Referral guidelines for TJR have been promulgated by many learned colleges and consumer advocacy groups (11). However, referrals for TJR are becoming so prolific that the numbers on surgical waiting lists may rise to unsustainable levels. For example, the almost 90,000 hip and knee TJRs performed in Australia (12) in 2011 is expected to double by 2020 (13). This mirrors international change (14) including the United States, where rises in hip (140%) and knee (670%) replacements over the next two decades will result in 570,000 hip and 3.5 million knee replacements being performed annually by 2030. The rate of increase of the utilization of TJR across all age groups is likely to exceed government projections and supply (15).

While TJR for knee and hip OA is a cost-effective solution (9), the volume of procedures leads to a high cost burden for the public and private health sectors and is a major part of the health expenditure spent on treating OA annually (5, 16). A survey of insurer and out of pocket costs of OA in the United States found that these costs were not only substantial and may be prohibitive for those seeking definitive treatment of OA, but that the greater prevalence of women with OA and their more intensive use of health care accounted for two-thirds of the increase in health care expenditure resulting from OA (2).

Although common, TJR is mainly performed on older patients with their attendant medical risks. A substantial rise in obesity is not only leading to more complicated outcomes of TJR surgery, but the prevalence is overrepresented (40–60%) in patients presenting for lower limb arthroplasty (17–19) increasing the risk for these high volume procedures.

Although the rate of revision surgery for failed TJR is only 0.5% per annum (20), making it to appear a highly successful procedure, 20–40% of patients remain dissatisfied. The main reason for this dissatisfaction is ongoing pain despite surgically satisfactory procedures. The rate of revision surgery alone may be an underestimate of failure of surgery (21) because dissatisfied patients continue to make ongoing demands for care from already overburdened healthcare resources despite not undergoing revision surgery.

Since the inception of the Swedish TJR registries for hip and knee OA, other registries now confirm the highly variable and at times paradoxical practices amongst surgeons. For example, the Australian Orthopaedic Association National Joint Replacement Registry has reported that totally cemented and hybrid total hip replacements consistently outperform total cementless replacements (20). Yet, the practice of implanting cementless prosthetic replacements continues to increase (20) with substantial cost implications because of the large cost differential between cemented and cementless prostheses. How surgeons use data and why pieces of evidence lack traction remains unclear.

Appropriate patient selection and response to TJR are intimately linked. Yet very little work has been done to clarify what is meant by appropriate patient selection or to understand what constitutes response to TJR. Recognizing who are poor responders, will allow clinicians to direct them to alternate non-surgical options for managing their OA or to undergo strategies to mitigate their risk profile prior to TJR so as to improve their response to surgery.

Variations in who receive TJR, and rising health care costs, have contributed to the need to ensure that the provision of TJR remains equitable, efficient, and safe in an environment of cost containment. The challenge for addressing the increasing demand for TJR is how to distribute limited resources, with the aim to preserve equity as part of the National systems of health care.

The inequity of insurance status’ and resources means that in some nations one sector absorbs the burden of TJR in place of another. For example, almost two-thirds of TJR in Australia are undertaken in the private health sector despite only one-third of Australians having private health insurance. It is not clear if the factors that drive good and poor response to TJR are the same in the public as in the private health arenas. Understanding the epidemiologic differences between patients from these two insurance categories will help future planning of service delivery and better inform models of care that are already in place.

Although prosthetic survival has improved significantly over the last two decades, the effect of rising numbers of primary TJRs is to increase the pool of patients who will require revision surgery in the future (22). The benefits of the current technology in enhancing fixation were not available before two decades or more and a surge in the requirement and expenditure for revision can be expected from TJR performed in the short term. It is anticipated that younger patients will comprise up to 50% of those requiring revision surgery (23).