Prevention and Management of Acute Musculoskeletal Infections


Ovid: Manual of Orthopaedics

Editors: Swiontkowski, Marc F.; Stovitz, Steven D.
Title: Manual of Orthopaedics, 6th Edition
> Table of Contents > 3 – Prevention and Management of Acute Musculoskeletal Infections

3
Prevention and Management of Acute Musculoskeletal Infections
Prevention of infection is the key to successful orthopaedic surgery.
Meticulous attention to aseptic technique in the operating room, proper
skin preparation and surgical scrub, the use of modern gown and mask
techniques, planning the operation to shorten the time the tissues are
exposed to air, laminar flow air, and prophylactic antibiotics (1,2,3,4)
are all important in the prevention of infection. None, however, is as
critical as meticulous debridement of wounds and the careful handling
of tissues to prevent cell death (4). When
infection does occur following an operation or from hematogenous
origin, early diagnosis and prompt effective treatment can prevent
disastrous complications.
I. Prevention
  • Elective surgery. Refer to Chap. 1, III, and Chap. 10, I, for techniques described for the prevention of operative and posttraumatic infections.
  • Early diagnosis
    • Whenever a patient’s postoperative or
      postinjury status does not follow the normal or expected course, the
      surgeon should be alert to the possibility of infection. A respiratory problem
      such as mild atelectasis may be a cause for persistent postoperative
      temperature elevation (this is especially common in patients who
      smoke), but such a potential diagnosis should not lull the surgeon into
      complacency. Wound infection may be the cause, or the two could be
      concurrent. Large hematomas can themselves be the cause of low-grade
      fever, but hematomas also represent the best culture media for bacteria
      and hence should be avoided or evacuated if present. Always obtain a
      culture of any evacuated hematoma.
    • When there is concern regarding a wound infection, inspect the wound and document the findings
      at least daily, using sterile technique. Inspect the wound for
      swelling, erythema, and serous or bloody drainage. Culture any
      drainage. Tense skin, erythema, and abnormal tenderness or swelling
      frequently are signs of low-grade inflammation and infection.
    • If the patient does not respond promptly to treatment or if the wound remains indurated, then aspiration should be carried out using aseptic technique with a large needle inserted into the wound area but away from the suture line.
    • A low-grade fever in patients who have
      had antibiotics is not uncommon. In such instances, the temperature
      rarely exceeds 37.8°C (100°F) and may show a mild afternoon elevation.
      The patient frequently feels lethargic and has mild anorexia. If the low-grade inflammatory process
      involves a joint, the patient complains of pain to passive motion of
      the joint, which should alert the surgeon to the possibility of a
      septic joint.
    • Be alert to the possibility of infection. Establish the diagnosis through cultures
      whenever possible, and treat the infection aggressively. If in doubt,
      the best course is generally to return the patient to the operating
      room and open the wound, irrigate and debride it to remove hematoma and
      necrotic wound tissue, and reclose the wound using the most “tissue
      friendly” suture technique (see Chap. 10). Consultation with another experienced surgeon can be helpful.
  • Treatment.
    Once the diagnosis of a musculoskeletal infection has been established,
    treatment proceeds as for acute osteomyelitis or septic arthritis. The
    principles of

    P.40


    treatment
    include removal of all dead tissue and any hematoma along with
    appropriate antibiotic therapy. The wound is nearly always left open
    for secondary closure except when the infection involves a joint. If
    the wound is closed, a suction drain is mandatory.

II. Bone and Joint Infections
  • Bones and joints represent special
    problems for the host defense mechanisms. Normal bone has an excellent
    blood supply, although there is slowing of the circulation in the
    metaphyseal region in children. Once pus forms under pressure, the vascular supply to bone is lost
    because of its rigid structure, resulting in areas of infected,
    devitalized bone. Septic emboli in bone or vascular thrombosis can
    cause additional devascularization. Ligaments and tendons are
    relatively avascular structures and do not handle infection well.
    Joints, with their avascular cartilage and menisci, pose a particular
    problem. Local phagocytic function can be deficient, and it is often
    difficult to ensure adequate delivery of humeral factors (antibodies,
    opsonins, complement). In addition to the direct destructive effect of
    cell breakdown on cartilage, the pus under pressure interferes with
    cartilage nutrition and blood supply to the periarticular structures.
    At particular risk is the epiphyseal blood supply, and avascular
    neurosis may be the result. Antibiotics can inhibit or cure an
    infection only when they can reach the infecting organism in
    bacteriostatic or bactericidal concentrations. Infections producing
    pressure in a bone or joint as well as in relatively avascular tissues
    can impede or prevent antibiotics from reaching the primary site of
    infection.
  • An acute infection of bone (hematogenous osteomyelitis),
    in its earliest phase, is a medical disease and can often be cured by
    prompt, appropriate antibiotic therapy. However, the time between
    initial infection and bone infarct is often short. If effective
    treatment is delayed and devascularization of the involved tissues
    results, then surgical treatment is a necessary adjunct to the
    antibiotic therapy. Even under the best of circumstances, late
    treatment (perhaps as early as 48 hours after the infection starts) may
    result in the loss of or abnormal function of the joint. Thus,
    appropriate antibiotic therapy must be initiated as early as possible.
    Appropriate therapy requires knowledge of the etiologic agent and its
    sensitivities. Every effort should be made to obtain a bacterial
    culture and determine sensitivity. Once the culture specimen is
    obtained, it is important to institute antibiotic therapy based on a
    probable diagnosis using the most effective broad-spectrum antibiotics.
  • Diagnosis
    • The earliest symptom or sign that may help differentiate a bone or joint infection is usually pain or localized tenderness in the periarticular region.
      In the infant, refusal to move or use an extremity may be noted first.
      The cardinal signs of infection redness, heat, and swelling may appear
      later than the pain and tenderness, or not at all. When examining a
      child with a fever of unknown origin, note any pain or alteration of
      the normal range of motions of a joint and carefully palpate all
      metaphyseal areas to determine local tenderness. Roentgenograms are of
      little value in making the early diagnosis, although careful comparison
      with the opposite side may show abnormal soft-tissue shadows.
      Roentgenographic evidence of bone or joint destruction is seen during
      the chronic phase of the disease. Osteomyelitis should always be
      included in the differential diagnosis for a patient with the
      radiographic appearance of a bone tumor (5). Radioisotopic bone scanning, especially indium imaging, is helpful in early localization of bone infection (6). Many authorities have advocated the use of magnetic resonance imaging in the diagnosis of osteomyelitis (7,8,9,10),
      but clinical context is of paramount importance in the evaluation of
      any abnormal findings. Erythrocyte sedimentation rate (ESR) and
      C-reactive protein (CRP) serum levels are useful in laboratory
      evaluations (11,12,13,14).
    • Identification of the infecting organism
      is essential. In the early stages of the disease, particularly if there
      is a spiking temperature, blood cultures can often yield the organism.
      If acute metaphyseal tenderness is present, then the organism can
      frequently be obtained by inserting a needle into the site of maximum
      tenderness. A serrated biopsy needle is useful if subperiosteal pus is
      not

      P.41


      encountered.
      If a joint is involved, then the effusion should be aspirated before
      joint lavage. Processing the aspirates should include the following:

      • Immediate Gram stain.
      • Inoculation of culture broth for aerobic and anaerobic cultures.
      • White blood cell count.
        If thick, purulent material is encountered, then dilution in broth
        occasionally enhances the growth of organisms by decreasing the
        concentration of leukocytes and humeral antibacterial factors. This is
        done routinely in the microbiology laboratory with fluid aspirates.
      • Determination of the character of the
        hyaluronic precipitate, the presence of fibrin clots, and any disparity
        between the glucose in the aspirate and blood glucose may prove helpful, but the Gram stain, culture, and cell count are most valuable (see Chap. 3).
  • Differential
    diagnosis. Care must be taken to differentiate soft-tissue infection,
    or cellulitis, from an infection occurring in a bone or joint
    .
    This is a particularly important precaution when the infection overlies
    a joint because any aspiration of a reactive sterile effusion by
    passing a needle through the soft-tissue infection may create a
    pyarthrosis. Tenderness and swelling from unrecognized trauma over a
    bone, particularly with some periosteal reaction, can present a
    confusing picture, but the absence of fever and systemic signs is
    helpful. Nonbacterial inflammatory arthritis, including viral and toxic
    synovitis and rheumatoid arthritis, must be included in a differential
    diagnosis, but until proved otherwise, think first of septic arthritis.
    Spontaneous hemorrhages in patients with hemophilia and fractures in
    paraplegic patients, particularly patients with meningomyelocele, are
    special situations that can confuse the picture.
  • Bacterial considerations (1,4,12)
    • In acute hematogenous osteomyelitis, Staphylococcus aureus
      is the most common etiologic agent in all age groups. In recent years,
      an increasing number of isolated strains have been found to be
      methicillin resistant. In infants younger than 1 month, a diversity of
      other bacteria must also be considered. Group B streptococci and
      gram-negative organisms such as Escherichia coli, Proteus species, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella
      species are all suspect. In infants with a complicated medical history,
      particularly those who have had prolonged indwelling venous catheters,
      extensive surgery, or intensive prior antibiotic therapy,
      coagulase-negative staphylococci and rarely anaerobic organisms such as
      Bacteroides fragilis and fungal agents such as Candida albicans (hard to diagnose) must also be considered.
    • In septic arthritis and osteomyelitis among infants younger than 1 month, S. aureus is the predominant etiologic agent. After the neonatal period and up to 4 years of age, Haemophilus influenzae is also a major cause of septic arthritis. In later childhood, the etiologic agents are the same as for adults, with S. aureus predominating. Neisseria gonorrhoeae
      must be seriously considered, particularly among adolescents with
      single (especially the knee joint) or multiple joint findings. If there
      has been a preceding infection or if there is a concurrent infection in
      another organ system, one may suspect that the etiologic agent is the
      same as that from the initiating focus. But, because this is not always
      the case, direct culture from the bone or joint infection is advised.
  • Special considerations
    • Infections of the intervertebral discs, or acute discitis, may be encountered in children without antecedent infection or surgery (15).
      When organisms have been recovered, they have usually been
      staphylococcal. Infants may merely refuse to stand or walk, whereas
      older youngsters complain of pain in the back or lower extremity. The
      infection usually is low grade, particularly among children younger
      than 5 years of age. Roentgenograms reveal that the involved disc
      narrows rapidly over the first 2 to 3 weeks. A bone scan shows
      increased activity in the adjacent vertebrae. Although the process
      often appears self-limited, the symptoms and course of the disease can
      be improved by plaster immobilization and antistaphylococcal
      antibiotics. The difficulty in

      P.42


      obtaining
      a bacterial diagnosis, even with needle biopsy, combined with the
      benign course of this condition, has led many clinicians to ignore
      efforts at establishing a bacterial diagnosis. The condition must,
      however, be differentiated from vertebral osteomyelitis with secondary
      disc destruction; in the latter condition, it is essential to obtain
      the bacterial diagnosis as an integral part of treatment of what can be
      a severe disease. The same precaution applies to disc infections
      following laminectomy. In these cases, an infection should be suspected
      when a postsurgical patient complains of increasing back pain starting
      1 to 2 weeks postoperatively.

    • Patients with hemolytic disorders, particularly those with sickle cell disease, are prone to the development of a subacute form of osteomyelitis. Salmonella infections are frequent, but other types of bacterial osteomyelitis are not uncommon (4).
      Because the diagnosis is usually made late, treatment is difficult and
      may require extensive surgical debridement and prolonged antibiotic
      therapy.
    • Another special problem is presented by the patient who sustains a puncture wound
      in the sole of the foot. Despite initial cleansing and occasional
      debridement, cellulitis, arthritis, or osteomyelitis involving the foot
      develops in many patients (11). This occurrence is most commonly caused by P. aeruginosa. Early surgical debridement of the infected, including the plantar fascia, combined with preoperative and postoperative anti-P. aeruginosa
      antibiotics, has been the most effective method of management. For a
      serious infection, treatment is 5 days of antibiotic therapy with an
      aminoglycoside (e.g., tobramycin) or an antipseudomonal beta-lactam
      (e.g., ceftazidime) administered parenterally. Recently, ciprofloxacin
      has been used in gram-negative bone and joint infections (1);
      it must not be used in prepubertal children, however. Appropriate
      sensitivities guide antibiotic selection. Duration of therapy is
      empirical and may be guided by the clinical appearance and the CRP or
      ESR (11,15).
      Aminoglycoside doses need to be adjusted according to peak and trough
      serum levels and monitoring must include weekly Serum Creatinine (Cr)
      measurements and regular audiologist evaluation. Patients with human
      immunodeficiency virus or acquired immunodeficiency syndrome can have
      septic joints, which frequently may be missed because of the relatively
      weak immune response to the infectious agent. Joint aspiration should
      be performed in this setting (16).
    • Lyme arthritis. Lyme arthritis, the most common vectorborne infection in the United States, is caused by the spirochete Borrelia burgdorferi, which is transmitted to humans primarily via the Ixodes scapularis tick from its natural hosts, deer and white-footed mice (17).
      Arthritis, the most common form of late Lyme disease (other forms being
      encephalopathy and polyneuropathy), can occur weeks to months after the
      original infection. Approximately 60% of untreated primary disease will
      develop arthritis (18). Clinical presentation
      includes fever and joint effusion, which may be confused with acute
      septic arthritis, especially in children (19).
      Treatment with oral antibiotics such as doxycycline for 4 weeks or the
      parenteral agent ceftriaxone for 2 weeks usually results in lasting
      cure. However a small percentage of patients experience ongoing
      symptoms despite antibiotic therapy. Possible reasons include
      persistent infection, residual joint damage, or a chronic autoimmune
      synovitis (20).
  • Requirements and characteristics of appropriate antibiotic treatment (1,4,21)
    • For initial treatment of bone or joint infection, choose a bactericidal antibiotic
      effective against the suspected organism and a route of administration
      that ensures delivery of therapeutic levels to the infected site. The
      intravenous (IV) route is generally preferred for initial treatment
      [although some agents such as gentamicin and tobramycin are effective
      given intramuscularly (IM)]. Recent studies (1)
      have indicated that oral antibiotics appear in therapeutic
      concentrations in bones and joints and, if given properly, can
      substitute for parenteral therapy in children. Most authorities,
      however, prefer the IV route.
    • The duration of parenteral treatment is 3 to 4 weeks for septic arthritis and 4 to 6 weeks for osteomyelitis (the longer duration for infections caused by S. aureus). In adults with selected organisms, the treatment may be completed using

      P.43



      oral quinolones after the initial pain, swelling, and fever have
      resolved with IV antibiotics. Quinolone antibiotics (ciprofloxacin,
      gatifloxacin, levofloxacin, moxifloxacin) have allowed oral therapy
      against a broad spectrum of bacteria including Pseudomonas (1). In treating children
      with osteomyelitis, treatment may be initiated with an IV agent such as
      nafcillin (Nafcil or Unipen), and the 4- to 6-week treatment course may
      be completed with oral dicloxacillin (Dynapen) or trimethoprim (Bactrim
      or Septra). For all ages the dosage of
      antibiotics (oral or parenteral) is at the upper therapeutic level.
      When appropriate, adequate bactericidal drug levels for both oral as
      well as parenteral agents should be documented. Providing parenteral
      antibiotics through home health care teams greatly reduces the cost of
      treatment. The differentiation between a mild, well-localized infection
      and a localized bone tumor can sometimes require a surgical biopsy (5). The CRP or ESR is also a helpful guideline to determine the duration of treatment (11). A summary of antimicrobial agents commonly used in acute bone and joint infections is presented in Table 3-1. These agents are known to enter bone and joint sites readily when given in adequate doses.

    • In an acute infection in which the organism is not immediately identified, the choice of therapy
      is determined by the organisms most commonly expected in the various
      age groups, along with the other factors previously listed. General
      guidelines are presented in Table 3-2.
    • A local instillation or continuous irrigation with an antibiotic solution is almost never indicated. Systemic antibiotics, properly administered, achieve adequate levels in viable tissues (1,4). In many posttraumatic conditions, delivery of local antibiotics in methyl methacrylate beads is worthwhile (21).
      This treatment is indicated especially when a delayed bone graft or
      soft-tissue muscle flap is planned. Some favorable reports have been
      published about an implantable pump with a reservoir for antibiotic
      (generally amikacin).
    • Continue antibiotics until the infection has been eliminated. A normal or declining ESR or CRP is one of the most helpful laboratory tests to indicate control of infection.
  • Adjunctive treatment. Most orthopaedists believe that the healing process is aided by immobilizing
    the infected area. There is disagreement over casting or splinting.
    Undoubtedly, however, patients are more comfortable when the infected
    area is immobilized. If damage to the bone is significant, cast
    immobilization may be important to prevent a pathologic fracture. If
    damage to articular cartilage is suspected, motion of the involved
    joint is recommended after a brief 1- to 2-day period of immobilization.
  • Surgical intervention.
    Appropriate antibiotic treatment instituted within the first 48 hours
    of acute osteomyelitis or septic arthritis is usually satisfactory.
    However, early diagnosis is rarely the case. If treatment is initiated over 48 hours after onset, it is important to determine whether medical treatment alone is adequate.
    Err on the side of more aggressive operative drainage. If the patient
    has been on an appropriate antibiotic for more than 24 hours without
    significant resolution of pain and temperature, then surgical
    intervention is indicated.
    • In a bone infection,
      metaphyseal or subperiosteal abscesses must be drained. If metaphyseal
      point tenderness is present, and there is doubt whether this represents
      significant metaphyseal or subperiosteal pus, then it is safer to err
      on the side of a small surgical exploration or aspiration with a biopsy
      needle. If pus is encountered, then open surgical drainage is indicated.
    • Joints
      • In joint infections, satisfactory evacuation of pus can be achieved by needle aspiration.
        When the joint is easily visible and palpable, such as with the knee
        joint, repeated needle aspiration is usually adequate to keep the joint
        decompressed. Aspiration should be done with a 16- to 18-gauge needle.
        Irrigation of the joint to ensure removal of as much cellular debris as
        possible is helpful (12). The hip joint presents special problems (12).
        The blood supply to the femoral head is intraarticular; hence, any
        increase in pressure can deprive the entire femoral head of its
        circulation. Because hip

        P.44



        P.45



        P.46



        P.47


        joint
        effusions are not readily palpable, it is difficult to be certain that
        repeated aspirations decompress the joint. For this reason, most
        authorities believe that immediate surgical drainage of a septic hip is
        indicated, and some believe that the shoulder should be treated
        similarly. The possible exception is in gonococcal arthritis (22).
        The hip joint can be drained anteriorly between muscle planes or
        posteriorly with a muscle-splitting incision. The capsule and synovium
        are opened and drains are inserted.

        TABLE 3-1 Antimicrobial Agents Commonly Used Initially in Acute Bone and Joint Infections
        Antibiotic Usual susceptible organisms Daily dosage (IV route) Comment
        Cefazolin (cephalosporins) Penicillinase-producing Staphylococcus aureus; will also treat streptococci, pneumococci, non–penicillinase-producing staphylococci, and Klebsiella pneumoniae 0–7 d: 40 mg/kg divided doses q12h
        Infant: 60 mg/kg divided doses q8h
        Child: 80 mg/kg divided doses q6h
        Adult: 3–6 g divided doses of 8h
        A drug of choice; IV route
        preferred, but may be given IM. Adjust adult dosage according to blood
        urea nitrogen or, preferably, the creatinine clearance
        Nafcillina Same as cefazolin 0–7 d: 50 mg/kg divided doses q12ha
        7 d–6 wk: 75 mg/kg divided doses q8h
        6 wk–3 y: 80 mg/kg divided doses q6h
        Child: 150 mg/kg divided doses q6h
        Adult: 2–12 g divided doses of 4–6 h
        A drug of choice
        Methicillin Same as cefazolin and nafcillin No longer commonly used; too many problems Monitor patients for proteinuria: drug has occasionally been implicated in adverse renal side effects
        Clindamycin S. aureus, pneumococci, streptococci (not enterococci), and many Bacteroides fragilis strains Pediatric: 10–20 mg/kg PO or IV or IM in 3–4 doses
        Adult: 600–900 mg of 6–8 h
        Considered an excellent agent for B. fragilis infections
        Penicillin G (aqueous) Streptococci (not enterococci), pneumococci, gonococci, and penicillin-susceptible staphylococci 0–7 d: 50,000 unit/kg divided dose q12h
        greater than 7 d: 75,000–100,000 unit/kg IV or IM divided doses q8h
        12 y–adult: 12–24 million units of 4–6 h
        Useful for open fractures contaminated with barnyard waste and for treatment of clostridia infection
        Ampicillin Same as penicillin G; also Haemophilus influenzae, some strains of Escherichia coli, Proteus, and Salmonella 0–7 d: 50 mg/kg divided doses q12h
        7 d–6 wk: 75 mg/kg divided doses q8h
        Infant: 100 mg/kg divided doses q6h
        Child: 150 mg/kg divided doses q6h
        12 yr–adult: 8–12 g
        H. influenzae now shows a 10%–20% ampicillin resistance in some areas. Empirin therapy must therefore be with ceftriaxone or cefuroxime
        Ceftriaxone Select gram-negative organisms or mixed infections 0–12 yr: 50 mg/kg once daily
        12 yr–adult: 2 g q24h
        Generally reserved for resistant or mixed infections
        Cefuroxime Select gram-negative organisms or mixed infections greater than 3 mo-12 yr: 75 mg/kg divided doses q8h Generally reserved for resistant or mixed infections
        Ceftazidime Select gram-negative organisms including Pseudomonas or mixed infections 12 yr–adult: 1.5 g q8h
        less than 12 yr not indicated
        12 yr–adult: 1 g q8–12h
        Same as cefuroxime
        Gentamicin Gram-negative infections less than 12 yr: 6–7.5 mg/kg in three equal doses Agent of choice for suspected gram-negative infections
        Tobramycin   12 yr–adult: 3–5 mg/kg in three equal doses (dose adjusted based on peak and trough levels) can be given as a single daily dose May be given either IV or IM.
        Renal function must be carefully checked, and therapy beyond 10 days
        must be administered cautiously because of potential nephrotoxicity and
        ototoxicity. May be synergistic with carbenicillin against some strains
        of Pseudomonas aeruginosa; also usually synergistic with
        penicillin against enterococci. Reduce dosage to 3 mg/kg/d as soon as
        clinically indicated. Follow with peak and trough serum levels if
        available
        aSome authorities recommend that nafcillin not be used in 0- to 7-day-old infants because of poor pharmacokinetics.
        From Hansen ST Jr, Ray CG. Antibiotics in orthopaedics. In: Kagan BM, ed. Antimicrobial therapy, 3rd ed. Philadelphia, PA: WB Saunders, 1980, with permission.
        TABLE 3-2 Tentative Selection of Therapy When Organisms Are Not Immediately Identified
        Situation Organisms suspected Suggested antibiotic choice
        Newborn (1 mo) Staphylococcus aureus Nafcillin plus gentamicin or tobramycin
           Osteomyelitis Streptococci
        Gram-negative bacteria including Escherichia coli, Klebsiella pneumoniae, Proteus group, Pseudomonas aeruginosa  
           Septic arthritis S. aureus
        1 mo–4 yr
           Osteomyelitis S. aureus Second-generation cephalosporin to cover H. influenzae
           Septic arthritis Haemophilus influenzae
        S. aureus
        Streptococci
        Second-generation cephalosporin to cover H. influenzae
        4 yr–12 yr
           Osteomyelitis
           Septic arthritis
        S. aureus First- or second-generation cephalosporin
        12 yr–adult
           Osteomyelitis S. aureus A cephalosporin (first- or second-generation agent) or nafcillin
           Septic arthritis S. aureus A cephalosporin or nafcillin (ceftriaxone if gonococcus is strongly suspected)
        Special considerations
        Chronic hemolytic disorders
           Osteoarthritis S. aureus A cephalosporin (second-generation if salmonella is suspected) or nafcillin until sensitivity results are available
           Septic arthritis Pneumococci
        Salmonella groupa
        Infections following puncture wounds of the foot Pseudomonas aeruginosa Ceftazidime actually achieves better drug levels than aminoglycosides (gentamicin or tobramycin)
        Infections following trauma or surgery S. aureus
        Streptococci
        Gram-negative organisms
        A first- or second-generation cephalosporin (or nafcillin) plus gentamicin or tobramycin
        aInfections caused by Salmonella
        should be documented first by culture and sensitivity testing before
        empirical treatment with agents such as ampicillin (or chloramphenicol)
        is initiated.
        From Hansen ST Jr, Ray CG. Antibiotics in orthopaedics. In: Kagan BM, ed. Antimicrobial therapy, 3rd ed. Philadelphia, PA: WB Saunders, 1980, with permission.
      • At times, the fibrin entering the joint
        as a transudate forms clots and isolates segments of the joint from
        decompression. Hypertrophy of synovium and adhesions may also affect
        the ability of the surgeon to decompress the joint adequately. Under
        these circumstances, it is advisable to debride the joint arthroscopically or with an open procedure. Joints amenable to arthroscopic lavage are the knee, shoulder, and ankle.
  • Chronic osteomyelitis
    presents a different problem from acute infection. Acute infection in
    the earliest phase is primarily a medical disease, with surgical
    techniques used as an adjunct. In chronic infection, the primary
    problem is surgical removal of all dead
    and poorly vascularized tissue. If this removal is properly done under
    appropriate antibiotic therapy, it is possible to eradicate most sites
    of chronic osteomyelitis. The operation must be carefully planned
    because it often involves significant removal of bone and surrounding
    tissues. In the case of chronic joint infections, it may mean complete
    resection of the joint with the creation of a pseudarthrosis or an
    arthrodesis. Rotational muscle flaps or free-tissue transfer may be
    required to cover areas of viable but poorly covered bone. Intravenous
    and oral antibiotics serve as valuable adjuncts. Patient quality of
    life can be profoundly impacted by chronic osteomyelitis (23); treatment leading to resolution of the infection does improve this impact.
  • Gas gangrene
    • Gas gangrene can be a fatal process. Prevention
      can be achieved by thorough debridement and removal of all devitalized
      tissue, delayed wound closure when in doubt, and antibiotic treatment
      as recommended previously.
    • Clostridium perfringens infections carry a 65% overall mortality rate, which increases to 75% in infants and elderly patients. The diagnosis
      should be suspected when the patient is pale, weak, perspiring, and
      more tachycardiac than the degree of fever warrants. The patient
      frequently complains of severe pain. Mental confusion and gas in the
      tissues are late signs, as are the characteristic mousy odor, jaundice,
      oliguria, and shock.
    • Other gas-producing species in addition to C. perfringens (ten isolated toxins), include E. coli, Enterobacter aerogenes, anaerobic streptococci, B. fragilis, and K. pneumoniae. Antitoxin does not appear to help much because it is neutralized as rapidly as it reaches muscle. Treatment consists of debridement and high doses of antibiotics. Penicillin is usually the best for the C. perfringens
      group; it should be given in amounts of 20 to 50 million units/day.
      Clindamycin or metronidazole are good alternative antibiotics in
      patients who are allergic to penicillin. Some clostridia are resistant
      to clindamycin, making it necessary to check sensitivities carefully.
      Hyperbaric oxygen is only an adjunct to surgery. Its use allows the
      surgeon to save more tissue than might otherwise be possible, and it
      does lower the mortality rate slightly.
      Although exceedingly uncommon, group A streptococcal
      myonecrosis can have a similar course and results in death in a high
      percentage of cases. It must be treated with aggressive surgical
      debridement or amputation in addition to appropriate antibiotic
      therapy. Toxic shock syndrome has also been noted in orthopaedic
      patients and is caused by unique staphylococcal strains with unusual
      phage types. Toxic shock syndrome is also a surgical condition, but it
      carries a more favorable prognosis. Necrotizing fasciitis can be caused
      by several bacterial types (most commonly group A streptococcus) and
      often requires debridement combined with appropriate antibiotic
      therapy. Infectious disease consultation is indicated for each of these
      infectious conditions.

P.48


III. Summary
  • Infections in the musculoskeletal system
    present special problems for treatment with antibiotics alone.
    Cartilage is avascular, tendon and ligaments are relatively
    hypovascular, and bone is vulnerable to situations that render it
    avascular. Because antibiotics can be effective only if they are
    delivered to the site of infection, every effort must be made to
    preserve a normal blood supply and normal joint fluid dynamics. The essentials of treatment are as follows:
    • Prompt diagnosis, with identification of the bacteria through culture and with sensitivity for determining the appropriate antibiotic
    • Rapid initial treatment with the most effective bactericidal antibiotic
    • Constant evaluation to assess the need for surgical drainage of pus or removal of devitalized tissue
    • Antibiotic therapy
      by a route that ensures adequate blood levels and administration until
      the signs of infection, as manifested usually by a decreasing ESR,
      resolve completely
    • Judicious use of immobilization and traction to improve patient comfort and provide the best possible environment for primary healing
  • The greatest benefit of antibiotics in musculoskeletal infection is in preventing
    the mortality and morbidity that result from chronic osteomyelitis and
    joint destruction from pyarthrosis. Even chronic infection can be
    controlled and a satisfactory functional result obtained in most
    patients by the use of surgery and appropriate antibiotics.
References
1. Greenberg RN, Kennedy DJ, Reilly PM, et al. Treatment of bone, joint, and soft-tissue infections with oral ciprofloxacin. Antimicrob Agents Chemother 1987;31:151–155.
2. Hendershot EF. Fluoroquinolones. Infect Dis Clin North Am 1995;9:715–730.
3. Henry
SL, Galloway KP. Local antibacterial therapy for the management of
orthopaedic infections: pharmacokinetic considerations. Clin Pharmacokinet 1995;29:36–45.
4. Mader JT, Landon GC, Calhoun J. Antimicrobial treatment of osteomyelitis. Clin Orthop 1993;295:87–95.
5. Cottias P, Tomeno B, Anract P, et al. Subacute osteomyelitis presenting as a bone tumor: a review of 21 cases. Int Orthop 1997;21:243–248.
6. Schauwecker DS. The scintigraphic diagnosis of osteomyelitis. AJR Am J Roentgenol 1992;158:9–18.
7. Boutin RD, Brossman J, Sartoris DJ, et al. Update on imaging of orthopedic infections. Orthop Clin North Am 1998;29:41–66.
8. Tang JS, Gold RH, Bassett LW, et al. Musculoskeletal infection of the extremities: evaluation with MR imaging. Radiology 1988;166:205–209.
9. Tehranzadeh J, Wang F, Mesgarazadeh M. Magnetic resonance imaging of osteomyelitis. Crit Rev Diagn Imaging 1992;33:495–534.
10. Unger E, Moldofsky P, Gatenby R, et al. Diagnosis of osteomyelitis by MR imaging. AJR Am J Roentgenol 1988;150:605–610.
11. Crosby LA, Powell DA. The potential value of the sedimentation rate in monitoring treatment outcome in puncture wound-related Pseudomonas osteomyelitis. Clin Orthop 1984;188:168–172.
12. Dagan R. Management of acute hematogenous osteomyelitis and septic arthritis in the pediatric patient. Pediatr Infect Dis J 1993;12:88–92.
13. Frederiksen B, Chritiansen P, Knudsen FU. Acute osteomyelitis and septic arthritis in the neonate, risk factors and outcome. Eur J Pediatr 1993;152:577–580.
14. Unkila-Kallio
L, Kallio MJ, Eskola J, et al. Serum C-reactive protein, erythrocyte
sedimentation rate and white blood cell count in acute hematogenous
osteomyelitis of children. Pediatrics 1994;93:59–62.
15. Cushing AH. Diskitis in children. Clin Infect Dis 1995;17:1–6.
16. Malin JK, Patel NJ. Arthropathy and HIV infection: a muddle of mimicry. Postgrad Med 1993;93:143–150.

P.49


17. Spiro ED, Gerber MA. Lyme disease. Clin Infect Dis 2000;31:533–542.
18. Steere AC. Lyme disease. N Engl J Med 2001;345:115–125.
19. Willis AA, Widmann RF, Flynn JM, et al. Lyme arthritis presenting as acute septic arthritis in children. J Pediatr Orthop 2003;23:11418.
20. Weinstein A, Britchkov M. Lyme arthritis and post-Lyme disease syndrome. Curr Opin Rheumatol 2002;14:383–387.
21. Ostermann PA, Seligson D, Henry SL. Local antibiotic therapy for severe open fractures: a review of 1085 consecutive cases. J Bone Joint Surg (Br) 1995;77:93–97.
22. Scopelitis E, Martinez-Osuna P. Gonococcal arthritis. Rheum Dis Clin North Am 1993;19:363–377.
23. Lerner
RK, Esterhai JL Jr, Polomano RC, et al. Quality of life assessment of
patients with posttraumatic fracture nonunion, chronic refractory
osteomyelitis and lower extremity amputation. Clin Orthop 1993;295:28–36.
Selected Historical Readings
Burnett JW, Gustilo RB, Williams DN, et al. Prophylactic antibiotics in hip fractures. J Bone Joint Surg (Am) 1980;62:457–462.
Clawson DK, Davis FJ, Hansen ST Jr. Treatment of chronic osteomyelitis with emphasis on closed suction-irrigation technique. Clin Orthop 1973;96:88–97.
Ha’eri GB, Wiley AM. The efficacy of standard surgical face masks: an investigation using “tracer particles.” Clin Orthop 1980;148:160–162.
Hamilton HW, Booth AD, Lone FJ, et al. Penetration of gown material by organisms from the surgical team. Clin Orthop 1979;141:237–246.
Lunseth PA, Heiple KG. Prognosis in septic arthritis of the hip in children. Clin Orthop 1979;129:81–85.
Monson TP, Nelson CL. Microbiology for orthopaedic surgeons: selected aspects. Clin Orthop 1984;190:14–22.
Patzakis MJ, Harvey P Jr, Ivler D. The role of antibiotics in the management of open fractures. J Bone Joint Surg (Am) 1974;56:532–541.
Perry
CR, Ritterbusch JK, Rice SH, et al. Antibiotics delivered by an
implantable drug pump: a new application for treating osteomyelitis. Am J Med 1986;80(6B):222–227.
Peterson AF, Rosenberg A, Alatary SD. Comparative evaluations of surgical scrub preparations. Surg Gynecol Obstet 1978;146:63–65.
Schurman DJ, Hirshman HP, Nagel DA. Antibiotic penetration of synovial fluid in infected and normal knee joints. Clin Orthop 1978;136:304–310.

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More