If this apparatus is not available the limb must be fixed on a double-inclined plane, so constructed that the angle of flexion can be adjusted to meet the requirements of the individual case (Fig. 70).
[Ill.u.s.tration: FIG. 81.--Extension applied by means of ice-tong callipers for Fracture of Femur.]
Hodgen"s splint, bent nearly to a right angle, may also be employed.
A careful watch must be kept on the circulation of the limb during the first few days, lest it be interfered with by the pressure of the apparatus.
In a considerable number of cases these means of retaining the fragments in apposition prove ineffectual, and it is necessary to have recourse to operative measures for mechanical fixation. Division of the tendo calcaneus (Achillis) is not to be recommended as a means of combating the backward tilting of the distal fragment.
In all cases the retentive apparatus must be worn for about four weeks, after which the limb is flexed over a pillow; but ma.s.sage and movement should be employed as soon as possible, as persistent stiffness of the knee is one of the most troublesome sequelae of these injuries.
Compound and complicated fractures are dealt with on the general principles governing the treatment of such injuries. Amputation may become necessary should gangrene ensue from injury to the popliteal vessels, or if infective complications threaten the life of the patient.
Operative interference may be called for to rectify deformities resulting from mal-union.
The #T- or Y-shaped fracture# is, as a rule, produced by direct violence, the force first breaking the bone above the condyles and then causing the proximal fragment to penetrate the distal and split it up into two or more pieces. The fracture implicates the articular surface, and the main fissure is usually through the inter-condylar notch; the lower end of the bone is sometimes severely comminuted.
The knee is broadened, and pain and crepitus are readily elicited on moving the condyles upon one another or on pressing them together. On moving the patella transversely, it may be felt to hitch against the edge of one or other of the fragments. The shortening may amount to one or two inches.
The treatment is carried out on the same lines as in supra-condylar fracture, but as the joint is implicated there is greater risk of subsequent impairment of its functions.
#Separation of the lower epiphysis# is a comparatively common injury.
It is seldom pure, a portion of the diaphysis usually being broken off and remaining attached to the epiphysis. It occurs usually in boys between the ages of thirteen and eighteen, from severe violence such as results from the limb being caught between the spokes of a revolving wheel, or from hyper-extension of the knee. It has also been produced in attempting forcibly to rectify knock-knee and other deformities in this region, and in making traction on the limb to correct deformities following recovery from tuberculous disease of the knee. As a rule, there is little displacement of the loose epiphysis, but it may pa.s.s in any direction, forward being much the most common (Fig. 82), and when displaced it is difficult to reduce and to maintain in position. The age of the patient, the mode of injury, the finding of the smooth broad end of the diaphysis in the popliteal s.p.a.ce or on the front of the thigh, according to the displacement, usually serve to establish the diagnosis. The X-rays afford reliable information as to the position of the fragments. Pressure on the popliteal vessels is a serious aggravation of the injury, and adds greatly to the difficulties of treatment.
[Ill.u.s.tration: FIG. 82.--Radiogram of Separation of Lower Epiphysis of Femur, with backward displacement of the diaphysis; pressure on popliteal vessels caused sloughing of calf.]
[Ill.u.s.tration: FIG. 83.--Separation of Lower Epiphysis of Femur, with fracture of lower end of diaphysis.]
The treatment is the same as for supra-condylar fracture, but, owing to the serious disability that follows on incomplete reduction, it may be necessary to have recourse to operation. After an epiphysial separation, the growth of the limb is sometimes, although not always, interfered with.
#Either condyle# may be broken off without the continuity of the shaft being interrupted, by a direct blow or fall on the knee, or by violent twisting of the leg. The separated condyle may not be displaced, or it may be pushed upwards or rotated on its transverse axis.
There is broadening of the knee but no shortening of the thigh, and the ecchymosis, crepitus, and pain are localised to the affected side of the joint; the knee can usually be moved towards the injured side in a way that is characteristic. If allowed to unite with the condyle displaced, the articular surface is oblique and bow- or knock-knee results.
If there is difficulty in replacing the broken condyle and maintaining it in position, it may be fixed by means of a steel nail inserted through the skin.
FRACTURE OF THE UPPER END OF THE TIBIA
#Fracture of the head of the tibia# is a comparatively rare injury. It may result from a direct blow, such as the kick of a horse, or from indirect forms of violence, and the line of fracture may be transverse or oblique. Occasionally the distal fragment is impacted into the proximal and comminutes it. In oblique fracture a gliding displacement is liable to occur and cause bow- or knock-knee.
Transverse fracture of the head of the fibula sometimes accompanies fracture of the head of the tibia, and there is always considerable effusion into the knee-joint. One or other of the condyles may be chipped off by forcible adduction or abduction at the knee.
[Ill.u.s.tration: FIG. 84.--Radiogram of Fracture of Head of Tibia and Upper Third of Fibula.]
The ordinary clinical features of fracture are well marked, and the diagnosis is easy. From some unexplained cause this fracture may take a long time, sometimes several months, to consolidate.
#Separation of the upper epiphysis# of the tibia, which includes the tongue-like process for the tubercle and the facet for the fibula, is also rare. It usually occurs between the ages of three and nine. The displacement of the epiphysis is almost always forward or lateral, and is accompanied by the usual signs of such lesions. The growth of the limb is sometimes arrested, and shortening and angular deformity may result.
_Treatment._--After reduction under an anaesthetic these fractures are usually satisfactorily treated in a box splint (Fig. 91), carried sufficiently high to control the knee-joint. When the head of the tibia is comminuted or split obliquely, weight-extension--direct from the bone, the ice-tong callipers grasping the malleoli or the calcaneus--may be used. Ma.s.sage and movement are employed from the outset.
Avulsion of the #tuberosity of the tibia# occasionally occurs in youths, from violent contraction of the quadriceps--as in jumping. The limb is at once rendered powerless; the osseous nodule can be felt, and on moving it crepitus is elicited.
This is best treated by pegging the tuberosity in position, and fixing the extended limb on an inclined plane to relax the quadriceps muscle.
In young, athletic subjects, the tongue-like process of the epiphysis (Fig. 85), into which the ligamentum patellae is inserted, may be partly or completely torn away, giving rise to localised swelling, and pain which is aggravated by any muscular effort--_Schlatter"s disease_ or "rugby knee." It has been frequently observed in cadets as a result of kneeling at drill. The treatment consists in rest and ma.s.sage, but the symptoms are slow to disappear.
[Ill.u.s.tration: FIG. 85.--Radiogram ill.u.s.trating Schlatter"s disease.]
The condition is liable to be mistaken for some chronic inflammatory condition of the bone, such as tubercle, unless an X-ray examination is made.
The #upper end of the fibula# is seldom broken alone. The chief clinical interest of this fracture lies in the fact that it may implicate the common peroneal nerve, and cause drop-foot.
DISLOCATIONS OF THE KNEE
Dislocation of the knee is a rare injury, and occurs as a result of extreme degrees of violence, especially of a wrenching or twisting character.
Rupture of the popliteal vessels, or pressure exerted on them by the displaced bones, may lead to gangrene of the limb, and necessitate amputation. The common peroneal nerve is frequently damaged. When the lesion is compound, also, amputation may become necessary on account of infective complications.
The varieties of dislocation are named in terms of the direction in which the tibia pa.s.ses: forward, backward, medial, and lateral.
#Dislocation forward# is the most common variety, and results from sudden hyper-extension of the knee, tearing the collateral and cruciate ligaments. The leg remains fully extended, and lies on a plane anterior to that of the thigh. The condyles of the femur are palpable posteriorly, and the skin is tightly stretched over them, or may even be torn, rendering the dislocation compound. The patella is projected forward, the quadriceps tendon is lax, and the skin over it is thrown into transverse folds. The limb is shortened by two or three inches.
#Dislocation backward# is usually due to a direct blow driving one of the bones past the other. The leg remains hyper-extended, the head of the tibia occupies the popliteal s.p.a.ce, while the lower end of the femur projects forward with the patella either in front or to one side of it.
The #medial and lateral dislocations# are generally incomplete, and are liable to be mistaken for separation of the lower epiphysis of the femur. When the tibia pa.s.ses _medially_, the lateral condyle of the femur forms a prominence, and there is a depression below it. The head of the tibia projects on the medial side, and the medial condyle is in a depression.
When the tibia is displaced _laterally_, the relative position of the prominences and depressions is reversed.
_Treatment._--In dislocations of the knee no special manipulations are necessary to restore the displaced bone to its place, and reduction is not accompanied by a distinct snap.
If, while the patient is fully anaesthetised, traction is made on the leg and counter-traction on the thigh with the knee in the flexed position, the bones can usually be replaced by manipulation.
After reduction has been effected, in antero-posterior dislocations, the limb should be flexed and placed on a pillow, ma.s.sage and movement being employed from the first. The patient is usually able to walk within a month.
In medial and lateral dislocations there is at first considerable tendency to re-displacement, and it is therefore necessary to secure the joint in a box splint, specially padded, for about fourteen days, ma.s.sage being employed from the first, and movement commenced when the splint is removed. It is usually about six weeks before the patient can use the limb with freedom.
In compound dislocations, and in those complicated by injury to the popliteal vessels, the question of amputation may have to be considered.
#Dislocation of the Superior Tibio-Fibular Articulation.#--This joint may be dislocated by twisting forms of violence applied to the foot or leg, or by forcible contraction of the biceps muscle. The displacement may be forward or backward, and the head of the fibula can be felt in its new position with the prominent tendon of the biceps attached to it. The movements of the knee are quite free, but the patient is unable to walk on account of pain. Reduction and retention are, as a rule, easy, and the ultimate result satisfactory. We have frequently met with this injury accompanying compound fractures of both bones of the leg resulting from railway and similar accidents.
By applying direct pressure over the displaced bone with the knee flexed, the dislocation is easily reduced. It is kept in position by a firm bandage or a light rigid splint.
#Total Dislocation of Fibula.#--Very rarely the fibula is separated from the tibia at both ends and displaced upwards. Bennett of Dublin has pointed out that in some persons the upper end of the fibula does not reach the facet on the tibia--a condition which might be mistaken for a dislocation.
INJURIES OF THE SEMILUNAR MENISCI
The semilunar menisci are two crescentic plates of white fibro-cartilage, which lie upon the upper end of the tibia, and serve to deepen the articular surface for the condyles of the femur. Each cartilage is firmly attached to the tibia by its anterior and posterior ends, and, through the medium of the coronary ligaments, is loosely attached along its peripheral, convex edge to the head of the tibia, the medial meniscus being connected also to the capsular ligament of the joint. The tendon of the popliteus muscle intervenes between the lateral meniscus and the capsule. The central, concave edges of the menisci are thin and unattached.