Septic arthritis of the hip caused by nontyphoidal salmonella: A case report

Introduction

Salmonellae is a group of pathogenic bacteria that belong to the family Enterobacteriaceae, which causes multiple enteric diseases in humans. Due to their many manifestations and the fact that some strains can infect abnormal areas like the extra intestinal regions, they are attracting more and more attention from the scientific community globally today.^[1], ^[2], ^[3] In the poor world, these various related disorders have created new treatment issues. According to reports, there are 3.4 million salmonella illnesses worldwide each year.^[4], ^[5] It is a significant issue for public health in emerging nations like India. The growth of multidrug resistance is leading to an increase in morbidity and death caused by these illnesses.^[6]

In this article, we’re going to look at a case of a delayed diagnosis of hip septic arthritis due to NTS infection, in a patient who did not have any underlying diseases. The patient was successfully treated with a two-stage hip joint reconstruction and long-term antimicrobial therapy.^[6] The patient was informed that data from the case would be submitted for publication, and his consent was taken for the same.

Case Presentation

A 65-year-old male presented with complaints of pain in right hip associated with high grade fever. The pain was sudden in onset with no preceding history of trauma. Progressively it became increasingly difficult for him to sit or walk. There was no prior history of such pain but for low back pain few years back. After 3 days of the onset of pain, the patient decided to get admitted at the nearby hospital and was treated conservatively with antibiotics after which the fever subsided but the pain persisted. He presented to our clinic 3 months following the onset. Patient was a known case of hypertension and was well controlled with the treatment. He had no history of other immunocompromising diseases, such as sickle cell anaemia, diabetes mellitus or human immunodeficiency virus. He had watery diarrhoea and a febrile episode that lasted for 2 weeks. On examination the right hip was in flexion and external rotation. The hip ROM was painful and restricted. Radiography of pelvis with both hips and right hip lateral view ([Figure 1]) demonstrated significant joint space narrowing with subarticular sclerosis and cystic changes seen along the right hip joint.

MRI revealed evidence of inflammation and fluid collection in right hip joint with destruction of the articular cartilage on both the side of the joint. It gave the additional important information that the collection of the fluid with broken compartment which is more suggestive of septic arthritis associated with osteoarthritic changes involving right hip joint ([Figure 2]).

Laboratory investigations showed:

C-reactive protein (CRP) level of 143 mg/L (normal range, 0–10 mg/L),

Erythrocyte sedimentation rate (ESR) of 33 mm/h (normal range, 0–20 mm/h),

Serum white blood cell (WBC) count of 7520/cmm (normal range, 4000-10000 / cmm).

Aspiration of right hip joint yielded cloudy yellow synovial fluid with a WBC count of 46,728/mm3 (93% polymorphonuclear neutrophil leukocytes). Salmonella serogroup D (nontyphoid) were grown in culture from aspirated synovial fluid.

As there was hip joint destruction due to prolonged exposure to NTS, we decided to perform a two- stage revision surgery using a posterolateral approach right hip. After the femoral head and neck was resected, all acetabular inflammatory tissues were debrided and excised. Copious lavage wash given with normal saline, vancomycin and gentamycin.Highly polished thinnest femoral stem was loaded with antibiotic cement. Hand held cementing done over the femoral head prosthesis matching the size of the patients resected femoral head (Figure:3). The antibiotics used for the cement were of 2 gentamycin 40 g pouch (Depuy CMW ). Here, our institution’s routine protocol was used to devise the cement spacer for joint infection.

Inj. ceftriaxone 2 g iv BD and Inj. Ofloxocin 2 units iv BD was initiated for 6 weeks with weekly assessment of CBC,CRP,ESR. After 6 weeks of antibiotic treatment, his CRP level reduced to 8 mg/L, his ESR was 19 mm/hr, and serum WBC count was 6800 /cmm. One month after the antibiotic treatment was discontinued, the infection markers were re-checked and was found within normal limits and the patient underwent conversion to total hip arthroplasty. Same surgical approach was used as stage one. For the identification of previously dissected tissue plane, nonabsorbable monofilament sutures were used in the stage one surgery which eased the exposure for second stage. A cementless femoral component (Solution stem- Depuy Synthes) and 36mm ceramic femoral head and a cementless acetabular component (Pinnacle cup and highly crossed polyethylene (Depuy Synthes) were used. The acetabular cup was augmented with two 6.5mm cancellous screws ([Figure 4]). Samples were taken during the second step of reimplantation for histological and microbiological research. There was no evidence of any infection.

At a 5-year follow-up, the patient’s CRP level was 4 mg/L, ESR was 18 mm/h, and the serum WBC count was 5200 /cmm suggestive of no recurrence of the disease. Good bone in-growth was seen around the implant with no sign of osteolysis or lucency ([Figure 5]).

The Harris hip score (HSS) was 95 points and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was 31 points.

Discussion

Adults with septic hip arthritis are quite uncommon, with an incidence of 2 to 10 per 100,000 person-years.^[7], ^[8], ^[9] It is, nonetheless, a potentially alarming illness. Bacterial enterotoxins and the host's immunological reaction to germs may both directly and indirectly cause septic arthritis to destroy cartilage.^[10], ^[11], ^[12] Joint degeneration, osteonecrosis, and joint instability can all result from delayed treatment of joint infections.^[13], ^[14] Only 1% of cases of septic arthritis are caused by salmonella typhoid.^[15] Typhoid and nontyphoid combined, the incidence of septic arthritis caused by salmonella is thought to be less than 0.1%-0.2% among the extraintestinal sequelae.^[16], ^[17], ^[18] The prevalence of NTS-related bone and joint infection among all salmonella cases in India is 0.06%.^[11] Additionally, people with underlying conditions such sickle cell disease, systemic lupus erythematosus, an immunological state, and diabetes mellitus are more likely to develop septic arthritis.^[3], ^[9] Although there were no underlying medical issues in our case, the organism may have been exposed for a longer period of time as a result of the fever and hip pain's insufficient treatment and delayed identification.^[19], ^[20] Within months of the fever's commencement, this virus caused the loss of all joint space. Complete debridement was challenging due to the hip joint's severe articular damage and periarticular osteomyelitis. Therefore, employing local antibiotic therapy, we completed phased repair for right septic hip arthritis.^[21], ^[22], ^[23] The preferred treatment for salmonella infection is a third-generation cephalosporin, however there have been occasional instances of antibiotic resistance in NTS serotypes.^[24], ^[25] Antibiotic susceptibility testing on our patient helped in the selection of the best medications for the effective eradication of the NTS infection.

Conclusion

Here, a rare case of NTS infection-related septic arthritis of the hip in a patient who had no other underlying medical problems was presented. In the management of the destroyed and disintegrated septic hip joint brought on by delayed diagnosis of NTS infection, a two-stage revision hip arthroplasty using a prosthesis made of antibiotic-loaded acrylic cement spacer and prolonged antimicrobial therapy should be taken into consideration.

Source of Funding

None.

Conflict of Interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.