Antibiotic-impregnated calcium phosphate cement as part of a comprehensive treatment for patients with established orthopaedic infection

The State of Local Antibiotic Use in Orthopedic Trauma

Fracture-related infections are a challenging complication in orthopedic trauma that often necessitates multiple surgeries. Early administration of systemic antibiotics and surgical intervention remains the gold standard of care, but despite these measures, treatment failures can be as high as 35%. For these reasons, the introduction of local antibiotics at the site of at-risk fractures has increased over the past decade. This review looks at the various measures being used clinically including local antibiotic powder, polymethylmethacrylate, biodegradable substances, antibiotic-coated implants, and novel methods such as hydrogels and nanoparticles that have the potential for use in the future.

Current application and future perspectives of antimicrobial degradable bone substitutes for chronic osteomyelitis

Chronic osteomyelitis remains a persistent challenge for the surgeons due to its refractory nature. Generally, treatment involves extensive debridement of necrotic bone, filling of dead space, adequate antimicrobial therapy, bone reconstruction, and rehabilitation. However, the optimal choice of bone substitute to manage the bone defect remains debatable. This paper reviewed the clinical evidence for antimicrobial biodegradable bone substitutes in the treatment of osteomyelitis in recent years. Indeed, this combination was proved to eradicate infection and facilitate bone reconstruction, which might reduce the cost and hospital stay. Handling was associated with increased risk of unwanted side effect to affect bone healing. The study provides some valuable insights into the clinical evaluation of treatment outcomes in the aspects of infection eradication, bone reconstruction, and complications caused by materials. However, achieving complete infection eradication and subsequently perfect bone reconstruction remains challenging in compromised conditions, hence advanced innovative bone substitutes are imperative. In this review, we mainly focus on the desired functional effects of advanced bone substitutes on infection eradication and bone reconstruction from the future perspective. Handling property was optimized to simplify surgery process. It is expected that this review will provide an important opportunity to enhance the understanding of the design and application of innovative biomaterials to synergistically eradicate infection and restore integrity and function of bone.

Challenges and Triumphs: Unusual Presentation of Tuberculosis in the Cuboid Bone Successfully Managed Through Surgical and Medical Intervention

This case report describes the unusual presentation of tuberculosis (TB) affecting the cuboid bone in a 16-year-old male patient. The patient presented with a one-year history of progressive foot pain, a discharging sinus, evening rise of temperature, weight loss, and loss of appetite. Clinical examination revealed soft tissue swelling and the presence of caseous material oozing from the sinus. Emergency debridement and curettage were performed, and bone cementing was carried out. An intraoperative sample was sent for a culture sensitivity test, histological analysis, and cartridge-based nucleic acid amplification test (CBNAAT). Histopathological examination, CBNAAT, and culture and sensitivity tests confirmed the diagnosis of Mycobacterium tuberculosis infection. Post-operatively, anti-tuberculous treatment was started. The patient fully recovered from TB of the cuboid.

Gentamicin-permeated cement to sustain mechanical support for the treatment of a chronic calcaneal abscess. A case report

INTRODUCTION AND IMPORTANCE

Chronic calcaneal osteomyelitis is a challenging condition associated with high relapse rates, requiring a multidisciplinary approach and various therapeutic options for effective management. We report a very rare case of a pyogenic osteomyelitis of the os calcis presented as a bone abscess.

CASE PRESENTATION

A diabetic male patient presented with chronic osteomyelitis of the calcaneus in the form of bone abscess with a cavity of 6*5 cm. After pus evacuation and debridement of the cavity, gentamycin-impregnated polymethylmethacrylate cement was used to locally assist in controlling the infection and to assure mechanical support. Antibiogram-based oral antibiotic was administrated for 6 weeks. At final follow-up, the patient could walk without any assistance and was able to raise his body on the operated heel, with no signs of infection.

CLINICAL DISCUSSION

This case illustrates successful conservative surgical treatment of calcaneal abscess using antibiotic-impregnated cement for mechanical support and local infection control.

CONCLUSION

Incorporating antibiotic-impregnated cement into conservative foot surgeries for deeply embedded calcaneal abscesses provides effective infection control, mechanical support, and functional preservation, leading to successful treatment outcomes.

A scoping review of the outcome reporting following surgery for chronic osteomyelitis of the lower limb

Chronic osteomyelitis (COM) of the lower limb in adults can be surgically managed by either limb reconstruction or amputation. This scoping review aims to map the outcomes used in studies surgically managing COM in order to aid future development of a core outcome set. A total of 11 databases were searched. A subset of studies published between 1 October 2020 and 1 January 2011 from a larger review mapping research on limb reconstruction and limb amputation for the management of lower limb COM were eligible. All outcomes were extracted and recorded verbatim. Outcomes were grouped and categorized as per the revised Williamson and Clarke taxonomy. A total of 3,303 records were screened, of which 99 studies were included. Most studies were case series (77/99; 78%) and assessed one method of reconstruction (68/99; 69%). A total of 511 outcomes were reported, which were grouped into 58 distinct outcomes. Overall, 143/511 of all outcomes (28%) were provided with a clear, in-text definition, and 231 outcomes (45%) had details reported of how and when they were measured. The most commonly reported outcome was 'recurrence of osteomyelitis' (62; 12%). The single-most patient-reported outcome measure was 'pain'. This study has highlighted significant inconsistencies in the defining, reporting, and measuring of outcomes across studies investigating surgical management for chronic osteomyelitis of the lower limb in adults. Future studies should clearly report complete details of how outcomes are defined and measured, including timing. The development of a standardized core outcome set would be of significant benefit in order to allow evidence synthesis and comparison across studies.

Antimicrobial Photodynamic Therapy Involving a Novel Photosensitizer Combined With an Antibiotic in the Treatment of Rabbit Tibial Osteomyelitis Caused by Drug-Resistant Bacteria

Osteomyelitis is deep tissue inflammation caused by bacterial infection. If such an infection persists, it can lead to dissolution and necrosis of the bone tissue. As a result of the extensive use of antibiotics, drug-resistant bacteria are an increasingly common cause of osteomyelitis, limiting the treatment options available to surgeons. Photodynamic antibacterial chemotherapy has attracted increasing attention as a potential alternative treatment. Its advantages are a broad antibacterial spectrum, lack of drug resistance, and lack of toxic side effects. In this study, we explored the impact of the new photosensitizer LD4 in photodynamic antimicrobial chemotherapy (PACT), both alone and in combination with an antibiotic, on osteomyelitis. A rabbit tibial osteomyelitis model was employed and microbiological, histological, and radiological studies were performed. New Zealand white rabbits (n = 36) were randomly divided into a control group, antibiotic group, PACT group and PACT + antibiotic group for treatment. In microbiological analysis, a reduction in bacterial numbers of more than 99.9% was recorded in the PACT group and the PACT + antibiotic group 5 weeks after treatment (p < 0.01). In histological analysis, repair of the damaged bone tissue was observed in the PACT group, and bone repair in the PACT + antibiotic group was even more significant. In radiological analysis, the X-ray Norden score showed that the severity of bone tissue defects or destruction followed the pattern: PACT + antibiotic group < PACT group < antibiotic group < control group.

Novel nanographene oxide-calcium phosphate cement inhibits Enterococcus faecalis biofilm and supports dental pulp stem cells

Background

Enterococcus faecalis (E. faecalis) is the most recovered species from the root canals after failed root canal treatment. Calcium phosphate bone cement (CPC) scaffold is promising for applications in endodontic treatment as a kind of root canal sealer. Graphene oxide (GO) has been extensively considered as a kind of promising nano-materials for antibacterial applications. In the present study, an injectable CPC-chitosan paste containing GO was developed for promising endodontic therapy. The antibacterial properties of this paste against E. faecalis biofilms as well as the support for human dental pulp stem cells (hDPSCs) were investigated.

Methods

CPC-chitosan composite with or without GO injectable scaffold was fabricated. The hDPSC growth and viability on scaffolds were investigated by live/dead assay. Antibacterial effects against E. faecalis biofilms were determined in clinical detin block samples.

Results

The antibacterial CPC-chitosan-GO disks had excellent hDPSC support with the percentages of live cells at around 90%. CPC-chitosan-GO also had greater antibacterial activity on E. faecalis than that of CPC-chitosan control using detin block models (p < 0.05).

Conclusions

The injectable CPC-chitosan-GO paste had strong effects on inhibition E. faecalis and hDPSC support, which could fill the void of adjusting paste to the defect and shaping in situ for promising endodontic therapy.

Long-term antibacterial activity of vancomycin from calcium phosphate cement in vivo

BACKGROUND

Periprosthetic joint infection is a major complication of total joint arthroplasty, with treatment requiring a two-stage exchange procedure and 6 weeks of systemic antibiotics. However, depending on the infection site, intravenous delivery of antibiotics like vancomycin (VCM) can have poor tissue transferability, thus reducing their therapeutic effect.

OBJECTIVE

This study demonstrates the 24-week in vivo release profile and antibacterial activity of VCM from calcium phosphate cement impregnated with VCM (CPC/VCM) and compares them with those from polymethylmethacrylate impregnated with VCM (PMMA/VCM).

METHODS

Rats were implanted with the test specimens between the fascia and quadriceps. After implantation for 24 weeks, the test specimens were removed and residual VCM was extracted to calculate the concentration of VCM released into rat tissues. We also examined the antibacterial activity of releasable VCM from the removed test specimens by placing them directly onto the surface of agar.

RESULTS

CPC/VCM released greater concentrations of VCM for a longer period of time within the 24 weeks than PMMA/VCM. Moreover, CPC/VCM released 1.4 to 26.1-fold more VCM than PMMA/VCM. Using Staphylococcus aureus, antibacterial activity was logarithmically correlated with VCM concentration across the entire concentration range tested (12.5-800 μg/mL). While the area within which inhibition was observed-the inhibition zone-for both CPC/VCM and PMMA/VCM formed and gradually shrank with time after implantation, that for CPC/VCM was significantly larger than that for PMMA/VCM in each week after implantation.

CONCLUSION

CPC/VCM releases greater amounts of VCM with antibacterial activity for longer periods of time than PMMA/VCM, suggesting that CPC is effective for facilitating the release of antibiotics for local action in patients with established postoperative infection.

Insights into treatment and outcome of fracture-related infection: a systematic literature review

INTRODUCTION

Standardized guidelines for treatment of fracture-related infection (FRI) are lacking. Worldwide many treatment protocols are used with variable success rates. Awareness on the need of standardized, evidence-based guidelines has increased in recent years. This systematic literature review gives an overview of available diagnostic criteria, classifications, treatment protocols, and related outcome measurements for surgically treated FRI patients.

METHODS

A comprehensive search was performed in all scientific literature since 1990. Studies in English that described surgical patient series for treatment of FRI were included. Data were collected on diagnostic criteria for FRI, classifications used, surgical treatments, follow-up protocols, and overall outcome. A systematic review was performed according to the PRISMA statement. Proportions and weighted means were calculated.

RESULTS

The search yielded 2051 studies. Ninety-three studies were suitable for inclusion, describing 3701 patients (3711 fractures) with complex FRI. The population consisted predominantly of male patients (77%), with the tibia being the most commonly affected bone (64%), and a mean of three previous operations per patient. Forty-three (46%) studies described FRI at one specific location. Only one study (1%) used a standardized definition for infection. A total of nine different classifications were used to guide treatment protocols, of which Cierny and Mader was used most often (36%). Eighteen (19%) studies used a one-stage, 50 (54%) a two-stage, and seven (8%) a three-stage surgical treatment protocol. Ten studies (11%) used mixed protocols. Antibiotic protocols varied widely between studies. A multidisciplinary approach was mentioned in only 12 (13%) studies.

CONCLUSIONS

This extensive literature review shows a lack of standardized guidelines with respect to diagnosis and treatment of FRI, which mimics the situation for prosthetic joint infection identified many years ago. Internationally accepted guidelines are urgently required to improve the quality of care for patients suffering from this significant complication.

A Case of Osteomyelitis after Calcaneal Fracture Treated by Antibiotic-Containing Calcium Phosphate Cements

Calcaneal osteomyelitis (CO) is considered to be difficult to cure when it turned into a chronic phase. We report one case of calcaneal osteomyelitis which arises after the operation of calcaneal fracture. Remission was obtained by performing curettage of the infected cancellous bone of the calcaneal body and filling antibiotic-containing calcium phosphate cements (CPC) within its bone defect. This one-stage surgery is useful to treat calcaneal osteomyelitis.

In Vivo Release of Vancomycin from Calcium Phosphate Cement

Calcium phosphate cement (CPC) has good release efficiency and has therefore been used as a drug delivery system for postoperative infection. The release profile of CPC has mainly been evaluated by in vitro studies, which are carried out by immersing test specimens in a relatively large amount of solvent. However, it remains unclear whether antibiotic-impregnated CPC has sufficient clinical effects and release in vivo. We examined the in vivo release profile of CPC impregnated with vancomycin (VCM) and compared this with that of polymethylmethacrylate (PMMA) cement. To evaluate the release profile in vitro, the test specimens were immersed in 10 mL sterile phosphate-buffered saline per gram of test specimen and incubated at 37°C for 56 days in triplicate. For in vivo experiments, the test specimens were implanted between the fascia and muscle of the femur of rats. Residual VCM was extracted from the removed test specimens to determine the amount of VCM released into rat tissues. CPC released more VCM over a longer duration than PMMA in vitro. Released levels of VCM from CPC/VCM in vivo were 3.4-fold, 5.0-fold, and 8.6-fold greater on days 1, 7, and 28, respectively, than those released on the corresponding days from PMMA/VCM and were drastically greater on day 56 due to inefficient release from PMMA/VCM. The amount of VCM released from CPC and PMMA was much higher than the minimum inhibitory concentration (1.56 μg) and lower than the detection limit, respectively. Our findings suggest that CPC is a suitable material for releasing antibiotics for local action against established postoperative infection.