Should patients with hip joint prosthesis receive antibiotic prophylaxis before dental treatment?

Isolation, identification and reviewing the health effect of HPC bacteria in household point-of-use (PoU) water treatment devices: a case study, Ahvaz, Iran

In Ahwaz, a city in west southern Iran, the majority of households are using Point of Use (PoU) water treatment units. The heterotrophic plate count (HPC) bacteria were isolated from these units while they were mounted on water distribution system in order to determine the variations in HPC and diversity of the bacterial population using polymerase chain reaction (PCR). Results showed that bacterial population regrowth in PoU units could increase HPC exceeding the limit of the 500 CFU/mL in outlet water. In around 70% of the input water samples, the HPC was less than 500 CFU/ml with a mean of 226.7 (CI 95%: 28.1-425.3). HPC in output treated water samples had an increasing trend from the start of the unit operation with a mean of 2416.4 (CI 95%: 1074.9-3757.9). Out of 49 detected bacterial strains, 20 strains were Gram-negative and 29 Gram-positive. Bacillus was the most frequent genes detected in inlet and outlet water samples. Most of the identified bacterial strains were opportunistic pathogens potentially dangerous for immunocompromised population. HPC population in PoU units significantly can be increased during a one-month period of operation, so replacement of the filters must be done regularly.

Metronidazole-induced encephalopathy in a patient with pyogenic spondylitis: a case report

Background

Metronidazole is an antimicrobial agent commonly used in the treatment of several protozoal and anaerobic infections. Neurotoxicity associated with metronidazole has been rarely reported, and the incidence of metronidazole-induced encephalopathy is unknown. Therefore, the accurate diagnosis of metronidazole-induced encephalopathy is often difficult because of the rarity of the disease.

Case presentation

An 86-year-old woman suffered from pyogenic spondylitis of the lumbar spine. Parvimonas micra, a gram-positive anaerobic bacterial species and a resident of the flora of the oral cavity, was identified in the biopsy specimens. Oral administration of metronidazole (1500 mg/day) was initiated. Forty-four days after initiating metronidazole (total intake of 66 g), she complained of tingling sensations in the upper limbs. After 4 days, she complained of additional symptoms including sensory disturbance of the tongue, dysarthria, and deglutition disorder. Characteristic brain magnetic resonance imaging findings on T2-weighted fluid-attenuated inversion recovery and diffusion-weighted imaging led to the diagnosis of metronidazole-induced encephalopathy. Metronidazole was discontinued, and her neurological symptoms improved 10 days after discontinuation. At 14 days after discontinuation of oral metronidazole, abnormal findings on diffusion-weighted imaging almost disappeared.

Conclusions

With the possibility of needing to prescribe metronidazole in the orthopedic field for the treatment of various infections, orthopedic surgeons are likely to encounter cases of metronidazole-induced encephalopathy. Thus, they should be able to recognize the condition and its potential complications. With increased awareness, early diagnosis with magnetic resonance imaging and discontinuation of metronidazole may become feasible when such patients are referred. Our report presents a detailed account of such a case, which may help in the early diagnosis and treatment of patients with metronidazole-induced encephalopathy. Furthermore, we recommend that patients treated with metronidazole should undergo careful and constant surveillance after starting antibiotic therapy.

Outcomes of Unilateral Total Hip Arthroplasty in Patients Aged Under 35 Years in Iranian Population: A Preliminary Study

Background:

The purpose of this study is to report outcomes of total hip arthroplasty (THA) in patients under the age of 35 years regarding pain and joint function.

Materials and Methods:

This preliminary analytic-descriptive study was performed in prospective consecutive series of forty-three patients younger than 35 years old who had undergone unilateral THA during a 36-month period. As the primary outcome, the severity of pain using visual analog scale (VAS) of 1–10, and as the secondary outcomes, joint range of motion (ROM) and the Harris Hip Score (HHS) were assessed in the preoperative visit, 1, 6, and 18 months after operation for each patient. Complications were recorded at 6 months and 18 months after surgery.

Results:

The data of VAS showed the mean severity of pain was significant between preoperation measurements and postoperative assessments (P < 0.001). The means of HHS and hip ROM were also statistically significant before the operation in comparison with postoperative assessments (P < 0.001 for both means). A total of 19 patients had postoperative complications including periprosthetic fracture in two patients, infection in two patients, cup loosening in three patients, limb length discrepancy in 10 patients, and heterotopic ossification in two patients. Seven patients had been readmitted.

Conclusion:

We believe THA using uncemented prosthesis has a high survivorship with low rate osteolysis in young patients with good bone stock. It is necessary to have longer follow-up to have a better evaluation on outcomes.

Antibiotic prophylaxis is not indicated prior to dental procedures for prevention of periprosthetic joint infections

Background and purpose - To minimize the risk of hematogenous periprosthetic joint infection (HPJI), international and Dutch guidelines recommended antibiotic prophylaxis prior to dental procedures. Unclear definitions and contradictory recommendations in these guidelines have led to unnecessary antibiotic prescriptions. To formulate new guidelines, a joint committee of the Dutch Orthopaedic and Dental Societies conducted a systematic literature review to answer the following question: can antibiotic prophylaxis be recommended for patients (with joint prostheses) undergoing dental procedures in order to prevent dental HPJI? Methods - The Medline, Embase, and Cochrane databases were searched for randomized controlled trials (RCTs), reviews, and observational studies up to July 2015. Studies were included if they involved patients with joint implants undergoing dental procedures, and either considered HPJI as an outcome measure or described a correlation between HPJI and prophylactic antibiotics. A guideline was formulated using the GRADE method and AGREE II guidelines. Results - 9 studies were included in this systematic review. All were rated "very low quality of evidence". Additional literature was therefore consulted to address clinical questions that provide further insight into pathophysiology and risk factors. The 9 studies did not provide evidence that use of antibiotic prophylaxis reduces the incidence of dental HPJI, and the additional literature supported the conclusion that antibiotic prophylaxis should be discouraged in dental procedures. Interpretation - Prophylactic antibiotics in order to prevent dental HPJI should not be prescribed to patients with a normal or an impaired immune system function. Patients are recommended to maintain good oral hygiene and visit the dentist regularly.

Do genetic susceptibility, Toll-like receptors, and pathogen-associated molecular patterns modulate the effects of wear?

Overwhelming evidence supports the concept that wear particles are the primary initiator of aseptic loosening of orthopaedic implants. It is likely, however, that other factors modulate the biologic response to wear particles. This review focuses on three potential other factors: genetic susceptibility, Toll-like receptors (TLRs), and bacterial pathogen-associated molecular patterns (PAMPs). WHERE ARE WE NOW?: Considerable evidence is emerging that both genetic susceptibility and TLR activation are important factors that modulate the biologic response to wear particles, but it remains controversial whether bacterial PAMPs also do so. WHERE DO WE NEED TO GO?: Detailed understanding of the roles of these other factors may lead to identification of novel therapeutic targets for patients with aseptic loosening. HOW DO WE GET THERE?: Highest priority should be given to polymorphism replication studies with large numbers of patients and studies to replicate the reported correlation between bacterial biofilms and the severity of aseptic loosening.

Acute Hematogenous Infection of Revision Total Hip Arthroplasty by Oral Bacteria in a Patient without a History of Dental Procedures: Case Report

The risk of periprosthetic joint infection from hematogenous bacterial seeding is increased in patients undergoing dental procedures that facilitate the development of bacteremia.

We herein report the case of a patient without a history of dental procedures who suffered from an acute metastatic infection of a hip prosthesis by the oral bacterium Streptococcus mutans 18 months after undergoing revision total hip arthroplasty. The patient was successfully treated by two-stage revision surgery.

It is important to realize that the efficacy of antibiotic prophylaxis against joint infections has not yet been convincingly proven. As a result, optimal dental hygiene and regular dental visits may be more important than antibiotic prophylaxis for maintaining joint health. Therefore, orthopedic surgeons should educate patients with joint prostheses about good oral health.

Bacterial findings in infected hip joint replacements in patients with rheumatoid arthritis and osteoarthritis: a study of 318 revisions for infection reported to the norwegian arthroplasty register

High rates of Staphylococcus aureus are reported in prosthetic joint infection (PJI) in rheumatoid arthritis (RA). RA patients are considered to have a high risk of infection with bacteria of potentially oral or dental origin. One thousand four hundred forty-three revisions for infection were reported to the Norwegian Arthroplasty Register (NAR) from 1987 to 2007. For this study 269 infection episodes in 255 OA patients served as control group. In the NAR we identified 49 infection episodes in 37 RA patients from 1987 to 2009. The RA patients were, on average, 10 years younger than the OA patients and there were more females (70% versus 54%). We found no differences in the bacterial findings in RA and OA. A tendency towards a higher frequency of Staphylococcus aureus (18% versus 11%) causing PJI was found in the RA patients compared to OA. There were no bacteria of potential odontogenic origin found in the RA patients, while we found 4% in OA. The bacteria identified in revisions for infection in THRs in patients with RA did not significantly differ from those in OA. Bacteria of oral or dental origin were not found in infected hip joint replacements in RA.