CHAPTER XXXVII. FRACTURES OF THE UPPER END OF TPIE FEMUR. (Part 1)

CHAPTER XXXVII. FRACTURES OF THE UPPER END OF TPIE FEMUR. Surgical Anatomy. — The upper end of the femur has three accessory centers of ossification ; one for the head, one for the greater, and one for the lesser trochanter. They all join the diaphysis at about the eighteenth year. Epiphyseal separations, however, are extremely rare in the upper end of this bone, except as a chronic condition in children, which is known as coxa vara. (See "Injuries to the Femoral Neck in Children," page 555.) The structure of the upper end of the femur, including the relation of compact and cancellous tissue, is of importance in explaining many Fig. 586. Figs. 585 and 586. — Coronal and nearly horizontal sections of the upper end of the femur showing the relative distribution of cancellous and compact tissue. H., head of femur. T., trochanter major. (Preston — Surg., Gynecol, and Obstet., Feb., 1914.) of the clinical conditions occurring in fractures (see Figs. 585 and 586). The upper end of the bone is composed of wide-meshed cancellated tissue, enclosed in a layer of compact structure which grows heavier as the shaft is approached. Closer examination of the cancellous tissue shows that it is disposed in two sets of planes, the socalled "tension planes" and "pressure planes." The former run upward from the outer portion of the shaft into the trochanter, and arch over into the neck and head; the latter ascend from the 531 532 FRACTURES AND DISLOCATIONS inner side of the shaft and pass into the head, while others arch over to the great trochanter. These planes are simply an arrange- ment of the cancellous tissue which renders the same amount of bone more capable of withstanding the pressure and tension to which the femur is subjected by use. The calcar femorale is a thickening in the internal structure of the neck which strengthens the angle of junction between neck and shaft. The neck joins the shaft at an angle of about 127 degrees, al- though variations occur between the limits of 121 and 141 degrees. In children the angle is more obtuse, while in old age it approaches the right angle. The great trochanter is often traversed by a continuation of the compact tissue of the posterior surface of the neck, and although this tends to strengthen the posterior aspect of the neck, yet the arrangement is not as strong as that found anteriorly. Numerous muscles are attached to the upper end of this bone, which influence the relative positions of the fragments in the pres- ence of unimpacted fracture of the neck. Raising of the lower fragment or, in other words, shortening of the lower extremity, is brought about by the action of the ham-string muscles, the adductor group, the glutei, rectus, sartorius, ilio-psoas, tensor vaginae femoris, pectineus and gracilis. Eversion of the lower extremity is the result of the weight of the thigh, the center of gravity being ex- ternal to the articulation of the hip. Eversion, in impacted cases, is due to the manner in which the base of the neck is driven into the trochanter and the fact that the anterior portion of the femoral neck is stronger than the posterior. In addition to the action of the pectineus and the adductor muscles, it will be observed that all the glutei tend to produce outward rotation. Fractures may occur in the neck, close to the head, midway be- tween the head and the great trochanter, or at the base of the neck where it joins the shaft. The last named position is by far the most common. In some instances the fracture may pass in such a manner that it involves the upper portion of the femoral shaft as well as the neck. Fractures have been divided anatomically ac- cording to the position of the break with relation to the capsule. Intra-capsular fractures show a much stronger tendency toward non-union than those outside the capsule. Surgically, however, this distinction is not of gTeat value, since it is almost impossible in a given case to say whether the fracture is within or outside of FRACTURES OF UPPER END OF FEMUR 533 the ligament. jMoreover, post-mortem findings have demonstrated the fact that in the majority of instances in which the neck is broken, the line of fracture is both intra- and extra-capsular ; that is, the fracture passes through the femoral attachment of the liga- ment. The more practical distinction is whether or not the frac- ture is impacted. Impaction consists, as a rule, in the base of the neck being driven into the substance of the great trochanter. If the neck is viewed from above one reason for the frequency with which eversion accompanies impaction will be apparent. The an- terior surface of the neck is almost straight and flush with the front edge of the trochanter, thus offering solid support to the anterior portion of the trochanter in the presence of direct vio- lence. The posterior surface of the neck is much curved and does not come flush with the posterior margin of the trochanter. This results in the posterior portion of the trochanter being much more poorh^ supported than is the anterior, and when direct violence is applied in this region of the bone the posterior aspect of the neck will be more likely to give way than the anterior. The result is, manifestly, eversion when impaction of the femoral neck occurs. The continuation of the compact tissue of the posterior surface of the neck into the trochanter, previously mentioned, tends to strengthen this portion of the bone ; yet this bony tissue is variable and even when present is not sufficiently heavy to increase the strength of the posterior aspect of the femoral neck so that it equals that found in the anterior portion. When the ring of compact tissue surrounding the junction of the neck and shaft is fractured, the neck crushes into the cancellous tissue of the trochanter with comparatively little resistance. The surgeon should know the bony landmarks in this region to be able to properly diagnose and treat fractures of the femoral neck. The crest of the ilium is subcutaneous throughout, the great trochanter can be recognized both by inspection and palpation, and the tuberosity of the ischium can be readily felt. The rela- tive positions of the anterior superior iliac spine, tuber ischii and trochanter major should be known under normal conditions in order that the variations occurring in fractures may be recognized. If a tape is stretched between the anterior superior iliac spine and the tuberosity of the ischium it will correspond to Nelaton's line (see Fig. 587). Normally Nelaton's line about touches the top of the great trochanter. In fracture of the femoral neck with short- 534 FRACTURES AND DISLOCATIONS ening, the top of the trochanter rises above this line. The fascia lata, composed of heavy fibrous tissue, is attached above to the outer lip of the iliac crest, and below to the external tuberosity of the tibia. Under normal conditions this fascia is tense and offers resistance when pressure is made between the iliac crest and tro- chanter; when fracture or disease of the femoral neck results in shortening, this portion of the fascia lata becomes lax, which con- dition may be recognized by comparison with the opposite side. The rarifying changes or osteoporosis occurring in old age affect the entire internal structure of the upper end of the femur, and tend to remove the calcar femorale, and the extension of the pos- terior surface of the neck which continues into the substance of the trochanter. In addition, the surface compact tissue becomes Fis:. 587. — Mapping out of Bryant's triangle and Nelaton's line. A line drawn from the anterior superior iliac spine to the tuberosity of the ischium is known as Nelaton's line and should about touch the top of the great trochanter. (See Fig. 600.) A vertical line dropped from the anterior superior iliac spine to the table on which the patient lies and a vertical line extended upward from the top of the great trochanter form two sides of Bryant's triangle while the third side is formed by Nelaton's line. Bryant's triangle — X.Y.Z. In fractures of the femoral neck the distance Y.Z. is usually shortened. A.S., the anterior superior iliac spine. S., Symphysis pubis. T.I., Tuber ischii. thinner and more brittle. These changes together wdth the alter- ation in the angle at which the neck joins the shaft explain, at least partially, the frequenc}^ of fracture of the femoral neck in the aged. Fracture of the head of the femur is an extremely unusual con- dition, only two or three cases having been reported. It is not an uncommon matter for fractures of the neck of the femur to involve the great trochanter, but isolated fracture of the trochanter is almost as rare as fracture of the head. The cases reported have been due either to direct violence or to muscular action. Isolated fracture of the lesser trochanter is also a rare condition. The re- ported cases seem to have been due to the action of the ilio-psoas. Etiology. — Fracture of the neck of the femur is essentially an accident of advanced life. Fractures of the femur constitute FRACTURES OF UPPER END OF FEMUR 535 Fig. 5SS. — Impacted fracture (if linse of femoral neck. Fig. 589. — Old ununited fracture of midillc of fesiioral neck with upward displace- ment of lower fragment. Tlie upward displacement nf the femur is plainly visible and the manner in which the fascia lata becomes lax betAveen the trochanter and iliac crest is readily appreciated. Fig. 591. Fig. Fig. 590. — Impacted fracture of neck of femur. 591. — Fracture of femoral neck with usual deformitv- •aising of trochanter. 536 FRACTURES AND DISLOCATIONS Fig. 592. Fig. 593. Fig. 592. — Fracture of rim of acetabulum. Upper arrow points to line of fracture while the lower indicates the detached fragment. Deformity controlled by Buck's exten- sion. Fig. 593. — Fracture of a small portion of the great trochanter with separation of the fragment. Result of muscular action. A condition which might readily be over- looked and considered as a "sprain" if the X-ray were not employed. Fig. 594. Fig. 595. Fig. 594. — Fracture through femoral neck about midway between head and tro- chanter. Deformity overcome by Buck's extension. Fig. 595. — Fracture through base of femoral neck with splitting off of lesser tro- chanter. FRACTURES OF UPPER END OF FEMUR 537 about six percent of all fractures, and fractures of the neck of the bone make up from one-third to one-fourth of all femoral frac- tures. ]\Iore than half of the fractures of the neck occur after the sixtieth year. They are more common in women than in men. Symptoms. — The physical signs and symptoms in fracture of the femoral neck vary according to whether or not impaction exists. In the unimpacted form the patient is unable to stand on the in- jured member. In fact the lower extremity lies in an entirely helpless attitude. Pain is constant, and increased on motion. The limb is usually completely everted so that the outer surface of the foot rests flat on the bed. The great trochanter is raised above Nelaton's line, and the fascia lata between the trochanter and iliac crest is found relaxed when compared with the opposite side. In- version of the limb, though extremely rare, may be present, instead of eversion. Crepitus and mobility may be elicited, but all manip- ulation should be most gentle and guarded, lest impaction, if present, be broken up. Rotation is particularly likely to loosen the impaction. The limb is shortened, though seldom more than two inches. The shortening is usually less pronounced immedi- ately following the accident than it is at the end of twenty-four or forty-eight hours. Traction upon the foot lessens the shortening, though recurrence is prompt when the foot is released. A slight fullness in the upper portion of Scarpa's triangle is usually noted. "When the fracture is impacted most of the above described symp- toms are present though less pronounced. Slight or moderate eversion is usually noted, and some shortening exists though it is by no means as great as is commonly seen in unimpacted cases. Crepitus is absent. Pain is usually present, though the degree is quite variable. Loss of function is by no means as constant and pronounced as in unimpacted fractures. In fact, a patient with a firmly impacted fracture of the femoral neck may be able to walk a considerable distance. This incomplete loss of function has not infrequently been the cause of incorrect diagnoses, the condition having been mistaken for a ''sprain." Impaction of the fracture produces some shortening of the femoral neck, which may some- times be recognized in the shorter arc described by the trochanter when the thigh is rotated. This shortening, how^ever, is often so slight that it is difficult of recognition, and since rotation is so likely to break up impaction it will usually be best to pass lightly over this symptom. The history given in the usual case of frac- 538 FRACTURES AND DISLOCATIONS Fig. 596. — Impacted fracture of the femoral neck, ing present and eversion is only moderate. Yerv slight degree of shorten- Fig. 597. — Impacted fracture of the neck of tlie femur in an old man. The limb is helpless. Very slight eversion and shortening present. There is no appearance of twisting of the thigh as seen in Fig. 62 6, nor is there any thickening of the thigh as seen in Fig. 598. Rontgenogram sho^vs fracture of the femoral neck. It is this type of case which is so often overlooked and diagnosed as a "sprain" especially if the pa- tient is able to walk. ^ Fig. 598. — Fracture of right femur through great trochanter. Note thickening of the thigh in its upper part and the eversion of the lower extremity. Compare the levels of the two knees which are directly in front of the camera. Right thigh slightly shorter. Picture taken a few minutes following the injury. Fig. 599. — Fracture just below the great trochanter. Note the eversion and shortening FRACTURES OF UPPER END OF FEMUR 539 ture of the femoral neck in elderly persons is one of slight trauma, such as a misstep, a twist of the thigh, or a fall in walking across the room. It is sometimes difficult to ascertain whether the fall pro- duced the fracture, or whether the fracture was spontaneous and resulted in the fall. Diagnosis. — The deep position of the femoral neck, surrounded by heavy muscles and fascige renders palpation of this portion of the bone extremely difficult. The diagnosis is based on the symp- toms just described, together with a careful examination of the lower extremity including mensuration and comparison with the uninjured member. The X-ray is invaluable in diagnosticating Fig. 600. — Drawing a line between the anterior superior iliac spine and the tuberosity of the ischium to determine the relative level of the greater tuberosity. Nelaton's line. (See Fig. 587.) the presence of fracture ; in fact it is the only means of determining accurately the details of the injury. Nelaton's line and Bryant's triangle (see Fig. 587), should be mapped out and the position of the trochanter determined with relation to the bony landmarks of the pelvis. (See ''Anatomy," page 533.) The case should be carefully inspected for the purpose of recognizing deformity, and accurate measurements should be made before manipulation in any form is attempted. The distance from the anterior superior iliac spine to the tubercle of the femur, and then to the internal malleolus should be taken with a steel tape, and compared Avith the distances between the corresponding bony prominences of the opposite lower extremity. In taking these measurements the patient should be placed squarely in bed so that 540 FRACTURES AND DISLOCATIONS a line drawn throngli the anterior superior iliac spines will be at right angles to the spinal column. In other words the pelvis should not be "tipped" at the time the measurements are being taken. Fracture of the femoral neck must be differentiated from dislo- cations of the hip, fracture of the acetabulum with or without dis- Fig. 601 and 602. — Measuring the length of the k)\ver extremity from the anterior supe- rior iliac spine to the tip of the internal mal- leolus. The legs should be parallel and the pelvis should not be tipped. In other word.s a line drawn through the anterior superior iliac spines should be at right angles with the median plane of the body. (See Figs. 603 and 604.) placement of the head, fracture of the pelvis, and fracture of the femoral shaft. The characteristic attitude as- sumed in luxations of the femoral head, the restricted mobility and, in some instances, direct palpation of the displaced head, should serve to distinguish dislocations of the hip from fracture of the femoral neck. In fractures of the fem- oral shaft the position occupied by the great trochanter will be found normal and the point of preternatural mobility will be lo- cated below it. When the thigh is rotated the trochanter will fail to follow the shaft. Fracture of the acetabular ring and certain FRACTURES OF UPPER END OF FEMUR 541 pelvic fractures are occasionally difficult to differentiate from fracture of the femoral neck unless a Rontgenogram is made. In fact the X-ray should be employed in almost all injuries about the Fig. 604. Fig. 603. — Measurements of the lower extremities taken with the legs parallel and the pelvis up-tipped. Fig. 604. — Shows the effect of tipping the pelvis when these measurements are being taken. hip. Inspection, palpation and mensuration may enable one to determine the seat of the lesion but it is impossible to ascertain the exact details and nature of the fracture without the aid of an X-ray plate. Moreover