Open Reduction and Internal Fixation of Displaced Lateral Condyle Fractures of the Humerus

 

Chapter 2

Open Reduction and Internal Fixation of Displaced Lateral Condyle Fractures of the Humerus

Kristan A. Pierz and Brian G. Smith

 

DEFINITION

• Lateral condyle fractures refer to fractures of the lateral aspect of the distal humerus and may involve any or all of the following: metaphysis, physis, epiphysis, and articular surface.

• Fractures of the lateral condyle of the distal humerus account for 10% to 15% of all pediatric elbow fractures, second in frequency only to supracondylar distal humerus fractures.

• Nondisplaced fractures may hinge on the articular cartilage, making them more stable than their unstable, displaced counterparts.

  ANATOMY

• Proximally, lateral condyle fractures almost always include some portion of the posterolateral metaphysis and then propagate along the physis before exiting through or around the ossification center of the capitellum.

• The articular cartilage may or may not be violated.

• The extensor carpi radialis longus and brevis muscles and lateral collateral ligament typically remain attached to the distal fragment.

• Anterior and posterior portions of the elbow joint capsule may be torn if there is significant displacement.

• Milch classified lateral condyle fractures based on the distal portion of the fracture line (FIG 1).

  • Milch type I fractures (the less common) traverse the metaphysis and physis as well as extend across the ossification center of the lateral condyle.

  • Milch type II fractures (the more common) extend from the metaphysis, through the physis, and exit in the unossified trochlea, medial to the capitellum ossification center. Displacement of the trochlear crista allows lateral translation of the forearm and increases the instability of this pattern.

• It is difficult to apply the Salter-Harris classification system to lateral condyle fractures since portions of the distal humeral epiphysis may not yet be ossified.

  • A fracture propagating from the metaphysis through the physis and then through the capitellum ossification center (Milch I) is analogous to a Salter-Harris type IV fracture.

  • A fracture that extends from the metaphysis through the physis and exits through the unossified trochlea medial to the capitellar ossification center (Milch II) may appear radi-ographically analogous to a Salter-Harris type II fracture, but its involvement of the articular cartilage is analogous to Salter-Harris types III and IV.

• A numeric classification system identifies fractures based on displacement.

  • Stage I fractures involve the metaphysis and physis but do not violate the articular cartilage, thus limiting their ability to displace.

  • Stage II fractures cross the articular surface but are minimally displaced.

• Stage III fractures are displaced fractures that cross the metaphysis, physis, and articular surface, frequently resulting in rotation of the distal fragment (FIG 2).

PATHOGENESIS

• The typical mechanism for a lateral condyle fracture is a fall on an outstretched hand.

• Adduction of a supinated forearm with the elbow extended can result in avulsion of the lateral condyle.

• Axial load of the forearm combined with valgus force can also propagate a fracture through the lateral condyle.

• Lateral condyle fractures usually occur as isolated injuries, although elbow joint subluxation and radial head or olecranon fractures may be associated.

  NATURAL HISTORY

• The natural history of lateral condyle fractures depends on the initial fracture displacement as well as the long-term viability of the growing physis.

• Completely nondisplaced lateral condyle fractures may heal regardless of treatment.

• Nondisplaced fractures can displace over time if the articular cartilage is violated or if there is significant associated soft tissue injury.

• Delayed union can occur even in nondisplaced fractures and may be due to poor metaphyseal circulation, bathing of the fracture in synovial fluid, or tension on the condylar fragment by attached muscles.

• Fractures that heal in near-anatomic alignment can yield excellent functional and cosmetic outcomes.

 

A

B

 

FIG 1 • Milch classification of lateral condyle fractures is based on location. A. Type I fracture line passes through the ossific nucleus of the capitellum. B. Type II fracture line passes medial to the capitellar ossific nucleus into the trochlear groove.

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A B C

 

FIG 2 • Numeric classification of lateral condyle fractures is based on displacement. A. Stage I fractures are nondisplaced and do not violate the articular surface. B. Stage II fractures violate the articular surface but are minimally displaced (0 to 2 mm). C. Stage III fractures are displaced more than 2 mm and may be rotated.

 

• Lateral condyle fractures associated with lateral physeal arrest can result in valgus deformity and tardy ulnar nerve palsy.

• Lateral condyle fractures associated with central physeal arrest can result in a “fishtail” deformity due to continued growth medially and laterally but limited growth in between.

   

  PATIENT HISTORY AND PHYSICAL FINDINGS

• Most patients report a fall, either on an outstretched hand or from some height, resulting in pain and inability to fully move the elbow.

• It may be difficult to obtain a history from a young child; therefore, parents or caregivers may need to be questioned.

• The clinician should be patient during the physical examination. Young children may be very fearful. The clinician should ask the child to point to what hurts most, and this part should be examined last. This allows the clinician to establish the pa-tient’s trust and rule out other associated injuries.

• The clinician should look for obvious deformity, swelling, ecchymosis, and open wounds about the elbow.

• The clinician should assess for pulses and capillary refill.

• Sensation is assessed by comparison with the uninvolved side. Rather than stroking a finger and asking a young child, “Do you feel this?” the clinician can rub the same site on both hands and ask, “Does it feel the same or different?”

• Motor function is assessed by observing for spontaneous movement during the entire encounter. A scared child may refuse to move when asked by a physician but may demonstrate voluntary movement when asked by a parent or sibling. Being playful during the examination can help. For example, when testing for ulnar nerve function, asking a 5-year-old to show you how old he or she is may be more rewarding than asking the child to spread his or her fingers.

• The wrist and shoulder are palpated before touching the elbow.

• A single finger is used to gently palpate the olecranon, medial epicondyle, posterior humerus, lateral condyle, and radial head to try to localize the site of injury. Crepitus suggests displacement and instability of the fracture fragment.

• Increased motion during varus stress testing suggests instability of the fracture. Due to pain, however, this test can rarely

  be done on an awake child. It is often reserved for intraoperative assessment rather than preoperative diagnosis.

  IMAGING AND OTHER DIAGNOSTIC STUDIES

• Radiographs of a suspected lateral condyle fracture should include anteroposterior (AP), lateral, and internal oblique views (FIG 3A–C).

• Valgus and varus stress radiographs can provide information about the stability of the fracture. Since such films are poorly tolerated in an awake child, they are rarely obtained outside of the operating room.

• For nondisplaced or minimally displaced fractures, magnetic resonance imaging (MRI) can be used to determine whether the articular surface is violated (FIG 3D).

  • Such studies, however, are expensive, are rarely needed for surgical decision making, and frequently require sedation in young children, so they are not obtained routinely.

• Arthrograms can provide detail about the articular con-gruity of lateral condyle fractures but are typically reserved for intraoperative assessment (FIG 3E).

  DIFFERENTIAL DIAGNOSIS

• Contusion

• Lateral collateral ligament strain or sprain

• Radial head or neck fracture

• Supracondylar distal humerus fracture

• Transphyseal fractures

• Medial condyle fractures

• Proximal ulna or Monteggia fractures

• Elbow dislocation

• Child abuse

  NONOPERATIVE MANAGEMENT

• Nonoperative management of lateral condyle fractures is typically reserved for nondisplaced or minimally displaced (less than 2 mm) fractures.

• The upper extremity is immobilized in a long-arm splint or cast with the elbow flexed 90 degrees and the forearm in neutral.

  • Casts that are excessively heavy or short on the upper arm tend to slide down, thus increasing the risk of later displacement.

     

     

     

     

     

     

     

     

    A B C

     

    D

    E

     

     

    FIG 3 • AP (A), lateral (B), and internal oblique

     

     

    (C) radiographic images of lateral condyle fracture. D. Sagittal plane MRI showing lateral condyle fracture extending into joint with minimal displacement.

    E. Intraoperative arthrogram. Dye is tracking into the fracture site medial to the capitellum.

     

    • Follow-up radiographs should be obtained in 3 to 5 days to assess for further displacement.

    • If displacement occurs, operative treatment is indicated.

    • If the fracture remains nondisplaced, long-arm casting is continued for another week and then repeat radiographs are obtained.

      • If still nondisplaced, the fracture is maintained in a long-arm cast for 3 to 4 weeks or until there is radiographic evidence of fracture union.

    • Delayed union may occur, requiring up to 12 weeks of im-mobilization. Poor vascularization of the fracture fragment and bathing of the fragment in articular fluid may contribute to this phenomenon.

      SURGICAL MANAGEMENT

    • Surgery is recommended for lateral condyle fractures with more than 2 mm of displacement or rotational deformity that occurs acutely or during the early follow-up period of nonoperative treatment.

    • Closed techniques with percutaneous pinning are reserved for minimally displaced fractures with a congruous articular surface confirmed by arthrography.

    • Open surgery is required for displaced fractures.

      Preoperative Planning

    • Preoperatively, a careful neurovascular examination should be performed and documented. Fortunately, unlike supracondylar fractures, isolated lateral condyle fractures rarely have any associated neurovascular injury.

    • Plain radiographs, including AP, lateral, and internal oblique views, should be adequate to make the decision to operate.

    • Displacement of more than 2 mm indicates the need for surgical intervention.

  • Displacement on two or more views suggests the need for open treatment.

  • Displacement on only one view suggests that the fracture may be hinging on intact articular cartilage and may be treat-able by percutaneous techniques.

  • Fractures with borderline displacement (2 to 3 mm) may be better assessed under anesthesia, where stress radiographs or an arthrogram can guide treatment.

    Positioning

  • The patient is placed in the supine position on the operating table and general anesthesia is induced.

  • The child should be brought to the edge of the operating table to facilitate fluoroscopic imaging of the operative limb (FIG 4).

     

     

     

    FIG 4 • Positioning the patient on the edge of the table allows easy access for fluoroscopy. The base of the unit may be used as an arm table.

     

• Care must be taken to prevent the patient’s head from rolling off the table’s edge. Placing a foam doughnut under the head can provide stability.

• The receiving end of a standard fluoroscopy unit can be used as the operative table for the involved limb. Bringing the fluoroscopy unit up from the foot of the bed allows room for

  the surgeon and assistant to access the lateral side of the elbow.

  • Alternatively, a hand table may be used and the fluoroscopy unit can be brought in after draping.

• A sterile tourniquet is recommended to allow full access to the elbow after draping.

   

   

   

  TECHNIQUES

   

  CLOSED REDUCTION AND PERCUTANEOUS PINNING

  • This technique is reserved for minimally displaced (2 to 4 mm) fractures.

  • Fracture stability should be assessed under anesthesia with varus stress radiographs and arthrography.

  • Two divergent smooth pins are recommended. Although 0.062-inch Kirschner wires are usually adequate, 5/64-inch Steinmann pins may be used in larger children.

  • The first wire is placed through the skin into the lateral condyle to engage the metaphyseal fragment distally.

    • The wire should be directed from distal lateral to proximal medial, penetrating the cortex medially.

  • A second wire is then placed in a similar manner, diverging at the fracture site.

    • Increasing the distance between the wires at the fracture site increases stability (TECH FIG 1A).

• Wires may cross the ossification center of the capitellum to improve divergence (TECH FIG 1B,C).

• Occasionally, a third wire is needed. This wire is added if, after placing the first two wires, there is still motion at the fracture site when the elbow is varus stressed under fluoroscopy.

• The wires can be cut and bent 90 degrees outside of the skin.

• Sterile felt can be placed between the skin and the cut end of the wire. This helps prevent the cut end of the wire from digging into the skin during the postoperative swelling phase.

   

   

  A B

   

  TECH FIG 1 • A. Intraoperative fluoroscopic image showing two percutaneously placed Kirschner wires stabilizing a lateral condyle fracture. B,C. AP and lateral views of fracture treated with two divergent Kirschner

  C wires.

   

  TECHNIQUES

   

  OPEN REDUCTION AND INTERNAL FIXATION

  • Unstable fractures require open treatment. This includes acutely displaced fractures as well as originally nondisplaced fractures that displace during early follow-up.

    Exposure

  • The lateral Kocher approach is used, although the dissection is typically facilitated by the rent in the brachioradialis that leads directly to the lateral condyle.

  • A 5- to 6-cm curvilinear incision is used, with two thirds of the incision proximal and one third distal to the elbow joint (TECH FIG 2A).

  • The interval is between the brachioradialis and the tri-ceps down to the lateral humeral condyle. The anterior articular surface of the elbow joint is exposed by working from proximal to distal and retracting the soft tissues of the antecubital fossa anteriorly.

    • Although the fracture hematoma can obscure distinct muscular planes, a tear in the aponeurosis of the brachioradialis may lead directly to the fracture site.

  • Dissection is kept anterior. Care should be taken to avoid stripping any of the soft tissues from the posterior aspect of the fracture fragment while the soft tissues are elevated off the anterior distal humerus, since this contains the blood supply to the lateral condyle epiphysis (TECH FIG 2B).

  • Exposure is complete when the trochlear or medial extent of the fracture can be assessed anteriorly.

    Fracture Reduction

• The goal of reduction is to achieve a congruent articular surface without any step-off.

• Lifting the anterior soft tissues with a Zenker retractor or similar instrument can allow direct visualization and inspection of the articular surface.

  • A Zenker retractor is narrow and angled, which makes it useful for lifting and retracting the anterior soft tissues without unnecessary stretch (TECH FIG 3A).

  • A small finger or elevator can be placed into the anterior elbow joint to palpate the trochlear–capitellar junction.

  • A common kitchen fork can be a useful instrument in this case.

    • Bending the outer tines back decreases the width of the fork and allows the central tines to fit into a small wound.

    • The central tines can be used to engage the distal fragment, which is then rotated and pushed into position.

  • Gaps between the tines allow room for placement of Kirschner wires (TECH FIG 3B).

 

 

A

A

 

B B

 

TECH FIG 2 • A. Kocher-type lateral incision is marked by dotted line. X marks lateral condyle. * marks olecranon.

B. Dissection is carried out anteriorly to expose the articular surface.

 

TECH FIG 3 • A. The Zenker retractor is narrow and angled, making it ideal to elevate the anterior soft tissues. A pen is shown for reference. B. A sterilized standard kitchen fork can be a useful reduction tool.

 

 

 

 

TECHNIQUES

 

• Alternatively, a Kirschner wire can be placed into the distal fragment and used as a joystick to help control the reduction.

Fixation

• Once the fragment is reduced, a smooth Kirschner wire is advanced from the metaphyseal portion of the distal fragment, across the fracture site, and into the medial cortex proximal to the fracture.

• A second Kirschner wire (or the original joystick wire) can now be advanced across the fracture site into the medial cortex.

• The wires can be cut and bent 90 degrees outside the skin to facilitate easy removal in the office in about 4 to 6 weeks.

  • Alternatively, they can be cut very short and bent under the skin. This may decrease the risk of pin tract infection, but it requires a return to the operating room for pin removal (TECH FIG 4).

• If the wires are to be cut and bent outside the skin, the wires enter the skin through a separate stab site posterior to the incision.

  • If a wire needs to be placed through the incision, it can be cut and the posterior skin can be pulled up and over the sharp cut end before closure.

• Increasing the gap between the wires at the fracture site increases rotational control.

• In older children with a larger metaphyseal fragment, a compression screw can be used rather than wires.

  • The prominent screw head may be symptomatic after healing, however, thus requiring a return to the operating room for removal.

  • Compressive threads across immature cartilage can impede growth in younger children.

  • This technique, therefore, is usually reserved for delayed unions or nonunions.

• In many cases, closure of the lateral periosteum may be possible with sutures. Such closure may lessen the chance of lateral spur formation, add stability, and speed healing.

   

   

   

   

   

  TECH FIG 4 • After reduction and pinning, Kirschner wires may be cut and bent. Here they are to be buried under the skin.

   

  Nonoperative management

   

  Postoperative bone spur

   

  Postoperative swelling

   

  Delayed union and nonunion

   

  Cubitus valgus and tardy ulnar nerve palsy

   

  Cubitus varus

  • Follow-up radiographs should be obtained within 3 to 5 days.

  • Any loss of reduction suggests instability and prompts the need for operative intervention.

  • A posterior or posterolateral metaphyseal bone spur frequently forms postoperatively. This is best seen on lateral radiographs. The bony prominence may give the clinical appearance of cubitus varus. Fortunately, this tends to improve over time and rarely requires intervention. Warning the parents initially of the probability of the occurrence can reduce anxiety later.

  • Placing felt over the cut, bend ends of the wires onto the skin decreases the risk of skin swelling over or pressing into their sharp tips while in the cast.

  • Bivalving the cast decreases the risk of postoperative compartment syndrome.

  • This occurs more commonly in fractures treated nonoperatively.

  • Prolonged casting of up to 12 weeks may be needed.

  • If the fracture does not heal, open reduction with bone grafting may be necessary.

  • Premature closure of the lateral physis may lead to gradual deformity as the medial side continues to grow.

  • Anatomic reduction decreases the risk.

  • Follow-up radiographs can reveal the deformity.

  • Nerve symptoms can take years to develop; therefore, patients should be counseled about signs and symptoms of ulnar nerve stretch.

  • Unstable fractures treated nonoperatively can displace proximally and laterally, allowing the elbow to drift into a varus position.

  • Doing careful early follow-up and fixing unstable fractures should prevent this.

   

  PEARLS AND PITFALLS

   

  POSTOPERATIVE CARE

  • The arm is placed in a long-arm cast with the elbow flexed 90 degrees and the forearm in neutral to slight pronation.

  • If there is significant swelling, the cast can be bivalved in the operating room and overwrapped the following week.

  • Radiographs are obtained in 1 week to look for any loss of reduction.

  • Wires can usually be pulled in 4 to 6 weeks.

    • Authors have debated the exact timing. Although some have shown adequate healing by 3 weeks, a period of 4 to 6 weeks is generally required; the decision should be based on radiographic evidence of early callus.

  • Gentle early active range of motion is encouraged after wire removal.

  • A removable posterior splint can be made for children who will not comply with activity modifications.

  • Physical or occupational therapy is rarely needed in children but may be recommended for those who fail to show improved range of motion.

    OUTCOMES

  • Patients who are treated quickly and whose fractures heal in an anatomic position with no subsequent growth arrest can expect excellent (90%) function and range of motion. Approximately 10% have minor loss of extension (10 to 15 degrees) at 1 to 2 years.

  • Outcome studies following patients into adulthood are lacking.

  • Patients who are treated with open reduction at 3 or more weeks after fracture are at greater risk for loss of range of motion (about 34 degrees), premature physeal closure, valgus deformity, tardy ulnar nerve palsy, and avascular necrosis, thus emphasizing the need for early treatment.

    COMPLICATIONS

  • Pin tract infections can occur but usually resolve after wire removal and oral antibiotics.

  • Posterior or posterolateral metaphyseal bone spurs frequently form postoperatively and are best seen on lateral radiographs (FIG 5). Fortunately, these tend to smooth over time and are rarely symptomatic; thus, they usually require no treatment.

  • Delayed union and nonunion are more common with nonoperative treatment than with surgical treatment.

  • Malunion may occur in unstable fractures treated nonoperatively or in those with premature growth arrest.

  • Avascular necrosis is more common after operative treatment than nonoperative management and is likely due to excessive posterior stripping that disrupts the epiphyseal blood supply.

 

 

 

 

FIG 5 • Lateral radiograph showing postoperative bone spur projecting from posterior metaphysis.

 

• Tardy ulnar nerve palsy can develop slowly with progressive valgus deformity following premature growth arrest or nonunion.

   

  REFERENCES

  1. Bhandari M, Tornetta P, Swiontkowski MF. Displaced lateral condyle fractures of the distal humerus. J Orthop Trauma 2003;17:306–308.

  2. Cardona JI, Riddle RT, Kumar SJ. Displaced fractures of the lateral humeral condyle: criteria for implant removal. J Pediatr Orthop 2002;22:194–197.

  3. Flynn JC, Richards JF Jr, Saltzman RI. Prevention and treatment of nonunion of slightly displaced fractures of the lateral humeral condyle in children: an end-result study. J Bone Joint Surg Am 1975;57A:1087–1092.

  4. Gorgola GR. Pediatric humeral condyle fractures. Hand Clin 2006;22:77–85.

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  6. Jakob R, Fowles JV, Rang M, et al. Observations concerning fractures of the lateral humeral condyle in children. J Bone Joint Surg Br 1975;57:430–436.

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  8. Marzo JM, D’Amato C, Strong M, et al. Usefulness and accuracy of arthrography in management of lateral humeral condyle fractures in children. J Pediatr Orthop 1990;10:317–321.

  9. Milch H. Fractures and fracture-dislocations of the humeral condyles. J Trauma 1964;4:592–607.

  10. Sullivan JA. Fractures of the lateral condyle of the humerus. J Am Acad Orthop Surg 2006;14:58–62.

  11. Thomas DP, Howard AW, Cole WG, et al. Three weeks of Kirschner wire fixation for displaced lateral condylar fractures of the humerus in children. J Pediatr Orthop 2001;21:565–569.

  12. Wattenbarger MD, Gerardi DO, Johnston CE. Late open reduction internal fixation of lateral condyle fractures. J Pediatr Orthop 2002;22:394–398.