Patient relevant outcomes of unicompartmental versus total knee replacement: systematic review and meta-analysis

Abstract

Objective To present a clear and comprehensive summary of the published data on unicompartmental knee replacement (UKA) or total knee replacement (TKA), comparing domains of outcome that have been shown to be important to patients and clinicians to allow informed decision making. Design Systematic review using data from randomised controlled trials, nationwide databases or joint registries, and large cohort studies. Data sources Medline, Embase, Cochrane Controlled Register of Trials (CENTRAL), and Clinical Trials.gov, searched between 1 January 1997 and 31 December 2018. Eligibility criteria for selecting studies Studies published in the past 20 years, comparing outcomes of primary UKA with TKA in adult patients. Studies were excluded if they involved fewer than 50 participants, or if translation into English was not available. Results 60 eligible studies were separated into three methodological groups: seven publications from six randomised controlled trials, 17 national joint registries and national database studies, and 36 cohort studies. Results for each domain of outcome varied depending on the level of data, and findings were not always significant. Analysis of the three groups of studies showed significantly shorter hospital stays after UKA than after TKA (−1.20 days (95% confidence interval −1.67 to −0.73), −1.43 (−1.53 to −1.33), and −1.73 (−2.30 to −1.16), respectively). There was no significant difference in pain, based on patient reported outcome measures (PROMs), but significantly better functional PROM scores for UKA than for TKA in both non-trial groups (standard mean difference −0.58 (−0.88 to −0.27) and −0.29 (−0.46 to −0.11), respectively). Regarding major complications, trials and cohort studies had non-significant results, but mortality after TKA was significantly higher in registry and large database studies (risk ratio 0.27 (0.16 to 0.45)), as were venous thromboembolic events (0.39 (0.27 to 0.57)) and major cardiac events (0.22 (0.06 to 0.86)). Early reoperation for any reason was higher after TKA than after UKA, but revision rates at five years remained higher for UKA in all three study groups (risk ratio 5.95 (1.29 to 27.59), 2.50 (1.77 to 3.54), and 3.13 (1.89 to 5.17), respectively). Conclusions TKA and UKA are both viable options for the treatment of isolated unicompartmental osteoarthritis. By directly comparing the two treatments, this study demonstrates better results for UKA in several outcome domains. However, the risk of revision surgery was lower for TKA. This information should be available to patients as part of the shared decision making process in choosing treatment options. Systematic review registration PROSPERO number CRD42018089972.

Osteoarthritis year in review 2019: epidemiology and therapy

“…The authors also investigated unicompartmental knee replacement separately, showing a lower survival rate (70%) than for total knee replacement. The latter is also supported by a recent systematic review with meta-analysis investigating 5-year revision rates 40 .…”

Early Economic Evaluation Demonstrates That Noncomputerized Tomography Robotic-Assisted Surgery Is Cost-Effective in Patients Undergoing Unicompartmental Knee Arthroplasty at High-Volume Orthopaedic Centres

“…However, there is also a relationship between procedure volume and outcomes. A systematic review that compared TKA with UKA noted that centres that perform 20% of their arthroplasty practice as UKA achieve lower rates of revision for unexplained pain or failures [6]. It is speculated that one of the reasons low-volume centres observe higher failure rates of UKA is poor patient selection where surgeons are more likely to offer UKA to patients with partial-thickness cartilage loss which is associated with poor outcomes compared to patients with bone-on-bone arthritis [26,27].…”

“…Our study corroborates this finding, indicating that non-CT r-UKA is cost-effective in centres conducting more than 30 non-CT r-UKA procedures per year and this improves dramatically in centres performing over 100 cases per year. Increasing the volume of non-CT r-UKA surgery and the frequency of procedures for individual surgeons ensures that surgeons reduce the learning curve, maintain their knowledge of the procedure, and ultimately, deliver improved outcomes [6,29].…”

“…ere are a number of documented surgical benefits associated with UKA when compared with TKA which include less perioperative morbidity, reduced blood loss, and shorter postoperative recovery and rehabilitation [3][4][5]. A recent systematic review and meta-analysis using data from randomised controlled trials, observational studies, and registry studies reported shorter mean length of stay, better functional patient-reported outcome measure scores, and fewer revisions compared to TKA [6].…”

Partial or total knee replacement? Identifying patients’ information needs on knee replacement surgery: a qualitative study to inform a decision aid

“…A reference group was initiated, the study findings consulted on, FAQ's determined and information prioritised to include in the decision aid. A systematic review has been completed comparing partial versus total knee replacement to help inform the FAQs [73]. The tool will be user-tested and evaluated in the clinical setting.…”