Hip fractures, the most severe and costly fall-related fractures, account for 350,000 hospital admissions per year.1 The majority of hip fractures result from low-impact falls, typically in patients over age 60 years. In fact, the increase in hip fracture with age is nearly exponential.2,3 With the predicted aging of our population, hip fractures will continue to increase in volume. Between 2000 and 2050, the elderly US population will increase by 135%,4 proportionately increasing the number of projected hip fractures. Considering that hip fractures account for 72% of total costs in terms of orthopedic fracture care in the elderly, the dramatic rise in hip fractures is of great concern for future costs of health care delivery in this field.5-7
In an effort to move toward a value-based system in which costs are reduced while quality of care is maintained, Medicare recently unveiled a new bundled payment system of reimbursement. Through this system, hospitals will be reimbursed for treatment provided to Medicare beneficiaries based on the expected costs of care, instead of through the traditional fee-for-service model. Given this development, orthopedic surgeons will need to develop interventions that reduce costs while maintaining quality of care after hip fracture surgery.
One of the most significant ramifications of a value-based system is that reimbursement for hip fractures may be standardized based on a single diagnosis regardless of the actual costs associated with treatment.8 In hip fracture cases, however, a wide range of factors, including degree of communition of the bone, presence of medical comorbidities,9 and amount of soft-tissue injury, can dramatically increase recovery time. In fact, one of the most important determinants of treatment costs related to hospital length of stay (LOS) is whether the fracture is a femoral neck or intertrochanteric fracture.10,11 Type of fracture is a significant determinant of surgical options, and these can dramatically change patient outcomes and costs of surgical care.12-16 In addition, hospital recovery time or LOS can vary widely based on type of surgery. As hospitalization costs account for 44% of the direct medical costs for hip fractures,17 differences in LOS can have major financial implications in a value-based system of reimbursement in which all forms of hip fracture are reimbursed a standard amount.
We conducted a study to analyze differences in hospital LOS for different forms of hip fracture repair to determine the potential financial repercussions of a bundled payment model of reimbursement. By performing a retrospective chart review at a large, level I trauma center, we were able to compare LOS and associated costs for total hip arthroplasty (THA), hemiarthroplasty (HA), cephalomedullary nailing (CMN), open reduction and internal fixation (ORIF), and closed reduction and percutaneous pinning (CRPP).
Materials and Methods
After receiving institutional review board approval for this study, we retrospectively reviewed all hip fracture cases treated at a level I trauma center between January 2000 and December 2009. Current Procedural Terminology (CPT) codes were searched for cases of low-energy falls that caused hip fractures that were resolved with THA, HA, CMN, ORIF, or CRPP. Patients who underwent HA or THA were grouped for analysis. Patients who were over age 60 years and had acetabular, proximal femoral, trochanteric, or femoral neck fractures were included in our search. Patients who had incomplete medical records or did not meet the age criterion were excluded from analysis.
We reviewed patient charts in our institutional electronic medical records database to collect these data: date of birth, age, sex, date of admission, date of discharge, American Society of Anesthesiologists (ASA) Physical Status score, complications, height, weight, start and stop times of procedure, whether or not the procedure was an emergent procedure, days from admission to surgery, 90-day readmissions, days from surgery to discharge, and general category of operation. We also recorded individual comorbidities, including prior myocardial infarction, dysrhythmia, atrial fibrillation, congestive heart failure, heart block, cerebrovascular disease, chronic obstructive pulmonary disease, emphysema, current smoking status, smoking history, renal disease, dialysis, cancer, and diabetes. Duration of surgery was calculated from recorded start and stop times. Body mass index was calculated using height and weight recorded during initial stay. LOS was recorded as the difference between the admission and discharge dates.
Mean total cost to the hospital ($4530/d patient was hospitalized) was obtained from the institution’s financial services. All fractional LOS values were rounded to the nearest whole number and multiplied by the per diem cost. Student t test was used to compare mean LOS and costs of HA/THA with those of all the other procedures. Additional tests were run to analyze differences in LOS and type of surgeries performed throughout the 9-year period. A multivariate regression model controlling for ASA score, body mass index, age, sex, and comorbidities was developed to analyze differences in LOS and costs for patients who underwent HA/THA versus CMN, ORIF, and CRPP. Significance was set at P = .05.