CLASSIFICATION 

DESCRIPTIVE

Clavicle fractures can be classified according to anatomic description, including location, displacement, angulation, pattern (e.g., greenstick, oblique, transverse), and comminution.

ALLMAN

Group I: fracture of the middle third (80%). This is the most common fracture in both children and adults; proximal and distal segments are secured by ligamentous and muscular attachments (Fig. 11.1).

FIGURE 11.1 Radiograph of a displaced middle third clavicle fracture.

Group II: fracture of the distal third (15%). This is subclassified according to the location of the coracoclavicular ligaments relative to the fracture (Fig. 11.2):

Type I: Minimal displacement: interligamentous fracture between the conoid and trapezoid or between the coracoclavicular and AC ligaments; ligaments still intact

Type II: Displaced secondary to a fracture medial to the coracoclavicular ligaments: higher incidence of nonunion

IIA: Conoid and trapezoid attached to the distal segment

IIB: Conoid torn, trapezoid attached to the distal segment

Type III: Fracture of the articular surface of the AC joint with no ligamentous injury: may be confused with first-degree AC joint separation

FIGURE 11.2 Classification of group II clavicle fractures. Type I: Fracture is nondisplaced. Type IIA: Both conoid and trapezoid ligaments are on distal segment, and proximal segment without ligamentous attachments is displaced. Type IIB: Conoid ligament is ruptured, trapezoid ligament remains attached to the distal segment, and proximal fragment is displaced. Type III: Distal clavicle fracture, involving only the articular surface of the AC joint; no ligamentous disruption or displacement occurs. These fractures present as late degenerative changes of the joint. (Adapted from Sajadi KR. Clavicle fractures: epidemiology, clinical evaluation, imaging, and classification. In: Ianotti JP, Miniaci A, Williams GR Jr, et al., eds. Disorders of the Shoulder: Diagnosis and Management: Shoulder Trauma. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2014:99–107.)

Group III: fracture of the proximal third (5%). Minimal displacement results if the costoclavicular ligaments remain intact. It may represent epiphyseal injury in children and teenagers. Subgroups include:

Type I: Minimal displacement

Type II: Displaced

Type III: Intra-articular

Type IV: Epiphyseal separation

Type V: Comminuted

ORTHOPAEDIC TRAUMA ASSOCIATION CLASSIFICATION OF CLAVICLE FRACTURES

See Fracture and Dislocation Classification Compendium at:

https://ota.org/research/fracture-and-dislocation-compendium

TREATMENT

NONOPERATIVE

Most minimally displaced clavicle fractures can be successfully treated nonoperatively with some form of immobilization.

Comfort and pain relief are the main goals. A sling has been shown to provide the same results as a figure-of-eight bandage, providing more comfort and fewer skin problems. The goals of the various methods of immobilization are as follows:

To support the shoulder girdle, raising the lateral fragment in an upward, outward, and backward direction (sling)

To depress the medial fragment (figure of eight)

To maintain some degree of fracture reduction (both)

To allow for the patient to use the ipsilateral hand and elbow

Regardless of the method of immobilization utilized, some degree of shortening and deformity usually result.

In general, immobilization is used for 4 to 6 weeks.

During the period of immobilization, active range of motion of the elbow, wrist, and hand should be performed.

OPERATIVE

The surgical indications for midshaft clavicle fractures have become more standard in the past 20 years.

The accepted indications for operative treatment of acute clavicle fractures are open fracture, associated neurovascular compromise, and skin tenting with the potential for progression to open fracture.

Controversy exists over management of midshaft clavicle fractures with substantial displacement (more than 100%), comminution (Z deformity), and shortening (>1 to 2 cm).

Although most displaced midshaft fractures will unite, studies have reported shoulder dysfunction and patient dissatisfaction with the resulting cosmetic deformity.

There is also more recent evidence that functional outcome may be improved in some of these patients with surgical treatment. Furthermore, the presence of a malunion may portend inferior function.

Controversy also exists over management of type II distal clavicle fractures.

Some authors have indicated that all type II fractures require operative management due to high rate of nonunion.

Others report that if the bone ends are in contact, healing can be expected even if there is some degree of displacement. In this situation, nonoperative management consists of sling immobilization and progressive range of shoulder motion.

Operative fixation may be accomplished via the use of:

Plate fixation: This is placed either on the superior or on the anteroinferior aspect of the clavicle.

Plate and screw fixation requires a more extensive exposure than intramedullary devices but has the advantage of more secure fixation counteracting tensile forces. Plate and screw fixation may be prominent, particularly if placed on the superior aspect of the clavicle.Adjunctive suture fixation (substitution) of the coracoclavicular ligaments may be helpful for distal fractures with limited area for screw purchase.

Newer low-profile implants and/or anteroinferior placement may preclude this finding.Intramedullary fixation: usually placed in retrograde fashion through the lateral fragment and then in anterograde fashion into the medial fragment or antegrade as a flexible implant that is then stiffenedUse of intramedullary fixation requires frequent radiographic follow-up to monitor the possibility of hardware migration and a second procedure for hardware removal.Older intramedullary pins are prone to skin erosion at the hardware insertion site laterally. Historically, these implants have been reported to be associated with complications in up to 50% of cases.

Operative treatment of type II distal clavicle fractures consists of reducing the medial fragment to the lateral fragment. This is accomplished by using either coracoclavicular fixation (Mersilene tape, sutures, wires, or screws) or fixation across the AC joint, through the lateral fragment and into the medial fragment (lateral clavicle plates).

COMPLICATIONS

Neurovascular compromise: This is uncommon and can result from either the initial injury or secondary to compression of adjacent structures by callus and/or residual deformity.

Subclavian vessels are at risk with superior plating.

Malunion: This may cause a bony prominence, and resultant shortening may be associated with poorer Disabilities of the Arm, Shoulder and Hand (DASH) scores at 1 year.

Nonunion: The incidence of nonunion following clavicle fractures ranges from 0.1% to 13.0%, with 85% of all nonunions occurring in the middle third. Factors that have been implicated in the development of nonunions of the clavicle include:

Severity of initial trauma (open wound)

Extent of initial displacement of fracture fragments Soft tissue interposition

Refracture

Inadequate period of immobilization Primary open reduction and internal fixation

Posttraumatic arthritis: This may occur after intra-articular injuries to the sternoclavicular or AC joint.

Intramedullary Fixation of Clavicle Fractures

DEFINITION

■    The clavicle is one of the most commonly fractured bones.

■    The site on the clavicle most often fractured is the middle third.9

■    The  midclavicular  region is the thinnest and  narrowest portion of the bone.

■    It is the only area not supported by ligament or muscle attachments.

■    It represents a transitional region of both cross-sectional anatomy and curvature.

■    It is the transition point between the lateral part, with a flatter cross section, and the more tubular medial.

■   Because  of the clavicle’s S shape, an axial load creates a very high  tensile force along  the anterior midcortex.  (Axial  load makes a virtual right angle at midclavicle.)

ANATOMY

■    The clavicle is the only long bone to ossify by a combination of intramembranous and endochondral ossification.6

■    Its  configuration  is  S-shaped,  a  double  curve; the medial curve is apex anterior and the lateral curve is apex posterior (FIG  1A).

■    The larger medial curvature widens the space for the neu-

rovascular structures, providing bony protection.

■    The clavicle is made up of very dense trabecular bone, lack- ing a well-defined medullary canal.

■    The cross-sectional anatomy gradually changes from flat lat- erally,  to  tubular  in  the midportion,  to  expanded  prismatic medially.

■    The clavicle is subcutaneous throughout, covered by the thin platysma muscle.

■    The supraclavicular nerves that provide sensation to the over- lying skin of the clavicle are found deep to the platysma muscle.

■    Very strong capsular and extracapsular ligaments attach the medial end to the sternum and first rib and the lateral end to the acromion and coracoid.

■    Proximal  muscle attachments include the sternocleidomas- toid,  pectoralis major,  and subclavius. Distal  muscle attach- ments include the deltoid and trapezius (FIG  1B).

■    The  clavicle  functions  by  providing  a  fixed-length  strut

through which the muscles attached to the shoulder girdle can generate and transmit large forces to the upper extremity.

PATHOGENESIS

■    The mechanism of clavicle fractures in the vast majority is a direct injury to the shoulder.10   Stanley and associates studied

106 injured patients; 87%  had fallen onto the shoulder, 7% were injured by a direct blow on the point of the shoulder, and only 6% reported falling onto an outstretched hand.

■    Stanley suggests that in the patients who described hitting the ground  with  an  outstretched hand,  the shoulder became the next contact point with the ground, causing the fracture. Stanley

Articular cartilage (AC joint)

stated that a compressive force equivalent to body weight would exceed the critical buckling load to cause the clavicle fracture.

NATURAL HISTORY

■    In the 1960s, both Neer7  and Rowe9  published large series of midclavicle fractures, showing very low nonunion rate (0.1% and 0.8%)  with closed treatment and a higher nonunion rate (4.6% and 3.7%) with operative treatment.

■    More  recent studies have  shown  that  nonunion  is  more common then previously recognized and that a significant per- centage of patients with nonunion are symptomatic.

■    Malunion  with shortening greater than 15 to  20 mm has also  been shown  to  be  associated with  significant  shoulder dysfunction.

■    McKee   and  colleagues5   identified 15  patients with  mal-

union of the midclavicle after closed treatment. All  patients had shortening of  more than 15 mm,  all were symptomatic and unsatisfied, and all underwent corrective osteotomy. Postoperatively all 15 patients improved in terms of function and satisfaction.

■    Hill  and associates4 reviewed 52 completely displaced mid-

shaft clavicle fractures and found that shortening of more than

20 mm had a significant association with nonunion and unsat- isfactory results.

■    Eskola  and  coworkers3   reported on  89  malunions  of  the

midclavicle, showing that shortening of more than 15 mm was associated with shoulder discomfort and dysfunction.

PATIENT HISTORY AND PHYSICAL FINDINGS

■    The diagnosis is usually straightforward and is based on ob- taining the mechanism of injury from a good history.

■    On  visual inspection the examiner will  frequently see no- table swelling or ecchymosis at the fracture site and possibly deformity of the clavicle, with drooping of the shoulder downward  and  forward  if  the  fracture is  significantly  dis- placed.  The  skin is inspected for  tenting at the fracture site and characteristic bruising and abrasions that might suggest a direct blow or seatbelt shoulder strap injury (FIG  2A,B).

■    Palpation over the fracture site will reveal tenderness, and

gentle manipulation  of  the upper extremity or clavicle itself may reveal crepitus and motion at the fracture site.

■    The amount of shortening is identified by clinically measur- ing the distance of  a straight line (in centimeters) from both acromioclavicular joints to  the sternal notch  and noting the difference (FIG  2C).

■    It is important to perform a complete musculoskeletal and

neurovascular examination of the upper extremity and auscul-

FIG 3 • Radiographs of the same displaced left  clavicle  fracture viewed from a standard AP projection (A) and a 45-degree cephalic tilt  projection (B).

tation of the chest to identify the rare associated injuries; these are more closely related to high-energy injuries.

■    Rib and scapula fracture

■    Brachial plexus injury (usually traction to upper cervical root)

■    Vascular  injury (subclavian artery or vein injury associ- ated with scapulothoracic dissociation)

■    Pneumothorax and hemothorax

IMAGING AND OTHER DIAGNOSTIC STUDIES

■    Two  orthogonal  radiographic projections are necessary to determine the fracture pattern and displacement, ideally 45- degree cephalic tilt and 45-degree caudad tilt views.

■    Usually  a  standard  anteroposterior (AP)  view  and  a  45- degree cephalic tilt (FIG  3) view are adequate.

■    In practice, a 20- to 60-degree cephalic tilt view will min-

imize interference of thoracic structures.

■    The film should be large enough to include the acromioclav- icular and sternoclavicular joints, the scapula,  and the upper lung fields to evaluate for associated injuries.

■    An  AP  view of  bilateral clavicles on a wide cassette to in- clude the acromioclavicular joints and sternum is fairly helpful in determining the amount  of  shortening; however, this is a multiplanar deformity and a CT  scan would have greater ac- curacy, although it is rarely required.

 

FIG 2 • A,B. Anterior and posterior photographs of a displaced right clavicle  fracture showing deformity of the clavicle and drooping of the shoulder girdle downward and forward. C.  Clinical picture of a displaced right clavicle  fracture, showing 3.5 cm of shortening, measured from the sternal notch to the acromioclavicular joint.

 

DIFFERENTIAL DIAGNOSIS

■    Sprain of acromioclavicular joint

■    Sprain of sternoclavicular joint

■    Rib fracture

■    Muscle injury

■    Contusion

■    Hematoma

■    Kehr sign: referred pain to the left shoulder from irritation of the diaphragm, signaled by the phrenic nerve. Irritation may be  caused  by  diaphragmatic  or  peridiaphragmatic  lesions, renal calculi, splenic injury, or ectopic pregnancy.

NONOPERATIVE MANAGEMENT

■    If the clavicle fracture alignment is acceptable, generally a simple configuration with less than 15 mm of shortening, then any of a number of methods of supporting the upper extrem- ity are adequate, including a figure 8 bandage, sling, sling and swathe, Sayre bandage, Velpeau dressing, and benign neglect, just to name a few.

■    Nordqvist and colleagues8  reported on 35 clavicle fracture

malunions with shortening of  less than 15 mm.  They  were all treated nonoperatively in a sling. All  35 had normal mobility, strength, and function compared to the normal shoulder.

■    A  prospective, randomized study2  comparing sling versus

figure 8 bandage showed that a greater percentage of patients were dissatisfied with  the figure 8  bandage,  and  there was no  difference in  overall  healing  and  alignment.  The  study concluded that the figure 8 bandage does little to obtain reduction.

SURGICAL MANAGEMENT

■    Indications for operative treatment of acute midshaft clavi- cle fractures are as follows:

■    Open fractures

■    Fractures with neurovascular injury

■    Fractures with severe associated chest injury or multiple trauma: patients who require their upper extremity for transfer and ambulation

■    “Floating  shoulder”

■    Impending skin necrosis

■   Severe   displacement: possibly 15 to 20 mm of shortening

■    In  a  multicenter, randomized,  prospective clinical  trial  of displaced midshaft  clavicle fractures, Altamimi  and  McKee1 showed that operative fixation compared to nonoperative treatment improved functional outcome and had a lower rate of both malunion and nonunion.

■    Potential advantages of intramedullary fixation of the clavi- cle are as follows:

■    Less soft tissue stripping and therefore potentially better healing

■    Smaller incision

■    Better cosmesis

■    Easier hardware removal

■    Less weakness of bone after hardware removal

■    Potential  disadvantages of  intramedullary  fixation  of  the clavicle are as follows:

■    Less ability to resist torsional forces

■    Skin breakdown from prominence distally

■    Pin breakage

■    Pin migration

■    Newer  designs and  techniques prevent pin  migration  by placing a locking nut on the lateral end and technically avoid- ing penetration of the medial fragment cortex.

Preoperative Planning

■    After the decision has been made to fix  a clavicle fracture, one must evaluate whether the fracture pattern is amenable to intramedullary pin fixation.

■    A simple fracture pattern in the middle third of the bone is ideal.

■    The fracture should not extend past the middle third of the bone.

■    Comminution  and butterfly fragments (usually anterior) are common and do not preclude intramedullary fixation  as long as the medial and distal main fragments have cortical contact.

Positioning

■    There are two good options for patient positioning that fa- cilitate use of an image intensifier or C-arm device, which will aid you during pin placement.

■    The patient can be placed supine on a Jackson  radiolucent surgical table so the C-arm  can be brought in perpendicular from the opposite side of the table, which is out of the way of the surgeon (FIG  4A,B).

FIG 4 • A,B. The patient is placed supine on  a Jackson radiolucent surgical table. A 1-L bag is placed under the affected shoul- der, medial to the scapula, and the arm  is prepared free and placed in an  arm  holder to aid  in fracture reduction. The C-arm can  be  brought in perpendicular from the opposite side  of the table, which is out of the way  of the surgeon and facilitates getting orthogonal radiographic views  of the fracture: 45-degree caudad tilt  view  (A) and 45-degree cephalic tilt  view

(B). C,D. Alternatively, the patient is placed in the beach chair  position on  the OR table, using a radiolucent shoulder-position-

ing  device. C.  The arm  is prepared free and placed in an  arm  holder to facilitate fracture reduction. The C-arm  is brought in from the head of the bed with the gantry rotated  upside down and slightly away from the operative shoulder and oriented with a cephalic tilt.  D.  The same beach chair  positioning shown sterilely draped.

 

■    A 1-L bag is placed under the affected shoulder, medial to the scapula, to aid in fracture reduction.

■    The arm is also prepared free and placed in an arm holder to facilitate fracture reduction.

■    This is our preferred method due to the ease and speed of the set-up and the ease of  getting orthogonal  radiographic views of  the  fracture  (45-degree cephalic  and  caudad  tilt views).

■    The other option is placing the patient in the beach chair po- sition on the OR table, using a radiolucent shoulder- positioning device (FIG  4C,D).

■    The C-arm is brought in from the head of the bed with the

gantry  rotated  upside  down  and  slightly  away  from  the operative shoulder and oriented with a cephalic tilt.

■    The arm is also prepared free and placed in an arm holder to facilitate fracture reduction.

INCISION AND DISSECTION

■            Mark   out the clavicle,   fracture site,   and  surrounding anatomy (TECH FIG 1A).

■            Use  the C-arm  to identify the appropriate position for

the incision, which should be  over  the distal end of  the medial fragment, in the Langer lines  of  the normal skin crease around the neck  (TECH FIG 1B).

■            Make an incision of about 2 to 3 cm over  the fracture site.

■            Divide  the subcutaneous fat down to the platysma mus- cle using electrocautery (TECH FIG 1C).

■            Although there is  usually very  little subcutaneous fat,

gently make full-thickness flaps  to include skin and sub- cutaneous tissue around the entire incision to facilitate exposure.

■            Bluntly  split  the platysma muscle in  line  of  its  fibers to

identify, protect, and retract the underlying supraclavic-

ular   nerves; its  middle branches are   frequently found near the midclavicle (TECH FIG 1D,E).

■            The  fracture site   is  then  usually easily   identifiable  in

acute injuries because the periosteum is disrupted and usually requires no  further division.

■            Remove  any   debris, hematoma,  or  interposed  muscle

from the fracture site.

■            If there are  butterfly fragments, be  careful to keep any soft  tissue attachments.

TECH FIG 1 • A.  Displaced right clavicle  fracture, showing the clavicle  and fracture site  marked out. B.  A skin incision of about

2 to 3 cm is made over  the distal end of  the medial clavicular fragment,  in the Langer lines  of  normal skin  creases around the neck.  C.  Incision  over  a clavicle  fracture site,  showing full-thickness flaps  to include skin and subcutaneous tissue around the en- tire  incision. This exposes the fascia  that covers  the platysma muscle. D.  Skin incision over  a displaced clavicle  fracture, with un- derlying platysma muscle and the middle supraclavicular nerves. E.  Intraoperative photo showing the platysma muscle bluntly split  in the line  of its fibers to identify an  underlying supraclavicular nerve, which is under the clamp. The fracture site  is usually easily  identifiable in acute injuries because the periosteum is disrupted and usually requires no  further division; as shown here, the medial clavicular fragment  is easily seen. (B,D: Courtesy of Steven B. Lippitt, MD.)

CLAVICLE PREPARATION

■            The   following technique  uses   a   modified  Hagie pin called the Rockwood Clavicle  Pin  (DePuy  Orthopaedics, Warsaw, IN) (TECH FIG 2A).

■            Use a bone-reducing clamp or towel clip to grab and el-

evate the medial clavicular fragment  through  the inci- sion  (TECH FIG 2B).

■            Size the diameter of the canal with the appropriate-size

drill  bit;  the C-arm  can  be  useful to judge canal fill and orientation of the drill.

■       The fit  should be  snug to maximize fixation, but not

too tight, to prevent splitting the bone.

■            Attach the chosen drill to the T-handle and ream out the intramedullary canal without penetrating the anterior cortex (TECH FIG 2C–E).

■            Next,   attach  the  appropriate-sized tap  (that  corre-

sponds to the drill  size)  to the T-handle and tap the

intramedullary canal  to  the  anterior  cortex  (TECH FIG 2F,G).

■            Elevate the lateral clavicular fragment through  the inci- sion; this can be facilitated by externally rotating the arm.

■            Use the same drill  bit  attached to the T-handle to ream

out the lateral fragment, but this   time,  under  C-arm guidance, penetrate  the  posterolateral cortex of   the clavicle  (TECH FIG 2H,I).

■       The   drill   should  exit   posterior and medial to the

acromioclavicular joint capsule (TECH FIG 2J).

■      To prevent the pin  nuts from being too prominent, make sure  the drill does not exit  in the upper half  of the posterolateral clavicle.

■            Attach the appropriate-sized tap to the T-handle and tap

the intramedullary canal of  the lateral fragment (TECH FIG 2K).

TECH FIG 2 • A.  The Rockwood Clavicle Pin instrument set  by DePuy  Orthopaedics, Warsaw, IN, which is a modified Hagie pin.  B. A bone-reducing clamp is used to elevate the medial clavicular fragment through the incision. C–E. The chosen drill is attached to a T-handle and the intramedullary canal of  the medial clavicular fragment is reamed without penetrating the anterior cortex. F,G. An appropriate-sized tap is attached to a T-handle and the intramedullary canal of  the medial clavicular fragment  is tapped to the anterior cortex. H,I.  The chosen drill is attached to a T-handle and the intramedullary canal of the lateral clavicular fragment  is reamed out, penetrating the posterolateral cortex under direct C-arm  guidance. (continued)

                                                                               K

TECH FIG 2 • (continued) J. When drilling out the posterolateral cortex of the lateral clavicular fragment, the drill should exit posterior and medial to the acromioclavicular joint capsule. To prevent the pin nuts from being too prominent, the drill  should not exit  in the upper half  of  the posterolateral clavicle.  K. The  appropriate- sized  tap is attached to the T-handle and the intramedullary canal of the lateral fragment is tapped. (C,H,J,K: Courtesy of Steven B. Lippitt, MD.)

PIN  INSERTION AND FRACTURE REDUCTION

■            Remove the nuts from the pin  assembly and attach the T-handle using a Jacobs chuck  to the medial end of the clavicle  pin.

■       This is the end with the large threads.

■       Never  tighten the chuck  over  the machined threads at either end.

■            Continue firmly  holding the lateral fragment while pass-

ing  the trocar end (lateral end) of  the clavicle  pin  into the intramedullary canal, out the previously drilled hole in the posterolateral cortex (TECH FIG 3A).

■            Once  you  are  just  through the cortex, make a small  inci-

sion  over  the palpable tip.

■            Bluntly  dissect the subcutaneous tissue with a hemostat until the tip  of  the pin  can  be  felt, and then place the

hemostat or  a  small  elevator under the tip  of  the pin to  facilitate the  pin’s   passage through  the  incision (TECH FIG 3B).

■       Drill  the  pin   out  laterally until  the  large  medial

threads engage the lateral fragment.

■            Now  switch the T-handle to the lateral end of  the pin and retract the pin   into the  lateral fragment (TECH FIG 3C,D).

■            Reduce the fracture by lifting the arm, and pass  the pin

into the medial fragment.

■      Use   the  C-arm   to  ensure that  the  pin   advances correctly down  the  line   of   the  medial fragment and that all  the medial threads cross  the fracture site.

TECH FIG 3  • A.  The  surgeon continues firmly  holding the lateral fragment while passing the trocar end (lateral end) of the clavicle  pin  into the intramedullary canal, out the previously drilled hole in the pos- terolateral cortex. Once  just  through the cortex, the surgeon makes a small  incision

A                                                                                                                      over  the palpable tip.  (continued)

B

TECH FIG 3 • (continued) B. The subcutaneous tissue is bluntly dissected with a hemostat until the tip of the pin  can  be  felt, and then the hemostat or a small  elevator is placed under the tip  of the pin  to facilitate the pin’s  passage through  the incision. C,D. The  T-handle is switched to the lateral end of the pin  and the pin  is retracted into the lateral fragment. (A,C: Courtesy of Steven B. Lippitt, MD.)

FINAL POSITIONING OF  PIN  AND FRACTURE COMPRESSION

■            Cold-weld the two nuts onto the lateral end of the pin.

■       First place the medial nut onto the pin,  followed by the smaller lateral nut.

■       Grasp  the medial nut with a  needle-nose pliers  and

then tighten the lateral nut against the medial nut using the lateral nut wrench (TECH FIG 4A,B).

■            Using  the lateral nut wrench and C-arm  guidance, now

advance the pin assembly into the medial fragment until it contacts the anterior cortex (TECH FIG 4C).

■            Break  the cold  weld by  grasping the medial nut with

needle-nose pliers   and then loosen the lateral nut by turning it counterclockwise using the lateral nut wrench.

■            Advance the medial nut against the posterolateral cor- tex  of the clavicle  to get desired compression across  the fracture site.

■            Cold-weld the  lateral nut  back   onto the medial nut

again.

■            Use the medial nut wrench to back  the pin  assembly out of the soft  tissues far  enough to expose the nuts, usually about 1 cm. This will enable the pin to be cut flush  to the lateral nut (TECH FIG 4D,E).

■            Finally,  use  the lateral nut wrench to advance the pin

assembly back  into the medial fragment with the same desired fracture site  compression (TECH FIG 4F,G).

A                                                                      B

TECH FIG 4  • A.  The  lateral end of the pin  with the larger medial nut is placed first,  closest to the skin,  followed by the smaller lat- eral  nut, in  preparation for  cold welding.  B.   To   cold   weld  the joint, the medial nut is grasped with  a   needle-nose  pliers,   and then the lateral nut is tightened against the medial nut using the lateral nut wrench. C.  Using  the lateral nut wrench and C-arm guidance, the  surgeon advances the pin  assembly into the medial fragment until it contacts the an-

C                                                                                                       terior cortex. (continued)

TECH FIG 4 • (continued) D,E. The medial nut wrench is used to back  the pin  assembly out of  the soft  tissues far  enough to expose the nuts, usually about 1 cm, to enable the pin  to be  cut  flush  to the lateral nut. F.  The  lateral nut wrench is used to advance the pin  assem- bly   back   into  the  medial fragment  with the same desired fracture site compression. G. Radiograph showing final  positioning of  the pin  assembly with fracture site  compression.

E                                                                              G                                                                                  (B–D,F: Courtesy of Steven B. Lippitt, MD.)

BUTTERFLY FRAGMENT MANAGEMENT AND WOUND CLOSURE

■            If an  anterior butterfly fragment exists,  cerclage is done using no.  0 or no.  1 absorbable suture.

■       Pass an  elevator under the clavicle  to deflect the su-

tures (TECH FIG 5A).

■       Then  pass  the suture in  a  figure 8 manner through the periosteum of the butterfly fragment and around the fragment and the clavicle  (TECH FIG 5B).

■            Close the periosteum overlying the fracture site with no. 0

absorbable suture in an  interrupted figure 8 manner.

■            Reapproximate the fascia  of  the platysma muscle using

2-0 absorbable suture in an interrupted figure 8 manner.

■            Close the subcutaneous tissue and skin of both  incisions.

TECH FIG 5 • A.  Cerclage of an  anterior butterfly fragment is accomplished by first  passing an  elevator under the clavicle  to deflect the sutures and then passing the suture, in a fig- ure  8 manner, through the periosteum of the butterfly fragment and around the fragment and the clavicle.  B.  Radiograph showing an  adequate reduction of  a  butterfly fragment. (A:  Courtesy of Steven B. Lippitt, MD.)

 

PIN  REMOVAL

■            The pin  is removed at 10 to 12 weeks if the fracture has healed.

■            The  patient is positioned on  his or  her  side  and a  local

anesthetic is delivered (TECH FIG 6A).

■            An incision is made over  the same previous lateral inci- sion  and the subcutaneous tissue is dissected using the hemostat until the medial nut is identified.

■            The medial nut wrench is used to extract the pin  assem-

bly (TECH FIG 6B,C).

■            If the nut is stripped, the T-handle and chuck  can be used to extract the pin  assembly.

TECH FIG 6 • A.  The patient is positioned on  his or her  side  and the lateral incision is infiltrated with local  anesthesia. B,C. The  surgeon makes an  incision over  the same previous lateral inci- sion,  dissecting through the subcutaneous tissue using the hemostat until the medial nut is iden- tified and freed up.  The medial nut wrench is then used to extract the pin assembly. (B: Courtesy of Steven B. Lippitt, MD.)

PEARLS AND PITFALLS

Avoid  splitting the clavicular fragments                        ■  If tapping the medial or lateral clavicular fragments is too tight, the surgeon and aid  in pin  insertion                                                  should redrill with the next larger drill size.

Achieve a more anatomic fracture reduction               ■  When advancing the pin  into the medial clavicular fragment, the surgeon should avoid starting too superior and anterior, which can  lead to malreduc- tion. Instead, the pin  should be  inserted more inferior and posterior to achieve a more anatomic reduction.

POSTOPERATIVE CARE

■    A  sling is worn for 4 weeks. During  this time the sling is removed at least five times a day for active range of motion of the elbow and active assisted range of motion of the shoulder to 90 degrees of forward flexion.

■    The sling is discontinued and full active range of motion of the shoulder is started at 4 weeks.

■   Progressive  resistance  exercises are started at 6 weeks if the patient achieved full range of motion and there is clinical and radiographic evidence of healing.

■    Once the clavicle fracture has healed, the pin is removed at 10 to 12 weeks, as described in the Techniques section (FIG  5).

FIG 5 • Radiograph showing a healed clavicle  fracture after pin assembly removal.

 

OUTCOMES

■    One of the authors (C.B.)  has performed intramedullary fixa- tion of some 300 acute fractures; there have been 60 malunions and 30 nonunions of the clavicle, with a nonunion rate of 1.2%.

■    Most  of the nonunions occurred in older, sick patients with polytrauma.

COMPLICATIONS

■    Pin  migration  is  rare with  this  technique because of  the locking nut on the lateral end of the pin, the blunt tip on the medial end of the pin, and technically avoiding penetration of the medial fragment cortex.

■    The risk of skin breakdown from pin prominence laterally can be minimized by making sure the drill exits the posterolat- eral clavicle in the lower half.

■    Neurovascular complications are rare.

■    There is no drilling toward the neurovascular structures with this technique.

■    When exposing the fracture site, the surgeon should stay on bone at all times.

■    Nonunion  rates are low as long as general fracture princi- ples are maintained, soft tissue stripping of the fracture site is minimized, the technique is followed to get adequate fracture site compression and alignment, and the patient is compliant with the postoperative protocol.

■    Malunion  can rarely occur, especially in fractures with large butterfly fragments. Good  imaging with the C-arm  allows the surgeon to start inserting the pin more inferior and posterior

down the line of the medial clavicular fragment to achieve a more anatomic reduction.

■    Infection is rare, especially with this technique, which has a relatively short surgical time and small exposure. Preoperative antibiotics,  meticulous handling of  the soft tissues, and ade- quate irrigation should be part of any surgical technique.

REFERENCES

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7.  Neer C. Nonunion  of the clavicle. JAMA  1960;172:96–101.

8.  Nordqvist A,  Redlund-Johnell  I, Von  Scheele A,  et al. Shortening of clavicle  after fracture,  incidence and  clinical  significance,  a  5-year follow-up of 85 patients. Acta Orthop  Scand 1997;68:349–351.

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