In order to allow for cost savings through coordination of care, healthcare delivery is transitioning towards centrally planned modes of care delivery [6]. ACOs and PCMHs represent two novel delivery models implemented as part of PPACA that will likely impact the care of diseases of the hip.

The PCMH is primarily a healthcare delivery model centered around primary care with a goal of creating better access to healthcare services, coordinating care and implementing prevention programs. PCMHs are similar in concept to ACOs, the difference between the two is best conceptualized by thinking of ACOs as comprised of many “medical homes” or as ACOs have been dubbed by some: a “medical neighborhood” [7].

An ACO is a healthcare network consisting of various physicians from different specialties, hospitals, and other non-physician healthcare providers that are contracted to provide coordinated care to a group of patients. The ACO is then typically accountable to a third party payer for the cost and quality of care provided to a population of patients. The Centers for Medicare & Medicaid Services (CMS) represent the largest ACO third party payer and are in the process of testing several ACO models. Medicare ACO programs include Medicare Shared Savings Program, Pioneer ACO model, and Advance Payment ACO model. The common goal in all ACOs is to find ways to improve quality and decrease overall costs. For example, as part of the CMS Shared Savings Program, Medicare fee-for-service programs are converted into ACOs that seek to lower their growth in health care costs while meeting performance standards on quality of care. These ACOs then share costs savings resulting from changes in practice with CMS.

In addition to implementing a financial reorganization, ACOs have also introduced a redistribution of healthcare delivery. Because there is increased provider accountability, ACOs incentivize a shift toward provider-led organizations and an orientation toward primary care, management and prevention of medical illness across the entire continuum of the care cycle. Thus, the fiscal responsibility in the management of hip osteoarthritis (OA), for example, may include aspects of the care cycle for which the orthopedic surgeon typically pays less attention such as pre-arthritic hip pain and prevention of progression to end stage hip OA. Similarly, for conditions like avascular necrosis of the hip that progress through a variety of degenerative stages prior to requiring orthopedic intervention, the orthopedic surgeon may begin to play more of an active (in concert with primary care physicians) in prevention of disease progression and disease management.

Central to the reorganization of how healthcare is delivered is a reorganization of how healthcare providers are reimbursed for their care of patients with certain disorders. Provider payment reform has long been considered a viable method for driving attention to the escalating costs of the U.S. healthcare system [8]. In this section, we outline payment methods resulting from healthcare delivery reorganization.

Traditionally, payment for orthopedic services has been based on a fee-for-service model. Such payment models created an orientation toward increasing the volume and intensity of service provided without necessarily rewarding the value of healthcare delivered. Thus pay for performance (P4P) incentive schemes evolved from fee-for-service models. These P4P models adopted fee-for-service models and created quality of care related bonuses based on standardized metrics for different aspects of care.

As ACOs have become more widespread, there is now a shift toward “bundled payments” or episode of care payments. Under this payment structure, a single payer provides payment to all providers for all care related to the treatment of a condition, e.g. hip osteoarthritis requiring a total hip arthroplasty (THA). In this example, for a patient presenting with hip OA requiring a THA, providers may receive a fixed payment for an “episode of care,” including pre-operative screening, in-patient admission, and the surgery itself as well as early post-operative (e.g., 30 days post-operatively) care, rehabilitation, and management of complications. The onus therefore is on the providers involved in these phases of care to maintain appropriate margins by providing care that is necessary and avoiding non-value-added interventions.

Early evidence for quality improvements and cost savings based on bundled payments has been promising. One of the earliest demonstrations for the impact of bundled payment on hip disease came from the Geisinger Health System (GHS) [9]. GHS physicians developed a program for implementing bundled payment for THA. GHS offered payers a guarantee that procedural and post-procedural costs (including costs related to re-admission) would be inculcated into a global payment scheme. After the introduction of their Provencare program, Geisinger reported a 3.6 % reduction in hospital length of stay, a 58 % reduction in 30-day re-admission, a 49 % reduction in deep venous thrombosis (DVT), and 67 % reduction in pulmonary embolism (PE) rate [8].

PPACA is largely credited with addressing the large number of uninsured people in the U.S. As such, moving forward there will be a larger number of patients with health insurance seeking appropriate care and obtaining necessary orthopedic services. There is theoretical evidence to suggest that universal access to healthcare coverage leads to increased utilization of orthopedic services. For example, trend data for hip arthroplasty utilization suggests that THA utilization spikes at the point of healthcare eligibility—i.e., at age 65 upon reaching the age of Medicare eligibility [10]. However there is also a theoretical concern that in the new universal healthcare model, the provision of health insurance alone will not achieve the goal of optimizing the musculoskeletal health of the population. Specifically, the vulnerable and under-represented population segments may not benefit equally from expanded healthcare coverage. Disparities in the provision of healthcare services have been well documented [11–13], and there are myriad reasons why vulnerable population segments may not seek medical care even when the access is available [14]. Furthermore, there are other possible reasons suggesting that even when these population segments seek care they may not receive the care that would otherwise be indicated for them. We briefly discuss some of the disparities in healthcare access for hip disease in order to outline how healthcare reorganization can help address some of these inequalities. Specifically, we use access to THA as a case example. Hip OA is a leading cause of disability in the U.S. and THA is an effective and safe procedure for alleviating pain and restoring physical function. Given the established efficacy, differential access based on race and/or socioeconomics represents a concerning disparity.

There is a well-established evidence base suggesting that there is an underutilization of THA for ethnic minorities and the socioeconomically disadvantaged [15]. Mahommed et al. used a Medicare database to analyze 61,568 patients who had had a primary THA and 13,483 who had a revision THA during a 1-year period. The authors found rates for primary THA were higher for whites than African Americans, and for those with a higher income [16]. Studies such as these suggest that beyond a lack of healthcare access, patient and provider specific reasons may represent potential reasons for consistently lower utilization of THA among vulnerable segments of the population. Patient specific reasons are thought to include lack of recognition of symptoms, a higher threshold for seeking care, ineffective communication of symptoms to providers, unfamiliarity with procedures and lower expectations of post-operative outcome. Some studies have suggested that many of these reasons for underutilization are related to a lack of access to a primary care physician who can play a role in initial referral and can facilitate trust by educating and communicating with patients in a culturally competent manner [15]. As such it is plausible that as healthcare reorganizes around a primary care model, disparities in underutilization of elective procedures may become addressed. However there is a significant onus placed on the primary care physicians, case managers, and care coordinators in this model to work with these populations in order to overcome aforementioned barriers to seeking care and understanding the disease process. Further, in light of the responsibility placed on these providers in the new healthcare models, it is crucially important that providers, payors, and healthcare deliver organizers understand that provider related biases affect patient utilization and access to healthcare services. One study found that both primary care physicians and orthopedic surgeons were less likely to offer joint arthroplasty to women when faced with standardized male and female actors [17]. Another study not directly related to orthopedics found that physicians were less likely to recommend cardiac catheterization to racial minorities who had the same medical history and symptoms as white counterparts [18]. Thus, as access to orthopedic care is expanded to a broader population, it is important to understand that ensuring equal access to care goes beyond enrollment in a health plan.

In addition to issues of underutilization, increased access to health insurance may raise the possibility of overutilization of elective procedures. Specific to the management of hip OA, this is an area of potential concern. With the introduction of more durable implants, there has been a recent trend toward increased utilization of hip arthroplasty among younger patients (age < 65 years) [19]. As such, with healthcare reorganization there will be increased pressure for utilization management in order to judiciously indicate patients for procedures. Musculoskeletal conditions such as hip OA will require orthopedically driven metrics for the management of various stages of disease, e.g. appropriate use of diagnostic and therapeutic interventions, and well-defined criteria for referral to a surgical specialist (more on this in subsequent sections).

Studies published prior to the introduction of universal healthcare coverage suggested that based on population senescence trends alone that there could be a supply side crisis for joint arthroplasty, i.e. there would not be enough arthroplasty surgeons to respond to the demand for joint replacement [20]. There has yet to be a revised projection incorporating demand based on universal healthcare coverage. As part of any revised projection however the previously projected supply side crisis is likely to become more pronounced. Supply side issues may become even more evident in other non-arthroplasty fields of orthopedic surgery. For example, in conditions like femoroacetabular impingement, which is being increasingly recognized, hip arthroscopy has been utilized to treat this condition at increased rates. Plausibly there may be a future supply side crisis for hip arthroscopists.

The manifestation of supply side crises for hip conditions will likely be increased wait times for surgeon availability. The experience of some European nations may serve as an example, i.e. where significant wait times for specialty care is the norm. In these countries, patients become accustomed to living with chronic conditions until a specialist is available [21]. Further, the affluent population segments seek care out of the insurance system by paying out of pocket in order to gain more immediate access to care. This phenomenon may eventually lead to a socioeconomic tiering of specialty care.