Gonococcal osteomyelitis and Kirschner-wire infection of the hand.

A cis–gender heterosexual woman in her 60s presented to the emergency department after sustaining a fall on her outstretched hand. She was found to have a comminuted fracture of the right 5th metacarpal. This occurred on a background of unprovoked left common iliac vein thrombosis 9 years prior for which she was prescribed dabigatran, anxiety and depression managed with fluoxetine, endometriosis with prior hysterectomy, and prior cholecystectomy. Six days post presentation she underwent a closed reduction and Kirschner wire (K–wire) insertion of the fractured metacarpal as a day–procedure. Twenty days after the procedure the patient presented to the emergency department with pain in the hand. There was mild erythema of the area. The two wires were electively removed five weeks post insertion, with findings of minimal granulation tissue without a purulent exudate. A superficial swab of the exit site was taken and sent for bacterial culture. N. gonorrhoeae was isolated from the intra–operative swab, confirmed by matrix assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectroscopy. Nucleic acid amplification testing (NAAT) using both the Cobas 4800 CT/NG assay and a supplemental test using a Seegene Allplex STI Essential assay detected N. gonorrhoeae DNA. Further history elicited prior gonococcal infection treated at age 15, followed by re–infection at age 17. The patient had also undergone treatment for pelvic inflammatory disease several decades previously. The patient identified as cisgender and heterosexual and had been married to their current partner for the last 15 years with no additional sexual partners in that time. The partner was tested with urine N. gonorrhoeae NAAT and was negative. Ceftriaxone 2 g daily was commenced post collection of blood cultures as well as throat, vaginal, anal and urine specimens for N. gonorrhoeae and Chlamydia trachomatis NAAT. None of these specimens detected either pathogen. Susceptibility testing of the isolate showed susceptibility to ceftriaxone, azithromycin and ciprofloxacin. Syphilis, hepatitis B and HIV serological studies were negative. A computed tomography (CT) scan did not find any collection in the abdomen and pelvis or persistent thrombosis. After two days of therapy with ceftriaxone the patient was treated with oral ciprofloxacin 750 mg twice daily for six weeks. Due to concerns of QT interval prolongation, fluoxetine was weaned and ceased. The patient was reviewed in the outpatient clinic and monitored for diarrhoea and Achilles tendonitis which did not occur. They completed 6 weeks of treatment with good resolution of function and no adverse effects of treatment. The patient was discharged from follow up post review 4 weeks after completion of therapy.

Ethan MacMinn: Writing – review & editing, Writing – original draft, Investigation. Jeffrey J. Post: Writing – review & editing, Conceptualization.

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request

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This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Osteomyelitis is a rare presentation of disseminated gonococcal infection. Most cases of gonococcal osteomyelitis are associated with septic arthritis. A 14–year–old girl was found to have a right shoulder septic arthritis with an associated osteomyelitis of the humeral head. Culture of the joint fluid yielded N. gonorrhoeae. The patient received 6 days of intravenous ceftriaxone, followed by 35 days of oral cefixime. Recovery of joint function was incomplete at six weeks and the patient was subsequently lost to follow up [3] . A case of gonococcal L3–L4 discitis and osteomyelitis with epidural collections associated with polyarticular septic arthritis was treated with eight weeks of intravenous ceftriaxone without surgical intervention [4] . A 37 year old man presented with a gonococcal urethritis and concurrent culture positive right foot abscess with magnetic resonance imaging (MRI) evidence of distal cuboid, fourth and fifth metatarsal osteomyelitis. The patient was planned for four weeks of intravenous ceftriaxone, however due to issues with treatment adherence only one week of therapy was completed. Subsequent examination suggested resolution [5] . A 59–year–old man with a history of coeliac disease who presented with three months of knee pain was found to have culture–positive gonococcal septic arthritis with clinical signs of osteomyelitis at the medial femoral condyle and trochlear on knee arthroscopy. He was managed with 6 weeks of intravenous ceftriaxone [6] . To our knowledge, the current case is notable as no other cases in the literature have been described associated with K–wire material without evidence of bacteraemia or concomitant mucosal infection. Case reports exist of infection of other prosthetic material. Prosthetic valve endocarditis [7] , [8] , pacemaker infection [9] , prosthetic joint infection [10] , and infection of penile prostheses [11] have all been reported. In the absence of any new sexual partners, we presume that this infection was distantly acquired, and either had settled in the metacarpal and resurfaced on either fracture or insertion of the K-wire or was ongoing in the pelvis and asymptomatic bacteraemia seeded the fractured metacarpal bone. It would be less likely that the infection was introduced by a contaminated instrument. Disseminated gonococcal infection is usually associated with an asymptomatic mucosal infection [12] . The usual timeframe from mucosal infection to dissemination of infection is unknown. Disseminated gonococcal infection is usually treated with seven days of antimicrobial agents, usually consisting of ceftriaxone which is changed to a suitable oral agent when fever has resolved [13] , [14] . Specific recommendations are lacking for osteomyelitis due to the rarity of gonococcal osteomyelitis. One factor impacting therapy of gonococcal osteomyelitis and DGI is antimicrobial susceptibility. Few antibiotics have documented breakpoints [15] , antimicrobial resistance is well documented, and clusters of multi–drug resistant gonococcal have been reported [16] . In Australia in 2022, resistance to penicillin and ciprofloxacin was reported as 38.8 % and 63.3 % respectively [17] . This is important given the generally increased duration of therapy that has been prescribed in the case reports of gonococcal osteomyelitis. The cases of prosthetic valve endocarditis were treated with six weeks of parenteral antibiotics in addition to replacement of the infected valve. The case report of prosthetic joint infection occurred in a right knee that was managed with a debridement, antibiotics and implant retention (DAIR) approach. They received 2 weeks of intravenous ceftriaxone followed by 12 weeks of oral ciprofloxacin. Gonorrhoea is a very common infection, with 33,742 cases notified in Australia in 2022 [16] . Gonococcal osteomyelitis and infections of prosthetic material are rare complications. A paucity of evidence regarding duration of treatment in these infections generally leads to a longer duration of treatment, in keeping with bone and prosthetic material infections involving other organisms.

Disseminated Neisseria gonorrhoeae infection is well described, with the most common manifestations including tenosynovitis and dermatitis or septic arthritis. Disseminated gonococcal infection usually occurs secondary to bacteraemia occurring post mucosal infection [1] . Dissemination of infection does not require an immunocompromised host. One case series of gonorrhoea cases identified that 0.25 % of cases were associated with septic arthritis over a 25–year period [2] . The literature regarding gonococcal osteomyelitis is limited to case reports. As a result, there is no robust data regarding duration of antimicrobial therapy.

The authors declare no conflict of interest.