Radiologic Imaging as a tool in opioid abusers.
It is important for Orthopedists to identify patients who may be at risk for misusing opioids in order to prevent complications. We have discovered over the years, various orthopedic conditions with typical radiologic findings for cellulitis, necrotizing fasciitis, abscess formation, discitis or osteomyelitis to septic arthritis and phlebitis. Being able to detect such radiologic findings may enhance your therapeutic options in the treatment of complications related to the use of opioids.
The monitoring of prescribed opioids for acute pain and non-cancer pain control during the recent years has certainly helped in decreasing the death rate from overdose. Two-third of the 64,00 deaths recorded deaths in 2016 were due to opioid use, while an increase in Fentanyl usage was recorded by the Health Department in Massachusetts.
Orthopedic Surgeons may have been responsible in prior years to play a role in that opioid crisis especially when in 2009 they were found responsible of 8 % of all the 200 million prescription of opioids. It was then proven that one in seven patients who uses an opioid and receives a refill for more than a month, has an increase in the probability of long-term usage. Any physician who may attempt to control acute pain through prescribing opioids may have as well contributed to this epidemic the country has seen for the last decades. I will refer you to an already published article:” Cannabinoids as a complement in Orthopedics” in the AMHE Newsletter # 270.
Opioids are used medically for pain relief and carry with them analgesic and central nervous system depressant effects with potential euphoria. When prescribed medications are misused or when diverted medications or illicit use of opioids like heroin, cocaine is used erratically, chronic and relapsing illness with an increase rate on morbidity and mortalities will increase. The term of “Opioid” refer to natural or synthetic substances which work on three main receptors systems (mu, delta and Kappa) giving them the potential to cause euphoria. They can be used intra-nasally (snorting or sniffing), subcutaneously (skin popping), intramuscularly (muscling) or intravenously (shooting up or mainlining).
Heroin (diacetylmorphine), a derivative of Morphine is the most common opioid abused. Other terms frequently used are dope, smack, china white, Junk and tar. Opium derived from the opium poppy which contains morphine and codeine (opiates) generally smoked or even eaten more often seen in the Middle East and in Asia more than in the United States. Prescribed opioid medications given in a postoperative period or to treat chronic low back pain have also contributed to the narcotic epidemic in the country. Finally, semi-synthetic opioids (Oxycodone, Hydrocodone) and synthetic opioids (Fentanyl, Tramadol, Methadone) play a large role in the mis-usage of these medications. The orthopedic surgeon needs to have a knowledge of the drugs used. These drugs when injected in the soft tissues may bring complications requiring our expertise.
Imaging plays an important role in the detection of complications in an opioid user. Radiologic findings in cocaine and amphetamines or ecstasy users can bring complications directly related to the use of contaminated needles into the soft tissues or bones requiring hospitalization. Soft tissues complications like cellulitis, abscess, necrotizing fasciitis, disc space infection, discitis, osteomyelitis, septic arthritis, septic phlebitis, myositis, Rhabdomyolysis or myopathies.
Let us review some of the different entities:
Soft tissue infections are certainly the most common and frequently related to the use of IV drugs especially when contaminated needles are being used. Injections to the subcutaneous tissue or in the muscle can result in cellulitis, manifested by a marked edema and erythema especially when a streptococcal or staphylococcal infection is suspected. Such infections can progress to an abscess formation in the subcutaneous tissue. In IV drug abusers showing skin punctures and cellulitis, ultrasound can be useful in diagnosing and evaluating the abscess looking for diffused thickening of the tissue and fluid collection which often will give a “cobble-stone” appearance of the edematous tissue.
You will find some limitation to the ultrasound technics especially when the collection is very painful and the skin contact is ill-tolerated by the patient, rendering impossible to use any pressure from the probe. The advantage of this test is that it can be performed at bedside. When an ultrasound can’t be performed, an MRI is considered next to discover dermo-hypodermal thickening with areas of high signal intensity. A regular X-ray of the area is suggested also to rule out any foreign metallic fragments like broken needle which can create as well an area of high intensity.
Necrotizing fasciitis although rare, is a life-threatening soft tissue infection rapidly spreading affecting the deep layers of adipose tissue, fascia and muscle. There is a high mortality rate reaching almost 30-50% of the cases. Other pathogen like Clostridium perfringens can be encountered in blunt injuries or in long bones open and contaminated fractures. This is common to find also a case of Gas Gangrene presenting with blisters, swelling and jaundice. The infection will progresses rapidly requiring a quick diagnosis and an aggressive treatment. High fever, dusky skin discoloration can be encountered. Radiography of the area involved can help in the diagnosis and often may demonstrate gas produced by a polymicrobial infection, rapidly spreading in the soft tissue. The gas gangrene can also be visualized by CT scan. Occasionally, MRI can show loss of muscle texture on T1 weighted imaging technique while edema and fluid collection are noted on a T2-weighted images. The clinical diagnosis once suspected with or without additional radiologic finding should not delay any surgical intervention for aggressive debridement and even amputation.
An abscess is characterized by the accumulation of purulent material mainly composed of inflammatory cells, proteins, bacteria and necrotic tissue within the subcutaneous or muscular tissue, commonly seen with IV drug abusers. The most common cause of skin abscess is due to a staphylococcus either methicillin susceptible or resistant, in almost 75% of cases. A superficial abscess (skin) can have a mixed flora especially when they are peri-oral, vulvovaginal or perirectal. An abscess may mimic a cellulitis but an ultrasound or a CT scan can make the differential diagnosis. A well circumscribed mass containing fluid with surrounding hyperechoic tissue can be discovered. A guided needle aspiration maybe performed using ultrasound technique for microbial diagnosis. Foreign bodies like broken infected needles or other material can be seen on X-Rays or CT Scans.
Infection of the intervertebral discs can be manifested by focal back pain generally relieved by rest with elevation in temperature, chills, and/or neurological deficit. There is often a challenge in diagnosing such infection because a delay of two to three weeks can lead to complications like permanent spinal cord injury causing major morbidity. Bone X-can show erosive changes on the endplates of the infected disc space as early as 6 weeks after the initial symptoms. MRI with contrast is the procedure of choice to visualize the end-plates of the adjacent vertebrae, the disc and the soft tissue of the area involved. The infected disc will appear hypo-intense on a T1 imaging technique while hyper-intense on a T2. A spine surgeon needs to have a high index of suspicion for discitis in any febrile patient using IV drugs presenting with back pain with or without neurological deficit but a recent bacteremia or endocarditis. Antibiotic therapy using fluoroquinolones are best used to treat this infection. Many in the past have done follow- up on such treated patient with repeated MRI studies or repeated sedimentation rate but more recent studies have shown ii to be unnecessary. Finally, resistant staphylococcal infections have puzzled the infectious disease world because the specific antibiotics are treating the infection with more difficulties.
Repeated intramuscular injections of opioids like heroin can lead to myotoxicity with muscle contractures. This phenomenon is due to Myositis. Although rare, it can be seen more often with cocaine injection. This has been a major complication in the opioid epidemic in the United States. Severe vasoconstrictions can be observed with subsequent ischemia and infarction at the local level. The cocaine myopathy can be seen earlier, within hours of an intravascular injection or even after smoking crack cocaine (alkaloid free-base). An acute myoblobinuria can complicate the picture with impending renal failure and elevation of Creatine Kinase (CK). If renal function is already compromised, an MRI study is the modality of choice and contrast especially with gadolinium should be avoided. A bone scan may be used to assess widespread of muscle involvement determined by the diffused accumulation of the radioisotope into the affected muscles. Adequate assessment will avoid a cocaine induced Rhabdomyolysis often manifested by a drop in the blood pressure, seizures disorders and often coma. No need to stress the need to know what kind of drug was used like cocaine, heroin etc. Local injection site infections and abscess formation into muscle tissue should not be confused with a true pyomyositis caused by hematogenous seeding of groups distant from the injection sites.
Infection of the soft tissues if left untreated will spread to the deeper structures especially bones and joints. Gradual inflammatory damage will extend to the periosteum and result in acute, subacute or chronic osteomyelitis. Around 35 % of bone involvement is necessary to be visible on plain radiologic studies. Then Periosteal reactions to Osteolysis can be visualized. The more the bone is involved the more a CT scan can demonstrate bone destruction and reactive bone which at the beginning of the infection can be limited. An MRI is the more reliable test to detect Osteomylitis and demonstrate the involvement of the soft tissues around. The presence of hardware with overlying soft tissue collection can alert the orthopedist on a direct invasion of the bone and the need for a surgical drainage with removal of hardware. Nuclear imaging can detect the early signs of infection around two weeks or even sometimes earlier. Bone scan with tagged white cells is preferred when MRI study is contraindicated.
Septic arthritis is a painful condition most commonly caused after an infection like an endocarditis or a pneumonia. The infection generally will spread by the blood stream or with by direct seeding. By example an Osteomylitis will spread to the adjacent joint especially if the infectious site is at the metaphyseal level. IV drug abusers have generally atypical infection around the site of injection and any joint closed to the infected area can get involved. Often the knee joint is interested and micro-organisms like Pseudomonas Aeruginosa or enterobacter species or bacterium avium can be easily reported. Generally, there is a monoarticular joint involvement with large effusion, swelling and painful range of motion. Radiographic studies will show effusion or early bony destruction. A joint aspiration to collect fluid is necessary to allow culture and sensitivity. MRI may show atypical changes and post-acute or chronic changes. Post contrast views can show nonspecific changes like hypertrophy of the synovium or any peri-articular soft tissue involvement, lymphadenopathy or fluid collection. Shot gun therapy is not recommended and specific antibiotic following recommendations on the antibiogram is the best way to approach the infection.
The superficial veins can develop inflammation with micro-thrombotic effects. A septic thrombophlebitis will follow. The inflammation among the IV drug abuser is generally after the infection has presented the classic signs of the Virchow triad, directly related to the puncture site on the vessel where the drug was is injected and resulting in an impaired blood flow because of the endothelial damage and the hypercoagulability. The most common vessel involved is the common femoral artery and the most causative infectious agent is the staphylococcus aureus. Local hyperemia and edema with a painful distension of the vessel with varices or skin pigmentation. If ultrasound or duplex scanning is used, one can detect wall thickening of the vessel or even some thrombi. The deep venous plexus should also be investigated while IV antibiotics, anti-inflammatory medications, with range of motion and ambulation are performed. More, anti-coagulation or thrombus removal may become necessary.
In conclusion, as orthopedists, we see IV drug abusers unfortunately, late after they have already developed complications and we may become the first to diagnose the problem. A good cooperation with the radiologist can elucidate many of these problems. The radiologist needs also to have sufficient knowledge in opioid use and mis-use of the patients presenting for the test. It is imperative to know the substance injected because it may permit a faster treatment and recovery. Often such patients are unaware of the sterile needles program available in their area. Teaching them how to use proper cleaning agent like alcohol prior to inject the drugs may also prevent any further site infection. Mental health providers and outreach programs bring complementary help to help in their recovery but only absolute changes in the habits of such patients will dictate a path to a full recovery.
Maxime Coles MD
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