Pyogenic Arthritis in Qatar

Nahman A. and Hammoudeh M.
Department of Medicine, Hamad Medical Corporation
Doha, Qatar

Abstract:

A retrospective study of patients diagnosed with pyogenic arthritis at Hamad Medical Corporation over the five-year period January 1st 1996 to December 31 2000 showed that only 24 patients out of 63 fulfilled the criteria for bacterial arthritis. Staph. aureus was the main organism isolated from the synovial fluid (72%). The mean duration between the onset of symptoms and admission was 11 days. Nearly half the patients (45%) were under 12 years of age. Earlier diagnosis and treatment gives a better outcome.

Key words: Pyogenic arthritis; septic arthritis; bacterial arthritis; infectious arthritis.

Introduction:

Bacterial arthritis is a serious infection with significant morbidity and mortality with an irreversible loss of joint function in 25-50% of surviving patients⁽¹⁾. In most cases bacteria infect the joint by hematogenous spread and the disease is typically mono-articular⁽²⁾ although poly-articular septic arthritis can occur. Early recognition, diagnosis and early proper therapy are very important to prevent joint damage. We present this study of cases of bacterial arthritis that were treated at Hamad Medical Corporation between 1996 and 2000.

Methods and Patients:

All files were reviewed of patients discharged with the diagnosis of septic, pyogenic, bacterial or infectious arthritis between January 1st 1996 and December 31st 2002. Only patients who fulfilled the following criteria were included:

1. Organisms isolated from the joint

2. Acute infection with an organism isolated from the blood, and other possibilities excluded.

3. No organism isolated but:

a) Clinical or radiological evidence of joint infection
b) Clinically acute arthritis with a very turbid synovial fluid after exclusion of other possibilities.
The files were reviewed thoroughly for all pertinent information regarding the clinical presentation, pre-existing rheumatic disease, investigation, timing of admission in relation to symptoms, treatment, course of the disease and the outcome after three months.

Results:

Sixty-three files were identified with the discharge diagnosis of infectious, pyogenic, septic or bacterial arthritis during the period of five years but only 24 patients fulfilled the criteria for inclusion as pyogenic arthritis (Table 1). There were more males affected⁽¹⁹⁾ than females⁽⁵⁾. The youngest patient in the study was 18 months old and the eldest was 81 years old at the time of admission. Eleven patients (45%) were in the pediatric age group (less than 12 years).

The knee was the most common joint involved (14/24) followed by the hip (5/24) and ankles (5/24) and DIP (1/24). Mono-articular involvement was seen in 23 patients and poly-articular involving two joints in only one patient who was diabetic and developed septicemia and bacterial arthritis following cardiac catherization. Initially he had arthritis of the knee followed by the hip.

The duration of symptoms before admission to the hospital varied from one day to two months with an average of 11 days. The initial diagnosis upon admission was septic arthritis in 19/24 (70%), reactive arthritis in 2/24 and other form of arthritis in 3/24. The duration after admission before a final diagnosis was established varied from one to 16 days with an average of three days.

The synovial fluid cell count ranged from 24,000 to 90,000 with a percentage of polymorphs from 90% to 98%. The synovial fluid culture was positive in 16/24 (66%), while the blood culture was positive in 4/24 (16%). Both synovial fluid and blood culture were positive in only two patients (8%). The synovial 

Table 1: Showing the distribution of the patients’ data including the age, gender,, duration of symptoms, organism, joint/s involved, and body fluid with positive culture.

fluid or blood cultures were negative in six patients (25%) who had received antibiotics prior to admission to the hospital.

Seven of the 24 patients had associated diseases; four (16%) were diabetic, two (8%) had pseudo-gout and one on steroids had idiopathic thrombocytopenia. Two patients previously had respiratory tract infection, one a urinary tract infection and one an abscess in the thigh.

The organisms isolated from the synovial fluid or blood were Staph aureus 14/18 (77%), Streptococci spp.2/18 (11%), Salmonella spp. 1/14 (6%) and Pseudomonas spp. 1/18 (6%).

Three months after discharge from hospital, eleven patients had no pain or functional disability; nine were lost to follow-up and four still had residual pain in the involved joint. These last four had proper therapy delayed for periods of ten days to two months before admission. One patient died with Staphylococcal septicemia and arthritis.

Discussion:

Septic arthritis includes all joint infection caused by pyogenic bacteria with the exception of tuberculosis. Early diagnosis and treatment is very important to reduce the significant associated morbidity and mortality. It is generally accepted that the outcome of joint infection will be good in previously healthy patients if appropriate therapy is given as early as possible ^(3,4,5). Delay in treatment beyond one week or the presence of serious systemic disease or joint damage is often accompanied by prolonged morbidity and not infrequently, by death⁽³⁾. Therefore it is essential to establish the diagnosis by synovial fluid analysis including smears and culture, and culture of blood and other body fluids.

One of the problems we faced while reviewing the files of all patients discharged with the diagnosis of septic arthritis was the lack of a proper approach to establish the diagnosis; many cases were treated empirically as septic arthritis without fluid culture. Only 24 cases out of 63 files fulfilled the pre-established criteria for septic arthritis. Most likely this does not reflect the true incidence of septic arthritis in the hospital but this number of patients would reflect the local data of this disease.

Close to half the patients (45%) were below 12 years of age (the pediatric age group).

The knee joint was most commonly involved (58%) followed by the hip and ankle (20% each). This finding is similar to other studies on septic arthritis⁽⁶⁾. Monoarticular involvement was seen in 23/24(96%) of patients and polyarticular was seen in one patient only. This is similar to the finding of Al-Ballaa in his studies of septic arthritis from a University hospital in Saudi Arabia⁽⁷⁾. A significant number of patients 8/24 (33%) presented to the hospital more than seven days after the start of symptoms. This caused major delay in initiating therapy. Patients who still had pain three months after treatment had an average duration of 30 days of symptoms before admission compared to 11 days for the total number of patients. Staph. aureus was the most common pathogen isolated from the joints (72%) similar to other studies in the region⁽⁷⁾ and in the west⁽⁸⁾ if gonococcal and brucella infections are excluded.

This study reflects the local data on this subject and as with other studies of this disease it emphasizes early diagnosis and early treatment to prevent joint damage and obtain better results. Staph aureus is still the most common organism causing bacterial arthritis followed by streptococcal infection (14%) and Gram-negative organisms (14%). This should help make the choice of initial antibiotic therapy before the results of culture become available.

References:

1. Kaandorp CJE, Krijnan P, Moens HJB et al. The Outcome of Bacterial Arthritis. Arthritis Rheum 1997; 40(5):8 84-892.

2. Epstei JH, Zimmerman III B, Ho G Jr. Polyarticular septic arthritis. J Rheum 1986; 13(6): 1105-1107.

3. McCarty DJ. Joint sepsis: A chance for cure (editorial). JAMA 1982; 247(6): 835.

4. Ho G Jr., Su EY. Therapy for septic arthritis. JAMA 1982; 247: 797-800.

5. Rosenthal J, Bole GG, Robinson WD. Acute nongonococcal infectious arthritis. Arthritis Rheum 1980; 23: 889-97.

6. Sharp JT, Lidsky MD, Duffy J et al. infectious arthritis. Arch Int Med 1979; 139: 1125-30.

7. Al Balaa S. Nongonococcal septic arthritis at a major teaching hospital in Riyadh, Saudi Arabia. Ann Saudi Med 1995; 15(2): 117-119.

8. Goldenberg DL, Reed JI . Bacterial arthritis. N Engl J Med. 1985; 312(12): 764-7.