A Malhas, R Chana, F Khan
knee arthroscopy, septic arthritis., serratia marcescens
A Malhas, R Chana, F Khan. A Case report of a Serratia Marcescens infective arthritis after a knee arthroscopy. The Internet Journal of Orthopedic Surgery. 2006 Volume 7 Number 2.
Major joint infections with
The largest outbreak of
We report a case of a
A 66 year old man was being followed up as an orthopaedic outpatient since 2002 for osteoarthritis on both knees. He also suffered from type II diabetes which was diet controlled and had a penicillin allergy. Otherwise he was in good health.
In 2006 he was referred to the urology department with recurrent balanitis and a tight phimosis. On the 07/03/2006 he underwent a circumcision and suffered an infection in the wound and had to have a repeat circumcision on the 26/04/2006. Mid-stream urine samples and wound swabs at the time revealed mixed organisms and skin/faecal flora respectively. He was discharged without further incident. A repeat urine sample culture resulted in no organisms grown.
On the 02/06/2006 (five weeks later) the patient underwent an arthroscopy of his right knee to reassess his osteoarthritis as he developed increasing pain (especially on the medial joint line). There were predominately grade III to IV changes throughout the knee and a stable vertical medial meniscal tear, which was resected. The procedure was performed with cefuroxime antibiotic cover and 10mls of 5% chirocaine intra-articularly for symptomatic relief. The patient was discharged without incident.
The patient presented to the accident and emergency department eight days later with a two-day history of severe right knee pain, swelling and redness. On examination, the knee was visibly swollen, hot to touch with a decreased range of movement. He was systemically well. Although his white cell count (WCC) was normal, his erythrocyte sedimentation rate (ESR) was 21mm/hr and C-reactive protein (CRP) was 179mg/l. Radiographs were unremarkable (Figure 1).
A knee aspiration was performed and the initial gram stain revealed no crystals, moderate white cells and no organisms.
The patient was admitted and started on a course of intra-venous (IV) clindamycin (due to his penicillin allergy). Cultures later identified a gram negative bacillus on enrichment culture and the patient was taken to theatre for an arthroscopic washout on the 14/6/6. The arthroscopy some revealed frank pus and a marked red pigmentation. The knee was washed out with 6L of normal saline and then 180mg of gentamycin was injected intra-articularly.
Final blood and aspirate cultures confirmed
An ultrasound scan of the urinary tract revealed no marked abnormality. A urine sample demonstrated no growth.
The patient's knee continued to swell and so received a further washout on the 17/6/6 with 9L of normal saline and an intra-articular injection of both 180mg gentamycin and 400mg ciprofloxacin was given.
The patient remained on IV antibiotics for ten weeks and his inflammatory markers were closely monitored (Graph 1).
Throughout he remained systemically well with normal WCC and well controlled blood sugar levels.
The patient was finally discharged on oral antibiotics on 25/8/6 once he showed clinical and biochemical signs of the infection resolving and his CRP returned to normal (and remained normal).
We feel that the episodes of urinary infection, post circumcision infection, past catheterisation and his history of diabetes lead to a colonisation of the patient's urinary tract system by
It is important to ask whether the organism spread via direct contamination or by haematological spread.
Septic arthritis itself carries an 11-15% mortality rate and around 40% of patients will require surgical intervention [12,13,14].
The antibiotics of choice in the literature are: amikacin, meropenim and ciprofloxacin [6,17]. Fortunately the patient was started on the later two shortly after the organism was identified. There are cases of increasingly resistant
In accordance with British Society of Rheumatology (BSR) approved guidelines on management of the swollen joint .
There was a high clinical suspicion of septic arthritis, which was immediately treated with IV antibiotics even though the initial stain was negative. Joint infection can often give negative cultures and indeed the organism was picked up on enrichment.
The antibiotics were adjusted appropriately on culture and sensitivity and the patient received a minimum of two weeks IV antibiotics, followed by oral antibiotics on discharge.
Inflammatory markers were used to guide the duration of treatment.
The joint was aspirated washed out on two occasions, until no further fluid collections occurred.
Potential septic arthritis must be treated with a high index of suspicion with prompt aspiration and administration of antibiotics. Rare pathogens require swift identification and appropriate management with microbiology input. Care must be taken to ensure that an infection is an isolated case and not the start of an epidemic. In any elective orthopaedic procedure, care must be undertaken to ensure there are no septic foci that may result in joint and bone infection, particularly in the urinary system.