Economic Decision Model Suggests Total Shoulder Arthroplasty is Superior to Hemiarthroplasty in Young Patients with End-stage Shoulder Arthritis.

BACKGROUND: Young patients with severe glenohumeral arthritis pose a challenging management problem for shoulder surgeons. Two controversial treatment options are total shoulder arthroplasty (TSA) and hemiarthroplasty. This study aims to characterize costs, as expressed by reimbursements for episodes of acute care, and outcomes associated with each treatment.

QUESTIONS/PURPOSES: We asked: for patients 30 to 50 years old with severe end-stage glenohumeral arthritis refractory to conservative management, (1) are more years of patient-derived satisfactory outcome by the Neer criteria and quality-adjusted life-years (QALYs) achieved using a TSA or a hemiarthroplasty; (2) does a TSA or a hemiarthroplasty result in a greater number of revision procedures; and (3) does a TSA or a hemiarthroplasty result in greater associated costs to society?

METHODS: The incidence of glenohumeral arthritis among 30- to 50-year-old patients, outcomes, reoperation probabilities, and associated costs from TSA and hemiarthroplasty were derived from the literature. A Markov chain decision tree model was developed from these estimates with number of revisions, cost of management for patients to 70 years old as defined by reimbursement for acute-care episodes, years with "satisfactory" or "excellent" outcome by the modified Neer criteria, and QALYs gained as principle outcome measures. A Monte Carlo simulation was conducted with a cohort representing the at-risk population for shoulder arthritis between 30 and 50 years old in the United States.

RESULTS: During the lifetime of a cohort of 5279 patients, hemiarthroplasty as the initial treatment resulted in 59,574 patient years of satisfactory or excellent results (11.29 per patient) and average QALYs gained of 6.55, whereas TSA as the initial treatment resulted in 85,969 patient years of satisfactory or excellent results (16.29 per patient) and average QALYs gained of 7.96. During the lifetime of a cohort of 5279 patients, a hemiarthroplasty as the initial treatment led to 2090 lifetime revisions (0.4 per patient), whereas a TSA as the initial treatment led to 1605 lifetime revisions (0.3 per patient). During the lifetime of a cohort of 5279 patients, a hemiarthroplasty as initial treatment resulted in USD 132,500,000 associated direct reimbursements (USD 25,000 per patient), whereas a TSA as initial treatment resulted in USD 125,500,000 associated direct reimbursements (USD 23,700 per patient).

CONCLUSIONS: Treatment of end-stage glenohumeral arthritis refractory to conservative treatment in patients 30 to 50 years old in the United States with TSA, instead of hemiarthroplasty, would result in greater cost savings, avoid a substantial number of revision procedures, and result in greater years of satisfactory or excellent patient outcomes and greater QALYs gained. On a population level, TSA is the cost-effective treatment for glenohumeral arthritis in patients 30 to 50 years old.

LEVEL OF EVIDENCE: Level II, economic and decision analysis study.