Alexandra M Leenders1,2, Nanne P Kort3, Koen L M Koenraadt4, Rutger C I van Geenen4, Jasper Most5, Bart Kerens6, Bert Boonen5, Martijn G M Schotanus5,7. 1. Department of Orthopaedics, Zuyderland Medical Centre, Dr. H. van der Hoffplein 1, 6162 BG, Sittard-Geleen, The Netherlands. alexandraleenders@hotmail.com. 2. Department of Orthopaedics, VieCuri Medical Centre, Tegelseweg 210, 5912 BL, Venlo, The Netherlands. alexandraleenders@hotmail.com. 3. CortoClinics, Steeg 6E, 5482 WN, Schijndel, The Netherlands. 4. Department of Orthopaedics, Amphia Hospital, Molengracht 21, 4814 CK, Breda, The Netherlands. 5. Department of Orthopaedics, Zuyderland Medical Centre, Dr. H. van der Hoffplein 1, 6162 BG, Sittard-Geleen, The Netherlands. 6. Department of Orthopaedics, AZ Sint-Maarten, Liersesteenweg 435, 2800, Mechelen, Belgium. 7. School of Care and Public Health Research Institute, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre, Universiteitssingel 40, 6229 ER, Maastricht, The Netherlands.
Abstract
PURPOSE: The aim of this two-centre RCT was to compare pre- and post-operative radiological, clinical and functional outcomes between patient-specific instrumentation (PSI) and conventional instrumented (CI) unicompartmental knee arthroplasty (UKA). It was hypothesised that both alignment methods would have comparable post-operative radiological, clinical and functional outcomes. METHODS: One hundred and twenty patients were included, and randomly allocated to the PSI or the CI group. Outcome measures were peri-operative outcomes (operation time, length of hospital stay and intra-operative changes of implant size) and post-operative radiological outcomes including the alignment of the tibial and femoral component in the sagittal and frontal plane and the hip-knee-ankle-axis (HKA-axis), rate of adverse events (AEs) and patient-reported outcome measures (PROMs) pre-operatively and at 3, 12 and 24 months post-operatively. RESULTS: There was a statistically significant difference (p < 0.05) in alignment of the femoral component in the frontal plane in favour of the CI method. No statistically significant differences were found for the peri-operative data or in the functional outcome at 2-year follow-up. In the PSI group, the approved implant size of the femoral component was correct in 98.2% of the cases and the tibial component was correct in 60.7% of the cases. There was a comparable rate of AEs: 5.1% in the CI and 5.4% in the PSI group. CONCLUSION: The PSI method did not show an advantage over CI in regard of positioning of the components, nor did it show an improvement in clinical or functional outcome. We conclude that the possible advantages of PSI do not outweigh the costs of the MRI scan and the manufacturing of the PSI. LEVEL OF EVIDENCE: Randomised controlled trial, level I.
PURPOSE: The aim of this two-centre RCT was to compare pre- and post-operative radiological, clinical and functional outcomes between patient-specific instrumentation (PSI) and conventional instrumented (CI) unicompartmental knee arthroplasty (UKA). It was hypothesised that both alignment methods would have comparable post-operative radiological, clinical and functional outcomes. METHODS: One hundred and twenty patients were included, and randomly allocated to the PSI or the CI group. Outcome measures were peri-operative outcomes (operation time, length of hospital stay and intra-operative changes of implant size) and post-operative radiological outcomes including the alignment of the tibial and femoral component in the sagittal and frontal plane and the hip-knee-ankle-axis (HKA-axis), rate of adverse events (AEs) and patient-reported outcome measures (PROMs) pre-operatively and at 3, 12 and 24 months post-operatively. RESULTS: There was a statistically significant difference (p < 0.05) in alignment of the femoral component in the frontal plane in favour of the CI method. No statistically significant differences were found for the peri-operative data or in the functional outcome at 2-year follow-up. In the PSI group, the approved implant size of the femoral component was correct in 98.2% of the cases and the tibial component was correct in 60.7% of the cases. There was a comparable rate of AEs: 5.1% in the CI and 5.4% in the PSI group. CONCLUSION: The PSI method did not show an advantage over CI in regard of positioning of the components, nor did it show an improvement in clinical or functional outcome. We conclude that the possible advantages of PSI do not outweigh the costs of the MRI scan and the manufacturing of the PSI. LEVEL OF EVIDENCE: Randomised controlled trial, level I.