Return to work and work activity limitations following total hip and knee replacement

Abstract

Purpose: Total hip (THR) and knee (TKR) replacement increasingly are performed in middle-aged individuals making return to work (RTW) a salient outcome. This research describes the characteristics of individuals with early and later return to work following THR and TKR. Additionally, at work limitations pre-surgery and upon returning to work and factors associated with workplace limitations were evaluated. Methods: 190 THR (males = 100; female = 90; mean age = 56 yrs, sd=9.9) and 170 TKR (males = 72; female = 98; mean age = 57 yrs, sd=7.2) of a total 931 cohort participants were eligible for the study (i.e., those working or on short-term disability pre-surgery). They completed questionnaires pre-surgery and one, three, six and twelve months post-surgery that included socio-demographics (age, sex, BMI, education, marital status and job status i.e., full- or part-time, short-term disability), job sector (business/administration, health/science/arts, sales and service, and trades/transportation/manufacturing), occupational physical demand (low, high and unable to determine), and the Workplace Activity Limitations Scale (WALS), a 12-item measure where respondents rate how much difficulty they experience carrying out work-related activities unassisted (score range 0-36 with lower scores indicating few limitations). Additionally, the WOMAC pain and function subscales were completed. THR and TKR were analyzed separately and all standardized measures were recoded, as necessary, so that lower scores represented no problems. In addition to descriptive statistics for the sample, the proportion of people working was calculated for each time interval. The association of age, sex, BMI, education, job sector and job demands with early (1 month) versus later (6 and 12 month) RTW was examined using ANOVA for continuous variables and polychoric correlations for categorical data. Results: 166 (87%) and 144 (85%) respondents RTW by twelve months following THR and TKR, respectively. Overall, people with THR (34%) returned to work earlier than those with TKR (23 %). Early RTW was associated with older age, male gender, university education, working in business/administration, and low physical demand work. For both groups, work limitations were significantly less than pre-surgery by one-year follow-up (pre-surgery: THR 12.6, TKR = 13.3; one-year post-surgery: THR=4.14, TKR=5.90). In THR, limitations upon RTW were similar irrespective of time of RTW, while for TKR, those with later return reported fewer limitations than those who returned early. WOMAC pain and function scores were associated with the WALS with Pearson r ranging from 0.53 to 0.78 for THR and from 0.53 to 0.75 for TKR. Conclusions: Overall, a high proportion of individuals, including workers in older age groups, return to work following THR or TKR although time of return is slightly later in TKR. Information on factors associated with time of return and the types of limitations experienced is valuable for clinicians in educating patients about the course of recovery.