Operative Techniques in Orthopaedic Surgery (4 Volume Set) 1st Edition

371. Intramedullary Fixation of Clavicle Fractures

Bradford S. Tucker, Carl Basamania, and Matthew D. Pepe

DEFINITION

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

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

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

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

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

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

images 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

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

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

images The larger medial curvature widens the space for the neurovascular structures, providing bony protection.

images The clavicle is made up of very dense trabecular bone, lacking a well-defined medullary canal.

images The cross-sectional anatomy gradually changes from flat laterally, to tubular in the midportion, to expanded prismatic medially.

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

images The supraclavicular nerves that provide sensation to the overlying skin of the clavicle are found deep to the platysma muscle.

images 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.

images Proximal muscle attachments include the sternocleidomastoid, pectoralis major, and subclavius. Distal muscle attachments include the deltoid and trapezius (FIG 1B).

images 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

images 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.

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

images

FIG 1  A. The clavicle is S-shaped and has a double curve. The medial curve is apex anterior and the lateral curve is apex posterior. B. Proximal muscle attachments to the clavicle include the sternocleidomastoid, pectoralis major, and subclavius. Distal muscle attachments to the clavicle include the deltoid and trapezius.

NATURAL HISTORY

images 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.

images More recent studies have shown that nonunion is more common then previously recognized and that a significant percentage of patients with nonunion are symptomatic.

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

images McKee and colleagues5 identified 15 patients with malunion 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.

images Hill and associates4 reviewed 52 completely displaced midshaft clavicle fractures and found that shortening of more than 20 mm had a significant association with nonunion and unsatisfactory results.

images 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

images The diagnosis is usually straightforward and is based on obtaining the mechanism of injury from a good history.

images On visual inspection the examiner will frequently see notable 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 displaced. 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).

images 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.

images

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.

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

images It is important to perform a complete musculoskeletal and neurovascular examination of the upper extremity and auscultation of the chest to identify the rare associated injuries; these are more closely related to high-energy injuries.

images

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).

images Rib and scapula fracture

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

images Vascular injury (subclavian artery or vein injury associated with scapulothoracic dissociation)

images Pneumothorax and hemothorax

IMAGING AND OTHER DIAGNOSTIC STUDIES

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

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

images In practice, a 20to 60-degree cephalic tilt view will minimize interference of thoracic structures.

images The film should be large enough to include the acromioclavicular and sternoclavicular joints, the scapula, and the upper lung fields to evaluate for associated injuries.

images An AP view of bilateral clavicles on a wide cassette to include 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 accuracy, although it is rarely required.

DIFFERENTIAL DIAGNOSIS

images Sprain of acromioclavicular joint

images Sprain of sternoclavicular joint

images Rib fracture

images Muscle injury

images Contusion

images Hematoma

images 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

images 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 extremity are adequate, including a figure 8 bandage, sling, sling and swathe, Sayre bandage, Velpeau dressing, and benign neglect, just to name a few.

images 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.

images 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

images Indications for operative treatment of acute midshaft clavicle fractures are as follows:

images Open fractures

images Fractures with neurovascular injury

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

images “Floating shoulder”

images Impending skin necrosis

images Severe displacement: possibly 15 to 20 mm of shortening

images 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.

images Potential advantages of intramedullary fixation of the clavicle are as follows:

images Less soft tissue stripping and therefore potentially better healing

images Smaller incision

images Better cosmesis

images Easier hardware removal

images Less weakness of bone after hardware removal

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

images Less ability to resist torsional forces

images Skin breakdown from prominence distally

images Pin breakage

images Pin migration

images Newer designs and techniques prevent pin migration by placing a locking nut on the lateral end and technically avoiding penetration of the medial fragment cortex.

Preoperative Planning

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

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

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

images 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

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

images 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).

images

FIG 4  A,B. The patient is placed supine on a Jackson radiolucent surgical table. A 1-L bag is placed under the affected shoulder, 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-positioning 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.

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

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

images 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).

images The other option is placing the patient in the beach chair position on the OR table, using a radiolucent shoulderpositioning device (FIG 4C,D).

images 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.

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

TECHNIQUES

INCISION AND DISSECTION

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

images  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).

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

images  Divide the subcutaneous fat down to the platysma muscle using electrocautery (TECH FIG 1C).

images  Although there is usually very little subcutaneous fat, gently make full-thickness flaps to include skin and subcutaneous tissue around the entire incision to facilitate exposure.

images  Bluntly split the platysma muscle in line of its fibers to identify, protect, and retract the underlying supraclavicular nerves; its middle branches are frequently found near the midclavicle (TECH FIG 1D,E).

images  The fracture site is then usually easily identifiable in acute injuries because the periosteum is disrupted and usually requires no further division.

images  Remove any debris, hematoma, or interposed muscle from the fracture site.

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

images

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 entire incision. This exposes the fascia that covers the platysma muscle. D. Skin incision over a displaced clavicle fracture, with underlying 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

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

images  Use a bone-reducing clamp or towel clip to grab and elevate the medial clavicular fragment through the incision (TECH FIG 2B).

images  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.

images The fit should be snug to maximize fixation, but not too tight, to prevent splitting the bone.

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

images  Next, attach the appropriate-sized tap (that corresponds to the drill size) to the T-handle and tap the intramedullary canal to the anterior cortex (TECH FIG 2F,G).

images  Elevate the lateral clavicular fragment through the incision; this can be facilitated by externally rotating the arm.

images  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).

images The drill should exit posterior and medial to the acromioclavicular joint capsule (TECH FIG 2J).

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

images  Attach the appropriate-sized tap to the T-handle and tap the intramedullary canal of the lateral fragment (TECH FIG 2K).

images

images

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. 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 appropriatesized 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

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

images This is the end with the large threads.

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

images  Continue 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 posterolateral cortex (TECH FIG 3A).

images  Once you are just through the cortex, make a small incision over the palpable tip.

images  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).

images Drill the pin out laterally until the large medial threads engage the lateral fragment.

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

images  Reduce the fracture by lifting the arm, and pass the pin into the medial fragment.

images 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.

images

images

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 posterolateral cortex. Once just through the cortex, the surgeon makes a small incision over the palpable tip. 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

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

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

images 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).

images  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).

images  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.

images  Advance the medial nut against the posterolateral cortex of the clavicle to get desired compression across the fracture site.

images  Cold-weld the lateral nut back onto the medial nut again.

images  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).

images  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).

images

images

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 lateral 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 anterior cortex. 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 assembly 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. (B–D,F: Courtesy of Steven B. Lippitt, MD.)

BUTTERFLY FRAGMENT MANAGEMENT AND WOUND CLOSURE

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

images Pass an elevator under the clavicle to deflect the sutures (TECH FIG 5A).

images 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).

images  Close the periosteum overlying the fracture site with no. 0 absorbable suture in an interrupted figure 8 manner.

images  Reapproximate the fascia of the platysma muscle using 2-0 absorbable suture in an interrupted figure 8 manner.

images  Close the subcutaneous tissue and skin of both incisions.

images

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 figure 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

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

images  The patient is positioned on his or her side and a local anesthetic is delivered (TECH FIG 6A).

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

images  The medial nut wrench is used to extract the pin assembly (TECH FIG 6B,C).

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

images

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 incision, dissecting through the subcutaneous tissue using the hemostat until the medial nut is identified 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

images

images

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

POSTOPERATIVE CARE

images 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.

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

images 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.

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

OUTCOMES

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

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

COMPLICATIONS

images 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.

images The risk of skin breakdown from pin prominence laterally can be minimized by making sure the drill exits the posterolateral clavicle in the lower half.

images Neurovascular complications are rare.

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

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

images Nonunion rates are low as long as general fracture principles 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.

images 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.

images 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 adequate irrigation should be part of any surgical technique.

REFERENCES

· Altamimi S, McKee M. Nonoperative treatment compared with plate fixation of displaced midshaft clavicle fractures. J Bone Joint Surg Am 2008;90A:1–8.

· Andersen K, Jensen PO, Lauritzen J. Treatment of clavicular fractures: figure-of-eight versus a simple sling. Acta Orthop Scand 1987; 58:71–74.

· Eskola A, Vainionpaa S, Myllynen P, et al. Outcome of clavicular fractures in 89 patients. Arch Orthop Trauma Surg 1986;105:337–338.

· Hill J, McGuire M, Crosby L. Closed treatment of displaced middlethird fractures of the clavicle gives poor results. J Bone Joint Surg Br 1997;79B:537–539.

· McKee M, Wild L, Schemitsch E. Midshaft malunions of the clavicle. J Bone Joint Surg Am 2003;85A:790–797.

· Moseley HF. The clavicle: its anatomy and function. Clin Orthop Relat Res 1968;58:17–27.

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

· 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.

· Rowe C. An atlas of anatomy and treatment of midclavicular fractures. Clin Orthop Relat Res 1968;58:29–42.

· Stanley D, Trowbridge EA, Norris SH. The mechanism of clavicle fracture: a clinical and biomechanical analysis. J Bone Joint Surg Br 1988;70B:461–464.



If you find an error or have any questions, please email us at admin@doctorlib.info. Thank you!