 weeks or longer. [31, 32] Conversion to a short arm cast can be considered after 4-6 weeks of immobilization. Wrist immobilization, if applied properly, can be maintained for 6-8 weeks without additional adverse effects on the long-term functional outcome. [33] After cessation of immobilization, the same protocol as for nondisplaced fractures must be followed.

In a study of long-term outcomes (mean follow-up, 7.3 years) in children with minimally displaced metaphyseal both-bone forearm fractures who were treated with a below-elbow cast instead of an above-elbow cast, Musters et al found that both primary (loss of forearm rotation) and secondary outcomes (ABILHAND-kids, DASH questionnaire, grip strength, radiologic assessment, and cosmetic appearance) were similar in the two groups. [34] The authors therefore suggested that children with such fractures should be treated with a below-elbow cast.

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Surgical Therapy

Surgical treatment is indicated for unstable DRFs. An unstable injury is defined as a fracture that does not reduce adequately with closed fracture manipulation or that loses reduction below acceptable reduction parameters despite appropriate immobilization techniques. [35, 36]

Indications

Graham proposed the following radiographic criteria for acceptable reduction of a DRF [37] :

  • Radial shortening less than 5 mm at the distal radioulnar joint (DRUJ) as compared with the contralateral wrist
  • Radial inclination of more than 15° on a posteroanterior (PA) image
  • Sagittal tilt on the lateral projection between 15° dorsal tilt and 20° volar tilt
  • Intra-articular fracture stepoff less than 1-2 mm of the radiocarpal joint

Articular incongruity less than 2 mm of the sigmoid notch of the distal radius is another critical radiographic parameter.

Radial shortening has been shown to be the most important reduction parameter because of its impact on the radiocarpal joint, the DRUJ, and, ultimately, functional outcome. [10, 37, 38, 39, 16, 40, 41, 31, 42, 43, 44, 45]  Palmer and Werner even found that minor axial shortening of 2 mm can alter the contact forces across the entire wrist joint. [42]

Complications of radial shortening include increased pressure on the triangular fibrocartilage complex (TFCC), pain caused by ulnocarpal impingement, increased lunate contact area, an increase of approximately 40% of the ulnar axial load, decreased and/or painful pronation or supination, and decreased grip strength. [38, 42, 46, 47]

Radial inclination less than 15° can cause an appearance of radial deviation of the wrist and changes the load distribution between the scaphoid and the lunate. [42, 48]

Most wrist fractures usually result in a dorsal tilt of the distal radius articular surface in the sagittal plane. Fernandez found that patients with a dorsal tilt more than 25° usually become symptomatic. [41]  Other authors have demonstrated that dorsal angulation is associated with decreased functional results. [39, 16]

Changes in sagittal tilt alter the biomechanics across the wrist joint. Pressure is dispersed over the entire articular surface of the distal radius and ulna at 11° of palmar tilt. As the sagittal tilt increases from 10° palmar tilt to 45° dorsal tilt, the axial load through the ulna increases from 21% to 67% of the total axial force. At 40° of dorsal tilt, most of the axial load is borne by the dorsal aspect of the radioscaphoid and ulnocarpal articulations without any load on the radiolunate joint. [49]

Intra-articular stepoff and gap on the distal radius articular surface have been studied extensively. It generally is agreed that more than 2 mm of articular displacement can lead to radiographic osteoarthritis (OA). [17, 50, 51, 52, 15]  However, radiographic OA does not always indicate poor functional outcome. [39, 41, 17, 53, 54, 33]

Trumble et al noted that intra-articular fractures with more than 1 mm displacement should be treated aggressively because, for example, the wrist articular cartilage is not as thick as that of the knee. [38]  This decreased thickness of cartilage may consequently diminish the ability of the wrist to remodel residual articular incongruity. [55, 15]  Anatomic reduction of the articular surface is recommended to decrease radiographic OA and optimize functional outcome. [47, 17, 51, 53]

In elderly patients, poor radiographic results do not necessarily signify poor functional outcomes. [41, 54]  Satisfactory functional outcomes, regardless of radiographic results, are observed in patients older than 60 years—not because they are older, but because of their lower functional demands. Therefore, nonoperative treatment of DRFs can yield satisfactory outcomes, especially in patients with low functional demands and in patients who are poor operative candidates. [3, 54]

Dorsally displaced extra-articular fractures

Closed reduction with percutaneous pinning is a simple and effective treatment for dorsally displaced extra-articular fractures with large metaphyseal fragments. [56] Cross-pinning with 0.062-in. diameter smooth pins in the radial styloid (two pins) and the dorsal ulnar aspect of the distal radius (one pin) has been shown to be a rigid construct in both torsion and cantilever bending. [57]

The radial styloid is anterior; thus, the radial styloid pins are to be directed in a dorsal proximal ulnar direction. [24] To avoid injury to the extensor tendons, the percutaneous pin should be inserted between the extensor tendons of the first and second, third and fourth, and/or fourth and fifth compartments (see the image below). [58]

Safe pin placement is possible on the dorsal dista Safe pin placement is possible on the dorsal distal radius between the first and second, third and fourth, and/or fourth and fifth extensor compartments.

Intrafocal (Kapandji) pins are another consideration, especially in the physiologically younger patient, but they should not be used initially in the presence of significant comminution or advanced osteopenia. [45, 59, 58] This technique is especially useful for reducing and holding fractures that redisplace after several weeks of immobilization.

Extensive comminution at the fracture site can occur in physiologically young patients involved in high-energy injuries and in osteoporotic patients with low-energy trauma. [11] When these fractures are reduced, the metaphyseal bone has resultant voids, which require filling with iliac crest bone grafts, allografts, or bone-graft substitutes.

McBirnie et al found a 22% malunion rate in unstable DRFs treated with bone grafting and fixation with a single Kirschner wire (K-wire). [60] This rate suggests that additional support, as with an external fixator or plate, is necessary with this type of treatment. The authors do not use dorsal plates for acute fractures, because some plates can irritate the extensor tendons, and they frequently have to be removed.

Newer low-profile plates and screws are now available. Current external fixators are easy to apply in neutral tension and can be used for fine-tuning difficult reductions. In association with dorsal bone grafts, external fixators maintain neutral tension in the dorsal aspect and can be removed early (~4 weeks) in some fractures.

Bone-void filler provides mechanical support and applies an osteoconductive material to the bone defect. [61, 62, 38, 47] The use of filler ultimately leads to more rapid fracture healing and a decreased incidence of the loss of reduction.

Alluri et al compared the biomechanical stability of Kirschner wire (K-wire) fixation, volar plating, and intramedullary (IM) nailing for unstable extra-articular DRFs with both constant and cyclical axial compression. [63]  More than 300 N of force was required to induce failure of the volar plate and the IM nail, whereas less than 150 M was required for failure of the K-wire construct. The first two constructs showed less than 1 mm of displacement during cyclic loading, whereas the third showed more than 3 mm. Both volar plating and IM nailing demonstrated the necessary biomechanical stability to maintain postoperative reduction in extra-articular DRFs.

Volarly displaced extra-articular fractures

Like its dorsal counterpart, a volar displaced fracture with noncomminuted metaphyseal fragments responds well to closed reduction with percutaneous pinning, which effectively restores the volar buttress in the presence of large volar metaphyseal fragments. The use of dorsal intrafocal pins for stabilization is controversial because these pins may aggravate the volar displacement and fail to restore anatomic alignment. Proper palmar tilt is readily achieved with closed reduction; however, excessive palmar tilt is still possible if volar metaphyseal fragmentation is not properly evaluated on initial radiographs.

With small, comminuted, volar metaphyseal fragments, compression of cancellous bone is expected, with resultant loss of the essential volar buttress. Volar plating stabilizes the fracture, and a bone-void filler may be added. Rigid fixation with a volar plate also permits early range of motion (ROM) out of the plaster splint.

Unlike small-fragment dorsal comminution, small-fragment volar metaphyseal comminution cannot be treated with ligamentotaxis because of the radiocarpal ligamentous anatomy. The volar ligaments are shorter, thicker, and stronger than the longer, thinner, and weaker dorsal ligaments. The stout volar ligaments tighten sooner with longitudinal distraction, resulting in dorsal tilt of the distal fragment. [33, 64, 65, 66]  Because of these strong volar ligaments, which are important for radiocarpal stability, the volar capsule should not be opened. [24] These observations further support the authors' use of a volar plate to reconstruct the volar buttress in the presence of significant volar metaphyseal fragmentation.

Intra-articular fractures

Intra-articular fractures involving dorsal and/or volar metaphyseal fragments are a combination of intra-articular and extra-articular displaced injuries. As such, their treatment plans are additive. Ideally, all intra-articular fragments should be anatomically reduced to retard the development of OA. Closed reduction and splint immobilization techniques are similar to those used for extra-articular fractures.

Dorsally displaced lunate facet die-punch fractures

Dorsally displaced lunate facet die-punch fractures should be anatomically reduced (with either an open or closed technique) to realign the radiolunate joint and the sigmoid notch and to restore the integrity of the medial complex. The dorsal ulnar fragment can be treated with closed reduction and stabilized with a single pin. However, a limited dorsal open reduction between the fourth and fifth extensor compartments may be necessary. [47]

If the dorsal metaphyseal fragments are small (comminuted), dorsal bone grafts (or substitutes) and external fixation are recommended, as described for extra-articular comminuted fractures. In either case, the intact volar cortex serves as a buttress against which stability of the dorsal fragment is maintained.

Volarly displaced lunate facet die-punch fractures

The volar fragment of the coronal split has a tendency to rotate dorsally when tension is applied to the volar capsule, and such displacement necessitates a volar open reduction. If this occurs, the volar medial fragment is buttressed with a small plate (see the image below). Volar plating does not have the same complications as dorsal plating and does not necessitate routine early hardware removal.

Postsurgical lateral radiograph shows a good reduc Postsurgical lateral radiograph shows a good reduction of the fracture with a volar buttress plate.

Dorsal and volar metaphyseal fragments

When displacement (instability) of dorsal and volar metaphyseal fragments is present, dual approaches are necessary. As always, a stable volar buttress is critical for providing a fulcrum against which the dorsal fragments are reduced. Volar plating provides this stability and prevents excessive volar displacement secondary to manipulation of dorsal fragments and/or placement of bone grafts. [60] When dual incisions are necessary, an attempt should be made to close the volar incision before the dorsal incision is made to minimize tissue swelling and to limit skin tension with wound closure. [15]

Radial styloid fractures

The isolated radial styloid fracture (ie, chauffeur's fracture) is uncommon. When present, this fracture should be critically evaluated for associated injuries, such as a scaphoid facet die-punch fracture and, more important, a carpal ligament injury. [15]

This fracture responds well to closed reduction and can successfully be pinned percutaneously. [47] However, if small metaphyseal fragments are present or if closed reduction is not successful, open reduction with internal fixation (ORIF), through either a direct dorsal approach or a standard volar (Henry) approach, must be considered. The latter is chosen when the styloid fragment is displaced volarly or when it has a large volar extension.

Most often, the styloid fragment is part of a four-part displacement pattern, as Melone described. [10] In this instance, the treatment of all components is additive. The reduction and stabilization of the radial styloid, dorsal lunate facet die-punch, and volar lunate facet die-punch fractures are assessed and treated as described above, either individually or in combination.

Central depression fractures

Central depression of lunate or scaphoid facets should be evaluated with computed tomography (CT) or plain tomography to fully assess the magnitude of articular stepoff. Impacted fractures more than 1-2 mm should be treated with reduction via a limited dorsal approach, with bone grafting for mechanical support, and with percutaneous pinning for stability. [47, 67] The reduction can be confirmed by means of fluoroscopy or, more precisely, via direct visualization (capsulotomy) or arthroscopy. Arthroscopically assisted reductions have the advantage of minimizing capsular scarring; however, arthroscopy has not yet been proved to improve outcomes. [15]

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Complications

Early complications

DRFs can directly or indirectly cause contusion, laceration, and/or entrapment of skin, tendons, nerves, fascia, muscle compartments, and vessels by bone fragments. [68, 69, 70] The potential for early soft-tissue complications increases with any delay in initial treatment; therefore, early initial reduction of the fracture can minimize the effects of these associated injuries.

Iatrogenic injury must also be avoided, regardless of whether treatment is conservative or surgical. Cast treatment can lead to skin pressure necrosis and median nerve compression. [68] Joint contractures are associated with the Cotton-Loder position (ie, excess palmar flexion with ulnar deviation). [10] Circumferential casts or dressings cannot allow for expected swelling, and compartment syndrome can subsequently occur. [68] Persistent finger edema can also result in stiffness of the digits. Casts that block finger motion are unnecessary and potentially harmful.

Surgical management of DRFs can also result in complications. Percutaneous placement of pins is technically simple but can easily injure extensor tendons and nerves. [71] Excessive traction by external fixation can lead to joint stiffness and injury of carpal ligaments. [65]  Rare cases of combined median and ulnar nerve palsy after ORIF have been reported. [72] Careful handling of soft tissues in all surgical approaches is essential to prevent postoperative skin damage and infection.

Caution should be used when bone grafts are used in intra-articular fractures to avoid intra-articular extravasation. Rupture of the extensor pollicis longus (EPL) can occur with surgical or nonsurgical treatment. Careful reduction of dorsal fragments helps to avoid this complication. In dorsal approaches to the wrist, releasing the EPL tendon from its compartment can also help to avoid tendon constriction and injury.

Early reflex sympathetic dystrophy (RSD) should always be suspected in the presence of inappropriate postoperative pain, swelling, and stiffness. RSD may be caused by tight dressings, unresolved nerve injury (eg, carpal tunnel syndrome), or inherent patient susceptibility to this complication. In any event, early recognition and treatment are effective in most cases. Removal of the instigating factors, active ROM of thumb and fingers, sensory stimulation, activities of daily living (ADLs) of the hand, and psychotropic medication all have beneficial effects.

Long-term complications

The list of long-term complications associated with DRFs is extensive and not within the scope of this article. This section provides a general overview of the common problems. Pain and extremity function should guide the treatment plan; radiographic findings guide the surgical approach.

Extra-articular malunion is often multidirectional and can result in malalignment of the DRUJ and the carpal bones. Typically, extra-articular malunions are shortened and tilted dorsally and treated with distal radial osteotomy, corticocancellous bone grafting, and dorsal-plate fixation. On correction of the distal radius alignment, the radial length and reduction of the DRUJ must be critically assessed.

Further considerations include ulnar shortening, distal ulnar ablation (Darrach), partial distal ulnar resection with or without interposition arthroplasty, or distal radioulnar fusion with ulnar pseudarthrosis (Sauve-Kapandji). Many of these DRUJ procedures can be performed without correction of the distal radius malunion. [37, 40, 41, 73]

Although many patients report excellent results after reconstruction of distal radius malunions (particularly DRUJ malalignment), data from good long-term outcome studies are lacking. An intra-articular stepoff more than 2 mm can lead to degenerative arthritis, but these radiographic findings have not been correlated with long-term patient outcomes.

Following treatment of DRFs, functional impairment is possible for as long as 2 years. For this reason, the authors continue aggressive therapy, including active and active-assisted ROM, progressive-resistance exercises, and work rehabilitation for as long as improvement is noted objectively. Only then is it appropriate to assess the need for reconstructive surgery.

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