The Knee.

—The knee is generally more accessible for operation than the elbow, as the important structures which should not be disturbed lie grouped upon its posterior aspect. Protection for one of these is protection for all, and the freedom with which the joint may be opened makes it especially easy to do either complete or partial operation. Here the surgeon should endeavor to preserve the epiphyses, especially in children, as they have much to do with the growth and length of the limb. So long as incision is confined to the anterior aspect of the joint it can be made in almost any manner. The usual method is that represented by line A in Fig. 220, by which a horseshoe flap is raised and the joint interior exposed. Occasionally the direction of the flap is reversed, and it is turned downward rather than upward. In the former case the ligamentum patellæ is divided; in the latter, the tendo patellæ. Whichever way the flap is turned it is made to include the patella, although this bone can be removed at any time. The lateral ligaments being divided, as well as the crucial, and the limb completely flexed, exposure of the joint surfaces is made. It is now possible to do an arthrectomy, a partial exsection or a complete one, according as the disease is more or less extensive. In the complete operation the articular surfaces of the femur and of the tibia are usually removed with an amputating saw. If this be introduced from the front and made to work its way backward the popliteal vessels should be amply protected against possible injury. Here it should be borne in mind that the leg is not constructed in a straight line, but that there is a lateral angle at the knee, as the femurs diverge as they pass upward, and this angle should be imitated in directing the saw and removing the bone end. Again, a slight bend anteriorly will make the limb more useful than one which is absolutely straight. The intent thus should be to give the knee at a slight angle anteriorly and interiorly, and the saw should be manipulated with great care. In a complete operation the patella is also removed. In tuberculous and other septic disease the capsule should be completely extirpated. This offers no difficulty, save at the posterior surface, where it may approach closely to the region of the great vessels.

Various modifications have been practised in these operations. Some open the joint by straight cross-incision with division of the patella, the latter being reunited with tendon or wire sutures. Others have practised a more complicated H-shaped incision, the transverse portion being carried either through the patella or just below it. The line marked B in Fig. 220 was suggested by Ollier. It is questionable whether any of these methods offer any advantages over the one first described.

After exsection it is desirable to maintain the bone ends in an accurate position if speedy reunion be desired, and for this purpose various methods are in vogue. The bones may be drilled and fastened together with tendon or wire sutures, or ivory nails may be driven in, one on each side, directing them obliquely, so that displacement cannot easily occur, or metal nails may be used for the same purpose. Another plan is to insert two long metal drills, one on either side, which perforate the skin two or three inches above the wound, and are passed downward and toward the other side so as to fix the surfaces, as it were, by a cross-forked arrangement. After two or three weeks these drills may be withdrawn. Fixation of this kind is advantageous, for when complete excision has been practised the surrounding tissues are lax and the parts are not easily held in position by external dressings alone. In a clean case, with careful hemostasis, very little drainage will be required. What is needed can be provided by an absorbable drain passed through the lower portion of the wound on either side. In a septic case it would be well to provide for ample drainage on each side.

The limb may be dressed upon a fenestrated wire or gauze splint, which is easier when frequent change of dressing can be foreseen, or it may be immobilized in a plaster-of-Paris splint.

The Ankle.

—The ankle is usually reached by an incision on either side, three or four inches in length, extending from above each malleolus downward and forward on to the tarsus. The knife-blade should be forced to the bone, so as to divide the periosteum, which is subsequently separated and lifted by an elevator, in order that the operation may be made subperiosteally. The fibula is usually first divided, with a chain saw or a chisel, an inch above its tip. The divided fragment is wrenched from its place with forceps, and severed from the ligaments by knife or scissors, being careful not to injure the external lateral ligament. The inner incision is made in practically the same way, the periosteum separated, the internal lateral ligament divided, and the end of the tibia forced through the incision by everting the foot. Its joint end may be removed with a saw, dividing on the same level and plane with the lower end of the fibula. Through the gap thus made the astragalus may be either removed or its upper surface divided with a metacarpal saw. The fresh bone surfaces left in this way will unite and ankylosis will result, unless fibrous or muscular tissue be interposed to favor the formation of a false joint.

As in other operations methods may be varied to meet the exigencies of certain cases. Longitudinal incisions may be placed farther forward than indicated above, as is shown in Fig. 221, which illustrated König’s method. Here the bone surfaces are divided with broad chisels. A transverse incision of the front and upper part of the ankle may be made, through which the tendons are exposed, lifted in a group out of harm’s way, and curetting and bone sawing performed. Kocher makes a semilunar incision from the outer border of the tendo Achillis to the outer border of the extensor tendons, its line passing beneath the external malleolus. By this method the joint is opened and the peroneal tendons divided, their ends being reunited after the completion of the balance of the work. This method is usually applicable in children.

Ample drainage is required in these cases, for the operation is seldom performed in the absence of septic complications. The foot should be kept in proper and right-angled position by metallic splints, or by plaster of Paris, the latter preferable, fenestra being cut in order to make access to the wound.

Excisions of the Tarsus and Osteoplastic Excision of the Heel.

—Removal of the tarsal bones is confined usually to cases of tuberculous disease, and may be performed by a variety of methods. Thus the tissues of the sole of the foot may be divided transversely by an incision carried from the tubercle of the scaphoid beneath the sole and across to a point one inch behind the base of the metatarsal. Through this, access can be made to the inferior surface of the tarsus. Conversely the upper portion may be exposed by a similar transverse incision across the dorsum of the foot, by lateral incisions, or by a combination of both. It is seldom necessary to divide the tendons, it being nearly always possible to gather them into a group and lift them out, while the bones are attacked with a sharp spoon or a chisel.

Occasionally the calcis becomes involved in cancerous or tuberculous disease and it would appear that removal of the heel proper would be all that is required. To meet these indications Wladimirov, in 1871, and Mikulicz, in 1880, independently devised a method by which the ankle-joint may be opened and as much of the heel and adjoining tarsus as necessary removed, the foot being later fixed in the extreme equinus position. This is referred to as osteoplastic excision or amputation of the heel. Fig. 222 illustrates the line of incision, which extends from the tubercle of the scaphoid beneath the heel to a point on the opposite side, then obliquely upward and backward to the base of each malleolus, and then transversely and posteriorly, thus including within its line the region of the heel. These incisions extend to the bone, the ankle-joint is opened posteriorly, the lateral ligaments divided, the lower extremities of the tibia and fibula removed with a saw, the astragalus and calcis separated from their attachments, and the posterior articular surfaces of the scaphoid and cuboid also removed. The lines of division of bone are indicated by dotted lines in Fig. 222. Thus the lower ends of the leg bones are brought into contact with the upper end of the divided tarsus by straightening the foot in the extreme equinus position and maintaining this position with wire sutures or bone or metal pins.

The cases in which this method is of use are rare, but when indicated it has usually given satisfactory results. It is a substitute for amputation of the leg, and it is often an open question as to which will give the most satisfactory result. It has probably not been practised a hundred times.