**1. Introduction**

484 Recent Advances in Arthroplasty

[70] Müller M, Morawietz L, Hasart O, Strube P, Perka C, Tohtz S. Diagnosis of

[71] Love C, Marwin SE, Palestro CJ. Nuclear medicine and the infected joint replacement.

[72] Kwee TC, Kwee RM, Alavi A. FDG-PET for diagnosing prosthetic joint infection:

[73] Schinsky MF, Della Valle CJ, Sporer SM, Paprosky WG. Perioperative testing for joint

[74] Cabrita H, Croci A, De Camargo O, De Lima A. Prospective study of the treatment of

[75] Whittaker JP, Warren RE, Jones RS, Gregson PA. Is prolonged systemic antibiotic

[76] Stockley I, Mockford BJ, Hoad-Red-dick A, Norman P. The use of two-stage exchange

[77] Bratzler DW, Houck PM. Antimicrobial prophylaxis for surgery: an advisory statement

[78] Xin-Yi Yang. Cong-Ran Li. Ren-Hui Lou. et al. In vitro activity of recombinant

Semin Nucl Med 2009;39:66–78. [PubMed: 19038601]

Clinics (Sao Paulo) 2007;62:99– 108. [PubMed: 17505692]

Journal of Medical Microbiology (2007), 56, 71–76.

Am 2008;90:1869–75. [PubMed: 18762646]

2009;91:700.]. [PubMed: 19092003]

404. [PubMed: 15820449]

Surg 2008;3:31.

[PubMed: 18704405]

18256078]

periprosthetic infection following total hip arthroplasty — evaluation of the diagnostic values of pre- and intraoperative parameters and the associated strategy to preoperatively select patients with a high probability of joint infection. J Orthop

systematic review and metaanalysis. Eur J Nucl Med Mol Imaging 2008;35:2122–32.

infection in patients undergoing revision total hip arthroplasty. J Bone Joint Surg

infected hip arthroplasties with or without the use of an antibiotic-loaded spacer.

treatment essential in two-stage revision hip replacement for chronic Gram-positive infection? J Bone Joint Surg Br 2009;91:44–51. [Erratum, J Bone Joint Surg Br

arthroplasty with depot antibiotics in the absence of long-term antibiotic therapy in infected total hip replacement. J Bone Joint Surg Br 2008;90:145–8. [PubMed:

from the National Surgical Infection Prevention Project. Am J Surg 2005;189:395–

lysostaphin against Staphylococcus aureus isolates from hospitals in Beijing, China.

Due to the growing of HIV pandemic in the world and especially in Africa during the last two decades, it has become more and more frequent to find HIV infected patients with an absolute indication of arthroplasty. In fact, the indication of arthroplasty in these patients may be a very challenging issue. Even though all of these patients are not immune depressed, due to the known natural history of HIV carriage, the risk of future immune depression remain and logically the risk of immediate, early, or late infection of arthroplastic implants and subsequent loosening or worse, generalized infection. The literature on this question remains very scarce ; the first section of this chapter will present a classification of HIV carriers elected to Arthroplasty, describe protective measures for each class of patients, and present immediate , short and mid term expected results, based an a systematic analysis, and Authors own experience. The second section will be focused on arthroplasty in sickle cell disease (SCD) carriers, as these types of patients usually demand arthroplasty at the end stage of secondary vascular necrosis, the most frequent adult joint complication of their genetic condition. Lastly, as Very few, if any, is known in case where both conditions (HIV & SCD) are combined in the same patient demanding arthroplasty, a short section will be proposed.

Section A: Arthroplasty in HIV carriers


Due to the spreading of HIV worldwide during the latest decades, it had become more and more frequent in the orthopaedic practice, to indicate an arthroplasty, especially of the hip, in patients living with HIV. This virus has been incriminated by many authors as a possible causal agent in the case of bone's aseptic necrosis. The profiles of the HIV infected patients are variable: some are previous known carriers, other are discovered at the time of the preoperative workup. The duration of the preoperative antiretroviral treatment vary also from one patient to another. Anyhow, the main question for the orthopedic surgeon is to find out what is the level of the immune system of a person living with HIV and who is a candidate for an arthroplasty? In another words, what is the infection risk of the implant,

Arthroplasty in HIV/SCD Carriers 487

carriage by western-Blot test, the next step is the CD4 lymphocytes count and the viral load measurement by up to date procedures. The CD4 lymphocyte count is the key point for HIV carriers classification. Patients with less than 500 CD4 lymphocytes / ML are considered immune depressed and named **class A arthroplasty demanders.** Depending on whether this count is above 300, les than 300 with no opportunistic disease, or less than 300 with an opportunistic disease, Class A patients are further sub divided **A1, A2 or A3**. Non immune depressed HIV seropositive Patients with low infection risk are classified **B**; if they were known before and under treatment, they are sub-divided **B1**, if they have more than 500 CD4/ML with no treatment, they are sub-divided **B2**. This makes a total of 5 classes of arthroplasty demanders living with the virus (**B1, B2, A1, A2, A3**) and thus, who need

Antiretroviral therapy (ARVT) was introduced in the early nineties with the aim to act against the multiplication of the HIV and therefore, to stop the destruction of the CD4 lymphocytes and subsequent immune depression. The drugs are numerous, but have been considered based on their action into 3 main classes which are: antiproteasis, nucleoside inhibitor of reverse transcriptases and non nucleoside inhibitor of reverse transcriptase. Into the middle of the decade, it clearly appeared that none of these classes could solely stop the viral replication and that, in the contrary, the triple combination was efficient. Shortly after, the common presentation became a triple antiretroviral fixed combination drugs commonly

There are two most common combinations that are: Efavirenz, Zidovudine and Lamivudine into one hand, and on the other hand, Niverapine, Stadivudine and Lamivudine. In case of drug resistance, a second line combination of Indinavir, Zidovudine and Lamivudine is proposed. The first line treatment, which is commonly used, has shown that besides few sides effects seen at the beginning of the treatment, that combination is usually well tolerated thereafter and it is efficient. In a large majority of patients the CD4 level will rise above 500/ML after weeks to months and the virus will be undetectable in the peripheral blood, making them significantly less contagious to their sexual partners. Many institutions in our country give drugs only to severely immune depressed carriers defined as AIDS patients. Moderately immune depressed and non immune depressed carriers are not treated. Therefore, it remained a question weather this policy does not favor the spreading of the disease through the world? Anyway, whenever an arhtroplasty is demanded by a

Finally, 5 types of HIV carriers have been considered among arthroplasty demanders; they

1. **B1** Arthroplasty demanders are already known as HIV carriers and under ARVT; they should never stop their treatment even the day before and after surgery. There is nothing to do more, compare to non carriers patients. Exceptionally, if their CD4 count is low, they are referred to their physician to find out if this low count is due to drug resistance or to a non compliant attitude. The surgery should be delayed, and the issue

2. Type **B2** arthroplasty demanders (HIV carriers with >500 CD4 lymphocytes/ML): they are not immune depressed no matter their viral load; they should be managed

specific protective measures and especially, antiretroviral therapy (ARVT).

**1.3 General principles of antiretroviral therapy** 

HIV carrier, a different protocol of ARVT should be associated.

may need a similar number of protocols regarding ARVT.

corrected by a second line protocol ARVT.

**1.4 Antiretroviral therapy in HIV carriers demanding arthroplasty** 

named TRITHERAPY.

whether immediately, in the short, the mid and even the long term? These questions may be better understood through a review of the pathogenesis of HIV infection.

### **1.1 Pathogenesis of HIV Infection**

HIV infection is due to the introduction of the related virus in the body mainly through unprotected sexual intercourses, secondly through blood transfusion, and more rarely through other ways. Sometimes the patient may present a minor inflammatory syndrome lasting for few days with a complete recovery and no detectable virus for a long period. In some people, the virus will spread into the body fluids and organs and will slowly, but surely, destroy a specific type of lymphocytes, named CD4; the problem is that, CD4 are the hard ware of the body immune system and thus, the protector against numerous common infectious agents. With time, and after many years, no matter the apparent normal clinical state, the CD4 lymphocytes count which is normally above 500 Cells/Ml, will decrease progressively with a proportional depression of the HIV carrier immunity. If nothing is done, the general status of the patient will decompensate with severe weight loss, anemia and fatigue. He will develop opportunistic infections or tumors which are exceptional in an immune competent person. The most common opportunistic diseases are from the skull to the foot: brain toxoplasmosis, mouth and esophageal candidiasis, lung tuberculosis and pneumocystoses, intestinal cryptosporidiosis, leg and generalized Kaposi angiosarcomas, and various lymphomas. At this stage, the majority of patients are killed by a combination of these diseases and their complications. It is obvious that clinical pictures of HIV carriers are numerous, depending on the level of the immune depression; a classification is therefore necessary. The WHO-AIDS has proposed such a classification based both on the clinical picture and biological markers. However, as far as arthroplasty is concerned, the extreme majority of demanders of this surgery look clinically well; therefore, except in case where they declare themselves, if a systematic sample of HIV serologogy is not done, the surgeon may be taking the risk of a major surgical procedure in an advanced immune depressed patient. In our practice where the HIV carriage is up to 10% into the general population, HIV screening is mandatory before any elective arthroplasty. No matter the result, the benefice is defendable. In fact, in one hand, negative patients may at least undergo an auto transfusion program while, in the other hand, virus carriers will be classified and appropriately managed before or during arthroplasty. Such classification is mainly based on immunological work up, since, as it had been said above, quite all patients look healthy.

### **1.2 Work up and classification of HIV carriers elected for arthroplasty**

After the diagnosis is done and an indication of arthroplasty is made, especially into the areas of high HIV carriage in the general population, the Orthopedic Surgeon should obtain an inform consent from his patient about this uncomfortable matter. In twelve years practice in our community, we have not had any of our patients for hip arthrosplasty resisting to the above arguments, but as with all medical information, discretion is the rule. If the patient is a known HIV carrier already on antiretroviral treatment, we will look up for his latest CD4 count and viral load. In the other cases, the screening is mandatory; if the patient is seronegative, he is managed conventionally with the advantage of auto transfusion program, provided hepatitis B and C serology are negative. In HIV positive screened patients, the next step is the confirmation western-Blot test; if the latest is negative; the patient is qualified as non HIV carrier and managed as usual. In case of confirmed HIV

whether immediately, in the short, the mid and even the long term? These questions may be

HIV infection is due to the introduction of the related virus in the body mainly through unprotected sexual intercourses, secondly through blood transfusion, and more rarely through other ways. Sometimes the patient may present a minor inflammatory syndrome lasting for few days with a complete recovery and no detectable virus for a long period. In some people, the virus will spread into the body fluids and organs and will slowly, but surely, destroy a specific type of lymphocytes, named CD4; the problem is that, CD4 are the hard ware of the body immune system and thus, the protector against numerous common infectious agents. With time, and after many years, no matter the apparent normal clinical state, the CD4 lymphocytes count which is normally above 500 Cells/Ml, will decrease progressively with a proportional depression of the HIV carrier immunity. If nothing is done, the general status of the patient will decompensate with severe weight loss, anemia and fatigue. He will develop opportunistic infections or tumors which are exceptional in an immune competent person. The most common opportunistic diseases are from the skull to the foot: brain toxoplasmosis, mouth and esophageal candidiasis, lung tuberculosis and pneumocystoses, intestinal cryptosporidiosis, leg and generalized Kaposi angiosarcomas, and various lymphomas. At this stage, the majority of patients are killed by a combination of these diseases and their complications. It is obvious that clinical pictures of HIV carriers are numerous, depending on the level of the immune depression; a classification is therefore necessary. The WHO-AIDS has proposed such a classification based both on the clinical picture and biological markers. However, as far as arthroplasty is concerned, the extreme majority of demanders of this surgery look clinically well; therefore, except in case where they declare themselves, if a systematic sample of HIV serologogy is not done, the surgeon may be taking the risk of a major surgical procedure in an advanced immune depressed patient. In our practice where the HIV carriage is up to 10% into the general population, HIV screening is mandatory before any elective arthroplasty. No matter the result, the benefice is defendable. In fact, in one hand, negative patients may at least undergo an auto transfusion program while, in the other hand, virus carriers will be classified and appropriately managed before or during arthroplasty. Such classification is mainly based on immunological work up, since, as it had been said above, quite all patients look healthy.

better understood through a review of the pathogenesis of HIV infection.

**1.2 Work up and classification of HIV carriers elected for arthroplasty** 

After the diagnosis is done and an indication of arthroplasty is made, especially into the areas of high HIV carriage in the general population, the Orthopedic Surgeon should obtain an inform consent from his patient about this uncomfortable matter. In twelve years practice in our community, we have not had any of our patients for hip arthrosplasty resisting to the above arguments, but as with all medical information, discretion is the rule. If the patient is a known HIV carrier already on antiretroviral treatment, we will look up for his latest CD4 count and viral load. In the other cases, the screening is mandatory; if the patient is seronegative, he is managed conventionally with the advantage of auto transfusion program, provided hepatitis B and C serology are negative. In HIV positive screened patients, the next step is the confirmation western-Blot test; if the latest is negative; the patient is qualified as non HIV carrier and managed as usual. In case of confirmed HIV

**1.1 Pathogenesis of HIV Infection** 

carriage by western-Blot test, the next step is the CD4 lymphocytes count and the viral load measurement by up to date procedures. The CD4 lymphocyte count is the key point for HIV carriers classification. Patients with less than 500 CD4 lymphocytes / ML are considered immune depressed and named **class A arthroplasty demanders.** Depending on whether this count is above 300, les than 300 with no opportunistic disease, or less than 300 with an opportunistic disease, Class A patients are further sub divided **A1, A2 or A3**. Non immune depressed HIV seropositive Patients with low infection risk are classified **B**; if they were known before and under treatment, they are sub-divided **B1**, if they have more than 500 CD4/ML with no treatment, they are sub-divided **B2**. This makes a total of 5 classes of arthroplasty demanders living with the virus (**B1, B2, A1, A2, A3**) and thus, who need specific protective measures and especially, antiretroviral therapy (ARVT).
