Short-to Mid-Term Survivorship of a Patient-specific Unicompartmental Knee Arthroplasty Implant Cast from a Three-Dimensional Printed Mold

The efficacy and safety of patient-specific instrumentation versus conventional instrumentation for unicompartmental knee arthroplasty: Evidence from a meta-analysis

BACKGROUND

The aim of this study was to compare the efficacy and safety of patient-specific instrumentation (PSI) and conventional instrumentation (CI) for unicompartmental knee arthroplasty. Our hypothesis was that the PSI would be superior to CI in improving implant positioning and clinical function.

METHODS

We searched electronic databases (PubMed, Web of Science, Embase, and Cochrane) to identify relevant studies published before July 1, 2023 that met our inclusion criteria. The identified reports at least included one of the following outcome variables: coronal component alignment, sagittal component alignment, number of outliers, hip-knee-ankle angle, postoperative complications, operative time and knee joint functional evaluation. For dichotomous variables, we calculated the risk ratio and its 95% confidence interval (CI). For continuous variables, we calculated the mean difference (MD) and its 95% CI. Heterogeneity of the included studies was assessed using the standard chi-square test. Meta-analyses were performed using RevMan 5.4. software. The meta-analysis was registered with PROSPERO (No. CRD42023454160).

RESULTS

A total of 9 articles were included in the analysis, consisting of 4 randomized controlled trials and 5 cohort studies. The study population comprised 494 patients, with 262 in the PSI group and 232 in the CI group. Our findings demonstrate that the PSI group exhibits superior tibial component coronal alignment compared to the CI group (MD = -0.66, 95% CI: -1.21 to -0.12, P = .02). Conversely, the CI group demonstrates better femoral component coronal alignment than the PSI group (MD = 0.89, 95% CI: 0.17-1.60, P = .01). No significant between 2 groups differences were observed in tibial component sagittal alignment, femoral component sagittal alignment, tibial coronal axis outliers, tibial sagittal axis outliers, femoral coronal axis outliers, femoral sagittal axis outliers, postoperative complications, operative time, hip-knee-ankle angle, and postoperative knee joint function score.

CONCLUSIONS

Our study findings suggest that the PSI confer an advantage in achieving superior tibial component coronal alignment, whereas the CI associated with better femoral component coronal alignment. However, no significant differences were observed between the groups in terms of other parameters. Future studies with larger sample sizes are needed to validate these findings.