BACKGROUND

Total knee (TKA) and hip arthroplasty (THA) effectively treat end-stage osteoarthritis by restoring mobility and reducing pain; however, it is unclear how balance and steadiness compare between TKA and THA patients. This study utilized wearable technology to objectively compare functional recovery between TKA and THA patients.

METHODS

Two Hundred Nine patients underwent TKA (n = 152) or THA (n = 57) and were followed for 1 year. Participants wore Apple Watches with HealthKit to track daily step count, steadiness, standing duration, gait speed, and estimated 6-minute walk test distance. Data were analyzed at baseline, 6 weeks, 6 months, and 12 months postsurgery. Propensity score matching (1:1 ratio) yielded a final cohort of 110 patients (55 TKA, 55 THA). A multivariate regression analysis was conducted to evaluate the effect of THA vs TKA on steadiness, adjusting for contralateral Kellgren-Lawrence classification, age, sex, and body mass index.

RESULTS

Both groups improved mobility and endurance, with similar increases in step count, standing duration, and 6-minute walk test distance over 12 months. THA patients showed significantly greater steadiness at 6 (0.63 vs 0.49, = .031) and 12 months (0.84 vs 0.66, = .044). Multivariate analysis confirmed that TKA was associated with lower steadiness scores.

CONCLUSIONS

This study, the first to utilize Apple HealthKit data to compare TKA and THA recovery, found that THA patients exhibit better steadiness and balance recovery at 6 and 12 months. These findings suggest that balance-focused rehabilitation may benefit TKA patients. Wearable technology provides valuable, objective insights, enabling personalized guidance and enhancing patient outcomes.