Disparities in Demographics in Hip Arthroplasty Between U.S. Active Duty Military and the ACS-NSQIP Clinical Registry.

INTRODUCTION: Patient demographics, such as sex and age, are known risk factors for undergoing revision following primary total hip arthroplasty (THA). The military population is unique because of the increased rates of primary and secondary osteoarthritis of the hip. Treatment options are limited for returning patients to their line of duty; however, THA has been shown to be an effective option. The primary purpose of this study was to evaluate and contrast the demographic differences of patients undergoing primary THA between the U.S. active duty military population and the general population. The secondary goal was to identify the proportion of primary THA performed at the MTF within the military health system (MHS). METHODS: This was an exempt study determined by the local institutional review board. A retrospective analysis of the MHS Data Repository (MDR) and the National Surgical Quality Improvement Program (NSQIP) was performed. The databases were used to identify the patients who underwent THA from January 1, 2015 to December 31, 2020. The MDR was used to identify demographics such as sex, age, setting of surgery, geographic location, previous military deployments, history of deployment-related injuries, branch of service, and rank. The NSQIP database was queried for sex and age. The median age of the population was compared using the Mann-Whitney U test and gender was compared using the Chi-square test. RESULTS: The MDR was used to evaluate 2,734 patients, whereas the NSQIP database was used to evaluate 223,832 patients. In the military population, patients who underwent THA were 87.7% male with an average age of 45 years, whereas in the general population as measured via the NSQIP database, 45.2% patients were male with an average age of 66.0 years. Comparing the two groups, we demonstrated that the military patients were significantly more likely to be younger (P < .001) and males (P < .001). Only 29.6% of primary THAs were performed within the MTF. CONCLUSIONS: Patients in the MHS are undergoing THA at a younger age and are more likely to be male compared to the general population. A significant portion of primary THAs in the MHS are also being performed at civilian institutions. These demographics may result in increased risk of revision; however, long-term studies are warranted to evaluate survivorship in this unique population.

The Cost of Stiffness After Total Knee Arthroplasty.

BACKGROUND: Stiffness after primary total knee arthroplasty (TKA) is debilitating and poorly understood. A heterogenous approach to the treatment is often utilized, including both nonoperative and operative treatment modalities. The purpose of this study was to examine the prevalence of treatments used between stiff and non-stiff TKA groups and their financial impact. METHODS: An observational cohort study was conducted using a large database. A total of 12,942 patients who underwent unilateral primary TKA from January 1, 2017, to December 31, 2017, were included. Stiffness after TKA was defined as manipulation under anesthesia and a diagnosis code of stiffness or ankylosis, and subsequent diagnosis and procedure codes were used to identify the prevalence and financial impact of multiple common treatment options. RESULTS: The prevalence of stiffness after TKA was 6.1%. Stiff patients were more likely to undergo physical therapy, medication, bracing, alternative treatment, clinic visits, and reoperation. Revision surgery was the most common reoperation in the stiff TKA group (7.6%). The incidence of both arthroscopy and revision surgery were higher in the stiff TKA population. Dual component revisions were costlier for patients who had stiff TKAs ($65,771 versus $48,287; P < .05). On average, patients who had stiffness after TKA endured costs from 1.5 to 7.5 times higher than the cost of their non-stiff counterparts during the 2 years following index TKA. CONCLUSION: Patients who have stiffness after primary TKA face significantly higher treatment costs for both operative and nonoperative treatments than patients who do not have stiffness.