Intraoperative detection of viable bone with fluorescence imaging using Visually Enhanced Lesion Scope in patients with bisphosphonate-related osteonecrosis of the jaw: clinical and pathological evaluation

Quantitative light-induced fluorescence-guided surgery for medication-related osteomyelitis of the jaw

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a challenging condition with increasing incidence, and the lack of clear surgical guidelines poses difficulties in its treatment.

METHODS

Quantitative light-induced fluorescence (QLF), which can distinguish between vital and necrotic bone tissue without the need for additional markers, was used to guide minimally invasive surgery in a 75-year-old patient with MRONJ.

RESULTS

This study demonstrated that QLF allows the real-time identification of infected and necrotic bone tissue during surgery, enabling precise and minimally invasive resection. We observed spontaneous bone recovery and remodeling in sclerotic bone areas that exhibited autofluorescence using a QLF device, suggesting its potential for preserving the bone tissue.

CONCLUSION

This study highlights the promising application of QLF as a valuable photodiagnostic tool in MRONJ surgery, offering a noninvasive and intraoperative device for differentiating pathological bone tissue. This approach can potentially improve the precision of surgical interventions and contribute to improved patient outcomes in MRONJ management.

Use of intra-operative fluorescence imaging in periprosthetic joint infection: State of the art and future perspectives

BACKGROUND

In periprosthetic joint infections (PJIs), the surgeon's role becomes pivotal in addressing the infection locally, necessitating the surgical removal of infected and necrotic tissue. Opportunity to enhance the visualization of infected tissue during surgery could represent a game-changing innovation.

OBJECTIVE

The aim of this narrative review is to delineate the application of intraoperative fluorescence imaging for targeting infected tissues in PJIs.

METHODS

A systematic review, adhering to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, was carried out. The search included multiple online database; MEDLINE, Scopus, and Web of Science. For data extraction the following were evaluated: (i) diagnosis of musculoskeletal infection; (ii) use of intraoperative fluorescence imaging; (iii) infected or necrotic tissues as target.

RESULTS

Initially, 116 studies were identified through online database searches and reference investigations. The search was narrowed down to a final list of 5 papers for in-depth analysis at the full-text level. Subsequently, 2 studies were included in the review. The study included a total of 13 patients, focusing on cases of fracture-related infections of the lower limbs.

CONCLUSION

The primary and crucial role for orthopedic surgeons in PJIs is the surgical debridement and precise removal of necrotic and infected tissue. Technologies that enable clear and accurate visualization of the tissue to be removed can enhance the eradication of infections, thereby promoting healing. A promising avenue for the future involves the potential application of intraoperative fluorescence imaging in pursuit of this objective.

The Therapeutic Effectiveness Using Fluorescence-Guided Surgery for MRONJ

Background. Long-term application of antiresorptive and/or antiangiogenic agents may cause oral disorders, including medication-related osteonecrosis of the jaw (MRONJ), which remains an incurable disease. Surgical treatment can help alleviate infection of the jaw and block the progress of the disease, but postoperative recurrence is often caused by incomplete resection of necrotic bone during surgery. The traditional method for determining the boundary of necrotic bone resection is primarily based on the color, geology, and microcirculation-based bleeding state according to the bone tissue, which is easily affected by the surgeon’s clinical experience and can cause insufficient resection of osteonecrosis bone. Recent studies have proposed using fluorescence technology-assisted necrotic bone resection. Objective. Systematic literature review was conducted to evaluate the therapeutic effectiveness of fluorescence-guided MRONJ surgery. Design. PubMed/MedLine, Scopus, and Web of Science databases were searched from inception to February 7, 2022. Randomized controlled trial (RCT) studies were evaluated according to the Cochrane risk of bias tool ROB 2, and non-RCT (N-RCT) studies were evaluated according to the ROBINS-I tool. Results. A total of 6 articles were included in the systematic review, including 4 N-RCT studies (1 retrospective study and 3 prospective studies) and 2 RCT studies, with 240 patients and 280 MRONJ lesions. The vast majority of studies were with moderate risk of bias, and the quality of the evidence was moderate. Conclusion. Evidence of moderate strength suggests that fluorescence-assisted techniques effectively determine the bone resection boundaries in MRONJ surgery. However, whether the prognosis of patients treated with fluorescence-guided surgery is significantly better than that of traditional surgery must be proved by randomized controlled studies with larger sample sizes and higher quality.

Investigation of the Effectiveness of Surgical Treatment on Maxillary Medication-Related Osteonecrosis of the Jaw: A Literature Review

Aim: Medication-related osteonecrosis of the jaw (MRONJ) occurs after exposure to medication (antiresorptive or antiangiogenic agents) for bone-related complications. It is more common in the mandible than in the maxilla. The present study investigated maxillary MRONJ in elderly patients through a meta-analysis. Methods: Keywords, including “MRONJ”, “maxilla”, and “surgery”, were entered into databases, including Embase, PubMed/MEDLINE, Cochrane Library, and ProQuest, which were searched systematically. Results: Investigating 77 studies, we found that 18 (2 case reports and 16 case series) papers conformed to the standards. The results revealed a 2.6:1 female-to-male ratio of disease occurrence. The average age of patients was 70.6 ± 5.5 years, and most patients were in the third stage (43.6%). The average time of medication usage was 50.0 ± 20.1 months. The pooled proportion of clinical efficacy of surgery was 86%. Conclusion: To prevent and manage MRONJ, all elderly patients should maintain proper oral hygiene and receive dental examinations regularly. Risk assessment and safety management of MRONJ should be performed by medical teams.

Fluorescent tetracycline bone labeling as an intraoperative tool to debride necrotic bone during septic hip revision: a preliminary case series

A plausible cause of persistent infection after septic hip revision may be the presence of nonviable osteomyelitic bone. Since surgical excision of these necrotic fragments is often challenging, the use of fluorescent tetracycline bone labeling (FTBL) as an intraoperative tool may pose an additional assessment aid to provide a visual index of surgical debridement. Methods: We present a single-center study performed in a university hospital from January 2018 to June 2020, in which all consecutive cases of chronic hip periprosthetic joint infection (PJI) undergoing revision using FTBL were retrospectively reviewed. In all cases, the patient was under treatment with tetracyclines at the moment of the revision surgery. During the surgery, all bone failing to fluoresce was considered nonviable and thus removed and sent for both culture and histology. Results: We include three cases in which the FTBL technique was used. In all cases, the histopathological examinations of the nonfluorescent removed bone were consistent with chronic osteomyelitis. Conclusion: The intraoperative use of FTBL successfully aided the surgeon to detect the presence of nonviable bone in all the presented cases of chronic prosthetic hip infection.

Can necrotic bone be objectively identified in chronic fracture related infections? - First clinical experience with an intraoperative fluorescence imaging technique

INTRODUCTION

Adequate debridement of necrotic bone is of paramount importance for eradication of infection in chronic osteomyelitis. Currently, no tools are available to detect the exact amount of necrotic bone in order to optimize surgical resection. The aim of the present study was to evaluate the feasibility of an intraoperative illumination method (VELscope®) and the correlation between intraoperative and pathohistological findings in surgically treated chronic fracture related infection patients.

METHODS

Ten consecutive patients with chronic fracture related infections of the lower extremity were included into this prospectively performed case series. All patients had to be treated surgically for fracture related infections requiring bony debridement. An intraoperative illumination method (VELscope®) was used to intraoperatively differentiate between viable and necrotic bone. Tissue samples from the identified viable and necrotic bone areas were histopathologically examined and compared to intraoperative findings.

RESULTS

In all included patients, the intraoperative illumination was deemed helpful to differentiate between necrotic and viable bone tissues during bony debridement. The histopathological examination of the samples showed good correlation of the intraoperative illumination findings with histopathological signs of necrosis for areas deemed dead and histopathological signs of intact bone for areas deemed vital during illumination.

CONCLUSION

The fluorescence-assisted, intraoperative detection of necrotic and viable bone using the VELscope® is an easy-to-use procedure that can help surgeons to optimize intraoperative bone resection in chronic fracture related infections by unmasking viable from necrotic bone tissue. This may help to improve resection techniques and eventually treatment outcome in patients in the future.

Fluorescence-guided surgical management of medication-related osteonecrosis of the jaws

Medication-related osteonecrosis of the jaw (MRONJ) results in progressive destruction of the jawbones, and advanced cases demand surgical intervention. The total removal of necrotic bone is required to prevent recurrence and infection. However, determining the limits between necrotic and healthy bone is a challenge. The use of fluorescence to detect tissue alterations and determine necrosis extension is a promising method to avoid inadequate bone debridement. In the literature, there are several studies and reported cases that successfully use fluorescence-guided surgery (FGS) of MRONJ. The objective of this study was to present a critical review of the literature regarding the intraoperative use of optic fluorescence to differentiate healthy and necrotic bone in MRONJ. Studies that evaluated the intraoperative use of optic fluorescence to determine the surgical margins of MRONJ were searched in Pubmed/Medline and Scopus databases using the following terms: "medication-related osteonecrosis of the jaws" and "fluorescence". Eighteen papers describing the intraoperative use of FGS in ONJ management were selected, totalizing 218 patients. Of those 18 papers, only 5 were prospective studies, and the other 13 were isolated case reports, case series, and technical notes. The use of FGS to delimitate the resection margin of MRONJ is a promising method. There is no need for the application of exogenous fluorophore to perform FGS and the most often used light device was the VELScope® system. Further prospective studies with larger samples are still required to ascertain the fluorescence validity as a supporting method in MRONJ surgical treatment and to establish clinical protocols.

Differences between auto-fluorescence and tetracycline-fluorescence in medication-related osteonecrosis of the jaw-a preclinical proof of concept study in the mini-pig

Objectives

Fluorescence-guided bone surgery is a well-established technique in the treatment of medication-related osteonecrosis of the jaw. No histopathological evidence for bone auto-fluorescence is currently available, and thus, any differences from tetracycline-fluorescence remain unclear. Therefore, the goals of this study were to find out if macroscopic and histological differences occur between the auto- and tetracycline-fluorescence in the delineation of viable and necrotic jawbone in the mini-pig.

Materials and methods

According to the proof of concept, osteonecrosis was provoked in eight Göttingen minipigs. Pigs were divided into two groups (AF group: no fluorochrome label; TF group: tetracycline label). Delineation of necrosis and viable bone was evaluated in vivo and in vitro macro−/microscopically, correlated to fluorescence properties and compared between the two study groups.

Results

No macroscopic and microscopic clinical differences were seen in fluorescence between the AF and TF groups. Macroscopic and microscopic viable bone fluoresced green, whereas necrotic bone showed no or only pale fluorescence in both groups. The auto-fluorescence was attributable to the arrangements and structure of collagen and the cell-filled bone lacunae.

Conclusion

Neither in vivo nor in vitro macroscopically differences are apparent between the auto-fluorescence and the tetracycline-fluorescence of bone. The auto-fluorescence is attributable to the arrangements and structure of collagen and the cell-filled bone lacunae. Tetracycline-fluorescence is a mixture of tetracycline (at the bone edges with increased bone formation) and large components of auto-fluorescence.

Clinical relevance

Because auto-fluorescence is easy to apply, reproducible, and does not rely on the subjective impression of the surgeon, it promises to be an important standardized alternative to tetracycline-labeled MRONJ therapy.

Can Autofluorescence Guide Surgeons in the Treatment of Medication-Related Osteonecrosis of the Jaw? A Prospective Feasibility Study

PURPOSE

The main limitation of surgical treatment of medication-related osteonecrosis of the jaw (MRONJ) is difficulty in defining resection margins. The aim of this study was to compare the efficacy of the surgeon's experience and autofluorescence-guided bone surgery to delimit resection margins for necrotic bone.

MATERIALS AND METHODS

MRONJ requiring surgical treatment was classified according to American Association of Oral and Maxillofacial Surgeons staging. To detect vital bone and resection margins, patients of each stage were randomly assigned to 1 of 2 surgical groups: an autofluorescence-guided surgery (AF) group and a conventional surgery (non-AF) group based on the surgeon's experience. Bone samples from the 2 groups were analyzed histopathologically. The main outcomes were defined as the absence of bone exposure or infection at the time of evaluation. Infection was defined as the presence of swelling, pain, or numbness in the area. Measurements were collected preoperatively and 1 week, 1 month, 6 months, and 1 year after surgery. Statistical analysis included descriptive statistics and the Fisher exact test to evaluate eventual differences between the 2 surgical protocols.

RESULTS

The 36 patients (21 women and 15 men) included in this study were equally divided into 2 groups according to the surgical protocol: 18 patients in the non-AF group and 18 in the AF group. Thirty-nine lesions were included in this analysis: 20 lesions in the non-AF group and 19 in the AF group. Histopathologic examination confirmed the necrotic nature of all bone samples. Statistical analysis showed no differences in necrotic bone exposure or signs of infections between the 2 surgical protocols at different times (P > .05).

CONCLUSIONS

Although the VELscope appears to be useful in guiding bone resection margins in patients with MRONJ, autofluorescence does not appear to be superior to conventional surgical techniques in mucosal healing and quality of life.

Antiresorptive treatment-associated ONJ

Osteonecrosis of the jaw (ONJ) is a severe complication of therapy with antiresorptive agents (e.g. bisphosphonates and denosumab), which are used to manage bone metastases from cancer, to reduce the incidence of skeletal-related events. Available data indicate that 0-27, 5% of patients exposed to antiresorptive agents may develop ONJ, depending on the number of infusions and the duration of therapy. Besides antiresorptive therapy, a number of risk factors for osteonecrosis have been identified. Oral surgical procedures, tooth extractions and infection to the jawbones are considered the main risk factors for developing ONJ, when receiving antiresorptive therapy. However, a growing number of patients develop ONJ without apparent risk factors, raising concern for other predisposing factors. Jaw bone necrosis may be irreversible, resulting in a chronic disease with negative impact on the quality of patients' lives. The role of risk reduction strategies like meticulous dental screening and optimal oral hygiene is fundamental for preventing development of ONJ. ONJ is usually treated conservatively to relieve the symptoms and manage jaw bone necrosis. In certain cases, surgical intervention is required. Future research should emphasize individual predisposition to ONJ, more effective preventive measures and more efficient therapeutic procedures.

Comparison of auto-fluorescence and tetracycline fluorescence for guided bone surgery of medication-related osteonecrosis of the jaw: a randomized controlled feasibility study

Recent studies have indicated that bone shows auto-fluorescence under an appropriate fluorescence lamp. The aim of this preliminary study was to compare the success rates of the established tetracycline fluorescence-guided bone surgery with auto-fluorescence-guided bone surgery in the treatment of medication-related osteonecrosis of the jaw (MRONJ). Forty patients suffering from MRONJ were referred for surgical treatment and were divided randomly into two groups: auto-fluorescence (n=20) or tetracycline fluorescence (n=20) guided bone surgery. The primary endpoint was treatment success, defined as the absence of exposed bone at 8 weeks after surgery. Secondary outcomes assessed were mucosal integrity, signs of infection, pain, and loss of sensitivity; these were evaluated descriptively at 10 days, 8 weeks, 6 months, and 1 year after surgery. At 8 weeks postoperative, 18/20 patients (90%) in the auto-fluorescence group and 17/20 patients (85%) in the tetracycline fluorescence group showed mucosal integrity (P>0.05). At the last follow-up, 94% in the auto-fluorescence group and 89% in the tetracycline fluorescence group presented complete mucosal coverage with no exposed bone, infection, or pain (P>0.05). There was no significant difference between the two techniques for any of the secondary outcomes (P>0.05). The results of this preliminary study show that auto-fluorescence-guided bone surgery has comparable success rates to the established tetracycline fluorescence-guided bone surgery.