High Yield Topics

Forearm Fracture

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Ovid: 5-Minute Orthopaedic Consult

Editors: Frassica, Frank J.; Sponseller, Paul D.; Wilckens, John H.
Title: 5-Minute Orthopaedic Consult, 2nd Edition
> Table of Contents > Forearm Fracture

Forearm Fracture
Simon C. Mears MD, PhD
Darryl B. Thomas MD
Basics
Description
  • Forearm fractures involve the bones of
    the forearm (the radius and ulna), and sometimes the fractures are
    associated with elbow and wrist injuries.
  • In addition to the bone injury, soft-tissue injuries may include compartment syndrome, neurapraxia, and vascular damage.
  • Adults are more susceptible than children to more severe injuries.
  • Adults also require a more exact
    reduction because they have less potential for bony remodeling, and the
    fractures have no innate stability.
  • Children <12 years old do not require anatomic reduction of forearm fractures.
  • Classification:
    • Multiple classification schemes
    • Important factors include:
      • Fracture location
      • Fracture configuration
      • Presence of any radioulnar or radiohumeral articular involvement
      • Isolated ulna shaft fractures are called “nightstick”’ fractures because they often are caused by blunt trauma.
  • Synonyms: Monteggia fracture (forearm
    fracture with radial head dislocation); Galeazzi fracture (forearm
    fractures with distal radioulnar joint dislocation); Both-bone forearm
    fracture
Epidemiology
No particular gender predilection
Incidence
Drivers involved in motor vehicle accidents are more
likely to have forearm fractures than passengers, especially with front
airbag deployment (1).
Prevalence
  • In children, forearm fractures are a common result of skateboarding, roller skating, and scooter riding (2).
  • Forearm fractures occur most frequently in boys aged 11–14 years and in girls aged 8–11 years (3).
Risk Factors
  • High-energy trauma
  • Osteoporosis
  • Gunshot wounds
Etiology
  • High-energy trauma (e.g., motor vehicle accidents, fall from a height, crushing injury)
  • Low-energy trauma (e.g., falls)
Associated Conditions
  • Fractures of the ulna may be associated with dislocation of the radial head, an injury called the “Monteggia fracture.”
  • Fractures of the radius may be associated
    with dislocation of the distal radioulnar joint, an injury termed the
    “Galeazzi fracture.”
Diagnosis
Signs and Symptoms
  • Pain
  • Swelling
  • Loss of elbow or wrist motion
  • Deformity
  • Important: Assessment of forearm for skin and soft-tissue (neurovascular) compromise
Physical Exam
  • Careful examination of the entire involved extremity is mandatory, including:
    • Detailed neurologic and vascular evaluations
    • Assessment of the soft tissues
  • Compartments, anterior (flexor) and posterior (extensor), are checked for evidence of compartment syndrome.
  • Compartment pressure is measured if the forearm feels “tight” or if the patient displays pain out of proportion to the injury.
Tests
Imaging
  • AP, lateral, and oblique views of the
    wrist and the entire forearm, as well as AP and lateral views of the
    ipsilateral elbow, are mandatory.
    • Fracture of one bone often is accompanied by dislocation of another.
    • Radiographic signs of injury to the distal radioulnar joint include:
      • Fracture at the base of the ulnar styloid
      • Widening of the joint space on the AP view
      • Dislocation of the radius relative to the ulna on the lateral view
      • Radial shortening >5 mm
    • If the radial head is located properly, a
      line drawn through the radial head and shaft on any radiographic
      projection should align with the capitellum of the elbow.
    • If dislocation of the radial head is
      suspected clinically, a lateral radiograph of the elbow with the arm in
      supination may be helpful.
Pathological Findings
  • Most forearm fractures are either transverse or short oblique in configuration.
  • Comminution is variable (none to moderate).
Differential Diagnosis
Look for associated wrist or elbow dislocations and interosseous membrane rupture.
Treatment
General Measures
  • Pain medication should be administered
    only after a careful physical examination, including documentation of
    neurovascular status.
  • The forearm should be elevated, with application of ice to the fracture site to help to reduce swelling.
  • In general, closed treatment of
    diaphyseal fractures is best used for stable (<50% of the shaft
    diameter displaced), isolated fractures of the distal 2/3 of the ulna
    with ≤10° of angular deformity.
  • Fractures of the proximal 1/3 of the ulna
    and fractures of the distal 2/3 of the ulna with >10° angulation are
    best treated operatively.
  • Pediatric both-bone fractures do not remodel well and should be treated with surgery if reduction cannot be maintained (4).
  • In addition, most radial shaft fractures,
    except those that are nondisplaced, and virtually all both-bone forearm
    fractures in adults (prone to shortening and angulation) require
    surgical management.
  • Closed forearm fractures of 1 or both
    bones that are displaced minimally should be splinted in a neutral
    position to prevent additional displacement and possible neurovascular
    injury.
  • In general, forearm fractures with
    associated ligamentous injuries, either distally (wrist) or proximally
    (elbow), are unstable injuries.
    • They are not always evident initially, and a high index of suspicion is required.
    • These more severe injuries require early
      surgical intervention for reduction and stabilization of both the
      forearm fractures and the associated ligamentous injuries.
Special Therapy
Physical Therapy
Early ROM of the elbow and fingers is important to help to reduce soft-tissue scarring and to prevent contractures.

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Medication
Acetaminophen plus a mild narcotic are used most often in the immediate postinjury period for pain control.
Surgery
  • Surgical options include percutaneous
    Kirschner wire fixation, external fixation, intramedullary nailing, and
    plate and screw fixation.
  • Acute bone grafting is unnecessary (5).
  • For open fractures, irrigation and
    débridement with the administration of intravenous antibiotics should
    be performed on an emergent basis.
    • If the open wound is not massively contaminated, the fractures are stabilized after débridement.
    • With massive contamination, fixation is performed in a delayed fashion.
  • Radial and ulnar fractures usually are stabilized rigidly with 3.5-mm dynamic compression plates.
  • Locking plates seem to have no advantages compared with nonlocking plates (6).
  • Pediatric fractures may be treated with plating or with intramedullary nailing.
    • Results with intramedullary nail fixation seem to be superior (7,8).
Follow-up
Prognosis
  • In general, most nondisplaced or
    minimally displaced fractures in children who undergo closed treatment
    heal well, with good return of forearm function (9).
  • Minimally displaced isolated ulna fracture have excellent results when treated with functional bracing (10).
  • The prognosis in adults with displaced fractures of the radius and ulna and closed treatment is poor.
  • For fractures treated with open reduction and rigid internal fixation, the prognosis for achieving union is ~95% (5).
  • Because rigid fixation allows early ROM,
    patients who have no associated severe soft-tissue injuries should
    experience only mild loss of forearm rotation.
Complications
  • Nonoperative treatment:
    • Decreased ROM (supination and pronation)
    • Synostosis (fusion of the radius and ulna)
    • Malunion (defined as any fracture healing with >20° of angulation or 1 cm of shortening) leads to loss of forearm motion (11).
    • Nonunion
  • Operative treatment complications include (in addition to those for nonoperative treatment):
    • Late infections
    • Iatrogenic nerve injuries
    • Vascular injuries
    • Loss of fixation
  • Compartment syndrome:
    • Compartment syndrome is a risk after any treatment.
    • It is manifested by exquisite pain on passive stretch of the digits.
    • Constrictive dressings should be released down to the skin at the 1st symptom or sign of compartment syndrome.
      • If pain is not improved, compartment pressure should be measured.
      • Confirmation of the diagnosis requires emergent fasciotomy of the forearm.
Patient Monitoring
  • Follow-up care should be arranged within
    1 week after injury for repeat physical examination and repeat
    radiographs before and after the application of a cast, to verify
    fracture position when cast treatment is chosen.
  • Additional follow-up every 2–3 weeks then
    is necessary to assess healing of the fracture site and to guide early
    ROM of the fingers and elbow.
  • Healing of closed forearm fractures usually takes 4–6 weeks for a child and 6–12 weeks for an adult.
References
1. Conroy
C, Schwartz A, Hoyt DB, et al. Upper extremity fracture patterns
following motor vehicle crashes differ for drivers and passengers. Injury 2006;Epub (doi:10.1016/j.injury.2006. 03.017):1–8.
2. Zalavras C, Nikolopoulou G, Essin D, et al. Pediatric fractures during skateboarding, roller skating, and scooter riding. Am J Sports Med 2005;33:568–573.
3. Khosla
S, Melton LJ III, Dekutoski MB, et al. Incidence of childhood distal
forearm fractures over 30 years: a population-based study. JAMA 2003;290:1479–1485.
4. Johari AN, Sinha M. Remodeling of forearm fractures in children. J Pediatr Orthop B 1999; 8:84–87.
5. Wright
RR, Schmeling GJ, Schwab JP. The necessity of acute bone grafting in
diaphyseal forearm fractures: a retrospective review. J Orthop Trauma 1997;11:288–294.
6. Leung
F, Chow SP. A prospective, randomized trial comparing the limited
contact dynamic compression plate with the point contact fixator for
forearm fractures. J Bone Joint Surg 2003;85A:2343–2348.
7. Fernandez
FF, Egenolf M, Carsten C, et al. Unstable diaphyseal fractures of both
bones of the forearm in children: plate fixation versus intramedullary
nailing. Injury 2005;36: 1210–1216.
8. Jubel
A, Andermahr J, Isenberg J, et al. Outcomes and complications of
elastic stable intramedullary nailing for forearm fractures in
children. J Pediatr Orthop B 2005;14:375–380.
9. Zionts
LE, Zalavras CG, Gerhardt MB. Closed treatment of displaced diaphyseal
both-bone forearm fractures in older children and adolescents. J Pediatr Orthop 2005;25:507–512.
10. Sarmiento A, Latta LL, Zych G, et al. Isolated ulnar shaft fractures treated with functional braces. J Orthop Trauma 1998;12:420–423.
11. Dumont CE, Thalmann R, Macy JC. The effect of rotational malunion of the radius and the ulna on supination and pronation. J Bone Joint Surg 2002;84B:1070–1074.
Miscellaneous
Codes
ICD9-CM
813.8 Forearm fractures
Patient Teaching
Patients should be told about the potential for loss of
pronation and supination of the forearm, depending on the severity of
the initial injury and the final angulation at the fracture site.
FAQ
Q: How long does a forearm fracture take to heal?
A: Forearm fractures in adults treated with plating take ~3–4 months to heal.

Q: Should plates be removed after healing?
A: Unless residual pain occurs, plates should be left intact. The reported risk of refracture after plate removal is 3–25%.

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