The Association Between Hospital Length of Stay and 90-Day Readmission Risk for Femoral Neck Fracture Patients: Within a Total Joint Arthroplasty Bundled Payment Initiative

Hip arthroplasty is increasingly performed as a treatment for femoral neck fractures (FNFs). However, these cases have higher complication rates than elective total hip arthroplasties (THAs). The Center for Medicare and Medicaid Services has created the Comprehensive Care for Joint Replacement model to increase the value of patient care. This model risk stratifies FNF patients in an attempt to appropriately allocate resources, but the formula has not been disclosed. The goal of this study was to ascertain if patients with FNFs have different readmission rates compared to patients undergoing elective THA so that the resource utilization can be assessed.

We analyzed all patients undergoing THA at our institution during a 21-month period. Patients classified by a diagnosis-related group of 469 or 470 were included. Multivariate and survival analyses were performed to determine risk of 90-day readmission.

Patients admitted for FNFs were older, had higher body mass indices, longer lengths of stay, and were more likely to be discharged to inpatient facilities than patients who underwent elective THA. Increased American Society of Anesthesiologists scores and FNF were also independent risk factors for 90-day readmission, and these patient were more likely to be readmitted during the latter 60 days following admission.

Results suggest that patients who undergo an arthroplasty following urgent or emergent FNFs have inferior outcomes to those receiving an arthroplasty for a diagnosis of arthritis. Fracture patients should either be risk stratified to allow appropriate resource allocation or be excluded from alternative payment initiatives such as Comprehensive Care for Joint Replacement.