Longitudinal changes in patient-reported outcome measures following total hip arthroplasty and predictors of deterioration during follow-up: a seven-year prospective international multicentre study.

AIMS: The primary aim of this study was to quantify the improvement in patient-reported outcome measures (PROMs) following total hip arthroplasty (THA), as well as the extent of any deterioration through the seven-year follow-up. The secondary aim was to identify predictors of PROM improvement and deterioration. PATIENTS AND METHODS: A total of 976 patients were enrolled into a prospective, international, multicentre study. Patients completed a battery of PROMs prior to THA, at three months post-THA, and at one, three, five, and seven-years post-THA. The Harris Hip Score (HHS), the 36-Item Short-Form Health Survey (SF-36) Physical Component Summary (PCS), the SF-36 Mental Component Summary (MCS), and the EuroQol five-dimension three-level (EQ-5D) index were the primary outcomes. Longitudinal changes in each PROM were investigated by piece-wise linear mixed effects models. Clinically significant deterioration was defined for each patient as a decrease of one half of a standard deviation (group baseline). RESULTS: Improvements were noted in each PROM between the preoperative and one-year visits, with one-year values exceeding age-matched population norms. Patients with difficulty in self-care experienced less improvement in HHS (odds ratio (OR) 2.2; p = 0.003). Those with anxiety/depression experienced less improvement in PCS (OR -3.3; p = 0.002) and EQ-5D (OR -0.07; p = 0.005). Between one and seven years, obesity was associated with deterioration in HHS (1.5 points/year; p = 0.006), PCS (0.8 points/year; p < 0.001), and EQ-5D (0.02 points/year; p < 0.001). Preoperative difficulty in self-care was associated with deterioration in HHS (2.2 points/year; p < 0.001). Preoperative pain from other joints was associated with deterioration in MCS (0.8 points/year; p < 0.001). All aforementioned factors were associated with clinically significant deterioration in PROMs (p < 0.035), except anxiety/depression with regard to PCS (p = 0.060). CONCLUSION: The present study finds that patient factors affect the improvement and deterioration in PROMs over the medium term following THA. Special attention should be given to patients with risk factors for decreased PROMs, both preoperatively and during follow-up. Cite this article: Bone Joint J 2019;101-B:768-778.

Females, younger patients and patients with high BMI have the highest pre-operative knee awareness measured using the Forgotten Joint Score.

PURPOSE: The Forgotten Joint Score (FJS) is a novel measurement for patients' awareness of their knee in daily life. By identifying factors that could explain pre-operative FJS levels, the clinician could better prioritize and single out patients who would benefit most from TKA. The aim of this study was to identify possible factors that may explain the variance of pre-operative FJS levels and evaluate the relationship between pre-operative FJS and pre-operative Oxford Knee Score (OKS). METHODS: Four-hundred and six individual knees undergoing primary TKA between 2014 and 2016 were included in the study. Age, gender, body mass index (BMI), pre-operative FJS and pre-operative OKS were obtained maximum 2 weeks prior to surgery. Kellgren-Lawrence (K-L) grade, alignment and joint space width (JSW) were evaluated on pre-operative radiographs. RESULTS: Mean FJS was 21.1 ± 15.6. Females, younger patients and patients with high BMI had significantly the worst pre-operative FJS (p < 0.005). Females scored 6.5 FJS points lower than males. A 0.2-point increase in FJS for every added year indicated improvement in knee awareness with age. A 0.4-point decrease in FJS points for every added BMI point indicated worse knee awareness with higher BMI. There was a strong positive correlation between pre-operative FJS and pre-operative OKS according to the Spearman's rank order test (p < 0.005). CONCLUSIONS: Females, younger patients and patients with high BMI had significantly the worst pre-operative joint awareness. FJS had a strong positive correlation to OKS in pre-operative patients for primary TKA. This information can be used for improved patient selection; clinically continuous low FJS despite weight loss and/or the passing of time may be indication for TKA. LEVEL OF EVIDENCE: Prospective cohort study, Level II.