Postoperative Care Navigation for Total Knee Arthroplasty Patients: A Randomized Controlled Trial

Abstract

Objective: To establish the efficacy of motivational interviewing-based postoperative care navigation in improving functional status after total knee arthroplasty (TKA) and to identify subgroups likely to benefit from the intervention.

Methods: We conducted a parallel randomized controlled trial in TKA recipients with 2 arms: postoperative care with frequent followup by a care navigator or usual care. The primary outcome was the difference between the arms in Western Ontario and McMaster Universities Osteoarthritis Index function score change, over 6 months postsurgery. We performed a preplanned subgroup analysis of differential efficacy by obesity and exploratory subgroup analyses on sex and pain catastrophizing.

Results: We enrolled 308 subjects undergoing TKA for osteoarthritis. Mean ± SD preoperative function score was 41 ± 17 (0-100 scale, where 100 = worst function). At 6 months, subjects in the navigation arm improved by mean ± SD 30 ± 16 points compared to 27 ± 18 points in the usual-care arm (P = 0.148). Participants with moderate to high levels of pain catastrophizing were unlikely to benefit from navigation compared to those with lower levels of pain catastrophizing (P = 0.013 for interaction).

Conclusion: Subjects assigned to the navigation intervention did not demonstrate greater functional improvement compared to those in the control group. The negative overall result could be explained by the large effect on functional improvement of TKA itself compared to the smaller, additional benefit from care navigation, as well as by potential differential effects for subjects with moderate to high degrees of pain catastrophizing. Greater focus on developing programs for reducing pain catastrophizing could lead to better functional outcomes following TKA.

Trial registration: ClinicalTrials.gov NCT01540851.

Conflict of interest statement

Potential Conflicts of Interest:

Losina: Deputy Editor, Journal of Bone and Joint Surgery

Wright: DePuy, a Johnson & Johnson Company

Katz: Deputy Editor, Journal of Bone and Joint Surgery; President-elect, Osteoarthritis Research Society International

© 2016, American College of Rheumatology.

Figures

Figure 1. Study enrollment and follow-up

1,234 persons were assessed for eligibility, of whom 624 were deemed eligible for enrollment. Of those eligble who agreed to participate, 154 subjects were randomized to each study arm. 136 and 133 subjects were analyzed in the usual care and care navigator study arms, respectively.

Figure 2. Pre-planned and exploratory subgroup analyses showing changes in WOMAC function scores from baseline to six months post-surgery

The effectiveness of the care navigator intervention was analyzed for subgroups divided by sex, pain catastrophizing score (cutoff of 20), and BMI (cutoffs of 30 and 35). Diamonds represent the mean difference in the 6 month change in WOMAC function between the care navigator group and the usual care group, adjusted for baseline WOMAC function scores. The lines show 95% confidence intervals. Negative values indicate functional improvement.