General Considerations

. Attributes of an Acceptable Approach to a Bone or Joint

. Factors to Consider When Choosing an Approach

Attributes of an Acceptable Approach to a Bone or Joint

The bones and joints must be exposed in a manner that ensures the preservation of the anatomic and physiologic functions of the area invaded. Major blood vessels, nerves, ligaments, and tendons must be avoided or protected. Maximal use must be made of muscle separation, with incision of muscles being avoided whenever possible. Transection of muscle bellies must be kept at an absolute minimum; tenotomy or osteotomy of the muscles at their origin or insertion is much preferred. Skin incisions must be made in such a manner that the vascular supply to the wound margins is not impaired and so that underlying implants such as bone plates do not create tension on the skin closure. No pedicles or sharp angles should exist in the incision because these points commonly undergo avascular necrosis and may produce wound breakdown, infection, or excessive scar formation. A cosmetically acceptable scar should be one goal of the surgery.

In general, the procedure should not add unnecessary trauma to that which the injured area has already sustained. Although the incision may be longer, an adequately large exposure is, in the final analysis, less traumatic than a smaller exposure. With the smaller approach, the surgeon tends to exert excessive pressure when retracting muscles, which directly injures the muscle and also impairs circulation to the area.

Factors to Consider When Choosing an Approach

The Area to be Exposed

The problem of choosing the best approach is easily solved in some instances. For example, there is only one logical way to expose the midshaft of the femur (see Approach to the Shaft of the Femur, Plate 77), and therefore the decision is easily made. Other regions do not lend themselves to such clear-cut answers. In some instances, the choice is purely a matter of the surgeon’s personal preference. The hip joint perhaps illustrates this best, there being many choices for exposure of this general region. Ultimately, it rests with the surgeon to evaluate all approaches and to adapt those most suitable.

The exposure required for bone plating is generally more extensive than for bone-pinning techniques. In this instance, it may be useful or necessary to combine two or more of the approaches illustrated. This is discussed further in the section “The Type of Fracture or Luxation.”

Aseptic Technique

The keystone on which success or failure of open bone and joint surgery rests is meticulous devotion to the ritual of aseptic technique. True enough, gentle handling of tissues and an anatomically sound approach are of utmost importance, but they go for naught in the presence of wound infection or osteomyelitis. The incidence of these sequelae can be reduced to less than 3% by attention to rigid asepsis and the proper use of antibiotic drugs. In clean cases, where no contamination or infection is suspected, an appropriate dose of a bactericidal antibiotic (e.g., a beta-lactam such as a cephalosporin or amoxicillin with clavulanic acid) is administered intravenously at the time of anesthesia and repeated in 90 minutes. It must be understood that to be effective at the time of surgery, the antibiotic drug must be administered preoperatively with sufficient time to allow effective serum levels of the drug to be present. Antibiotic medications are not administered postoperatively unless contamination or infection is suspected, or serious tissue damage is noted during surgery. In such cases, antibiotic medications are continued for at least 7 days postoperatively. Choice of antibiotic drug used long term should be based on culture and sensitivity of samples taken during surgery.

A detailed discussion of the methods of sterilization of packs, gowns, and other supplies is beyond the scope of this book. In general, autoclaving at 250° F and 15-lb pressure and with a contact time of 12 to 15 minutes is the most practical way of sterilizing instruments and cloth materials such as drapes and gowns. Sterilizer indicators ¹ that undergo a color change when exposed to proper sterilization conditions should be used in every pack. Total time in the autoclave is different from contact time; total time is that which is sufficient for steam penetration of the largest pack for the minimum contact time of 12 to 15 minutes. Sterilizer indicators are the only means of establishing the correct total time. Ethylene oxide is also a very useful sterilization method because it allows sterilization of items that would be damaged by heat and therefore allows the use of electric drills and other hardware store items in surgery.

Proper skin preparation, positioning, and draping of the patient are critical elements of aseptic technique that are commonly neglected. For all procedures on limbs, including the hip or shoulder region, a stockinette draping procedure is advised. Draping the whole limb in a sterile, double-thickness cotton stockinette allows the limb to be handled by the surgeon and manipulated in any way necessary. When reducing fractures, the need for alignment of the total limb in all planes is obvious. When reducing luxations, the whole limb can be used to supply additional leverage or torque to aid in reduction.

The limb is clipped circumferentially from the inguinal or axillary area with a #40 blade and electric clippers to some distance distal to the proposed skin incision. For approaches to the hip or shoulder, the clipping extends proximally to the midline of the back. When the approach is below the elbow or stifle, the clipping usually starts just above the toes and extends proximally only to the elbow or stifle region. Adhesive tape is applied to the toes or foot to form a stirrup from which the leg can be suspended. The remaining unclipped area is covered with gauze or a latex or plastic glove and adhesive tape (Figure 1A and B).

Figure 1 A, The unclipped portion of the lower limb is covered with roller gauze bandage or a latex or plastic glove from the toes proximally to the clipped area. B, Adhesive tape is used to make a stirrup and to cover the gauze or glove.

The patient is next placed on the surgery table with the clipped leg uppermost and the leg suspended by adhesive tape attached to the stirrup and to an infusion stand or a hook in the ceiling (Figure 2). Abduction of the limb to a 45- to 60-degree angle from midline is adequate to allow skin disinfection and draping.

Figure 2 Suspension of the clipped limb preparatory to skin disinfection. An infusion stand or a hook in the ceiling is used. Adhesive tape can be run directly to the infusion stand from the tape stirrup or to an elongated S-shaped metal rod interposed between the ceiling and the foot.

Povidone-iodine ² (“organic iodine”) or chlorhexidine³ preparations have proved most efficacious for disinfection of the patient’s skin. Using sterile gauze sponges immersed in surgical scrub preparation diluted 50% with sterile saline solution or water, the patient’s skin is scrubbed, starting in the area of the incision and working outward to the limits of the clipped area. After 1 minute of scrubbing, the suds are wiped off with dry, sterile sponges. Again, the wiping starts in the area of the incision and proceeds toward the periphery of the clipped area. This cycle is repeated 5 times, and after the final rinse the whole area is sprayed or wiped with povidone-iodine or chlorhexidine solution, or 70% to 80% isopropyl alcohol, which is allowed to remain and dry on the skin. Povidone-iodine and chlorhexidine surgical scrubs are also highly effective for the scrubbing of the surgeon’s hands.

The patient is now ready for draping as soon as the surgeon or assistant is gowned and gloved. Four sterile towels are first placed around the leg at the inguinal or axillary region (Figure 3). The circulating assistant now grasps the leg on the unprepped area and cuts the suspending tape while holding the leg in position. The surgeon grasps the foot through a sterile towel that has been partially rolled (Figure 4A) and then wraps the towel around the unprepped area while holding the limb up and away from the table. The towel is folded over the toes and secured with towel clamps (Figure 4B). Now the rolled stockinette is placed over the foot (Figure 4C) and unrolled down the leg, taking care not to touch any unprepped areas in the process. When the stockinette meets the towels, the two are joined together and attached to the skin with towel forceps (Figure 5A). A method for the hip or shoulder region is shown in Figure 5B and C. (The cotton gauze stockinette is previously prepared and sterilized. Cut the stockinette twice as long as the leg, using a suitable diameter for the thigh or brachium. Pull half the stockinette inside the other half and tie or tape the cut ends together to make an elongated bag. Roll the uncut end toward the closed end as if rolling a stocking. Wrapping and sterilizing complete the preparation. Alternatively, a presterilized impervious stockinette ⁴ can be used.)