gms | German Medical Science

Objectives: Younger and physically active patients increasingly demand a return to high activity and sports after total hip arthroplasty (THA). However, due to the risk of implant wear and loosening, patients are often advised against high impact activities. The current study evaluates factors predicting the postoperative activity level and the impact of the activity level on revision rates following THA.

Methods: This retrospective study included 4,152 hips in 3,828 patients aged 45–75 that underwent primary THA for primary osteoarthritis between 2009–2019 with a minimum follow-up of 2 years. Pain and Lower Extremity Activity Scale (LEAS) were accessed prior to implantation and 2-years after surgery. Patients were grouped according to their activity level 2 years after surgery in low (LEAS 1-6), moderate (LEAS 7–13), or high (LEAS 14–18) activity. Groups were compared with Chi2-Test for categorial variables and analysis of variance (ANOVA) with multiple comparisons for continuous variables. A Kaplan-Meier curve was plotted to predict implant survival, differences in implant survival between the activity groups were calculated with log-rank test. Logistic regression was performed to assess correlation between LEAS at the 2-year follow-up and predicted implant survival. Cox proportional hazards model was used to adjust for confounding variables (Age, BMI, Sex, CCI, ASA) when comparing the outcome variable “time to revision” between activity groups.

Results and conclusion: Pain and LEAS improved from pre- to 2 years postoperative (p<0.001, respectively). The activity level at the 2 year follow-up was low in 6.2%, moderate in 52.9%, and high in 40.9% of the patients. Younger age, lower BMI, ASA, and CCI, male sex, and higher preoperative LEAS correlated with higher activity at 2 years (p<0.001). Predicted 5-year revision free survival in the low active group was 94.2%, in the moderate active group 98.8%, and in the high active group 99.3%. Predicted 7-year revision free survival rates were 94.2% in the low active group, 96.9% in the moderate active group, and 98.4% in the high active group. The predicted revision-free survival rates between the activity groups were favorable for higher active patients (p<0.001). After adjusting for potential confounding variables (Age, BMI, Sex, ASA, CCI), the low activity group still showed a higher risk for revision compared to the moderate active group (HR 0.17, p=0.002) and the highly active group (HR 0.11, p<0.001).

High physical activity 2 years after THA with participating in sports like jogging several times a week did not increase the risk for revision surgery. THA patients should not be prevented from a highly active lifestyle.