Can Physical Therapy Improve Hip, Knee Surgery Outcomes?

Physical therapy after total hip (THR) or total knee replacement (TKR) surgery is standard care for all patients. A new study, appearing in the Oct. 1 issue of the Journal of Bone & Joint Surgery (JBJS), also found that physical therapy before joint replacement surgery, or “prehabilitation,” can diminish the need for postoperative care by nearly 30 percent, saving an average of $1,215 per patient in skilled nursing facility, home health agency or other postoperative care.

Approximately 50 million U.S. adults have physician-diagnosed arthritis. As the condition progresses, arthritis patients often require THR and/or TKR to maintain mobility and life quality. The number of THRs is expected to grow by 174 percent (572,000 patients) between 2005 and 2030, and TKRs by 673 percent (3.48 million). In recent years, the length of hospital stay following surgeries has decreased from an average of 9.1 days in 1990 to 3.7 days in 2008, while the cost of post-acute care, primarily in skilled nursing facilities and home health agencies, has skyrocketed.

Utilizing Medicare claims data, researchers were able to identify both preoperative physical therapy and postoperative care usage patterns for 4,733 THR and TKR patients. Postoperative, or “post-acute” care, was defined as the use of a skilled nursing facility, home health agency or inpatient rehabilitation center within 90 days after hospital discharge. Home health agency services included skilled nursing care, home health aides, physical therapy, speech therapy, occupational therapy and medical social services.

Approximately 77 percent of patients utilized care services following surgery. After adjusting for demographic characteristics and comorbidities (other conditions), patients receiving preoperative physical therapy showed a 29 percent reduction in postoperative care use. In addition:

• Fifty-four percent of the preoperative physical therapy group required postoperative care services, compared to 79.7 percent of the patients who did not have preoperative therapy;
• The decline in postoperative care services resulted in an adjusted cost reduction of $1,215 per patient, due largely to lower costs for skilled nursing facility and home health agency care; and
• Preoperative physical therapy cost an average of $100 per patient, and generally was limited to one or two sessions.

“This study demonstrated an important opportunity to pre-empt postoperative outcome variances by implementing preoperative physical therapy along with management of comorbidities before and during surgery,” said orthopedic surgeon Ray Wasielewski, M.D., co-author of the study.

Study Details
Historical claims data was analyzed using the Centers for Medicare & Medicaid Services Limited Data Set files for Diagnosis Related Group 470. Analysis included descriptive statistics of patient demographic characteristics, comorbidities, procedures, and post-acute care utilization patterns, which included skilled nursing facility, home health agency or inpatient rehabilitation facility during the 90-day period after a surgical hospitalization. To evaluate the associations, the study authors utilized bivariate and multivariate techniques focused on post-acute care use and total episode of care costs.