This article is dedicated to the specialist in pediatric surgery, Professor Dr. R.T. Carbon (Erlangen, Germany) with heartfelt gratitude for his educational impact. We thank the Radiological Institute of the Erlangen University Hospital (Director: Prof. Michael Uder) for providing the X-rays and CT scans.

NOTE: The following procedures were approved by the head of department and meet all other institutional requirements.
1. Pre-operative Computed Tomography
NOTE: A helical computed tomography of the entire chest wall is taken following the local standards before the protocol begins.
<img alt="Figure 1" src="/files/ftp_upload/52124/52124fig1highres.jpg" /> 
Figure 1: Preoperative CT-Scan. (a) Axial view shows oblique and longitudinal fractures. (b) Sagittal view shows anterior-posterior dislocation or sternal kinking. (c) Coronal view gives an overview over oblique and longitudinal fractures. (d) Volume rendering technique (VRT) gives an overview over the entire anterior chest wall showing rib fractures, manubrium and corpus sterni fracture
<ol>
	<li>Scan the chest wall for injuries. Inspect the complete anterior chest wall including examination of soft tissue, cartilage and bones.
	<ol>
		<li>Look for bone fractures at the manubrium, corpus sterni and adjacent ribs I to VII on both sides. Look for cartilage disruption. Be aware of cartilage disruption and sternocostal separation not to miss any cause of instability.</li>
		<li>Perform a three dimensional evaluation. See the whole chest wall in the modus of three dimensional reconstructed pictures by evaluating each axial, coronal and sagittal picture in detail.</li>
	</ol>
	</li>
	<li>Pinpoint the fracture:
	<ol>
		<li>Take the distance from the upper sternal edge (jugulum) to the fracture. Use the sagittal view for measuring.</li>
		<li>In case of oblique fracture or multiple fractures measure both distances to jugulum, the cranial and the caudal edge of the fractures. Take the distance between those edges. The additional use of the coronal pictures might be helpful in this case.</li>
	</ol>
	</li>
	<li>Determine the thickness of presternal soft tissue. Evaluate and measure the thickness of presternal soft tissue at the point of the fracture.</li>
	<li>Estimate the length of the possible surgical incision, performed in the midline. 
	NOTE: The basic approach needs to be at least 60 mm plus thickness of presternal soft tissue to get a proper access to a transverse fracture.
	<ol>
		<li>In case of oblique fracture or multiple fractures add the distance between the cranial and the caudal edge of the fractures to the basic approach. 
		NOTE: There might be a need of a longer incision in obese patients, if there are scars in the determined region or for other reasons.</li>
	</ol>
	</li>
</ol>
2. Surgical Treatment
<img alt="Figure 2" src="/files/ftp_upload/52124/52124fig2highres.jpg" /> 
Figure 2: Surgical approach. (a) Positioning on the back gives access to the entire anterior chest wall and both axles; chest tube were already inserted bilaterally in this case. (b) After drawing the landmarks such as jugulum and sternoclavicular joints (above) the midline is identified and the incision performed. Pectoral muscle was dissected from the anterior sternum. A raspatory is inserted subperiostally. (c) The approach gives full access to any fracture identified. In this case two transverse fractures are shown.
2.1) Initial surgical procedures:
<ol>
	<li>Perform the operation under general anesthesia following the local standards while the patient is intubated. Place the patient in a supine position. Rest the arms on an arm board which must be placed less than 90&#176; to the midline of the body and level the board with the floor. This might be useful if insertion of a chest tube becomes necessary.</li>
	<li>Remove superficial soil, debris, jewelry and transient microbes before applying antiseptic agents. Leave hair at the surgical site in place whenever possible.
	<ol>
		<li>Commence disinfection following the local standards. Start from the cleanest area, usually the operative and/or incision site and proceed in a concentric fashion to the least clean area. Allow the disinfectant solution to dry completely naturally. Ensure that the antiseptic solution remains in contact with the skin for the required period of time as recommended by the manufacturer.</li>
	</ol>
	</li>
	<li>Secure free access at least to the jugulum, the umbilicus and the axillary midline on both sides. Mark anatomical landmarks such as sternoclavicular joints on both sides, the upper sternal edge at the jugulum, the lower sternal edge and xiphoid, the seventh rib bilaterally and the umbilicus using a sterile pen.
	<ol>
		<li>Draw the midline now between jugulum and umbilicus and mark the cranial and caudal edge of the fractures as measured in step 1.2. Add half of the basic approach cranial and the other half caudal to the edges of the fractured region of sternum.</li>
	</ol>
	</li>
	<li>Double check the correct position of the fracture(s) and of the midline, then perform the midline incision respecting the anatomical layers in soft tissue.</li>
	<li>Remove presternal haematoma by a vertical incision along the length of the haematoma and wash out as much as possible with 0.9% saline.</li>
	<li>Cautiously take away the pectoral muscle bilaterally, beginning from the midline to the margin of the sternum whilst respecting the anatomical layers. Be aware of bleeding from smaller vessels and stop them. Identify the fracture.</li>
	<li>Expose the intercostal margin of the sternum, both, cranial and caudal of the fracture. Perform an incision of the sternal periosteum longitudinally along the front edge of the sternum. Cautiously dissect the periosteum from the bone laterally and on the posterior surface of the sternum using an elevatory or raspatory device. 
	NOTE: Preparation very close to the bone during this procedure is very important to prevent injuries to the adjacent internal thoracic vessels and the mediastinum.</li>
	<li>Expose the fracture and clear the fracture cautiously. Usually retrosternal haematoma will appear at this time, wash out as much as possible with 0.9% saline.</li>
</ol>
<img alt="Figure 3" src="/files/ftp_upload/52124/52124fig3highres.jpg" /> 
Figure 3: Surgical safety. (a) Measuring the sternal thickness and insert an elevator device. (b, c) Depth limited drilling.
<ol start="9">
	<li>Measure the thickness of the sternum with a blunt instrument. Do not use a common &#8220;lot&#8221; due to possible retrosternal injuries. Prepare a drilling machine with a drill of the length of sternal thickness or shorter if not clear.</li>
	<li>Reduce the bone fragments by elevating the posteriorly depressed fragments with an elevator device which can be inserted through the same subperiosteal approach shown in step 2.1.7. Assemble the laterally dislocated fragment should be by lateral compression. Use a pointed ball forceps, weller clamp or compression wires if necessary.</li>
</ol>
<img alt="Figure 4" src="/files/ftp_upload/52124/52124fig4highres.jpg" /> 
Figure 4: Fixation options of the plates. (a) Transverse fracture at corpus sterni: fixation with a pointed ball forceps and locked screws. (b) Oblique fracture at manubrium: reduction with compression wires , the first plate has been fixed yet. (c) Multiple transverse fracture; fixation of the plate using compression wires at the manubrium (above) and pointed ball forceps (below).
2.2) Transverse fractures and oblique fractures of sternal body:
<ol>
	<li>Mark the midline of the sternum using a pen or electrocautery.</li>
	<li>Insert a small pointed ball forceps to the posterior surface of the sternum using the intercostal space next to the fracture, again keeping very closed to the sternal bone. Use the intercostal space of the depressed fragment first.
	<ol>
		<li>Put a longitudinal plate next to the midline and fix it with the pointed ball forcipes. 
		NOTE: At least three screw holes of the plate should cover the cranial and the caudal main fragment. In case of a single fracture, a seven or eight-hole plate offers the correct fixation. Using longer plates is necessary in multiple fractures, where a longer distance needs to be fixed.</li>
	</ol>
	</li>
	<li>Fix the plate with locked screws, drilling each hole using a drilling guide and the drill as chosen under step 2.1.9 thus ensuring depth limited drilling and a secured locked fixation of each screw to the plate. Again, fix each main fragment with at least three screws.</li>
	<li>Put a second plate on the other side of the midline and repeat the steps 2.2.2-2.2.3.</li>
</ol>
2.3) Longitudinal fractures, oblique manubrium fractures and sternocostal separation:
<ol>
	<li>Reduce the fracture as shown under step 2.1.10.</li>
	<li>Insert one small pointed ball forceps to the posterior surface of the sternum on each side using the intercostal space next to the fracture, again keeping very close to the sternal bone. Put a transverse plate from rib to rib, bridging the sternum with its fragments and fix it with the pointed ball forcipes. Place at least three screw holes laterally of each fracture. 
	NOTE: In case of a single fracture, a seven or eight- hole-plate offers the correct fixation. The use of longer plates usually becomes necessary for multiple fractures.</li>
	<li>Fix the plate with locked screws; use a drilling guide and the drill as chosen under step 2.1.9 thus ensuring depth limited drilling. Again, fix each of the main fragments with at least three screws.</li>
	<li>For osteosynthesis of each injured level, repeat steps 2.3.1-2.3.3.</li>
</ol>
<img alt="Figure 5" src="/files/ftp_upload/52124/52124fig5highres.jpg" /> 
Figure 5: Operative results. (a) Long parallel plates, each fragment was fixed with 3 screws. (b) Postoperative chest x-ray showing longitudinal sternal plate and three transverse plates fixing oblique manubrium fracture, sternocostal separation of second rib and fracture of third rib on the right side. (c) Lateral view of x-ray shows correct position of two parallel plates fixing a fracture located at sternal corpus.
<ol start="5">
	<li>Double check the correct position of all plates. Examine the anterior chest wall for sufficient stability. Look for any bleeding and stop it. Rule out pleural lesions. If a pleural lesion is indicated or suspected, insert a chest tube into the pleural cavity on the affected side using an axillary approach.</li>
	<li>Insert a subcutaneous drainage if necessary. Place the tube in front of the sternum and percutaneously divert about 5 cm away from the lower edge of the wound.</li>
	<li>Close the wound respecting the anatomical layers. Suture the periosteal incisions to preserve sternal blood supply. Approximation of the pectoral muscle to the midline is recommended to ensure a proper coverage of the implants with soft tissue.</li>
	<li>Take a chest x-ray after surgical treatment to rule out pneumothorax and hemothorax. The additional lateral view will show the position of the sternal fragments and of the implants.</li>
</ol>

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The first author has a consultant agreement with Synthes CMF. No funds were received in connection to the presented study. The coauthors are not involved in any conflict of interest.

Although most of the sternal fractures are treated conservatively, sometimes a surgical fixation becomes necessary. The sternal anatomy and the stability of the anterior chest wall are restored by a stable fixation employing a locked plate osteosynthesis. Using very slim plates (1.5 mm or 2.0 mm thickness) provides a proper stability on the one hand and high convenience for the patient on the other hand12. Very good results are also described for the application of any locked plate, for example LCP System or plates developed for other bones like the cervical spine or the distal radius6,27.
Locked plates are considered to provide the advantage of a biological fixation to be functional as an internal fixator with significantly reduced friction between plate and bone9. The positioning of such an internal fixator on the anterior sternal surface provides a sufficient fixation of the convex surface of the fracture and thus reducing traction forces to the fracture. At the same time each respiratory movement induces compression to internal sternal cortex and to the fracture thus stimulating bone healing. Each screws needs to be locked securely to enable the efficiency of the internal fixator.
As we recommend the fixation of each fragment with at least three screws, there could be limitations in case of very short fragments. Possible solutions are the bridging of those fragments and the use of special plates, which allow longitudinal and transverse fixation rolled into one. In the future, &#8220;T&#8221; or &#8220;H&#8221;-shaped plates could be helpful in those situations.
Some surgeons show a reluctance to operate on the chest wall, probably due to a lack of experience in this particular region. There is a need for a simple and safe method for sternal stabilization1,12. The above described method represents one possible standard and reduces the risk of complications due to the operative procedure by a precise preoperative planning, subperiosteal dissection of soft tissue, and depth limited drilling. There lies the difference in the use of any other plates not providing the possibility of depth limited drilling (Table 1), whereas the preoperative planning, the steps of preparation, and reduction of the fracture could be performed analogously to the described way of this manuscript.
As a three dimensional reconstructed CT scan allows the diagnosis of fractures to sternum and concomitant fractures with high sensitivity the surgeon gets detailed information about the injury28,29. The CT shows the particular position and the direction of the fracture as well as any dislocation. This important information simplifies the preoperative planning of the intended surgical approach as shown in steps 1.1-1.5. Furthermore, it allows a precise planning of the number and design of the plates which should be employed for fixation as shown in the steps 2.2-2.3. A possible limitation of a CT scan lies in difficulties showing undislocated fractures and disruption of cartilage although they could contribute to the instability of the chest wall.
The subperiosteal dissection and the depth limited drilling are the two most important steps for surgical safety.
Reducing the sternal fragments to their anatomic position usually necessitates an approach to the posterior wall of the sternum. This procedure may injure mediastinal organs, surrounding vessels and the sternal blood supply7,18. Performing strictly subperiosteal dissection around the sternum as shown in step 2.1.7 will minimize the risk of complications. Fractures which show a lateral dislocation, could have their fragments move very closely to the internal mammary vessels. In those cases the surgeon needs to be aware of any injury to those vessels which could cause severe bleeding. At the time a bleeding in this particular region is identified, the surgeon needs to stop it immediately through an intercostal approach to the internal mammary vessel. The dissection of intercostal muscles and the insertion of a spreader in the affected intercostal space provides a quick and proper access to the injured vessel.
Drilling too deep has to be avoided, as it may cause life-threatening injuries to the mediastinum. This is ensured by depth limited drilling in combination with the measurement of the sternal thickness and the choice of a drill bit of corresponding length12.
Summarizing the discussed procedure and possible limitations, performing anterior sternal plating with low profile locked titanium plates is to be expected successful, if a preoperative planning by computed tomography, subperiostal dissection, and depth limited drilling is performed.

Sternal fractures are rare and occur in about 3-8% of all trauma victims1. Usually, these fractures are caused by blunt trauma. Most can be treated conservatively with a sufficient consolidation of the fracture. Some fractures show prolonged healing or even a lack of consolidation with the consecutive development of a pseudarthrosis and persistent painful instability2,3. In these cases surgical stabilization has to be considered. Respecting the different trauma-mechanisms responsible for sternal fractures such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, a primarily stabilization of the fractures should be considered4-6. Possible indications for surgical treatment are: severe or persistent pain; respiratory failure or dependency on mechanical ventilation; shifted, overlapping or impacted fractures, as well as deformity or instability of the sternum; hunched posture and restricted movement of the trunk7.
There is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum in order to restore anatomical shape and normal function of the anterior chest wall. In this context anterior sternal plating provides the best stability and is therefore increasingly used in the majority of cases. The advantage in stability by using a plate instead of wires has already been described in sternum closure after median sternotomy8. The use of locked plates gains importance due to their advantages in biological internal fixation. The principle of a locked plate is the fixation between the threaded screw head and the threaded screw hole of the plate. Thereby the locked plate acts as an internal fixator with the advantage of a minimized plate-bone contact preserving the periosteal blood supply below the plate9.
However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications. Difficulties in preoperative planning, severe injuries to mediastinal organs or failure of the performed method may be possible reasons10. Only case reports or small series are described for each procedure. Table 1 shows different surgical methods and a selection of trails describing and analyzing them.
<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>OP-technique</td>
			<td>Year</td>
			<td>Author</td>
			<td>Study</td>
			<td>Number of patients with surgery</td>
			<td>Outcome</td>
		</tr>
		<tr>
			<td colspan="6">locked plate fixation</td>
		</tr>
		<tr>
			<td>3.5/4.0 mm fixed angle plate (LCP)</td>
			<td>2010</td>
			<td>Gloyer et al. [10]</td>
			<td>Osteosynthesis of traumatic manubriosternal dislocations and sternal fractures with a 3.5/4.0 fixed angle plate (LCP)</td>
			<td>3</td>
			<td>no functional restrictions, no pain</td>
		</tr>
		<tr>
			<td>locked plate (TiFix)</td>
			<td>2010</td>
			<td>Queitsch et al. [3]</td>
			<td>Treatment of posttraumatic sternal non-union with a locked sternum-osteosynthesis plate (TiFix).</td>
			<td>12</td>
			<td>consolidation in all cases</td>
		</tr>
		<tr>
			<td>low profile titanium plate (MatrixRib)&#160;</td>
			<td>2013</td>
			<td>Schulz-Drost et al. [11]</td>
			<td>Surgical fixation of sternal fractures: locked plate fixation by low-profile titanium plates - surgical safety through depth limited drilling</td>
			<td>10</td>
			<td>after 12 weeks consolidation in all cases, no dislocation, patient satisfaction 1.4, no complications in follow up</td>
		</tr>
		<tr>
			<td>SternaLock</td>
			<td>2005</td>
			<td>Wu et al. [12]</td>
			<td>Sternal nonunion: a review of current treatments and a new method of rigid fixation</td>
			<td>2</td>
			<td>good functional outcome</td>
		</tr>
		<tr>
			<td colspan="6">Steel wires</td>
		</tr>
		<tr>
			<td>Stainless steel wires</td>
			<td>2002</td>
			<td>Athanassiadi et al. [1]</td>
			<td>Sternal fractures: retrospective analysis of 100 cases</td>
			<td>2</td>
			<td>good functional outcome</td>
		</tr>
		<tr>
			<td>Stainless steel wires</td>
			<td>2002</td>
			<td>Potaris et al. [13]</td>
			<td>Management of sternal fractures of 239 cases</td>
			<td>4</td>
			<td>good functional outcome</td>
		</tr>
		<tr>
			<td>Sternal wire, bone graft</td>
			<td>2002</td>
			<td>Coons et al. [15]</td>
			<td>Sternal non union: Case report</td>
			<td>2</td>
			<td>one patient with non union</td>
		</tr>
		<tr>
			<td>Steel wires</td>
			<td>2009</td>
			<td>Abdul Rahman et al. [16]</td>
			<td>Comminutes sternal fracture - a sternotomy wire fixation: report of 2 cases</td>
			<td>2</td>
			<td>good functional outcome</td>
		</tr>
		<tr>
			<td>Steel wires</td>
			<td>2009</td>
			<td>Celik et al. [17]</td>
			<td>Sternum fractures and effects of associated injuries</td>
			<td>2</td>
			<td>good functional outcome</td>
		</tr>
		<tr>
			<td colspan="6">non locking plate</td>
		</tr>
		<tr>
			<td>Ant. 6 hole plate, bone graft</td>
			<td>2004</td>
			<td>Bonney et al. [18]</td>
			<td>Sternal fractures: anterior plating rationale</td>
			<td>3</td>
			<td>plate removal after 12 months for personal resons</td>
		</tr>
		<tr>
			<td>Ant. Cervical plates with 4 holes</td>
			<td>2009</td>
			<td>Ciriaco et al. [6]</td>
			<td>Early repair of isolated traumatic sternal fractures unsing a plate system</td>
			<td>6</td>
			<td>one plate removed for sternal pain</td>
		</tr>
		<tr>
			<td>Plate with 3 screws on eachs side of fracture</td>
			<td>1993</td>
			<td>Kitchensens and Richardson [19]</td>
			<td>Open fixation of sternal fractures</td>
			<td>2</td>
			<td>good functional outcome</td>
		</tr>
		<tr>
			<td>T-shaped compression steel plate, non-locking screws</td>
			<td>2006</td>
			<td>Al-Qudah [20]</td>
			<td>Operative treatment of sternal fractures</td>
			<td>4</td>
			<td>2 plates removed no reasons named</td>
		</tr>
		<tr>
			<td>two 8 hole one-third tubular plates; H-plate</td>
			<td>2006</td>
			<td>K&#228;licke et al. [21]</td>
			<td>Traumatic manubriosternal dislocation</td>
			<td>2</td>
			<td>no functional restrictions, no pain</td>
		</tr>
		<tr>
			<td colspan="6">other devices</td>
		</tr>
		<tr>
			<td>2 threaded Steinmann pins, sternal wires</td>
			<td>2005</td>
			<td>Molina [22]</td>
			<td>Evaluation and operative technique to repair isolated sternal fractures</td>
			<td>12</td>
			<td>pin migration in one patient</td>
		</tr>
		<tr>
			<td>Blount staples</td>
			<td>2011</td>
			<td>Abdelhalim El Ibrahimi et al. [23]</td>
			<td>Traumatic manubriosternal dislocation: A new method of stabilization postreduction</td>
			<td>1</td>
			<td>good functional outcome</td>
		</tr>
		<tr>
			<td>Titanium mandibular plates</td>
			<td>2007</td>
			<td>Richardson et al. [24]</td>
			<td>Operative fixation of chest wall fractures: an understood prcedure?</td>
			<td>35</td>
			<td>3 plates removed (1 cardiac surgery, 1 clicking sensation, 1 insurance reasons)</td>
		</tr>
	</tbody>
</table>
Table 1: Fixation options &#8211; a selection of trails. Modified from HARSTON7.
Recently published surveys usually describe the successful anterior plating with a good outcome11.
The use of low-profile-locked titanium plates guarantees a proper stabilization with high patient comfort. Furthermore the fixing of those plates provides surgical safety, as depth limited drilling is used12.
Hence, this manuscript describes one option to stabilize different types of sternal fractures in a step-by-step guidance for anterior sternal plating using low profile locking titanium plates. In addition, preoperative planning is described step by step.
Diagnosis, Assessment, and Plan:
Any patient admitted to the emergency department primarily is managed by performing the ABCDE-rules, known from the Advanced Trauma Life Support, ATLS25. Thereby life-threatening injuries should be detected and immediately treated or ruled out. Afterwards, a detailed survey of the whole patient needs to be performed to detect any injury. If the patient suffers from pain in the chest or even shows an unstable chest wall with paradox respiratory movements, a sternal fracture needs to be ruled out.
Any patient with suspected sternal fracture receives helical computed tomography of the thorax. In context with suspected concomitant injuries, all patients are examined by a whole body multi-slice CT. A three-dimensional reconstruction of CT data can describe the fracture&#8217;s morphology in detail6. The affected region needs to be described as well as the fracture&#8217;s direction and possible dislocation of the fragments.
As indications for surgical treatment the unstable anterior chest wall needs to be considered as well as fracture displacement and a persistent, painful instability of more than seven days7,12. Once the decision for surgery of the sternal fracture is made, a reassessment of any concomitant injury should be performed, in order to put the treatment of multiple injuries in an appropriate sequence.
The following protocol shows one possible standard for surgical treatment of (isolated) sternal fractures whereby the possibility of a conservative treatment in most types of fractures needs to be emphasized at this point. In case of concomitant rib fractures additional considerations, which are not shown here, become necessary.

<table border="0" cellpadding="0" cellspacing="0" width="757">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">Name of Material/ Equipment</td>
			<td style="width:155px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:251px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;"></td>
			<td style="width:155px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">MatrixRIB</td>
			<td style="width:155px;">DePuySynthes CMF</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">LCP Forefood/Middlefood 2.4/2.7</td>
			<td style="width:155px;">DePuySynthes CMF</td>
			<td style="width:119px;"></td>
			<td>only compression wires are employed</td>
		</tr>
	</tbody>
</table>

surgical fixation of sternal fractures: preoperative planning and a safe surgical technique using locked titanium plates and depth limited drilling

Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method.
This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture&#8217;s morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures.
Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels.
Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology.

The preoperatively performed computed tomography provides a detailed survey of the whole sternum and the adjacent ribs. Using different windows of the CT data allows a detailed analysis of the bones as well as the adjacent cartilage of the ribs and the surrounding tissue. All fractures of the injured anterior chest wall should be detected. Axial pictures show injuries to cartilage in soft tissue window and disruption of sternocostal joints. Furthermore, the bone window shows longitudinal and oblique fractures of sternum, whereas transverse fractures are rarely detected in this plane. Coronal reconstructed pictures describe the fracture&#8217;s direction from a similar point of view to the one during surgical treatment. The dislocation of the fragments in relationship to the midline can be described properly. The sagittal view shows the dislocation of fragments in the anterior &#8211; posterior direction. A possible disruption of angulus sterni, the synchondrosis between manubrium and corpus sterni is shown best in this plane. These steps are shown in Figure 1a-d.
Following the steps 1.2-1.4 allows a concise planning of the surgical approach. The supine positioning allows full access to anterior chest wall and both axles (Figure 2a). Marking the landmarks simplifies the identification of the midline as shown in step 2.3 (Figure 2b).
All injured parts of the sternum and the adjacent ribs can be reached without problems while performing a median approach following steps mentioned above (Figure 2c).
Performing an incision of the sternal periosteum longitudinally along the front edge of the sternum and inserting an elevator device to the posterior surface allows the reduction of any dislocated fragment and prevents injuries to the adjacent internal thoracic vessels and the mediastinum as shown in Figure 4a. Moreover, depth limited drilling can be carried out by measurement of the sternal thickness at first (Figure 3a) and the choice of a drill bit with the corresponding length (Figure 3b, c).
The insertion of a pointed ball forceps might be difficult in some cases, e.g., at the manubrium. In those cases anteriorly placed compression wires (length = maximum sternal thickness) will help to reduce the fracture and fix the plate temporarily (Figure 4a-c).
The fixation of each fragment using at least three screws usually shows a proper stabilization for transverse as well as for oblique and longitudinal fractures (Figure 5a, b). Fixing separated ribs to the sternum can be performed by sterno-costal plating as well leading to a stable conjunction26 (Figure 5b).
At the time, all unstable parts of the anterior chest wall are fixed by plates. The anterior chest wall appears as a stable sternocostal union with physiologic respiratory movement. Respecting anatomical layers obtains the most precise wound closure; wound complications are usually rare.
Postoperatively taken chest x-rays in two planes show the correct reduction of the fracture and the correct positioning of the implants which were administered (Figure 5c). The 6 week follow up usually shows first callus surrounding the fracture and after twelve weeks consolidation usually can be observed.

Watch this Scientific Journal Video about Surgical Fixation of Sternal Fractures: Preoperative Planning and a Safe Surgical Technique Using Locked Titanium Plates and Depth Limited Drilling at JoVE.co

Surgical Fixation of Sternal Fractures: Preoperative Planning and a Safe Surgical Technique Using Locked Titanium Plates and Depth Limited Drilling

Here we present a method to stabilize sternal fractures by using locked titanium plates in a low profile design. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates provides a safe surgical way.

Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the ...

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62.7K Views.  University Hospital Erlangen. Here we present a method to stabilize sternal fractures by using locked titanium plates in a low profile design. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates provides a safe surgical way.

Video: Surgical Fixation of Sternal Fractures: Preoperative Planning and a Safe Surgical Technique Using Locked Titanium Plates and Depth Limited Drilling

Surgical Technique for Spinal Cord Delivery of Therapies: Demonstration of Procedure in Gottingen Minipigs

This is a compact visual description of a combination of surgical technique and device for the delivery of (gene and cell) therapies into the spinal cord. While the technique is demonstrated in the animal, the procedure is FDA-approved and currently being used for stem cell transplantation into the spinal cords of patients with ALS. While the FDA has recognized proof-of-principle data on therapeutic efficacy in highly characterized rodent models, the use of large animals is considered critical for validating the combination of a surgical procedure, a device, and the safety of a final therapy for human use. The size, anatomy, and general vulnerability of the spine and spinal cord of the swine are recognized to better model the human. Moreover, the surgical process of exposing and manipulating the spinal cord as well as closing the wound in the pig is virtually indistinguishable from the human. We believe that the healthy pig model represents a critical first step in the study of procedural safety.

Short visual description of the surgical technique and device used for the delivery of (gene and cell) therapies into the spinal cord. The technique is demonstrated in the animal but is entirely translatable and currently being used for human application.

This is a  compact visual description of a combination of surgical technique and device  for the  delivery of (gene and cell) therapies into the spinal ...

The Mouse Round-window Approach for Ototoxic Agent Delivery: A Rapid and Reliable Technique for Inducing Cochlear Cell Degeneration

Investigators have utilized a wide array of animal models and investigative techniques to study the mammalian auditory system. Much of the basic research involving the cochlea and its associated neural pathways entails exposure of model cochleae to a variety of ototoxic agents. This allows investigators to study the effects of targeted damage to cochlear structures, and in some cases, the self-repair or regeneration of those structures. Various techniques exist for delivery of ototoxic agents to the cochlea. When selecting a particular technique, investigators must consider a number of factors, including the induction of inadvertent systemic toxicity, the amount of cochlear damage produced by the surgical procedure itself, the type of lesion desired, animal survivability, and reproducibility/reliability of results. Currently established techniques include parenteral injection, intra-peritoneal injection, trans-tympanic injection, endolymphatic sac injection, and cochleostomy with perilymphatic perfusion. Each of these methods has been successfully utilized and is well described in the literature; yet, each has various shortcomings. Here, we present a technique for topical application of ototoxic agents directly to the round window niche. This technique is non-invasive to inner ear structures, produces rapid onset of reliably targeted lesions, avoids systemic toxicity, and allows for an intra-animal control (the contra-lateral ear). Results stemming from this approach have helped deeper understanding of auditory pathophysiology, cochlear cell degeneration, and regenerative capacity in response to an acute injury. Future investigations may use this method to conduct interventional studies involving gene therapy and stem cell transplantation to combat hearing loss.

Various methods exist for introducing ototoxic agents to the cochleae of animal models. Presented is a surgical protocol for delivery of ototoxic agents to the round window niche. The procedure is reliable, creates targeted intra-cochlear lesions, and avoids mechanical damage to the microarchitecture. Examination of cochlear self-repair/regeneration is possible.

Investigators have utilized a wide array of animal models and investigative techniques to study the mammalian auditory system. Much of the basic research ...

Using Saccadometry with Deep Brain Stimulation to Study Normal and Pathological Brain Function

The oculomotor system involves a large number of brain areas including parts of the basal ganglia, and various neurodegenerative diseases including Parkinson's and Huntington's can disrupt it. People with Parkinson's disease, for example, tend to have increased saccadic latencies. Consequently, the quantitative measurement of saccadic eye movements has received considerable attention as a potential biomarker for neurodegenerative conditions. A lot more can be learned about the brain in both health and disease by observing what happens to eye movements when the function of specific brain areas is perturbed. Deep brain stimulation is a surgical intervention used for the management of a range of neurological conditions including Parkinson's disease, in which stimulating electrodes are placed in specific brain areas including several sites in the basal ganglia. Eye movement measurements can then be made with the stimulator systems both off and on and the results compared. With suitable experimental design, this approach can be used to study the pathophysiology of the disease being treated, the mechanism by which DBS exerts it beneficial effects, and even aspects of normal neurophysiology.

This paper describes the use of quantitative measurement of eye movements in conjunction with stimulation of focal areas of the deep brain in order to study physiology, pathophysiology, and the mechanisms of deep brain stimulation.

The oculomotor system involves a large number of brain areas including parts of the basal ganglia, and various neurodegenerative diseases including ...

Generation of a Humanized Mouse Liver Using Human Hepatic Stem Cells

A novel animal model involving chimeric mice with humanized livers established via human hepatocyte transplantation has been developed. These mice, in which the liver has been repopulated with functional human hepatocytes, could serve as a useful tool for investigating human hepatic cell biology, drug metabolism, and other preclinical applications. One of the key factors required for successful transplantation of human hepatocytes into mice is the elimination of the endogenous hepatocytes to prevent competition with the human cells and provide a suitable space and microenvironment for promoting human donor cell expansion and differentiation. To date, two major liver injury mouse models utilizing fumarylacetoacetate hydrolase (Fah) and uroplasminogen activator (uPA) mice have been established. However, Fah mice are used mainly with mature hepatocytes and the application of the uPA model is limited by decreased breeding. To overcome these limitations, Alb-toxin receptor mediated cell knockout (TRECK)/SCID mice were used for in vivo differentiation of immature human hepatocytes and humanized liver generation. Human hepatic stem cells (HpSCs) successfully repopulated the livers of Alb-TRECK/SCID mice that had developed lethal fulminant hepatic failure following diphtheria toxin (DT) treatment. This model of a humanized liver in Alb-TRECK/SCID mice will have functional applications in studies involving drug metabolism and drug-drug interactions and will promote other in vivo and in vitro studies.

Here, we present a novel humanized mouse liver model generated in Alb-toxin receptor mediated cell knockout (TRECK)/SCID mice following the transplantation of immature and expandable human hepatic stem cells.

A novel animal model involving chimeric mice with humanized livers established via human hepatocyte transplantation has been developed. These mice, in ...

Intravital Microscopy of Tumor-associated Vasculature Using Advanced Dorsal Skinfold Window Chambers on Transgenic Fluorescent Mice

Tumor and tumor vessel development, as well as tumor response to therapeutics, are highly dynamic biological processes. Histology provides static information and is often not sufficient for a correct interpretation. Intravital evaluation, in which a process is followed in time, provides extra and often unexpected information. With the creation of transgenic animals expressing cell-specific markers and live cell tracers, improvements to imaging equipment, and the development of several imaging chambers, intravital microscopy has become an important tool to better understand biological processes. This paper describes an experimental design for the investigation of tumor vessel development and of therapeutic effects in a spatial and temporal manner. Using this setup, the stage of vessel development, tip cell and lumen formation, blood flow, extravasation, an established vascular bed, and vascular destruction can be visualized and followed. Furthermore, therapeutic effects, intratumoral fate, and the localization of chemotherapeutic compounds can also be followed.

This protocol describes the intravital imaging of transgenic mice expressing cell-specific fluorescent markers. Intravital imaging provides a non-invasive method for high-resolution observations in living animals using implantable windows through which the microscopic visualization of processes is possible. This method is especially useful to study longitudinal processes.

Tumor and tumor vessel development, as well as tumor response to therapeutics, are highly dynamic biological processes. Histology provides static ...

Using In Vitro Live-cell Imaging to Explore Chemotherapeutics Delivered by Lipid-based Nanoparticles

Conventional imaging techniques can provide detailed information about cellular processes. However, this information is based on static images in an otherwise dynamic system, and successive phases are easily overlooked or misinterpreted. Live-cell imaging and time-lapse microscopy, in which living cells can be followed for hours or even days in a more or less continuous fashion, are therefore very informative. The protocol described here allows for the investigation of the fate of chemotherapeutic nanoparticles after the delivery of doxorubicin (dox) in living cells. Dox is an intercalating agent that must be released from its nanocarrier to become biologically active. In spite of its clinical registration for more than two decades, its uptake, breakdown, and drug release are still not fully understood. This article explores the hypothesis that lipid-based nanoparticles are taken up by the tumor cells and are slowly degraded. Released dox is then translocated to the nucleus. To prevent fixation artifacts, live-cell imaging and time-lapse microscopy, described in this experimental procedure, can be applied.

Using In Vitro Live-cell Imaging to Explore Chemotherapeutics Delivered by Lipid-based Nanoparticles

Live-cell imaging is a powerful tool to visualize dynamic processes. The examination of fixed cells provides only static pictures, which can lead to misinterpretation and confusion about the process. This work presents a method to study uptake, drug release, and intracellular localization of liposomal nanoparticles in living cells.

Conventional imaging techniques can provide detailed information about cellular processes. However, this information is based on static images in an ...

A Rat Model of Orthotopic Liver Transplantation Using a Novel Magnetic Anastomosis Technique for Suprahepatic Vena Cava Reconstruction

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep learning curve. The introduction of the cuff technique for anastomosis of the portal vein (PV) and infrahepatic vena cava (IHVC) has significantly simplified the transplant procedure in rats. However, due to the short anterior wall of the recipients' suprahepatic vena cava (SHVC), the cuff technique is very difficult to use for the reconstruction of the SHVC. Most researchers in this field still use the hand-suture technique for SHVC reconstruction, which makes it the bottleneck step in rat orthotopic liver transplantation. The magnetic anastomosis technique (i.e., magnamosis) is a method of connecting two vessels using the attractive force between two magnets. Our recent study has shown that the magnetic anastomosis technique is superior to the hand-suture technique for SHVC reconstruction in rats. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using the novel magnetic anastomosis technique. In this model, the reconstruction of the PV and IHVC was performed by the standard cuff technique, while the reconstruction of the bile duct (BD) was performed by a stent technique. The hepatic re-arterialization was not performed. The magnetic anastomosis technique made SHVC reconstruction much easier and significantly shortened the anphepatic phase. After a reasonable learning curve, even researchers without advanced microsurgical skills can produce reliable and reproducible results using this rat model of OLT.

The reconstruction of the suprahepatic vena cava (SHVC) remains a difficult step in rat orthotopic liver transplantation. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using a novel magnetic anastomosis technique.

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep ...

Laparoscopic Radical Left Pancreatectomy for Pancreatic Cancer: Surgical Strategy and Technique Video

Radical resection margins, resection of Gerota&#8217;s (perirenal) fascia, and adequate lymph node dissection are crucial for an adequate oncological resection of left-sided pancreatic cancer. Several surgical techniques have been described in recent years, but few were specifically designed for minimally invasive approaches. This study describes and demonstrates a standardized and reproducible technique for an adequate oncological resection of pancreatic cancer: laparoscopic radical left pancreatectomy (LRLP).
A 61-year-old woman presented with an incidental finding of a 3 cm mass in the left pancreas suspect for malignancy. Imaging did not reveal distant metastases, central vascular involvement, or morbid obesity, hence the patient was suitable for LRLP. This study describes the main steps of LRLP for pancreatic cancer. First, the lesser sac is opened by transecting the gastrocolic ligament. The splenic flexure of the colon is mobilized and the inferior border of the pancreas including Gerota&#39;s fascia is dissected down to the inferior border of the spleen. The pancreas is tunneled and hung, including Gerota&#8217;s fascia with a vessel loop. At the pancreatic neck, a tunnel is created between the pancreas and the portal vein, likewise a vessel loop is passed. The pancreas is then transected using the graded compression technique with an endostapler. Both the splenic vein and artery are transected before completing the resection. The entire specimen is extracted in a retrieval bag via a small Pfannenstiel incision.
Duration of the surgery was 210 min with 250 mL blood loss. Pathology revealed a R0-resection (&#62;1 mm) of a well-to-moderately differentiated adenocarcinoma originating from an intraductal papillary mucinous neoplasm. A total of 15 tumor-negative lymph nodes were resected. This is a detailed description of LRLP for left-sided pancreatic cancer as is currently being used within the international, multicenter randomized DIPLOMA (Distal Pancreatectomy Minimally Invasive or Open for PDAC) trial.

Oncologically safe left pancreatectomy requires radical resection (R0), Gerota&#8217;s (perirenal) fascia resection, and adequate lymph node dissection. This study describes the technical details of laparoscopic radical left pancreatectomy (LRLP), used in the first international multicenter randomized trial comparing minimally invasive with open left pancreatectomy for pancreatic cancer, the DIPLOMA trial.

Radical resection margins, resection of Gerota&#8217;s (perirenal) fascia, and adequate lymph node dissection are crucial for an adequate oncological ...

Sleeve Gastrectomy in Mice using Surgical Clips

The number of people who are overweight and obese is continually increasing both in the adult and adolescent populations. This coincides with the increased universal phenomenon of type 2 diabetes (T2D) and other metabolic problems. Bariatric surgery, such as SG, is currently one of the most effective and commonly used long-term treatment for obesity and T2D, but the association between them is not completely explored yet. The mechanisms underlying the outcomes seen after bariatric surgery in humans can be investigated based on preclinical animal studies. The SG reduces body weight, glucose levels and many metabolic parameters, and is easy to perform with a low incidence of complications. The goal of this work is to provide a simple method and an uncomplicated preclinical model of bariatric surgery in animals for researchers.

The prevalence of diabetes and obesity is continuously increasing worldwide. The mechanisms between diabetes, obesity and their associated mortality and co-morbidities need to be further investigated. Here, we present a protocol for sleeve gastrectomy (SG) in animals as an uncomplicated preclinical model of bariatric surgery.

The number of people who are overweight and obese is continually increasing both in the adult and adolescent populations. This coincides with the ...

Endaural Endoscopic Atticoantrotomy (Retrograde Mastoidectomy) using a Constant Suction Bone-drilling Technique

Endoscopic middle ear surgery is a widely employed minimally invasive surgical technique to address middle ear and mastoid pathology. Bone drilling is the main technical challenge of endoscopic middle ear surgery. The accompanying video describes the detailed protocol of a constant-suction bone-drilling technique and the procedure of endaural exclusive endoscopic atticoantrotomy (retrograde mastoidectomy) using this technique. The main components of this bone-drilling technique include a soft and flexible suction tube, which is placed into the tympanic cavity to provide constant suction, and a soft sleeve, which is wrapped around the drill shaft to prevent the high-speed rotating shaft from damaging the lens of the endoscope. With these simple modifications, the traditional otological electrodrill can be used for drilling a tiny endaural incision in endoscopic middle ear surgery. Based on this bone-drilling technique, endaural endoscopic atticoantrotomy (retrograde mastoidectomy) can be successfully established for the removal of various amounts of bone, depending on the extent of the lesion. The short-term postoperative outcome seems promising.

Endaural Endoscopic Atticoantrotomy Retrograde Mastoidectomy using a Constant Suction Bone-drilling Technique

In this paper, we present the protocol and short-term outcomes of endaural exclusive endoscopic atticoantrotomy using a constant suction bone-drilling technique.

Endoscopic middle ear surgery is a widely employed minimally invasive surgical technique to address middle ear and mastoid pathology. Bone drilling is the ...