Total joint arthroplasty has become a highly successful treatment option for sufferers of hip or knee arthritis, providing pain relief and return of joint function for most patients who undergo these procedures. By 2030, it is expected that more than 3 million total knee arthroplasties and 500,000 total hip arthroplasties will be performed annually in the United States. “With the projected exponential growth in total joint arthroplasty, there have been concerns about the overwhelming workload for the medical community and increasing financial burden on society,” says Javad Parvizi, MD, FRCS.

Despite the great success that has been seen with arthroplasty, complications can still occur, leading to prolonged inpatient care, hospital readmission, or reoperation. Dr. Parvizi says that minimizing these complications is an important goal for patients and their surgeons because it would have a major impact on reducing the healthcare burden. “Early readmission following total joint arthroplasty has been of particular interest to clinicians and the healthcare system,” he says. “Limiting unplanned readmissions has become a driving force in many pay-for-performance compensation models.”

Lingering Questions

Readmission rates of 4.0% to 8.5% have been reported within 30 days of discharge following total joint arthroplasty in recent studies, and some research suggests that readmission rates after both primary and revision total hip arthroplasty have increased in elderly recipients of these procedures. This increase may be attributable to changes in the duration of hospital stay and discharge disposition, but studies are still lacking in this regard. “Although clinical investigations have made substantial contributions to our knowledge about readmission patterns, many questions remain,” says Dr. Parvizi. “Our efforts to decrease future readmission rates will depend on getting a better understanding of the causes of readmission and its predisposing factors.”

Joint-Arthroplasty-Readmissions-Callout

New Research

In a study published in the Journal of Bone & Joint Surgery, Dr. Parvizi and colleagues sought to determine the true incidence of unplanned readmission after total joint arthroplasty at a single large-volume institution. The research team also aimed to determine the specific indications for these readmissions and identify predisposing factors for being readmitted. A total of 10,633 admissions for primary arthroplasty, including 5,207 knees and 5,426 hips, were used in the analysis. A database was used to identify patients requiring an unplanned readmission within 90 days of discharge.

 

“Our efforts to decrease future readmission rates will depend on getting a better understanding of the causes of readmission and its predisposing factors.”

 

According to the study, 3.1% and 5.3% of admissions for joint arthroplasty required at least one readmission within 30 and 90 days, respectively. The most common cause of readmission was joint-related infection, followed by knee stiffness, wound-related issues, and cardiovascular problems (Figures 1 and 2). Several independent predictors of readmission within 90 days were also found, including discharge to inpatient rehabilitation, increased duration of hospital stay, and decreased distance between home and the hospital, in addition to several other patient demographics. When unplanned readmissions were stratified by type of joint arthroplasty, infection was the most common cause of readmission following total hip arthroplasty. Knee stiffness was the most common cause of readmission following total knee arthroplasty.

Several theories could explain the findings observed in the analysis by Dr. Parvizi and colleagues. For example, patients may be monitored more closely by rehabilitation personnel than at home, which in turn can improve the detection of complications that lead to readmission. It is also possible that skilled facilities seek input from an arthroplasty center more frequently and at a lower threshold, perhaps acting out of fear of possible legal repercussions. “Many of the leading indications for readmission are multifactorial,” says Dr. Parvizi. “Their incidence may therefore not provide an accurate representation of quality of care at a particular treating institution.”

Examining the Implications

Early readmission following total joint arthroplasty has been targeted as a potential quality performance metric. “With proposed changes in reimbursement policy, higher rates of unplanned readmissions following arthroplasty will penalize providers,” Dr. Parvizi says. “As such, it’s important for clinicians to appreciate the characteristics of readmissions following total joint arthroplasty.” He notes that more data similar to those collected in his study are necessary, and on a grander scale, because many investigations seeking to identify the incidence or causes of early readmission are conflicting or vary significantly.

Dr. Parvizi says that his analysis reaffirms that readmission rates are not inconsequential. “It’s critical that we take a proactive approach to limiting complications in total joint arthroplasty with effective prophylactic measures,” he says. “Efforts are needed to prevent longer hospitalizations and discharges to inpatient facilities. These tactics are necessary to
limiting the physical and psychological toll that readmission takes on patients.”

References

Zmistowski B, Restrepo C, Hess J, Adibi D, Cangoz S, Parvizi J. Unplanned readmission after total joint arthroplasty: rates, reasons, and risk factors. J Bone Joint Surg Am. 2013;95:1869-1876. Available at: http://jbjs.org/article.aspx?articleid=1746515.

Pulido L, Parvizi J, Macgibeny M, et al. In hospital complications after total joint arthroplasty. J Arthroplasty. 2008;23(Suppl):139-145.

Zmistowski B, Hozack WJ, Parvizi J. Readmission rates after total hip arthroplasty. JAMA. 2011;306:825.

Iorio R, Robb WJ, Healy WL, et al. Orthopaedic surgeon workforce and volume assessment for total hip and knee replacement in the United States: preparing for an epidemic. J Bone Joint Surg Am. 2008;90:1598-1605.

Losina E, Walensky RP, Kessler CL, et al. Cost-effectiveness of total knee arthroplasty in the United States: patient risk and hospital volume. Arch Intern Med. 2009;169:1113-1121.