CHAPTER XXXII. FRACTURES OF THE STERNUM. (Part 1)

CHAPTER XXXII. FRACTURES OF THE STERNUM. Surgical Anatomy. — The sternum is rarely fractured. Firstly, because of the protection afforded by the arms in case of accident, and secondl}^, because of its situation and structure. It is composed of a soft, spongy tissue encased in a layer of compact bone, and is supported by the ribs and costal cartilages which act as a series of springs which absorb and modify shock. The sternum is usually ossified from six centers ; one each, for the manubrium and ensiform appendix, and four for the gladiolus. Fig. 537. — The sternum. M., manubrium; X., xyphoid cartilage; C, clavicle. The costal cartilages are numbered in order. Considerable variation occurs in the ossification of this bone. The lower sections of the gladiolus are not uncommonly ossified by two centers for each segment, and in anomalous instances lack of fusion between these lateral centers may result in a foramen or fissure in the lower part of the second portion of the sternum, even in adult life. This condition might be mistaken for a fracture if one is not 453 454 FRACTURES AND DISLOCATIONS acquainted Avitli the anomaly. The centers of ossification in the sternum make their appearance in order from above downward, the first being seen as early as the fifth foetal month, w^hile the center for the lower segment of the gladiolus is often not present until the second year. The center for the xyphoid cartilage may make its appearance anywhere between the second and eighteenth years. Fusion of the different segments of the sternum begins at about puberty in the low^er end of the gladiolus, and proceeds upward until the process is completed at about the twenty-fifth year. The xyphoid joins the gladiolus at about fort}'. The period at which fusion occurs between the manubrium and gladiolus is variable. They are usually continuous on the surface after middle life though the center of the articulation often remains soft even in the aged. The anterior mediastinum with its contents lies directly behind the sternum. The pectoralis major is attached to the anterior surface of the bone. The sternomastoid, sternothyroid and sternohyoid are at- tached to the upper end, w^hile the abdominal muscles are attached either directly or through their aponeuroses to the lower end of the bone. The diaphragm and triangularis sterni find attachments to the lower portions of the posterior surface. The anterior mediastinum with its contents lies directly behind the sternum. The heart lies directly behind the lower two-thirds of the sternum (excepting the xyphoid cartilage) . The pericardium is separated from the bone by the remains of the thymus gland above, and a small quantity of areolar tissue below\ The junction of the first and second pieces of the sternum may be felt as a transverse ridge on the bone, passing between the attachments of the second costal cartilages. Violent hyperextension, or overflexion of the spine, particularly the latter, may produce fracture of the sternum. The violent im- pact of the chin against the upper portion of the bone is said to have produced the condition. A blow on the chest ma}^, in rare instances, produce fracture. Gunshot injuries of this bone are not uncommonly seen even in civil life. In the aged, when ossification invades the costal cartilages, and the chest as a wdiole is more rigid, fracture is more easily produced ; but, on the other hand, the occupation and mode of life of those advanced in years expose less to trauma. A number of irregular types of fracture have been reported in which the condition was diagnosed FRACTURES OF THE STERNUM 455 as eoinpound, eommiinited, multiple or longitudinal. These types of fracture, however, are extremely unusual in the sternum, the great majority being simple and transverse at, or near, the junction of the first and second pieces of the bone. The next most common deformity is one in which the upper fragment is displaced forward and slightly overlaps the lower piece. The common deformity con- sists in a displacement of the lower end of the upper fragment behind the lower fragment. The deformity is so characteristic and pronounced that a diagnosis can usually be made by inspection alone. Fig. 538. — Fracture of the sternum. Arrow indicates position of fracture which is in perfect reduction. Case of Dr. N. A. Thompson. Sometimes, however, a simple transverse fracture may exist without displacement, when the condition can only be recognized by palpa- tion, pressure being made first on one fragment and then on the other. The next most common site of fracture is at or near the junction of the first and second pieces of the gladiolus and resembles closely the more usual fracture occurring at Ludwig's angle. Symptoms. — The close relation existing between the sternum and thoracic viscera frequently results in complications involving these structures. It is seldom that we find fracture of the sternum un- accompanied by other injuries, so that the symptom-complex fre- 456 FRACTURES AND DISLOCATIONS quently includes conditions such as fracture of the ribs, fracture of the spine, penetrating wounds of the chest, etc. In fracture of the sternum the patient usually assumes a hollow-chested attitude which is characteristic both in the erect and recumbent positions. Respira- tion is usually painful, rapid and superficial, resembling that seen in fracture of the ribs. Inspection and palpation of the chest usually reveals the charac- teristic deformity in the upper part of the sternum. When no deformity exists, crepitus is, as a rule, elicited without difficulty and in some instances may, by means of the stethoscope, be recog- nized with every respiration. Dislocations between the first and second portions of the sternum, in young persons, produce practically the same symptoms except that crepitus is more likely to be cartilaginous. The distinction between the two, however, is clinically of little importance. Cyanosis and dyspnoea may occur as the result of direct pressure from the displaced fragment. Treatment. — When deformity is absent from the first, or if reduc- tion has taken place spontaneously as sometimes occurs in normal respiration or in coughing, the only indication in the treatment is immobilization, which is most satisfactoril}^ accomplished by strap- ping the chest with adhesive plaster in a manner similar to that employed in fracture of the ribs. Direct pressure on either of the fragments may be obtained by a pad of gauze properly placed and held in position by adhesive plaster placed diagonally across the chest. A plaster cast including the chest and shoulders may be employed instead of the adhesive, although it does not accomplish the purposes of fixation any more satisfactorily. When deformity is present, it should be corrected before the chest is fixed. The reduction of displacement is accomplished in all instances by upward traction on the upper fragment, and downward traction on the lower. As a rule this is effected by posture, the traction and countertraction being applied indirectly through the muscles and other portions of the thorax. If the patient is placed on a table in the dorsal position with head and shoulders over the edge so that hyperextension of the spine is accomplished, reduction will usually follow without further manipu- lation of the fragments. Raising the arms above the head and direct pressure on the projecting fragment will facilitate correcting the deformity when simple hyperextension of the spine proves insuf- FRACTURES OF THE STERNUM 457 ficient. After the fragment has been brought into proper position the chest is fixed as previously described. Operative Treatment. — Various methods have been described for the open treatment of these deformities when simpler methods have failed to accomplish reduction, but it will be unnecessary to enter into the minutia? of these surgical procedures since they all are based Fig. 539. — Method of correcting deformity in overriding fracture of sternum. Fig. 540. — The method shown in Fig. 539 has been supplemented l)y di pressure on the inner ends of the clavicles vi^ith the finger tips. t upward on the same principles of traction, counter traction and manipula- tion after the fragments have been exposed by incision. Elevation has been accomplished by means of screws inserted into the depressed fragment. As a rule it will not be a difficult matter to pry the depressed portion of the sternum back into position with some strong instrument such as a periosteal elevator. The greatest care should 458 FRACTURES AND DISLOCATIONS be exercised not to insert the instrument too far or in any way, either by cutting or laceration of the tissues, to open the pleural or pericardial sacs. In operating in this region we should bear in mind the course of the internal mammary artery one-half inch external to, and parallel with the lateral border of the sternum. If the origin of the pectoralis major interferes with the operative manipulations the fibres should be cut away so that the fragments are properly exposed. When reduction has been accomplished the incision is to be closed without drainage, and provision made in the fixation apparatus for the subsequent dressing of the wound during the after-treatment. After-Treatment. — Fixation of the chest should be maintained for from six to eight weeks following the accident and heavy work or violent exercise forbidden for another two or three weeks. Differ- ent types of steel braces and apparatus have been used with success to immobilize the chest and neck though they are seldom called for in a simple case. Prognosis. — The prognosis of simple, uncomplicated fracture of the sternum is good both as to life and function, but the frequency with which this fracture is associated with severe crushing injuries, such as fractures of the spine and complications of the thoracic viscera, renders the outlook variable, since the prognosis in these i:: stances is that of the complication rather than the fracture itself. CHAPTEE XXXIII. FRACTURES OF THE RIBS. Surgical Anatomy. — The surprising degree of trauma which the ribs are capable of withstanding is the result of their mobility and the natural spring which they possess. The first rib is the shortest, the seventh the longest. They are diagonally placed so that the posterior end of a given rib is at a considerably higher level than the anterior extremity. They increase in obliquity from above downward to the ninth rib, below which they become again more horizontal. The upper seven ribs are connected with the sternum through their own costal cartilages. The next three are attached through their cartilages to the ribs above, while the remaining two are floating. The first rib joins the sternum through its cartilage just below and behind the sterno-clavicular articulation. The sec- ond costal cartilage joins the sides of the sternum at Ludwig's angle. The lower border of the pectoralis major leads to the fifth rib, while the first visible digitation of the serratus magnus is attached to the sixth. The lower border of the tenth rib forms, from a surgical standpoint, the lower border of the thorax. The inferior margin of each rib is grooved on its deep aspect for the corresponding intercostal vessels. The sixth and seventh ribs are the ones most frequently fractured. The upper two ribs are more or less protected by the clavicle, while the heavy muscles of the back and the unattached condition of the eleventh and twelfth renders these lower ribs even more capable of withstanding trauma. The ribs may be broken by direct or indirect violence. The former occurs when the rib is fractured and driven inward at the point of impact ; the latter when breaking results from bending, as in forcible compression of the chest wall. The weakest point in the rib is just anterior to the angle, and it is here that fracture most often occurs when the result of indirect violence. The costal cartilages may be broken, a not uncommon site being at their junc- tion with the ribs. The close relations existing between the ribs and pleura account for the frequency of complications involving 459 460 l^^RACTURES AND DISLOCATIONS this membrane and the underlying lung, especially in fractures produced by indirect violence. When a single rib is fractured there is little tendency toward displacement, since both ends are fixed, and the intercostal mus- cles maintain its relations with the ribs above and below. "When a number of consecutive ribs are fractured there is greater proba- Fractures of third, fourth, fifth and sixth ribs. bility of deformity, as is also the case when a single rib is broken in two or more places. Dislocation of the ribs may occur at either end, though their structure and the strength of their articulations render fracture by far the more common injury. Dislocation may occur at the vertebral ends of the ribs or at the mesial end of the first, second, eighth, ninth and tenth costal cartilages. FRACTURES OF THE RIBS 461 Symptoms. — Pain is a constant sj^mptom, being well localized in the region of the fracture. It is greatly increased by breathing, especially by deep inspiration. Coughing and sneezing render the suffering momentarily more intense. The patient usually stands or sits in an attitude characteristic of the condition, with the trunk Fig. 542. — Caving- in of chest with fracture of a number of ribs, the result of direct violence. Note the flattened condition of the chest on the patient's right side. Case seen with Dr. H. R. McGraw. Fig. 543. — Fracture and dibpluccuieut of a costal cartilage. bent slightly forward and toward the injured side. Respiration is shallow and rapid. The pectoral excursion on the injured side is usually less than that observed on the well side of tlie chest. Abnormal mobility is often present in the fractured rib near the site of the break. Crepitus may, or may not, be present accord- 462 FRACTURES AND DISLOCATIONS ing to the relation of the serrated ends of the fragments. Swell- ing of the parts is slight, if present at all. Ecchymosis may make its appearance within the first twenty-four to forty-eight hours following the accident. The lung may be penetrated by one of the fractured ends. Bloody expectoration and subcutaneous emphysema are the most common indications of this complication. In pronounced cases the subcutaneous tissues of the chest, face, neck and arms may be extensively distended with air. Palpation gives a distinct sense of crepitation when air exists within the tis- sues. Traumatic pneumonia may follow if the lung is injured. Diagnosis. — The diagnosis is based on the symptoms just de- scribed, together with a careful and systematic examination of the chest. The ribs should be palpated in order, from above down- ward, for the purpose of recognizing crepitus and abnormal mo- bility. If pressure is made on a given rib, anteriorly (say the seventh), while the fingers of the opposite hand rest on the same rib in the posterior axillary line, the motion imparted to the rib, anteriorly, may be recognized by the opposite hand if the rib is intact between the points of palpation. If fracture is present, crepitus may be elicited in this manner, and dissolution of con- tinuity appreciated when present. As previously stated the ribs possess a certain amount of spring, wdiich quality should be tested w^hen examining for fracture. If the chest be gently compressed antero-posteriorly pain wdll be produced or increased at the seat of fracture, which is promptly recognized and indicated by the pa- tient. Crepitus, even with shallow respiration, may sometimes be determined by the stethoscope. Fractures of the posterior ex- tremities of the ribs are not infrequently extremely difficult to diag- nose because of their deep situation under the heavy muscles of the back. In such instances a radiogram will make the diagnosis possible. Treatment. — Fixation of the injured side of the chest is the first indication in fractures of the ribs. This is best accomplished by strapping the chest wdth zinc oxide adhesive plaster. The usual method of applying the adhesive straps or swathe to the back first, and then encircling the chest during expiration is contrary to the principles of surgical anatomy in this region. The anterior por- tion of the chest is the movable part, while the spinal portion is fixed. The strapping therefore should be done from before back- ward (see Fig. 544). AA^ien the injured side of the thorax is FRACTURES OF THE RIBS 463 fixed, relief from suffering is prompt and pronounced. The fact that the chest in respiration moves as a whole, renders it unneces- sary to always apply the strapping directly over the rib fractured. If the lower portion of the chest is fixed on the affected side, relief will follow, even though the fracture be situated in one of the upper ribs. In other words, if the lower four or five ribs are fixed on the aft'ected side motion in the entire half of the chest will be restricted. In severe fractures of the ribs, or in those presenting symptoms of pulmonary complications the strapping should not be applied too tightly, lest additional injury be done to the lung by forcing a displaced fragment or spicule into its substance. If suft'ering is not sufficiently relieved by strapping, the use of opiates Fig. 544. — Adhesive plaster strapping for fracture of the ribs. may be necessary during the first day or two following the accident. In fleshy persons, especially in women with pendulous breasts, fixation of the thorax is more difficult. The amount of subcu- taneous tissue renders the skin more mobile and cutaneous irrita- tion seems to be more readily produced, accordingly strapping is less satisfactory. In these cases a swathe snugly surrounding the lower chest will usually answer the purpose better than strapping. Subcutaneous emphysema does not ordinarily call for special measures, yet should the condition become severe it may be re- lieved by multiple incisions. After-Treatment,— The fixation dressing should be maintained for a period of about three weeks. In the milder cases in which a single rib is fractured, the patient may be up