The impact of surgical intervention and antibiotics on MRONJ stage II and III - Retrospective study.

OBJECTIVES: Metastatic bone disease and osteoporosis are the main indications for bisphosphonates and anti-resorptive agent therapy. Inhibition of bone turnover and angiogenesis are mainly responsible for the development of Medication Related Osteonecrosis of Jaws (MRONJ) as therapeutic side-effect. Yet, the role of infection for the development and recurrence of MRONJ is not fully elucidated. The aim of this retrospective study is to explore if a difference in antibiotic regimes has an impact on the surgical intervention needed to achieve a painless stable stage of the disease. Furthermore, we investigated concomitant submucosal infections in local relation to the MRONJ site.

METHODS: A retrospective study (2006-2015) of 143 patients treated with MRONJ stage II and stage III in a single institutional university hospital was performed. All patients experienced at least one surgical intervention and received antibiotics. Their medical records, pathological and microbial findings were reviewed. Data was controlled for the achievement of an event free time period of at least 12 months.

RESULTS: We investigated the number and kind of treatments that were performed on patients with MRONJ stage II and III to achieve a painless stable stage of the disease. The first and second healing approach differed significantly from each other (p < 0.05). In 7 (4.9%) cases up to four surgical interventions were needed to achieve oral rehabilitation. In 135 (95.1%) of all cases a segmental resection could be prevented, with extended decortication being the most applied method. Patients under perioperative ampicillin/sulbactam showed a significant reduction for a second or fourth intervention compared to the clindamycin group (p < 0.05). Results for a third intervention presented a similar difference between both groups, but were not significant (p = 0.06). Intraoperatively in 76 out of 241 (31.5%) cases presented putrid submucosal infections. The isolated bacteria were gram-negative facultative anaerobes (39.1%) and strictly anaerobic bacteria (gram-positive/38.2%, gram-negative/19.1%). Susceptibly of the cultured bacteria were significantly (p < 0.05) in favor to ampicillin/sulbactam (79.1%) compared to clindamycin (49.5%).

CONCLUSION: The perioperative antibiotic regime for patients with MRONJ stage II and III undergoing surgically treatment does have an influence on the recurrence of the disease. Further investigation is needed to elucidate the role of infection in the treatment of MRONJ.