Pent-up demand for total shoulder arthroplasty prior to Medicare eligibility at age 65 years: evidence from a national patient database and national survey data.

BACKGROUND: Rising utilization rates of total shoulder arthroplasty (TSA) paired with an aging US population herald increased future economic burden. Previous research has demonstrated evidence of "pent-up demand" in health care (delaying medical care until financially able) accompanying insurance status changes. The purpose of this study was to determine pent-up demand for TSA in the years leading up to Medicare coverage at age 65 years while identifying key drivers underlying this trend, including socioeconomic status. METHODS: The incidence rates of TSA were evaluated using the 2019 National Inpatient Sample database. The observed increase in incidence between the ages of 64 years (pre-Medicare group) and 65 years (post-Medicare group) was compared with the expected increase. The expected frequency of TSA was subtracted from the observed frequency of TSA to calculate pent-up demand. Excess cost was calculated by multiplying pent-up demand by the median cost of TSA. The Medicare Expenditure Panel Survey-Household Component was used to compare health care cost and patient experience between pre-Medicare patients (aged 60-64 years) and post-Medicare patients (aged 66-70 years). RESULTS: The expected and observed increases in TSA procedures from age 64 years to age 65 years were 402, for an incidence rate increase of 0.13/1000 population (12.8% increase), and 820, for an incidence rate increase of 0.24/1000 population (27% increase), respectively. The 27% increase represented a sharp jump in comparison to the 7.8% annual growth rate between age 65 years and age 77 years. This resulted in pent-up demand between age 64 years and age 65 years of 418 TSA procedures and excess cost of $7.5 million. Mean total out-of-pocket expenses were significantly higher for the pre-Medicare group than for the post-Medicare group ($1700 vs. $1510, P < .001). Compared with the post-Medicare group, the pre-Medicare group exhibited a significantly higher proportion of patients who delayed Medicare care because of cost (P < .001), could not afford medical care (P < .001), had problems paying medical bills (P < .001), and were unable to pay medical bills (P < .001). Physician-patient relationship experience scores were significantly worse in the pre-Medicare group (P < .001). These trends were even stronger for low-income patients when data were broken down by income status. CONCLUSIONS: Patients likely delay elective TSA until reaching Medicare eligibility at age 65 years, resulting in substantial added financial burden to the health care system. As US health care costs continue to rise, it will be crucial for orthopedic providers and policy makers to be aware of pent-up demand for TSA and its possible associated drivers, especially socioeconomic status.

Comparison of the early results of minimally invasive vs standard approaches to total knee arthroplasty: a prospective, randomized study.

A prospective, randomized study was performed to compare early clinical and radiographic outcomes of total knee arthroplasty using either standard or minimally invasive surgical approaches. Fifty-nine patients were randomized into 3 groups: a standard median parapatellar incision (n = 19), a "mini mid-vastus" (n = 20), or a "quad sparing" group (n = 20). The procedures were performed by a single surgeon using similar perioperative protocols at 1 hospital. Postoperatively, the quad sparing group demonstrated some statistically significant (P < .05) improvement in week 2 and greater but not in weeks 1 and 6 compared to the other groups. No significant differences occurred regarding postoperative complications or radiographic alignment of the implants. In conclusion, our study demonstrated that the quad sparing group had some improved early results without compromising safety or efficacy.

Differential effects of nicotine and smoke condensate on bone cell metabolic activity.

OBJECTIVE: Delayed or impaired healing of skeletal trauma in patients who smoke has been attributed to vascular responses of nicotine absorption and/or a direct effect of nicotine or other smoke components on bone cells. In vivo studies indicate variability in osteosynthetic response to nicotine versus smoke inhalation. We tested the hypothesis that components of cigarette smoke other than nicotine may be responsible for the adverse skeletal effects of smoking. DESIGN: In vitro cultures of MC3T3-E1 osteoblastlike cells were exposed to varying doses of nicotine or condensates of cigarette smoke. Metabolic assays included alkaline phosphatase activity, collagen synthesis, and total protein synthesis as well as cell proliferation. RESULTS: Variations in the degree of response were noted between bone cell preparations. Nicotine elicited a significant dose-dependent stimulation of bone cell metabolism in all studies. This was detected as increases in alkaline phosphatase activity and increases in total protein and collagen synthesis. Responses were noted with nicotine doses as low as 12.5 ng/mL (half the nicotine level circulating in smokers). In one study, maximum stimulation occurred at 250 ng/mL with levels reaching 74% (total protein) and 104% (collagen) greater than control cultures. In a second study, 222% and 627% stimulation of protein and collagen synthesis over controls was noted using 100 ng/mL. Addition of the nicotine receptor antagonist mecamylamine reduced the nicotine stimulation. Preparations of smoke condensate with equivalent nicotine concentrations reduced all indices of metabolic activity. Cell proliferation was stimulated by both nicotine (20-25%) and smoke condensate (38-46%). CONCLUSION: The data suggest that nicotine acts as a direct stimulant of bone cell metabolic activity. Smoke condensate containing equivalent levels of nicotine elicits an inhibitory effect. A probable speculation is that the delay in clinical healing of skeletal trauma in smoking patients may in part be a result of absorption of components of smoke other than nicotine.