Fractures in Special Circumstances: (Vascular-Compartment Problems, Nonaccidental Trauma, Pathologic Fractures)



Fractures in Special Circumstances: (Vascular-Compartment Problems, Nonaccidental Trauma, Pathologic Fractures)


Dennis Wenger

Scott Mubarak



VASCULAR AND COMPARTMENT PROBLEMS

On the battlefield, arterial injuries are transported, and the decision to expose the artery is already partly made. The amputation rate is low because of prompt expert repair. For closed fractures with arterial damage, the amputation rate is often high because of late recognition of the problem.


Arterial Injury

In fractures with arterial injury, the maximal permissible interval between injury and repair is 6-8 hours, depending on the degree of arterial occlusion, the state of the collaterals, and shock. These 6-8 hours may pass quickly while the patient is given narcotics and a doctor is
found to split the cast. The doctor often realizes there is trouble but may fail to act immediately and decisively, hoping that the situation will miraculously improve.

“Education is education. We should learn everything and then choose which path to follow”

Malala Yousafzai

“Unfortunately, in the emergency department, a child with a fracture plus ischemia does not appear startlingly different from a child with a simple fracture”






Figure 19-1 Volkmann ischemia. Top. Normally the pressure in the brachial artery is 120 torr. Muscle is perfused at a pressure of 30 torr. Bottom. Muscle ischemia. If the pressure within the muscle compartment is raised about 30 torr, muscle will not be perfused, but the radial pulse is not necessarily occluded.

Slowly the surgeon comes to appreciate that hope is not enough and calls for an arteriogram or transfers the case to another hospital. Every minute should count, because invisible changes are taking place in the muscles and nerves of the limb. Yet in many patients we have cared for, hours have been frittered away. Successful care comes from a high index of suspicion and early arterial repair. Successful care produces a normal limb and delay a Volkmann contracture or gangrenous limb.


Physical Signs

Unfortunately, in the emergency department, a child with a fracture plus ischemia does not appear startlingly different from a child with a simple fracture. A crying child, with his limb swathed in splints and bandages and surrounded by distraught relatives is not easily viewed with cool, clinical detachment. A quick squeeze of a protruding digit or nail bed for capillary filling is often considered sufficient to demonstrate an intact circulation. You can demonstrate the fallacy of this sign the next time you are in the operating room (OR). Inflate the tourniquet before the limb is exsanguinated. Squeeze the digits and note that capillary return is still present. This test only indicates that blood is present in the limb and not that it is circulating.

In recent years, the guesswork has been taking from these problems by direct measurement of compartment tissue pressure and by the use of Doppler pulse meters.


The Three Faces of Arterial Occlusion

If occlusion is not recognized on admission, there is usually a considerable delay before anyone notices it. A child’s ischemic pain may be borne stoically by the staff and attributed to fracture pain or clouded by opiates. Pulses are hidden by a cast, splint, or traction making observation difficult. Remember that a splinted limb should be relatively painless. Pain after reduction should be attributed to ischemia until proven otherwise. A special trap is painless ischemia in a child with a nerve palsy.


Complete Arterial Occlusion

The pulse is absent, the veins are empty, and in the course of an hour or two the limb becomes white and cold. Failure of nerve conduction produces glove and stocking anesthesia and paralysis. After a few more hours, rigor mortis results in the muscles shortening, and attempts to overcome this are painful. Pain is extreme. Later the skin becomes marbled, and gangrene follows.



Incomplete Occlusion—Compartment Ischemia

Ischemia of muscle, called Volkmann ischemia (Fig. 19-1), is compatible with an intact pulse and adequate peripheral circulation. The first signs are pain in the muscle and pain on stretching the muscle. For this reason, we do not advise strong analgesics for children with fractures that have a reputation for vascular problems. Compartment ischemia may be a sequel to an arterial injury (Holden Type I) or to direct compartment injury (Holden Type II) (Fig. 19-2). Frequently there is sufficient arterial flow to maintain a pulse and distal circulation, but the muscles and nerves become hypoxic and damaged. The outcome of muscular ischemia is a Volkmann contracture. Compartment syndromes will be described in more detail later in this chapter.


Compensated Occlusion

This is most often seen in the child with a supracondylar fracture who has an adequate distal circulation but no pulse (Fig. 19-3). The extremity may be a little cool, but there are no signs of nerve or muscle ischemia. Despite occlusion of the major artery, the collaterals maintain an adequate circulation. The best treatment is immediate reduction. Apart from worrying and ordering an hourly check on sensation and movement, there is nothing special to do. A Doppler can be used to detect a faint pulse. Arteriography and exploration are usually meddlesome. Within a few weeks, the pulse returns, and we have yet to see a child with claudication in this circumstance.


Sites of Fracture Associated with Vascular Damage

Although any fracture carries the hazard of vascular damage, the problem is most likely in supracondylar fractures, elbow dislocations, fractures of the shaft of the femur, especially the distal one-third (Fig. 19-4), dislocation of the knee, fractures of the proximal tibia physis, grossly displaced fractures of the ankle and talus, and midtarsal dislocations.







Figure 19-2 Compartment ischemia may be due to arterial injury (Type I) or to increased compartment pressure (Type II).






Figure 19-3 Compensated occlusion. Anastomotic channels maintain perfusion at low pressure and sufficient to sustain the tissue but insufficient to produce a pulse at the wrist. The pulsations have been abolished, but the flow remains. If an eponym had been attached to this condition, it would be diagnosed infrequently.






Figure 19-4 In the hour that followed this injury, the leg became cold, white, anesthetic, and weak. The pulse was absent. After the fracture was reduced under general anesthesia, the veins became full, the foot warm and pink. The pulse did not return for several weeks. The femoral artery passes through the adductor opening at this site, where it is liable to injury.


“The most common causes of ischemia are undoubtedly tight casts and deformity at the fracture site”


Types of Arterial Injury

The incidence of arterial damage, as distinct from ischemia, in fractures is not known.

Lesions in Discontinuity. There is complete transsection of the vessel.

Lesions in Continuity. Intimal lesions. Intimal tears and contusions can only be diagnosed with confidence by arteriotomy. The distal part of the vessel is empty and stringlike. The condition is indistinguishable from spasm until the intima is inspected.

Spasm. Traction has been shown experimentally to produce spasm. Application of this observation has reduced the incidence of Volkmann ischemia in fractures of the femoral shaft. However, in the past, the importance of “temporary spasm” has been greatly overplayed at the cost of many limbs.

Compression. The most common causes of ischemia are undoubtedly tight casts and deformity at the fracture site. Release the cast or align the limb, and the circulation comes bounding back. Kinking and stretching of vessels has been convincingly demonstrated after high tibial osteotomy.

Thrombosis. Prolonged occlusion owing to any cause will produce propagating thrombosis.

Aneurysm. After a few days or weeks, the site of the fracture becomes painful, red, swollen, and warmlike an infection, but when it is drained, there is a gush of blood. The aneurysm may be caused by a partial tear of the artery at the time of fracture; by the end of a pin, drill, or screw; or by a mycotic infection. Small vessels may be tied off, but major vessels require a graft.

Whenever you embark on releasing a hematoma, bear in mind that it may be a false aneurysm. Listen for a bruit; consider an arteriogram. Check on the whereabouts of your vascular surgeon before you start, just in case you will need help.




Treatment of Limb Ischemia

If the circulation does not improve rapidly, you must make preparations to take the child to the OR immediately. As soon as diagnosis of ischemia is reached, it is obviously a matter of extreme urgency, and you must not be put off by any other service commitments or by an anesthesiologist telling you that the child has a full stomach. You should carry out surgery with the help of a vascular surgeon. However, in civilian practice, vascular surgeons do not have much experience with the problem, and you cannot look to them to make all the decisions. Your hospital or orthopedic service should maintain a roster of surgeons who can help you. The growing group of microvascular surgeons may be your best ally.








Figure 19-5 This girl fell out of a tree. She almost died during the next 12 hours because of hypotension from a ruptured spleen and a hemothorax. The fractured femur was placed in skin traction. The combination of muscle hypoxia owing to hypotension and somewhat tight bandaging produced a white, anesthetic leg. Arteriogram shows no damage at the fracture site but complete vascular occlusion caused by compartment compression. All compartments were opened, and the arteries were dilated with Fogarty catheters.


Treatment Steps—Limb Ischemia

Arteriography. Arteriography is only of value if it can be carried out immediately: do not waste time rounding up staff. Arteriography always takes at least an hour, whatever you are told, and in most cases, this time could be better spent relieving ischemia. It will demonstrate the site of occlusion, although it will probably not disclose the type of lesion. The site of occlusion is usually opposite the fracture site. In one case, we suspected that the cause of ischemia may have been tight bandaging; however, the arteriogram showed an intimal tear opposite the fracture site. Ideally, arterial damage should be recognized early and repaired before irreversible complications occur.

Treatment of the Arterial Lesion. Direct inspection is the only certain way to determine the nature of the lesion. For this reason, we expose the vessel widely through one of Henry extensile exposures. The effectiveness of repair can be judged, the extent of muscle damage can be discerned, and wide fasciotomy may be carried out.

Lesions in Continuity. When the artery is constricted at the level of the fracture, an intimal tear or contusion is most likely. In most cases, a vascular, neurovascular, or plastic surgeon (with vessel repair training) will be doing the procedure with you. A segment of artery can be excised. The proximal end is flushed out. The distal part is dilated and cleared of thrombus with a Fogarty catheter and end-to-end suture undertaken if this can be done without tension; otherwise, a reversed saphenous graft is often inserted.


Lesions in Discontinuity

Lesions in discontinuity are repaired or grafted.

Fasciotomy. Subcutaneous fasciotomy is quick and easy. It leaves little scar but does not decompress the deep flexor compartments (Fig. 19-5). For this reason, open fasciotomy is mandatory. In the calf, all four compartments must be opened-anterior, peroneal, superficial, and deep posterior. In the arm, the deep flexors and extensors require decompression.

Do not excise any muscle at this time. It is impossible to distinguish the sick from the dead. After arterial repair and fasciotomy, distal pulses should become palpable and the veins should fill. The skin can never be closed after fasciotomy, because the muscle has swelled. Cover the extensive wound with a petroleum gauze dressing.

Care of the Fracture. Is internal fixation the ideal method? The Vietnam experience suggested that it might add to morbidity because of infection and nonunion. Our experience is limited, but for children who have not been injured on the battlefield, we favor internal fixation whenever possible, because traction may pull the anastomosis apart.


A cast, which prevents examination of the entire limb, should not be used. External fixation works well and can be a good choice.

Complications. Because thrombosis affects up to 20% of repairs, the circulation must be closely watched postoperatively. If there are signs of failure, the vessel will need to be explored once again and the thrombus removed.

Note-Keeping and Public Relations. Parents of children in whom ischemia is noticed late usually believe that this catastrophe is somebody’s fault. These cases usually go to litigation. Keep scrupulous notes; every time you see the child, record your findings and note the time. Put down everything; nothing is too insignificant. Because the case may end up in court, you or your colleague will need the type of help that only pages and pages of detailed documentation can provide. You must also be aware of nursing notes—sometimes they contain helpful bits of information that can help you to better manage the patient.

Request your colleagues’ advice, as needed. Not only may this be helpful, but their written notes may be useful as well. If the case is referred to you, you should keep in touch with the original doctor. Do not jump to the conclusion that it is their fault. All notes regarding prior care should be even-handed and not blame anyone for their decision making.

The Aftermath. In a few days, you will know whether a normal limb may be expected or whether amputation or reconstruction will be required. The reward of early repair will be a normal limb. Wet gangrene usually requires early amputation and secondary suture. In children, it is worth skin-grafting a stump in order to preserve length, particularly if it allows you to save the knee joint. Similarly, all efforts should be made to save the distal physis and joint, no matter what anatomic region is involved (to avoid “stump overgrowth” of bone).


COMPARTMENT SYNDROMES

A rise in the pressure within a closed compartment may tamponade the muscles and nerves so that they become ischemic. Muscles are normally perfused by blood at a pressure of about 30 torr in a compartment with a tissue pressure of 3-4 torr. If the compartment pressure exceeds 30 torr, the muscle will receive no blood, but the main arteries will not be compressed, the pulse will get through (Fig. 19-6).

In everyday use, compartment pressure often exceeds 30 torr for a few minutes at a time. When making a fist, the muscle becomes hard, the pressure rises, and the muscle loses its circulation for a time.






Figure 19-6 Mechanisms of compartment hypertension.







Figure 19-7 Method of measuring intra-compartmental pressure. The anesthesia department can provide an epidural catheter, which has many small holes in the sidewall of the distal tip of the catheter.

You may have noticed the effects when applying a cast on a leg. Have you noticed how your assistant, who is grasping the toes, always drops the leg just before you have finished? This is because your assistants’ forearm muscles are somewhat ischemic during the time they grip; when they reach their limit, they drop the leg.

The science of compartment syndromes has been much advanced by experimental models. The anterior compartment of a dog’s leg can be injected with blood to raise the pressure. Studies of nerve and muscle show that irreversible changes begin after 6-8 hours of ischemia. After 24 hours, the muscle shows only slight histologic changes, despite the fact that it is dead and will undergo necrosis later. Muscle damage is related to the duration of ischemia. Nerve damage is related to the compartment pressure. At first, there is loss of conduction, which quickly returns when the pressure is lowered, but prolonged compression causes nerve degeneration.

Compartment pressures may be measured by several techniques (Fig. 19-7). The wick or slit catheter works well; however, special catheters are not always available. A very suitable replacement is an epidural catheter (from the anesthesia department), which has holes in the sidewall at the tip. Special patented bedside units have been developed and are used in some centers.

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Nov 17, 2018 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Fractures in Special Circumstances: (Vascular-Compartment Problems, Nonaccidental Trauma, Pathologic Fractures)
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