Use of hyperbaric oxygen therapy (HBO) to treat cases of established BON does not appear to be effective.[1,9,18,19] However, evidence indicates that HBO in addition to discontinuation of bisphosphonate therapy may benefit patients with BON. Definitive evidence is pending while research in this area continues.
Another possible approach involves surgical manipulation and uses bone labeling with tetracycline. In this modality, the patient is treated with a standard dose of tetracycline a few days presurgery. During the surgery, when bone is exposed, the Wood's lamp is shone over the bone. Necrotic bone does not fluoresce and is removed. The procedure continues until fluorescence is seen, suggesting the presence of vital bone.
Discontinuation of bisphosphonate therapy
The literature does not support discontinuing bisphosphonate therapy to enhance the healing process. Bisphosphonates accumulate in a patient's skeleton and could remain active for several years, especially in patients who have been treated with an intravenous bisphosphonate for longer than a year. There is anecdotal evidence that even with discontinuing zoledronic acid therapy for patients who develop BON, the osteonecrotic process clinically progresses and can extend to contiguous sites. However, discontinuing bisphosphonate therapy is advocated by some authors, especially when a procedure to treat BON is planned.[6,9]
Some clinicians believe that discontinuing the drug for patients scheduled for surgery to treat the necrotic area may be beneficial, although this belief is not supported by scientific study. It is recommended that such a drug holiday be maintained until clinical evidence of healing is observed. However, controversy surrounds this issue,[Level of evidence: IV] and further research is needed.
In summary, a potential drug holiday for patients on bisphosphonates must be considered in the context of presence or absence of osteonecrosis. In view of the lack of scientific evidence from randomized controlled studies, risk and benefits of drug discontinuation must be determined by the prescribing physician. In patients who are being treated with bisphosphonate therapy and who need invasive procedures, there is no scientific information that supports a drug holiday and that this will prevent the development of BON. In patients with osteonecrosis who need invasive procedures, a drug holiday may be beneficial. On the other hand, there is emerging evidence that patients with multiple myeloma and osteonecrosis may be maintained on bisphosphonate therapy without the risk of progression of the osteonecrotic process.