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Jun-Mo Park1, Hyunjeong Kim1

Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Kyungpook Na-tional University Hospital, Daegu, Korea

In the case of isolated sternal fractures, conservative treatment with analgesics is common, but pain can persist for morethan 10 weeks, which can significantly interfere with daily life. Ultrasound-guided paravertebral nerve block is reportedto be a successful means of pain control in patients with chest wall injury or rib fracture. A 70-year-old female patient presented with anterior chest pain that had persisted for 2 weeks despite conservative treat-

ment. Sagittal reconstruction chest computed tomography and sternum lateral oblique x-ray revealed an isolated sternalfracture. An ultrasound-guided bilateral paravertebral nerve block was performed for pain control. After performing theprocedure twice at a 1-week interval, the patient reported complete pain alleviation, and no other problems were observedover the 3-month follow-up period.

Ultrasound-guided bilateral paravertebral nerve block can help patients with isolated sternal fractures to manage painand return to normal activities sooner than with oral analgesics.

Key Words: Fracture, Nerve block, Pain management, Sternum, Ultrasonography

Sternal fractures are not uncommon and havebeen reported to occur in 3.7% of patients hos-pitalized after a traffic accident.1 Before the useof seatbelts became mandatory, a sternal fracturewas a marker for high-energy trauma. After theuse of safety belts was legislated, the number ofpatients surviving traffic collisions increased,accompanied by an increase in patients present-ing with sternal fractures as a result of these ac-cidents.The morbidity and mortality rates of sternalfractures are determined by associated injuries

to the internal thoracic organs, with isolated ster-nal fractures considered benign lesions in the ab-sence of accompanying cardio-respiratorydamage.1,2 More than 95% of sternal fracturesare treated conservatively.2 The most importantfactor in the treatment of isolated sternal frac-tures is adequate pain control, usually managedwith oral analgesics.3

Few studies, however, have been published re-garding the functional effects of isolated sternalfractures on daily activities. According to onestudy, although chest pain was the most fre-

Treatment of Isolated Sternal Fracture with Ultrasound-GuidedParavertebral Nerve Block: a Case Report and Literature Review

Received: Aug. 26, 2019Revised: Oct. 12, 2019Accepted: Oct. 15, 2019

Corresponding Author: Jun-Mo Park, Department of Anesthesiology and Pain Medicine, Kyungpook NationalUniversity Chilgok Hospital, 807 Hoguk-ro, Buk-gu, Daegu 41404, Korea Tel: +82-53-200-2643 Fax: +82-53-200-2027 E-mail: pjm4013@naver.com

Kosin Medical Journal 2019;34:152-160.https://doi.org/10.7180/kmj.2019.34.2.152

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quently reported and persistent symptom, con-tinuing for an average of 10.9 weeks, the dura-tion of pain was significantly prolonged inpatients older than 50 years of age presentingwith an isolated sternal fracture.4 This prolongedchest pain often necessitates the administrationof oral analgesics for a relatively long period, butthis long-term use can be limited by the side ef-fects of non-steroidal anti-inflammatory drugs(NSAIDs) and opioids.5 In particular, older pa-tients may have underlying medical conditionsthat contraindicate analgesic use. Other patientsmay have to return to their daily lives before thepain has subsided, which can be difficult to dowhen undergoing conservative treatment alone.

We report a case of successful management ofpain in a patient with an isolated sternal fractureusing an ultrasound-guided bilateral paraverte-bral nerve block.

CASE

A 70-year-old female patient presented with an-terior chest pain that had persisted for 2 weeks.The patient had no pertinent medical historyother than 10 years of anti-hypertensive drugmedication. The patient reported a fall 2 weeksbefore visiting the pain clinic, hitting her chestagainst a stone, followed by chest pain. The painwas less severe when she remained still but wors-ened when she coughed or spread her arms, andshe reported difficulty with bending her chestforward or turning over in bed. The patient's vi-sual analog scale (VAS) score was 7 out of 10.

She was examined at a local clinic near her homeand was told that her sternum had cracked. Thatdoctor recommended rest and prescribed anNSAID medication. However, her symptoms hadnot improved, and she complained that theNSAID was causing facial swelling and heart-burn. In addition, the patient was planning anoverseas trip with her family in 2 weeks. She vis-ited our clinic to address her pain so she couldtravel unencumbered. A sternal fracture was already suspected at the

other facility, and the pain had persisted evenafter 2 weeks of adequate treatment. We therebyperformed chest computed tomography (CT) in-cluding sagittal reconstruction, x-rays of thesternum lateral and lateral oblique aspects, elec-trocardiography (ECG), and a cardiac enzymetest to check for any accompanying injuries. Athorough physical examination was also con-ducted on the patient, and no specific abnormalsigns were found other than intense, localizedtenderness at the mid portion of the sternal body.A recent fracture was observed at the sternum be-tween the third and fourth ribs on the sagittal re-construction chest CT and sternum lateraloblique x-ray (Fig. 1A, 1B). There was mild softtissue edema around the fractured area, but nohemorrhage, and no soft tissue injury that wouldindicate a pathologic fracture. No abnormalitieswere found on the ECG or cardiac enzyme test.As such, we decided to perform an ultrasound-guided bilateral paravertebral nerve block at thespace between the third and fourth ribs to allowthe patient to return to normal daily life sooner,particularly, to travel abroad with her family after

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2 weeks. The patient was placed in the prone po-sition, the third and fourth ribs were visualizedwith C-arm guidance (Fig. 2A), and the skin wasmarked along the running direction of each rib(Fig. 2B). After sterilization of the skin, a curvedtransducer (1.5–4.6 MHz) for a GE Logiq7 ul-trasound machine (Tokyo, Japan) was placedparallel to the direction indicated on the skin andmoved medially to check the spinous and trans-verse processes of the third thoracic vertebra.The transducer was then moved laterally alongthe skin markings to locate the thoracic paraver-tebral space for injection (Fig. 2C). The trans-ducer was moved slightly in the cephalad andcaudal directions perpendicular to the directionof the rib indicated on the skin to confirm thatthe rib was excluded from the path of the needle(Fig. 3A). A 10-cm, 22-gauge SonoPlex cannulawith facet grinding (Pajunk GmbH, Geisingen,Germany) was inserted in the lateral to medial

direction using an in-plane technique. After itwas confirmed that the needle was placed in theregion under the transverse process and that noblood or air was withdrawn during negative as-piration, a mixture of 10 mL of 0.5% lidocaineand 20mg of methylprednisolone acetate wasslowly injected. During the injection, concomi-tant anterior movement of the parietal pleura waschecked by ultrasound to confirm that the drugwas injected into the correct location (Fig. 3B).After completing this procedure on one side, itwas repeated on the other side. Thirty minutes after the procedure, the patient’s

VAS score of the pain caused by coughing orspreading her arms was reduced to 2 out of 10,without any complications. Since the patientcomplained of side effects from the NSAID, tra-madol and a skeletal muscle relaxant were pre-scribed, and the patient was asked to return for afollow-up in 1 week. After 1 week, the patient

Fig. 1. (A) Sternum lateral oblique x-ray. (B) Sagittal reconstruction chest CT. Arrows indicate fracture site.

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Fig. 2. (A) C-arm view showing the direction of the third and fourth ribs. (B) Skin was marked along therunning direction of the third and fourth ribs. (C) Curved transducer was placed parallel to the di-rection indicated on the skin and moved medially and laterally along the skin markings and cepha-lad and caudally to locate the thoracic paravertebral space for injection.

Fig. 3. (A) Ultrasound view showing the ribs were excluded from the path of the needle. (B) Ultrasoundview showing anterior movement of the parietal pleura (small arrow). T: target region, TP: trans-verse process, needle (arrow head), tip of needle (large arrow).

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reported that her VAS score was about 1 or 2 outof 10 for most of the day. She also did not com-plain of any particular side effects of the pre-scribed drugs. Since the patient was concernedthat the pain would recur during the plannedoverseas trip with her family 1 week later, theprocedure was repeated, and the same drugs wereprescribed. The patient followed up with us 2weeks after the trip and reported that she had notfelt any pain during the trip and that she hadsince stopped taking the pain medication becausethe pain had completely subsided. At her 3-month follow-up, the patient reported a return tonormal activities without pain, and no abnormal-ities were found on lateral and lateral oblique x-rays of the sternum; thus, her treatment wasterminated.

Approval of this study was waived from theEthics Committee of Kyungpook National Uni-versity Chilgok Hospital based upon their policyon case reports. The authors obtained writtenconsent from the patient to publish this case re-port.

DISCUSSION

In the present case report, after ultrasound-guided bilateral paravertebral nerve block wasperformed twice, the patient’s pain was success-fully relieved and she was able to return to dailylife early. This is the first report on pain manage-ment of an isolated sternal fracture with an ultra-sound-guided bilateral paravertebral nerve block.

In 2014, through a retrospective analysis of a

total of 32,746 cases of injuries including sternalfracture between 2007 and 2010 using the Na-tional Trauma Data Bank, Yeh et al. reported that84% of sternal fractures were associated with caraccidents, with sternal fracture confirmed in3.7% of all patients hospitalized due to a colli-sion.1 According to Oyetunji et al., the most com-mon cause of sternal fracture is car accidents,and the second most common cause is falls.6

Other common causes are motorcycle injuries,pedestrian injuries from cars, and cyclist injuries.They also reported that most traumatic sternalfractures occur as one of multiple traumatic in-juries rather than in isolation. Sternal fracture isoften associated with severe blunt trauma andfrequently associated with severe intrathoracicand vertebral injuries. The injuries most com-monly associated with sternal fracture are ribfracture (57.8%), lung contusion, closed pneu-mothorax or hemothorax, closed thoracic or lum-bar vertebra fracture, concussion, and bluntcardiac injury. The morbidity and mortality ratesassociated with sternal fracture are determinedby the level of internal thoracic organ damage ac-companying the injury, with a mortality rateranging from 4 to 45%.2 For this reason, it is im-portant to check for the presence of accompany-ing injuries in all patients presenting with sternalfracture, and current protocols call for cardiacmonitoring, serial ECG, and hospitalization forfurther examination as needed.7 However, iso-lated sternal fractures without other thoracic in-jury do not necessarily require this level of care.In the absence of accompanying cardio-pul-monary complications, an isolated sternal frac-

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ture is considered a benign injury.2,3

Previously, before the use of routine CT for di-agnosis and evaluation in blunt trauma patients,lateral chest x-ray was considered the most use-ful method for diagnosing sternal fractures, andsternal fractures were considered clinically sig-nificant injuries associated with high morbidityand mortality rates.8 According to Perez et al.,most sternal fractures can only be observed onCT, are clinically insignificant, require no changein treatment protocol, and are accompanied by alow mortality incidence.8 Terry et al. noted thatCT remains the best diagnostic imaging methodfor trauma patients for the rapid identification ofmultiple injuries.9 However, due to the curvatureof the anterior chest wall, an axial image maymiss a sternal injury, as the sternum may be ex-cluded from the image. They suggested includinga sagittal reconstruction image to increase agree-ment among imaging physicians and confidencein the diagnosis and recommended adding sagit-tal reconstruction to the standard chest traumaCT protocol. The sagittal reconstruction imagecan be appended to the exam with little or no ad-ditional cost to the patient or the institution andwithout exposing the patient to additional radia-tion. In the present case, the sagittal reconstruc-tion image (Fig. 1B) was used to diagnose theisolated sternal fracture and check for the pres-ence of accompanying injuries with a high levelof accuracy.Sternal fracture or dislocation usually occurs in

the sagittal plane, rendering the lateral view ofthe sternum best suited to accurate diagnosis.8

Conventional radiography can sometimes fail to

visualize such fractures. In addition, the lateralview of the sternum is an unattractive option forcritically injured patients, especially those withmultiple injuries. As such, ultrasound-based di-agnosis is increasingly relied upon in emergencydepartments for sternal fracture patients andother types of trauma patients.10 The use of ultra-sound to detect sternal fractures can be as sensi-tive or even twice as sensitive as conventionalradiography. Ultrasonography allows physiciansto quickly and easily identify the presence or ab-sence of sternal fracture in trauma patients. Sternal fracture can cause short- and long-term

sequelae. De Oliveria et al. reported that persist-ing chest pain was the most common short-termsequelae and the duration of chest pain after ster-nal fracture was between 2 and 28 weeks, withan average of 8 to 12 weeks (mean period of 10.9weeks) for all age groups, and noted that pain du-rations were significantly prolonged in patientsover 50 years of age.4 Chest pain can worsen incold weather or while performing certain maneu-vers such as lifting, walking, or lying down.They also reported that the mean length of timethat had to be taken off work was 5.1 weeks. De-layed complications from sternal fractures areuncommon; however, some do present with de-layed complications and poor functional out-comes. Racine et al. reported that delayedhemothorax occurred in 12.5% of patients withsternal fracture.11 However, the clinical signifi-cance of delayed hemothorax remains uncertain.They reported that the proportion of patients withmoderate to severe disability was significantlyhigher for sternal fracture than other types of

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minor thoracic trauma. According to the systematic review of the liter-

ature published between 1990 and 2017 by Kleiet al., the majority of patients with sternal frac-tures (more than 95%) received conservativetreatments such as bed rest, oral analgesics, andorthotics.2 They found that proper pain controlwas critical, because sternal fractures can causepain during breathing that results in respiratorycomplications due to respiratory insufficiency.Although it is often necessary to take oral anal-gesics for an extended period of time in the con-servative treatment of sternal fractures due toprolonged pain, long-term treatment may not bepossible due to the side effects of NSAIDs oropioids.5 In particular, older patients or patientswith underlying diseases may not be good can-didates for the NSAIDs or opioids used in con-servative treatment.7 Because of these issues,several new treatments have been introduced totreat these patients, including infiltration of localanesthetics directly into the fracture site with asubcutaneous cannula, periosteally positionedcatheter, or sternal catheter.7 Recent develop-ments of new procedures using ultrasound arealso being applied to the treatment of patientswith sternal fracture.12,13

Recently, ultrasound has been used not only forthe diagnosis of sternal fracture but also for thetreatment in more and more cases.12,13 In the pres-ent case, only 2 weeks after sternal fracture, con-servative management with oral analgesics wasneeded. However, the pain was not controlled byNSAIDs, and NSAIDs could no longer be takendue to their side effects. Moreover, in order to be

able to safely travel abroad, it was necessary toreturn to daily life early. The ultrasound-guidedbilateral paravertebral nerve block was chosenafter taking the patient’s medical background andpersonal circumstances into account and per-formed to help the patient return to normal activ-ities sooner.

The ultrasound-guided paravertebral nerveblock is used during surgeries for breast cancer,inguinal hernia repair, lithotripsy, and video-as-sisted thoracic surgery; however, it is most com-monly used for perioperative pain managementand pain management in patients with multiplerib fractures.14 Thoracic paravertebral block is amethod of injecting drugs into the thoracic ver-tebrae close to the spinal nerve from the interver-tebral foramen. This procedure allows for theipsilateral somatic and sympathetic nerve block,and characteristically, the injected drug spreadsup and down the injection site to enable blockadein multiple dermatomes. The intercostal nervesinnervate the costotransverse joints, the ribs (1–12), the costosternal joints, and the sternum.Since the intercostal nerve originates from thethoracic spinal nerve, it was able to block the cor-responding intercostal nerve that innervated thefractured sternal region. Unlike the intercostalnerve block, one procedure on one side was suf-ficient because the drug spread to the level belowor above the injection site. This procedure hasthe advantage of being easier and more familiarbecause it has been used by more and more anes-thesiologists as well as pain medicine doctors inrecent years.In most cases, conservative treatment is all that

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is necessary, but some sternal fracture patientsdo require surgical treatment. Recently, surgicaltreatment has been recommended when the frac-ture is displaced, unstable, causing severe pain,or associated with flail chest threatening cardio-pulmonary function.7 In chronic cases, surgicaltreatment is considered only when persistentpain, non-union, or cosmetically unacceptableexternal appearance is associated with the case.Most researchers do not support surgical treat-ment without a definite indication.

In conclusion, isolated sternal fracture is con-sidered a benign injury in the absence ofother associated cardio-pulmonary conditions.Conservative treatment is typical, and delayedcomplications rarely occur. However, conserva-tive treatment may be insufficient in older pa-tients, those with conditions contraindicating theuse of oral analgesics, or those that need toquickly resume normal activities. In these cases,an ultrasound-guided bilateral paravertebralnerve block may help control pain and allow thepatient to return to normal activities sooner thanwith treatment with oral analgesics alone.

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