BACKGROUND:
Recently, self-directed physical therapy (SDPT) programs have gained popularity following total knee arthroplasty (TKA). This study evaluated the safety and efficacy of the routine use of an SDPT program in a nonselect patient population.

METHODS:
This is a single-surgeon, retrospective study of 296 consecutive patients from August 2016 to October 2017 discharged home after primary, unilateral TKA and enrolled in a web-based SDPT program. Patients were seen 2 weeks after surgery and outpatient physical therapy (OPPT) was prescribed if flexion was less than 90°, upon patient request, or inability to use the web-based platform.

RESULTS:
Overall, 195 of 296 (65.9%) patients did not require OPPT (SDPT-only) while 101 of 296 were prescribed OPPT (34.1%, SDPT + OPPT). In SDPT + OPPT, 66.3% were for flexion < 90°, 27.7% by patient request, 5.0% received a prescription but did not attend OPPT, and 1.0% due to inability to use the web-based platform. The rate of manipulation under anesthesia was 2.36% overall (SDPT + OPPT, 6.93%; SDPT-only, 0.0%). Multivariate analysis identified elevated Charlson comorbidity index, elevated body mass index, higher preoperative SF12 mental score, and loss of flexion at 2 weeks as independent predictors associated with the need for OPPT.

CONCLUSION:
Web-based SDPT is safe and effective for most patients eligible for home discharge after TKA. It is difficult to preoperatively predict those patients who will require OPPT; therefore, we recommend close follow-up. It is critical to preserve these services for patients who require them after TKA as up to a third of patients required OPPT.