CHAPTER XLIV. (Part 1)

CHAPTER XLIV. INJURIES JUST BELOW THE KNEE— FRACTURES OF THE TIBIA AND FIBULA (UPPER ENDS). The injuries occurring in this region of the leg and to be con- sidered under this heading are: fracture of the upper end of the tibia (either into or below the knee-joint), separation of the upper tibial epiphysis, fracture of the upper end of the fibula, separation of the upper tibial epiphysis and dislocations of the upper tibio- fibular articulation. Surgical Anatomy. — The broad, expanded, upper extremity of the tibia which forms the tuberosities, is largely subcutaneous and can be readily palpated just below the plane of the knee-joint. The inner tuberosity presents a horizontal groove on its posterior aspect for the insertion of a portion of the semimembranosus. The cir- cumference of the tuberosity is taken up by the attachment of the capsule and the internal lateral ligament. In like manner the circumference of the outer tuberosity is taken up by the capsule on the outer side of the joint, but the external lateral ligaments of the knee are not attached to this bone but to the head of the fibula. The posterior aspect of the outer tuberosity articulates with the upper end of the fibula, and half-way between the tibial tubercle and the fibular head is inserted the lower end of the ilio-tibial band. The upper end of the tibia is composed of cancellous tissue which is encased in a thin layer of compact bone. The heavy compact tissue of the shaft grows rapidly thinner as the upper end of the bone is approached. Fracture of the upper end of the tibia is the result of direct or indirect violence, usually the former. The line of fracture may be vertical, entering the joint cavity, or it may be transverse and below the articulation. Transverse fracture of the upper end of the tibia is usually the result of direct violence and the displace- ment is, as a rule, not great. The superficial position of the bone accounts for the frequency of compound fractures in this region, especially when produced by direct violence. When the fracture 620 INJURIES JUST BELOW THE KNEE 621 enters the joint it is usnally the resnlt of violent adduction or abduction of the leg. T-fractures however are usually the result of violence transmitted to the upper end of the bone in the long axis of the tibia. When this mechanism obtains in the production of fracture of the upper end of the tibia the shaft is driven upward into the upper fragment and usually splits it into two or more pieces. The upper fragment is sometimes extensively comminuted. This type of fracture is most frecpiently the result of a fall from Fig. 674. — Lateral view of the knee before the epiphyses have joined the shaft. Note how the iipper epiphysis of the tibia extends downward anteriorly to include the tubercle of the tibia. This formation is spoken of as the "lipping" of the upper tibial epiphysis. a height in which the patient lands on the foot. In rare instances the shaft may be driven upward into the upper fragment without splitting the latter and the result is likely to be impaction with shortening of the leg, but no abnormal mobility, crepitus, etc. Most of the fractures of the upper end of the tibia entering the joint cavity are accompanied by spreading of the tuberosities. The action of the lateral ligaments in producing fracture of the tuber- osities or of the femoral condyles has been described under "Dislo- cations of the Knee," and again under ''Fractures of the Lower 622 FRACTURES AND DISLOCATIONS End of the Femur." Fracture and avulsion of the spine of the tibia due to the pull of the crucials is a complication of disloca- tions of the knee, and has been mentioned under that heading. The upper epiplwsis of the tibia is ossified from a single center which makes its appearance soon after birth and joins the shaft at about the twentieth year. The epiphyseal cartilage corresponds roughly to a horizontal plane about one inch below the top of the bone. Anteriorly however it dips downward as it approaches the anterior border, to pass under the tibial tubercle. A not uncom- mon anomaly is for the tibial tubercle to be ossified by a separate Fig. 676. Figs. 675 and 676. — An anomaly in the ossification of the upper end of the tibia which is likely to be mistaken for fracture of the tibia. A close examination of an X-ray plate (not print) will show the supposed fragment to be surrounded by a layer of compact tissue and the contour of ossicle does not correspond to the portion of the tibia from which it is supposed to have been broken off. Moreoyer this type of anomaly is almost invariably bilateral. center. This downward extension of the epiphysis to include the tibial tubercle is of importance clinically. The quadriceps extensor is attached to the tubercle through the ligamentum patellae, and with violent contraction of this muscle the anterior part of the epiphysis (the tubercle of the tibia) may be partially or completely separated from the diaphysis. Complete separation of the tibial epiphysis is an extremely rare condition but a starting of the tubercle with a corresponding partial detachment of the epiphj^sis is not uncommon in youth. The upper extremity of the fibula does not enter into the forma- INJURIES JUST BELOW THE KNEE 623 Fig. 677 Fig. 677. — Vertical fracture of upper end of tibia. Fig. 6 7 8. -^Vertical fracture of upper end of tibia. Fig. 67J 679 680. Fig. 679. — Fracture of upper end of tibia involving the external articular surface. Fig. 680. — Splitting of upper end of tibia. Vertical fractures of the upper end of the tibia such as those shown on this page are not uncommon, and if not accurately reduced considerable disturbance in joint function may result. Operative measures are frequently indicated to obtain the best results. 624 FRACTURES AND DISLOCATIONS tion of the knee-joint, thoug-h the two external lateral ligaments of the knee are attached to it. The long head of the biceps (outer hamstring muscle) is inserted around the base of the styloid process, and the attachments of the soleus, peroneus longus and extensor longus dig^itorum are continued upward from the shaft onto the upper extremity of the bone. This epiphysis of the fibula begins to ossify about the fourth jeRr and joins the shaft at about the twenty-fifth. Violent contraction of the biceps is known to have caused fracture of the upper end of the fibula, or separation of the epiphysis, and adduction of the leg has produced the same result through the pull of the external lateral ligaments. Fracture of the upper end of the fibula just below the head of the bone is usually the result of direct violence. Occasionally it accompanies fracture of the upper end of the tibia. The upper tibio-fibular articulation is a simple arthrodial joint with very limited motion. The articular surfaces entering into its formation are flat and the integrity of the joint depends entirely on the strength of the ligaments holding the two bones together. This joint possesses an anterior and a posterior ligament which are thickenings in the capsule surrounding the articulation. Anterior and posterior displacements are prevented as long as the force is not sufficient to rupture these ligaments. Upward displacement is prevented not only by these ligaments but by the interosseous membrane and the lower tibio-fibular articulation. The importance of displacements of the upper end of the fibula depends mainly on the fact that the peroneal nerve winds around the neck of the bone and may be injured with direct violence to the outer side of the leg, or when the head of the fibula is luxated. This nerve can be felt beneath the skin behind the tendon of the biceps. It passes between the tendon of the biceps and the outer head of the gastrocnemius and then winds around the neck of the fibula. It passes forward to join the anterior tibial artery and gives off branches, as it passes down the front of the leg, to supply the extensors of the foot. Injury to this nerve is accompanied by foot drop. Etiology.- — Fractures of the upper ends of the tibia and fibula are usually due to direct violence. Forcible adduction or abduction of the leg may result in fracture of the tuberosities. A^iolence transmitted in the axis of the leg may produce fracture of the upper end of the tibia and fibula, although all forms of indirect INJURIES JUST BELOW THE KNEE 625 violence are more likely to produce fracture below the middle of the shaft. Symptoms. — Because of the variety of fractures which occur in this region, the symptoms seen in different cases vary considerably. The swelling and deformitj^ which accompany simple transverse fracture of the upper end of the tibia may be remarkably slight. I have seen a number of cases suffering from this type of fracture in which the patient was able to bear weight on the leg. The dis- ability, however, is usually complete. Abnormal mobility is almost invariably present although impaction of the lower, into the upper fragment, may result in the leg being quite firm. When the frac- ture is of the T-type or in instances in w^hich one of the tuberosities Fig. 681. — Fracture of upper end of tibia. Note thickening at point indicated by arrow. is broken off, articular distention and traumatic arthritis develop rapidly. Under these circumstances the lateral stability of the knee is usually lost and abnormal lateral mobility is apparent as soon as the parts are manipulated. The leg may be adducted or abducted to an abnormal degree and this maneuver usually pro- duces crepitus. In T-fracture of the upper end of the tibia or in fracture of one of the tuberosities, the tuberosities may be spread to such an extent that the condition is readily recognized by inspection alone. (See Figs. 681 and 682.) The parts below the knee are tender and painful. Fracture in this region, due to direct 626 FRACTURES AND DISLOCATIONS violence, is often compound and if the line of fracture enters the joint it may be followed by suppurative arthritis. Avulsion of the tubercle of the tibia is accompanied by a more or less upward displacement of the patella according to the extent of tearing in the lateral expansions of the aponeurosis of the quadri- ceps extensor. The loose detached fragment can be palpated without difficulty unless the swelling is intense. The ligamentum patellae is abnormally lax. Rupture of the patellar ligament gives Fig. 682. — Longitudinal fracture of the upper end of the right tibia. Tuberosities spread so that finger may be pressed into external articular cavity just above prominence indicated by arrow. Such a fracture will interfere with the use of the knee-joint unless the fragments are brought together and held in place. Operation is usually necessary in this type of case to secure the best results. a similar symptom-complex except for the absence of the detached fragment of the tubercle. Separation of the upper tibial epiphysis is attended by symptoms similar to fracture in this region. The epiphysis may be displaced in any direction. The crepitus produced by manipulation is soft and cartilaginous. The condition is extremely rare. Fracture or epiphyseal separation of the upper end of the fibula is accompanied by local tenderness and pain especially when the leg is used. It is often possible to move the head of the bone about. Crepitus is usually elicited without difficulty. If the fracture is INJURIES JUST BELOW THE KNEE 627 tlirough the tibio-fibnlar articulation or below it, pressure on the shaft of the bone, in the middle of the leg, will produce pain at the seat of fracture. Injur}^ to the peroneal nerve will be productive of characteristic symptoms in motion and sensation throughout the distribution of the nerve. In luxations of the fibular head the upper end of the bone is more prominent than normal and its dis- placement either forward or backward is, as a rule, easily recog- nized. Injuries to vessels and nerves are not as common in this region of the leg as they are in fractures of the lower end of the femur but when they do occur the same train of symptoms will become mani- fest. Diagnosis. — There is, as a rule, little difficulty in recognizing fracture in this region. A simple transverse break, however, just below the tibial tuberosities, may, in rare instances, be difficult to determine without the aid of the X-ray. In the exceptional cases in which the shaft is impacted into the upper fragment with- out splitting the latter, abnormal mobility may be absent, but the condition should be recognized by the shortening of the leg, and in some instances there W'ill be sufficient angular deformity to indi- cate the nature of the lesion. The X-ray is of the greatest value in determining the nature of the injury in the exceptional cases in which the physical signs are indefinite. When the upper end of the fibula alone is fractured the patient may be able to get about, though the use of the member entails more or less swelling and pain. This fracture has not infrequently been overlooked in spite of the fact that pressure in the middle of the shaft is productive of pain at the site of the lesion, if the fracture is below or through the upper tibio-fibular articulation. If the frac- ture is above this level it should be recognized by direct palpation. Treatment. — The desiderata in the treatment of these fractures are : reduction of deformity, immobilization of the fragments and restoration of function after the fragments have united. The details of treatment will vary with the type and severity of the fracture. In a simple transverse fracture of the upper end of the tibia, deformity is often slight and reduction easy. Strong traction on the leg with direct pressure over the displaced frag- ment will usually effect reduction. The fragments, however, are often so well apposed that nothing in the way of treatment is indi- cated aside from fixation. The lower extremity should be immo- 628 FRACTURES AND DISLOCATIONS bilized on a long posterior splint extending from just above the heel to a point a short distance below the buttock. The regulation ham splint may be used or one may be made of plaster. The knee should be fixed in a position just short of complete extension and the padding employed should be so disposed as to evenly and firmly support the lower extremity throughout the length of the splint. If there is any tendency for the foot to be rotated inward or out- ward the splint should include the foot. This may be accomplished by a posterior plaster splint extending downward to include the heel and sole of the foot. The same result may be had by means of a long plaster stirrup extending well up onto the thigh, or the long side T-splint, similar to that used in fractures of the hip, may be employed. Whichever splint is used the means of securing it in position will be found in adhesive strips and bandages. In cases in which the traumatic reaction is severe, and rapid in onset, it may be advisable to postpone manipulation of the parts until it has subsided. This is particularly true when the fracture has entered the knee-joint with the development of a traumatic arthritis. When the fracture enters the joint cavity the correction of deform- ity and maintenance of the fragments in proper reduction is usually much more difficult than in simple transverse fracture. In a T-fracture, or breaking otf of one of the tuberosities, an attempt should be made to force the fractured surfaces together so that the articular surfaces on the head of the tibia will be in proper relation with the condyles of the femur. This is often a difficult matter and requires skillful manipulation. If one of the tuber- osities has been broken off, lateral deviation of the leg to the opposite side will often facilitate reduction of the displaced frag- ment. If the fracture is of the T-type with separation of the tuberosities, adduction or abduction of the leg will accomplish nothing. Under these circumstances strong traction in the axis of the tibia will be necessary while the tuberosities are forced together by lateral pressure. In some cases it will be impossible to approximate the tuberosities in this manner, and in other instances the tendency to recurrence" of deformity may be so great that the tuberosities separate as soon as traction and lateral pressure are removed. Under these circumstances open reduction either with or without internal fixation is indicated. Not infrequently a loose fragment of bone between the tuberosities acts as an obstacle to reduction and will require removal before the fragments can INJURIES JUST BELOW THE KNEE 629 be broug-lit into proper position. In instances in which the shaft has been driven into the upper end of the tibia with extensive comminution, the destruction of bone may be so great that it is impossible to restore the original contour of the upper extremity of the bone. In this type of case continuous traction by means of Buck's extension will often accomplish more than any other method. AYhen extension is employed for this purpose the lower extremity should be so fixed to the splint that the traction does not pull the axes of the tibia and fibula into the same straight line, otherwise the normal lateral angle of the knee will be obliterated. AYhat has been said of the treatment of fracture of the upper end of the tibia applies equally well in separation of the upper tibial epiphysis. Avulsion of the tibial tubercle in the adult usually calls for operative treatment to secure the fragment in proper position. Straps of