Composition of pathogenic microorganism in chronic osteomyelitis based on metagenomic sequencing and its application value in etiological diagnosis.

BACKGROUND: Traditionally, conventional microbiological culture methods have been used to detect pathogenic microorganisms in chronic osteomyelitis. However, these methods have been found to have a low detection rate, complicating the precise guidance of infection treatment. This study employed metagenomic next-generation sequencing (mNGS) to detect these microorganisms in chronic osteomyelitis with three main objectives: 1). Gain a deeper understanding of the composition of pathogenic microorganisms in chronic osteomyelitis. 2). Compare the microbial detection rates between mNGS and the standard culture methods used in laboratories to enhance the effectiveness of the traditional culture methods. 3). Explore the potential of mNGS in etiological diagnosis. METHODS: Fifty clinically confirmed intraoperative bone tissue samples of chronic osteomyelitis from January 2021 to December 2021 were collected and subjected to mNGS and microbiological testing, respectively. The orthopaedic surgeon combined clinical manifestations and related examinations to determine the causative pathogens. RESULTS: The culture method obtained 29 aerobic and parthenogenic anaerobic bacteria, 3 specific anaerobic bacteria, and 1 yeast-like fungus. Thirty-six aerobic and parthenogenic anaerobic bacteria, 11 specific anaerobic bacteria, and 1 yeast-like fungus were obtained by mNGS, and 2 Mycobacterium tuberculosis(MTB) strains were detected. However, there was no significant difference in the overall positive detection rate between mNGS and the culture method (P = 0.07), and the two were not statistically significant in detecting aerobic and partly anaerobic bacteria (P = 0.625). But, mNGS was significantly superior to culture in detecting anaerobic bacteria and Mycobacterium tuberculosis (P<0.05). CONCLUSIONS: The mNGS method has enhanced our understanding of the distribution of pathogenic microorganisms in chronic osteomyelitis. Traditional culture methods help isolate and cultivate aerobic and facultative anaerobic bacteria, and fungi, and are also utilized for antibacterial drug sensitivity tests. However, mNGS has shown superior capabilities in detecting anaerobic bacteria, MTB, and mixed infection bacteria. This finding offers invaluable guidance for improving laboratory microbial culture and detection conditions. Hence, mNGS should be judiciously used for chronic osteomyelitis, and PCR can be implemented for certain difficult-to-culture microorganisms, such as MTB.

[Clinical safety about repairing the peripheral nerve defects with chemically extracted acellular nerve allograft].

OBJECTIVE: To discuss the clinical safety about repairing the peripheral nerve defects with the acellular allogeneic nerve. METHODS: The 41 patients (male 38, female 3, age 10 - 55 years old, average 28.9 years old) who were performed chemically extracted acellular nerve allograft transplanting to repair nerve defects from 2002 to 2011. The average interval from injury to nerve repairing was 4.1 months (range, 10 hours to 9 months). There were 41 cases nerve defects including 10 brachial plexus nerves, 3 radial nerves of upper arm, 4 ulnar nerves of forearm, 12 digital and toe nerves, 2 sciatic nerves, 2 femoral nerves, 3 tibial nerves and 5 common peroneal nerves. There were 12 cases combined fractures and 20 soft tissue injury or defects. The average length of the nerve allograft to bridge the nerve defects was 6.1 cm (range, 2 - 10 cm). No immunosuppressive drugs were used in all cases. The clinical safety was evaluated through physical examination, blood biochemistry and immunity detection. RESULTS: All cases were followed up post-operation. They got primary wound healing except 2 superficial infection who got delay healing through dressings changing. No any adverse effects happened including immunological rejection, hypersensitivity reaction, deep infection, hepatotoxicity and nephrotoxicity. CONCLUSIONS: It is safe and feasible to repairing human peripheral nerve defects with chemically extracted acellular nerve allograft.

[Transplantation of large anterior latissimus dorsi muscular flap combination with musculus rectus abdominis flap].

OBJECTIVE: To study the value and surgical techniques of transplantation of large anterior latissimus dorsi muscular flap combination with musculus rectus abdominis flap. METHODS: Three cases (2 male and 1 female) with skin defect and bone exposed were reviewed from May 2005 to January 2007. Two patients suffered from trauma, and 1 suffered from tumor resection. Flaps size were: 60 cm x 32 cm, 55 cm x 30 cm and 50 cm x 25 cm, flaps pattern including: 1 free flap with 2 ends of vascular, 1 flap with pedicle and free vascular end, 1 flap with 2 ends of pedicle. RESULTS: Two flaps survived completely, 1 flap with necrosis edge eventually healed after change of dressing. The infection had been effectively controlled and ready for function recovered. One case caused by trauma recovered with fracture healing, full weight-bearing and restore the original work. CONCLUSIONS: Large anterior latissimus dorsi muscular flap combination with musculus rectus abdominis flap can be used for repair of large skin defect. For the difficulty and technical requirements, surgical indications should be strictly controlled.

[The application of external fixator for complex tissue defect in the forearm].

OBJECTIVE: To discuss the curative effect of the external fixator for complex tissue defect in the forearm. METHODS: From May, 2005 through December, 2008, the external fixators were used in 17 patients to treat the complex tissue defect in the forearm caused by trauma. There were 11 male and 6 female, with a mean age of 25.6. All patients were accompanied with the exposure of tendon, muscle or screw. The skin defect ranged from 7 cm x4 cm to 19 cm x9 cm. All patients underwent pedicle flap repair. The flap ranged from 10 cm x 6 cm to 20 cm x 15 cm. The proximal pedicle of the flap was sutured into a tubular. The position of the pedicle was fixed by the external fixator. The pin was at the ulnar and the iliac (n=5), and the radius and the iliac (n=12). The immobilization lasted 3 to 8 weeks, 5.1 weeks in average. RESULTS: All patients were followed up for 3 to 20 months, 11.3 in average. All pedicle flaps survived with no pressure ulcer, or no erosion in the axilla. No compartment syndrome or osteomyelitis occurred. Four to six week after surgery, the pedicle was cut. Infection occurred at the cutting end in 1 patient. The wound healed after addressing. The wound in the other 16 patients healed successfully. The fracture of the ulnar and the radius healed 8.5 or 15 weeks after surgery, 13.5 weeks in average. Eleven patients underwent second stage reshape and function restoration. The function of the hands and forearms recovered satisfactorily. Eleven patients returned to their work. Six patients can live with basic function for living. CONCLUSIONS: The external fixator used for complex tissue defect in the forearm can keep the position of the pedicle, replacing plaster fixation. It can reduce the incidence of flap and vessel spasm, and get good outcomes.