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Osteoporosis can be a challenging condition. It is often a silent one also… until it announces itself with an osteoporosis-related fracture.

Being proactive about appropriate screening for osteoporosis and management can be helpful for our patients. It is not always straightforward, however, and treatment guidelines can be complex. Patients are sometimes sceptical also about adding a medication for a condition that they can’t see and that is one in which often they don’t feel the negative effects of it until the fateful day they sustain a fracture.

I often find it challenging to go through the benefits and risks of adding medication without completely scaring the patient away! One complication I find especially tricky to explain is osteonecrosis of the jaw. I was thus very happy to see this recently updated GPnotebook page on bisphosphonate-related osteonecrosis of the jaw (BRONJ).

BRONJ is a strange condition for which the pathogenesis has not been well determined. The criteria for a diagnosis are quite specific. The American Society for Bone and Mineral Research criteria are:

• Patients with current or previous treatment with a bisphosphonate.

AND

• Exposed bone or otherwise necrotic bone in the maxillofacial region that has persisted for more than 8 weeks.

AND

• No history of radiation therapy to the jaws.

Thankfully, this is not a common condition, with an incidence of 0.7/100,000 person-years of exposure and a prevalence of 0.06% in long-term oral bisphosphonate receivers. I do think, however, that this prevalence rate makes it worthwhile to discuss it with patients and try to minimise their risk if we can.

There are many different factors that increase a person’s risk of getting BRONJ while on a bisphosphonate, and having a knowledge of them is of practical use to us in primary care.

In addition to a longer duration of treatment (more than 2–3 years), the bisphosphonate potency is a factor determining risk. Intravenous forms such as zoledronic acid carry a higher risk than lower-potency oral forms.

Local factors increasing the risk include dentoalveolar surgical procedures, concomitant oral disease and poor oral hygiene. Systemic factors can also play a role, with renal dialysis, anaemia, immunosuppression, rheumatoid arthritis, smoking, obesity and diabetes increasing risk. Prednisolone and methotrexate, used in autoimmune diseases, are associated with an additional inhibition of remodelling in oral bisphosphonate use – hence also increasing the risk of BRONJ.

Saving this long list of risk factors to my desktop for reference for when I am next considering starting a bisphosphate is going to be my first change in practice after researching this area, but another question is: how does the condition present?

I admit that I have never seen a case in my patient population. The updated page states that it can present with dental pain or clinical symptoms suggestive of local infection at the site of the osteonecrosis. It can, however, be asymptomatic and picked up incidentally at the dentist or in the surgery.

Certainly, this is not a GP diagnosis, and where suspected it should be referred onwards to a specialist, who may use X-rays, dental cone beam or spiral computed tomography initially and on occasion scintigraphy, positron emission tomography or magnetic resonance imaging.

Management is very much guided by our specialist colleagues and involves cessation of bisphosphonate therapy, analgesia, antimicrobial mouth rinses, oral antibiotics or surgical management.

When it comes to BRONJ, prevention is definitely better than cure, but there are some things that we can do to help minimise risk. One simple action that I ask my patients to do is go for a dental appointment prior to starting a bisphosphonate for an examination and to optimise oral hygiene.

Oral surgery in patients on bisphosphonates needs to be carefully planned and may need specialist advice, and patients who have undergone dental implant placement procedures should get regular dental checkups.

I find this aspect of bisphosphonates the trickiest to discuss but this page takes you through other factors relating to bisphosphonate prescribing and this one includes some more general information on these drugs.