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ORIF Middle rd Forearm Fractures SOORYA ORTHOPAEDIC HOSPITAL

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					Middle Third Forearm Fractures
For descriptive purposes, as well as for operative considerations, forearm fractures are
classified by location, being categorized as proximal, middle, or distal third fractures. The
middle third of the radius stretches from the radial bow to the beginning of diaphyseal
straightening. The ulna is relatively straight and can be divided using longitudinal
dimensions alone. (See also the eMedicine articles Forearm Fractures, Distal-Third Forearm
Fractures, and Fractures, Forearm.) Images of these fractures are depicted below.




Anteroposterior radiograph of a displaced, midshaft both-bone forearm fracture in
an adolescent with a transitional growth plate. This fracture should be treated as
an adult injury.




Lateral radiograph of a displaced, midshaft, both-bone forearm fracture in an
adolescent. Note that the alignment in this view appears to be adequate; however,
the radius is short.
Lateral radiograph of an open middle third fracture of the radius and ulna. Note
the proximity of the bones to soft tissue.




Anteroposterior radiograph of an open middle third fracture of the radius and ulna.
The joints above and below the fracture are visible.




Middle third forearm fracture.


Treatment objectives for both-bone forearm fractures have remained relatively constant,
with early extremity range of motion. To understand the management of forearm fractures,
the idea of the forearm axis was created, combining the function and anatomy of the wrist,
forearm, and elbow. The coordinated, independent function of the wrist, forearm, and elbow
is necessary to place and orient the hand in space. Injury to any of these components can
result in a significant deficit. The 3 basic stabilizers of the forearm are as follows:

      Distal radial-ulnar joint
      Interosseous ligament
      Proximal radioulnar joint.

Recent studies

      Prasarn et al reported on a treatment protocol for repair of infected nonunions of
       diaphyseal forearm fractures in 15 patients, 13 of whom initially had fractures of
       both the radius and ulna. The protocol consisted of aggressive surgical debridement,
       definitive fixation after 7 to 14 days, tricortical iliac crest bond grafting for segmental
       defects, leaving wounds open to heal by secondary intention, 6 weeks of culture-
       specific I.V. antibiotics, and early active range-of-motion exercises. All but 3 of the
       patients had at least 50º of supination/pronation and 30-130º of flexion/extension
       arc. Excluding one failure in which resolution took 46 months, average time to union
       was 13.2 weeks (range, 10-15 weeks).
      Guitton et al described 13 pediatric patients with an isolated diaphyseal fracture of
       the radius, 10 of whom were treated with manipulative reduction and immobilization
       with an above-elbow cast, and 3 of whom were treated with plate-and-screw
       fixation. All 13 patients, with at least 1-year follow-up, regained full elbow flexion
       and extension and full forearm rotation. According to the authors, treatment of
       isolated diaphyseal radius fractures in skeletally immature patients is associated with
       a low complication rate and excellent functional outcome.
      Teoh et al compared the differences in radiographic and functional outcomes in
       children with unstable both-bone diaphyseal forearm fractures after treatment with
       either IM fixation or plate fixation with screws. Plate fixation and IM nailing both
       resulted in good or excellent functional and radiologic outcomes. For the patients
       with plates, radiographs showed complete healing, with reconstitution of the radial
       bow. Three patients in the IM group did not regain their natural radial bow. No
       nonunion or malunion was observed, and there were no significant differences in the
       loss of forearm motion and grip strength between the 2 groups. Osteomyelitis was
       more likely to occur in the IM fixation group, and ulnar never palsy occurred in the
       plate-fixation group.



For a review of Galeazzi and Monteggia forearm fractures, see the eMedicine articles
Galeazzi Fracture and Monteggia Fracture).

For excellent patient education resources, visit eMedicine's Breaks, Fractures, and
Dislocations Center. Also, see eMedicine's patient education article Broken Arm.

Problem
Unlike fractures in infants and children, fractures of the adult forearm are unstable.
Nonunions and malunions of both-bone forearm fractures are functionally and cosmetically
limiting, with midshaft radius or ulna angulation substantially impeding forearm rotation.

Frequency
According to the AO (Arbeitsgemeinschaft für Osteosynthesefragen [Association for
Osteosynthesis]) documentation center, forearm fractures accounted for 10-14% of all
fractures between 1980 and 1996.

Etiology
Middle third, or diaphyseal, forearm fractures commonly result from a direct blow or a fall
from a height. Other causes include gunshot wounds, motor vehicle accidents, and
pathologic bone fractures.
Presentation
Patients with middle third forearm fractures present following an identifiable traumatic
event. Multiple injuries to the musculoskeletal and associated systems frequently occur in
conjunction with forearm fractures. In patients who sustain multiple traumas, any life-
threatening injuries take priority in treatment and stabilization. Forearm fracture
management objectives remain the same whether they are isolated or occur in the
polytrauma setting, with early stabilization recommended.

Physical examination of the patient with a forearm fracture includes a close inspection of the
skin to rule out puncture wounds and abrasions. Additional soft-tissue evaluation is
performed to rule out compartment syndrome, which is associated with low- and high-
velocity injuries. A careful neurologic and vascular examination is carried out to identify any
deficits that were caused by the injury. Loss of posterior interosseous nerve (PIN) function
in Monteggia fracture patterns has been well described. The PIN innervates the extensor
musculature below the elbow, which functions to extend the digits.

Anterior interosseous nerve (AIN) palsy also may be present and is often overlooked
because this finding has no sensory component. A division of the median nerve, the AIN
arises from the posterior aspect of the median nerve, 5 cm distal to the medial humeral
epicondyle, and passes between the heads of the pronator teres. The AIN is primarily a
motor nerve; injury to it can cause paralysis of the flexor pollicis longus (FPL) and flexor
digitorum profundus (FDP-I) to the index finger, causing loss of pinch between the thumb
and index finger. The AIN terminates in sensory fibers to the distal radioulnar, radiocarpal,
intercarpal, and carpometacarpal joints. Palsy has been associated with internal fixation of
forearm fractures, as well as with tight external dressings.

Indications

Nonoperative treatment of middle third forearm fractures is reserved for isolated ulnar shaft
fractures, better known as nightstick fractures. (See also Interventions for Isolated
Diaphyseal Fractures of the Ulna in Adults, on Medscape.) Radiographs of the wrist and
elbow must be obtained in isolated radius and ulna fractures to rule out Monteggia and
Galeazzi injury patterns. These injuries are best treated surgically in the adult patient.

Both-bone middle third forearm fractures in adults are unstable injuries that lead to
shortening and angulation. The goal of treatment is to achieve a stable anatomic reduction.
The literature recommends open reduction and internal fixation (ORIF) for displaced
fractures of the middle third of the forearm in adults to restore early forearm motion.
Precise anatomic reduction is necessary to re-establish the radial bow and proper
interosseous space and therefore to maintain normal motion.Even small amounts of
malalignment may lead to a functional disability at the wrist and/or elbow.

Nondisplaced both-bone middle third forearm fractures are rare in adults; when present,
however, they may be treated in a long arm cast for 6-12 weeks with the elbow flexed to
90º and the wrist in neutral rotation. Careful, weekly radiographic follow-up is required
because these fractures may displace. If displacement occurs, ORIF is required to restore
the normal anatomic relationship of the radius and ulna.
All open forearm fractures require appropriate irrigation and debridement with subsequent
surgical stabilization. Open fractures of grades I, II, IIIa, and (occasionally) IIIb are treated
according to the same principles of closed fractures in association with meticulous
debridement of the soft tissues. Results of the debridement and immediate internal fixation
of open fractures are comparable to those of the surgical treatment of closed fractures.

Open wound management is recommended, with repeated debridement as necessary.
Primary closure of the extension incisions of the traumatic wound may be performed, and
delayed wound closure may be performed once the soft tissues have declared themselves.
Forearm fractures accompanied by soft-tissue loss that results in an inability to cover plates
may require other forms of stabilization. Temporary stabilization with an external fixator
may be achieved while planning soft-tissue coverage with rotational or free flaps in
conjunction with delayed (secondary) internal fixation (plating).

Most forearm fractures in children can be stabilized and treated by means of closed
reduction and cast immobilization. Occasionally, some pediatric forearm fractures can be
unstable, leading to displacement, radioulnar angulation, rotational malalignment, and
encroachment of the interosseous space.Angulation of greater than 10º results in loss of
rotation   in   children   older   than    10     years  and     should    be    avoided.

Intramedullary (IM) stabilization was introduced in France in 1984 as an alternative to plate
fixation in children, in an attempt to avoid extensive exposure and soft-tissue
stripping.Since then, IM fixation has gained widespread acceptance in the United States for
the surgical treatment of pediatric forearm fractures. Indications for IM fixation are the
inability to maintain an adequate closed reduction (defined as an angulation of >15 º), a
malrotation of greater than 30º, a 100% diaphyseal offset, and loss of the interosseous
space.

Relevant Anatomy

The ulna is the stable unit about which the radius rotates. Force transmission is initiated at
the wrist (the distal radioulnar joint) level and is translated longitudinally between the
radius, ulna, and interosseous membrane, through the forearm axis, and to the elbow. An
applied compressive load travels along the proximal radius, transferring tension forces to
the interosseous membrane, which transfers a compressive load to the proximal ulna. 14 This
mechanism accounts for the inequality in the contact forces between the radius and ulna at
the wrist and elbow. Fracture and/or dislocation of the forearm lead to disruption of this
longitudinal relationship and affects wrist, forearm, and elbow function.

Contraindications

The forearm joint must be reconstructed anatomically to regain and re-establish
function. Every effort should be made to maintain normal anatomic relationships.

Contraindications to surgical treatment include life-threatening trauma conditions, which
may delay or preclude surgical intervention. Rarely are patients so medically unstable
that both-bone forearm fractures cannot be promptly treated by surgery.
Middle Third Forearm Fractures: Treatment


Surgical Therapy
Early surgical intervention (within the first 6-8 hours) is optimal to avoid radioulnar
synostosis. Fixation options include plate fixation, external fixation, and IM nailing. 15 Plate
fixation with anatomic reduction is thought to produce the best functional results in closed
or open fractures. External fixation is primarily indicated for open grade IIIb and IIIc
fractures with severe soft-tissue injury. Additional secondary procedures are often
necessary, and when used for definitive fracture treatment, external fixation results in a
67% adequate functional result. The role of IM nailing is not clearly defined; however,
several implant options are currently available.16,17,18 Images after surgery are depicted
below.




Anteroposterior radiograph of a completed open reduction and internal fixation
(ORIF) of a middle third forearm fracture.




Anteroposterior radiograph of a completed fixation of a middle third forearm
fracture.
Lateral radiograph of a completed open reduction and internal fixation (ORIF) of a
middle third forearm fracture.


Restoration of the radial bow is the goal and is best achieved with stable internal fixation
techniques using 3.5-mm compression plates. The ulna is fairly straight and may be treated
with relative stability techniques.




Surgical approaches
Displaced fractures of the middle forearm in the adult are best treated with open surgical
reduction and internal fixation. The surgeon should be familiar with several surgical
approaches to the forearm because of the wide variety of fracture patterns that can occur.
The soft-tissue injury of closed and open fractures may dictate the exposure utilized, with
the length of the incision being determined by the fracture.

The diaphysis of the middle third of the radius may be exposed using the Henry approach or
the Thompson approach.

The Henry approach

The Henry approach, also known as the anterior approach or the volar approach, is
extensile and may be extended from the wrist to the elbow. This approach exposes the flat
tension surface of the radius, which is ideal for plate application. In addition, fasciotomies
for compartment syndromes are best implemented through this approach. The incision
begins 1 cm lateral to the biceps insertion and extends distally to the radial styloid. The
fascia is split, and the brachioradialis and the extensor wad (the extensor carpi radialis
brevis and longus) are radially retracted. The radial artery, which must be protected, is
identified as it extends along the flexor digitorum superficialis. The radial sensory nerve may
be found on the undersurface of the brachioradialis. The median nerve can be found
between the palmaris longus and the flexor carpi radialis. The flexors and the median nerve
can be retracted toward the ulna, and the middle third of the radius is exposed.

The Thompson approach
An alternative means of exposing the radius may be performed using a Thompson, or
dorsolateral, approach. This approach is best suited for exposure of the proximal and middle
thirds of the radius; however, it is not an extensile approach. The incision begins at the
lateral epicondyle and extends along the extensor wad over the dorsolateral border of the
radius. The fascia is incised, and the interval is developed between the mobile wad and the
extensor digitorum, exposing the supinator muscle. In the proximal third of the exposure,
the PIN passes through the supinator muscle at right angles to the muscle fibers. The
forearm is supinated, protecting the PIN, and the insertion of the supinator is elevated,
exposing the subcutaneous tension surface of the radius.

The ulna approach

The ulna is exposed along the subcutaneous border between the flexor and extensor carpi
ulnaris. Depending on the fracture pattern, the extensor or flexor muscle is elevated from
the ulna in preparation for plating. The dorsal cutaneous branch of the ulnar nerve is found
6-8 cm proximal to the ulnar styloid and must be identified and protected.

Preoperative Details
A preoperative plan should be determined. The fracture is outlined on the radiograph, cut
out, reduced or realigned, and drawn on another sheet, with the definitive fixation placed in
the best position.

Depending on the fracture type and the soft-tissue injury, prepare the operating room staff
for the planned procedure. Be prepared to harvest iliac crest bone graft if necessary.
Primary bone grafting is controversial but is recommended when comminution is more than
33% of the bone circumference. Have available a 3.5-mm fracture reduction set, a
radiolucent hand table, a C-arm, and allograft bone graft, if necessary.

The plate that has gained widespread acceptance is the 3.5-mm dynamic compression
plate. The development of indirect reduction techniques and a more biologic approach to
plate fixation of forearm fractures has been enhanced by newer plate designs, such as the
limited contact dynamic compression plate. In most cases, a plate of adequate length,
applied with appropriate technique, is of sufficient strength to support functional load while
the fracture heals. At least 8 cortices above and below the fracture are usually required,
except in the case of a pure transverse fracture, which is effectively held with 6 cortices on
each side. In cases of comminution, 10- or 12-hole plates are typically required.

An external fixator may be necessary in high-energy and high-grade open fractures. The
choice of fixator is determined by the surgeon's experience and comfort.

The operative consent should be written in such a way that it covers all possibilities and
fixation options. Risks of the operative procedure must be thoroughly explained and
understood by the patient and, if present, his/her family.

Intraoperative Details
Most middle third forearm fractures are easily approached with the patient in the supine
position and the arm extended on an arm board or hand table. The surgical events are as
follows:
      History and physical examination findings should be reviewed for possible antibiotic
       allergies, and a broad-spectrum antibiotic should be administered prophylactically.
       Although support for prophylactic antibiotics is limited in the literature, 1 g of first-
       generation cephalosporin (Ancef) is usually administered preoperatively and
       continued for 3 doses postoperatively. Vancomycin 1 g IV or clindamycin 600 mg IV
       is administered to those patients with a penicillin allergy.
      Pad all upper and lower extremity bony prominences outside the surgical field (ie,
       the elbows, wrists, knees, peroneal areas, greater trochanters, heels).
      Apply the appropriately sized padded tourniquet to the patient.
      Use sterile prep and drape.
      Elevate the extremity and exsanguinate the arm; raise the tourniquet 100 mm Hg
       above systolic.
      The radial approach, volar or dorsal, exposes the radius. Reduce the radius fracture
       with sharp or dull fracture reduction forceps as the assistant applies longitudinal
       traction.
      Apply a compression plate, and place an interfragmentary compression screw
       through or outside the plate, as the fracture dictates.
      A C-arm radiograph can be used quickly to check alignment and screw placement.
      Approach the subcutaneous border of the ulna with the arm flexed 90 º.
      Reduce the ulna fracture.
      Apply a small-fragment 3.5-mm dynamic compression plate or a limited-contact
       dynamic compression plate. A minimum of 6 cortices above and below the fracture
       site is indicated. Whenever possible, interfragmentary compression screw fixation
       should be performed, either through or outside the plate fixation.
      Check with the C-arm as needed.
      Irrigate wounds.
      Perform a bone graft if necessary. Although controversial, bone graft may be applied
       to grossly comminuted fractures. Retrospective comparison of comminuted forearm
       fractures has led to questions regarding the need for acute bone grafting. No
       differences in healing rates and time to union are apparent in these small series,
       suggesting that routine bone grafting is not indicated. Larger, prospective studies are
       required. Should the surgeon decide to place supplemental autogenous bone graft,
       this may be harvested from the olecranon, the distal radius, and/or the drill bit on
       each screw placement. Care in bone graft placement is necessary to avoid violation
       of the interosseous membrane and to prevent synostosis.
      Release the tourniquet and obtain hemostasis. Drains may be used per the
       preference of the surgeon.
      Close the wound. If the tension is too great, leave the wound open and return in 2-3
       days for delayed primary closure.
      Apply sterile dressings and protect the forearm with a sugar-tong splint or a
       functional fracture brace for support.

Postoperative Details
The patient's neurovascular status and forearm swelling should be monitored for possible
compartment problems. The neurovascular status is monitored in the operating room and in
the postanesthesia recovery room. Beginning on postoperative day 1, a physical therapist is
consulted to assist in digital range of motion. To avoid hematoma formation, progressive
wrist and elbow motion are delayed for 3-5 days. If any question exists regarding the
stability of internal fixation or patient reliability, external functional bracing should be
instituted to provide support for the forearm skeleton—and still permit functional use of the
extremity—through a careful interosseous mold created by the splint.

Follow-up
Forearm rotation is initiated as the patient's comfort allows, often between the first and
second week postoperatively. The patient is monitored as an outpatient at 2 weeks, 6
weeks, 12 weeks, and 4-6 months postoperatively with anteroposterior and lateral
radiography. Activity modification should be limited to activities of daily living during
fracture healing, which should be completed by 3-4 months postoperatively. Once the
fracture is healed (as demonstrated radiographically), the patient may progressively return
to sports and resume a normal lifestyle.

Complications

Restoration of the radial bow is important to the functional outcome. Failure to restore the
radial bow to within 5% of the contralateral side results in a 20% loss of forearm rotation,
as well as loss of grip strength. Complications of forearm fractures include the following:

      Refracture after plate removal
      Nonunion
      Malunion
      Infection
      Neurovascular injury
      Compartment syndrome
      Radioulnar synostosis

The incidence of refracture of the forearm after plate removal is unknown but has been
reported to be 4-25%. Factors that contribute to refracture include premature plate removal
at less than 1 year, delayed union, nonunion, the use of 4.5-mm dynamic compression
plates, and poor surgical technique. Plate removal can be considered when cortical
remodeling under the plate is radiographically present, typically after 18 months. Forearm
protection after plate removal is recommended for 6 weeks, and a return to sports or other
activities is delayed for 3-4 months.

Forearm plate removal is not without risk, including infection and nerve injury.The incidence
of these complications is 10-20%, and plate removal is not routinely recommended.

Malunion and nonunion of forearm fractures have been occurring less commonly since the
use of compression plating became a standard treatment. With proper technique and a
compliant patient, the nonunion rate is approximately 2%.

Infection after operative treatment of forearm fractures is uncommon. The incidence of
infection in open fractures has been reported to be 0-3%. Acute infections require standard
treatment with irrigation and debridement, and the hardware should not be removed if the
fixation is stable. When the hardware is stable, it maintains length, rotation, and alignment
and assists in wound care. In late infections, treatment is similar, and plate removal may be
performed if the fracture is healed.

During the initial injury that causes a forearm fracture, neurovascular injury also may occur.
Vascular injuries usually involve 1 major artery and do not lead to loss of hand viability.
Nerve injuries are usually neuropraxias, and recovery occurs spontaneously. In complete
nerve transection, exploration and primary repair, delayed primary repair, or nerve
grafting is performed when appropriate. The results of nerve repair are variable depending
on the nature of the wound and the extent of the nerve injury. Iatrogenic nerve injury most
often involves a branch of the radial nerve. The PIN can be injured during the dorsal
approach, and the radial sensory nerve can be injured during the volar approach.

Compartment syndrome usually occurs in high-energy injuries but may occur in low-energy
injuries as well. A high index of suspicion is necessary, and expedient compartment releases
are performed (see the eMedicine article Compartment Syndrome, Upper Extremity).

A 0-11% (most commonly, 3%) incidence of radioulnar synostosis has been reported. Risk
factors include fracture of the radius and ulna at the same level, head injury, infection,
high-energy trauma, the single-incision surgical approach, bone graft within the
interosseous space, screws that are too long, and a 2-week – delayed operation. Bone
scanning should be used to monitor the maturity of the bony synostosis. Once the activity
has decreased, the synostosis can be resected within 1-2 years postfracture.

				
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