During pregnancy there is increased risk of musculoskeletal disorders and injuries. This is due to numerous anatomical, physiological, and hormonal changes women experience during pregnancy such as change in gait, postural parameters, as well as sensory feedback.
The influences of increased hormones such as estrogen and relaxin initiate the remodeling of soft tissues, cartilage and ligaments. Certain skeletal joints such as the pubic symphysis and sacroiliac joint particularly have increased laxity.
Possible etiologic factors for postpartum pelvic pain include protracted delivery, epidural anesthesia, history of previous back pain, muscle weakness, and excessive pelvic relaxation secondary to increased levels of the hormones progesterone and relaxin during delivery, leading to acute pathologic separation of the symphysis pubis and posterior sacroiliac ligament insufficiency .
Pelvic infection can be the underlying etiological factor for postpartum pelvic pain. Approximately 6% of live births result in postpartum infection in the developed world. The main cause of infection following a normal vaginal delivery is mastitis and urinary tract infection. The majority of postpartum infections are typically gram-positive Staphylococcus and Streptococcus species . In addition Escherichia coli, Chlamydia trachomatis and anaerobic bacteria have also been implicated. Group A Streptococcus is especially significant. It has been associated with a 20–25% risk of mortality secondary to a toxic shock like syndrome induced by its exotoxin. It should, therefore, be managed with caution. Postpartum septic arthritis is exceptionally rare and there is as such little previously published on the topic.
Nearly half of all postpartum women experience some form of lower back and posterior pelvic pain . These symptoms are most frequently self-limiting and managed conservatively. This case illustrates that some postpartum women who present with seemingly benign symptoms may subsequently develop a rapid clinical deterioration. Indeed, our patient presented with a systemic inflammatory response syndrome secondary to an evolving septic arthritis. Although the focus of sepsis was not immediately identified she was aggressively resuscitated and treated with intravenous antibiotics.
Septic infection of sacroiliac joint usually develops as a result of hematogenous seeding due to a bacteremic episode. It may also occur as a result of joint aspiration or local corticosteroid joint injection or after trauma to the joint without an obvious break in the skin. Bacteria may also gain entry into the joint by direct introduction or extension from a contiguous site of infection .
Virtually every bacterial organism has been reported to cause septic arthritis. The microorganisms responsible for bacterial arthritis are largely dependent on host factors. The most common etiological agent of all septic arthritis is Staphylococcus aureus and Streptococcus spp. is also associated with septic arthritis.
Risk factors for postpartum septic arthritis include recent bacteremia, rheumatoid arthritis, corticosteroid therapy, patients with diabetes mellitus, leukemia, cirrhosis, granulomatous diseases, cancer, hypogammaglobulinemia, intravenous substance abuse, or renal disease.
The classical presentation of acute septic arthritis includes recent onset of fever, malaise, and local findings of pain, warmth, swelling, and decreased range of motion. However, patients may present with atypical symptoms.
As in this case, peripheral blood leukocyte counts might be elevated and most patients display elevated C-reactive protein levels. Aspirated fluid analysis is also very important and should be sent for aerobic, anaerobic, mycobacterial, and fungal culture prior to the initiation of antimicrobial therapy.
Plan radiology and ultrasonography are helpful in diagnosis. Computed tomography scans have limited use during the early stages of septic arthritis, however, they may enable the visualization of joint effusion, and soft tissue swelling therefore, CT scan is more sensitive than plain radiography particularly in sacroiliac joint.
An MRI scan is very useful diagnostic tool for the early determination of sacroiliitis in particular, because sacroiliac joint is difficult to access, due to its ability to displays greater resolution for soft tissue abnormalities than CT scan or radiography. Radionuclide scans are often able to detect localized areas of inflammation.
Patients who start treatment after experiencing symptoms for seven days or more demonstrate a poor outcome. Therefore, prompt diagnosis and rapid initiation of therapy are of the utmost importance in limiting the morbidity associated with septic arthritis. In addition, early physical therapy and aggressive mobilization are important for optimal recovery . Delay in diagnosis can also lead to a longer time being taken to clear the joint infection with appropriate therapy.
The outcome in patients with septic arthritis due to some of the more virulent organisms such as superantigen-producing S. aureus and certain gram-negative bacilli is poor in spite of the use of optimal therapy.