What proportion of people have long-term pain after total hip or knee replacement? An update of a systematic review and meta-analysis

Abstract

Objectives: To update our previous systematic review to synthesise latest data on the prevalence of long-term pain in patients who underwent total hip replacement (THR) or total knee replacement (TKR). We aim to describe the prevalence estimates and trends in this review.

Design: Systematic review and meta-analysis.

Data sources: Update searches were conducted in MEDLINE and Embase databases from 1 January 2011 to 17 February 2024. Citation tracking was used to identify additional studies.

Eligibility criteria: We included prospective cohort studies reporting long-term pain after THR or TKR at 3, 6, 12 and 24 months postoperative.

Data extraction and synthesis: Two reviewers independently identified studies as eligible. One reviewer conducted data extraction, checked by a second reviewer. The risk of bias assessment was performed using Hoy's checklist. Bayesian, random-effects meta-analysis was used to synthesise the results.

Results: For TKR, 68 studies with 89 time points, including 598 498 patients, were included. Multivariate meta-analysis showed a general decrease in pain proportions over time: 21.9% (95% CrI 15.6% to 29.4%) at 3 months, 14.1% (10.9% to 17.9%) at 6 months, 12.6% (9.9% to 15.9%) at 12 months and 14.6% (9.5% to 22.4%) at 24 months. Considerable heterogeneity, unrelated to examined moderators, was indicated by substantial prediction intervals in the univariate models. Substantial loss to follow-up and risk of bias led to low confidence in the results. For THR, only 11 studies were included, so it was not possible to describe the trend. Univariate meta-analysis estimated 13.8% (8.5% to 20.1%) and 13.7% (4.8% to 31.0%) of patients experiencing long-term pain 6 and 12 months after THR, respectively, though concerns in risk of bias results reduced confidence in these findings.

Conclusions: Our review suggests that approximately 22% of patients report pain 3 months post-TKR, with 12%-15% experiencing long-term pain up to 2 years. At least 14% report pain 6-12 months after THR. Given the prevalence of chronic postsurgical pain, implementing existing and developing new preventive and management strategies is crucial for optimal patient outcomes.

Prospero registration number: CRD42023475498.

Keywords: Chronic Pain; Hip; Knee; Meta-Analysis; ORTHOPAEDIC & TRAUMA SURGERY; Systematic Review.

Figure 1. Study selection flow chart. *22 studies included both populations. THR, total hip replacement; TKR, total knee replacement.

Figure 2. Summary of risk of bias assessments in TKR studies. Each block represents one study. Red represents an overall high risk of bias in a study; yellow represents an overall moderate risk of bias. TKR, total knee replacement.

Figure 3. Multivariate meta-analysis of proportions over time in TKR studies plot. Grey dots and lines represent reported proportions across studies and time, while dark dots and lines show the multivariate meta-analysis results. The size of grey dots is proportional to the log of inverse variance. TKR, total knee replacement.

Figure 4. Forest plot of proportions over time in THR studies. Squares and bars represent the mean proportion of individual studies. Diamonds represent the point estimate and Crl of the meta-analysis results. The bars show the corresponding prediction intervals. Red circles and minus signs represent overall high risk of bias. Yellow circles and question marks represent overall moderate risk of bias. CrI, credible intervals; RE, random effects; RoB, risk of bias; THR, total hip replacement.