Evaluation of the Visionaire Instrumentation for Total Knee Arthroplasty Using Computer Navigation (original) (raw)
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The Journal of Arthroplasty, 2013
total knee arthroplasty patient-specific instrumentation navigation accuracy This investigation evaluated the Smith and Nephew VISIONAIRE patient-specific cutting block (PSCB) system for total knee arthroplasty. A consecutive series of 60 patients was recruited. Intraoperative computer navigation was used to evaluate the accuracy of the cutting blocks in the coronal and sagittal planes for the tibia, as well as rotational plane for the femur. The PSCB would have placed 79.3% of the sample within ±3°of the preoperative plan in the coronal plane, while the rotational and sagittal alignment results within ±3°w ere 77.2% and 54.5% respectively. The VISIONAIRE PSCB system achieved unacceptable accuracy when assessed by computer navigation. There might be many sources of error, but caution is recommended before using this system routinely without objective verification of alignment.
International Journal of Research in Orthopaedics
Background: The aim of the study was to analyze and compare the accuracy, efficiency and functional evolution between the first- and second-generation Patient-specific instrumentation (PSI).Methods: We report our experience in TKA using PSI Visionaire System® (Smith and Nephew®) in 456 procedures. The patients were divided into first- (N=272) and second-generation PSI design (N=184). For the accuracy was analyzed the mechanical results, namely Hip-knee-ankle (HKA) alignment post-TKA and outliers’ frequency; for the efficiency was analyzed the length time surgery, the length of stay and satisfaction, for the functional outcomes was compared the evolution at pain, range of motion, gait perimeter and the domains of the Western ontario and mcmaster osteoarthritis index (WOMAC). The t-test for independent samples was applied in the continuous numeric variables and Qui square tests in the dichotomic nominal variables. Statistical significance was p value<0.05.Results: The alignment of ...
Bone Joint J , 2016
Aims We conducted a randomised controlled trial to assess the accuracy of positioning and alignment of the components in total knee arthroplasty (TKA), comparing those undertaken using standard intramedullary cutting jigs and those with patient-specific instruments (PSI). Patients and Methods There were 64 TKAs in the standard group and 69 in the PSI group. The post-operative hip-knee-ankle (HKA) angle and positioning was investigated using CT scans. Deviation of > 3° from the planned position was regarded as an outlier. The operating time, Oxford Knee Scores (OKS) and Short Form-12 (SF-12) scores were recorded. Results There were 14 HKA-angle outliers (22%) in the standard group and nine (13%) in the PSI group (p = 0.251). The mean HKA-angle was 0.5° varus in the standard group and 0.2° varus in the PSI group (p = 0.492). The accuracy of alignment in the coronal and axial planes and the proportion of outliers was not different in the two groups. The femoral component was more flexed (p = 0.035) and there were significantly more tibial slope outliers (29% versus 13%) in the PSI group (p = 0.032). Operating time and the median three-month OKS were similar (p = 0.218 and p = 0.472, respectively). Physical and mental SF-12 scores were not significantly different at three months (p = 0.418 and p = 0.267, respectively) or at one year post-operatively (p = 0.114 and p = 0.569). The median one-year Oxford knee score was two points higher in the PSI group (p = 0.049). Conclusion Compared with standard intramedullary jigs, the use of PSI did not significantly reduce the number of outliers or the mean operating time, nor did it clinically improve the accuracy of alignment or the median Oxford Knee Scores. Our data do not support the routine use of PSI when undertaking TKA. Cite this article: Bone Joint J 2016;98-B:1043–9. Between 6% and 12% of total knee arthro-plasties (TKAs) fail as a result of malposition and malalignment of the components. 1,2 Mal-alignment also contributes to instability, asep-tic loosening and unexplained pain. 3-5 Patient-specific instrumentation (PSI) has been introduced to improve the positioning of components. Other postulated benefits are increased surgical efficiency and a potential reduction of complications due to avoidance of medullary canal violation and reduced operating time. Comparative trials involving the use of PSI which used plain radiographs to assess the mechanical axis and alignment of the components have produced variable results. 6-9 Three studies used CT scans to analyse the positioning of the components. Woolson et al 10 did not show any improvement of alignment in their underpowered study. The tibial slope in the PSI group had more outliers. An outlier is most often defined as deviation by > 3° from the planned alignment. Ng et al 11 showed more accurate tibial coronal and both femoral and tibial rotational alignment in their PSI group. Due to randomisation by the choice of the patient this study had a high risk of selection bias. Roh et al 12 showed no difference in accuracy or outliers between standard and PSI instrumentation. The loss to follow-up in the PSI group was > 15% and a per-protocol analysis was described. There was thus a high risk of attrition bias. Furthermore, their CT analysis program is primarily used in maxillofacial surgery and dentistry, and has not been validated for use in orthopaedic surgery. 12
Technical and surgical causes of outliers after computer navigated total knee arthroplasty
Journal of Orthopaedics, 2019
Background: Navigated total knee arthroplasty (TKA) improves implant and limb alignment but outliers continue to exist. This study aimed to determine the technical and surgical causes of outliers. Methods: This retrospective cohort study included 208 patients who had undergone navigated TKA. Limb and implant alignment indices were measured on post-operative CT scans: mechanical femoro-tibial angle (MFTA); coronal femoral angle (CFA); coronal tibial angle (CTA); sagittal femoral angle (SFA); and sagittal tibial angle (STA). Values outside 0°± 3°for MFTA and SFA, 90°± 3°for CFA, CTA and STA were considered outliers. Intraoperative navigation data and CT scans were evaluated to categorize the causes of sagittal and coronal plane outliers into hip centre error; ankle centre error; heterogeneous tibial cement mantle; malalignment accepted by surgeon; suboptimal knee balance; and no obvious explanation. Results: Of the 1040 measurements (five per TKA), the overall incidence of outliers was 10.4% (n = 108). Femoral component outliers (CFA + SFA, n = 51) were all attributable to hip centre error. Tibial component outliers (CTA + STA, n = 43) were attributable to ankle centre error (n = 6), heterogeneous cement mantle (n = 20), malalignment accepted by the surgeon (n = 6) and no obvious cause (n = 11). MFTA outliers were attributable to hip centre error (n = 4) or suboptimal knee balance (n = 10). Conclusions: Surgeon related errors can be minimized by a meticulous operative technique. These results indicate scope for additional technical improvement, especially in hip centre acquisition, which may further reduce the incidence of outliers.
Patient-Specific Instrumentation Does Not Improve Accuracy in Total Knee Arthroplasty
Orthopedics, 2015
Patient-specific instrumentation (PSI) has been introduced as a tool to increase the accuracy of total knee arthroplasty (TKA) compared with conventional instrumentation (CLI). However, previous studies have shown inconsistent results. The authors conducted a meta-analysis to compare the performance of PSI to CLI in TKA. PubMed, EMBASE, and Cochrane Central Register of Controlled Trials electronic databases were systematically searched to identify eligible trials published between 2000 and March 2014. Two reviewers independently assessed methodological quality according to the Cochrane Handbook. Subgroup analyses were performed based on the different study designs (randomized, controlled trial [RCT] vs nonrandomized, controlled trial [non-RCT]), preoperative magnetic resonance imaging vs computed tomography, and systems of PSI to explore the source of heterogeneity. Fourteen studies (7 RCTs and 7 non-RCTs) involving 1906 patients were included. There were no statistical differences with respect to the outliers of mechanical axis, coronal femoral component, sagittal femoral component, femoral component rotation, operative time, blood loss, and length of hospital stay between PSI and CLI groups. The number of outliers in coronal tibial components (odds ratio, 2.29; 95% confidence interval, 1.20 to 4.35; P=.01) and sagittal tibial components (odds ratio, 1.67; 95% confidence interval, 1.16 to 2.42; P<.01) was significantly lower in the CLI group than in the PSI group. Based on the numbers available, the use of PSI compared with CLI was not likely to improve the accuracy of component alignment and treatment effects of TKA. Further high-quality RCTs are warranted to confirm the authors' results. [Orthopedics. 2015; 38(3):e178-e188.]
BMC Musculoskeletal Disorders, 2013
Background: There are few Scandinavian studies on the effect of computer assisted orthopedic surgery (CAOS) in total knee arthroplasty (TKA), compared to conventional technique (CON), and there is little information on effects in pain and function scores. This retrospective study has evaluated the effects of CAOS on radiological parameters and pain, function and quality of life after primary TKA. Methods: 198 primary TKAs were operated by one surgeon in two district hospitals; 103 CAOS and 95 CON. The groups were evaluated based on 3 months post-operative radiographs and a questionnaire containing the knee osteoarthritis outcome score (KOOS), the EQ-5D index score and a visual analogue scale (VAS) two years after surgery. Multiple linear regression method was used to investigate possible impact from exposure (CON or CAOS). Results: On hip-knee-ankle radiographs, 20% of measurements were > ±3°of neutral in the CAOS group and 25% in the CON group (p = 0.37). For the femoral component, the number was 5% for CAOS and 18% for CON (p < 0.01). For the tibial component, the difference was not statistically significant (p = 0.58). In the sagittal plane, the surgeon tended to apply more femoral flexion and more posterior tibial slope with CAOS. We observed no statistically or clinically significant difference in KOOS score, VAS or ΔEQ-5D (all p values >0.05), but there was a trend towards better scores for CAOS. Operation time was 3 minutes longer for CON (p = 0.37). Conclusions: CAOS can improve radiological measurements in primary TKA, and makes it possible to adjust component placement to the patient's anatomy. Overall , the two methods are equal in pain, function and quality-of-life scores.
Bone Joint J, 2016
AIMS: We conducted a randomised controlled trial to assess the accuracy of positioning and alignment of the components in total knee arthroplasty (TKA), comparing those undertaken using standard intramedullary cutting jigs and those with patient-specific instruments (PSI). PATIENTS AND METHODS: There were 64 TKAs in the standard group and 69 in the PSI group. The post-operative hip-knee-ankle (HKA) angle and positioning was investigated using CT scans. Deviation of > 3° from the planned position was regarded as an outlier. The operating time, Oxford Knee Scores (OKS) and Short Form-12 (SF-12) scores were recorded. RESULTS: There were 14 HKA-angle outliers (22%) in the standard group and nine (13%) in the PSI group (p = 0.251). The mean HKA-angle was 0.5° varus in the standard group and 0.2° varus in the PSI group (p = 0.492). The accuracy of alignment in the coronal and axial planes and the proportion of outliers was not different in the two groups. The femoral component was more flexed (p = 0.035) and there were significantly more tibial slope outliers (29% versus 13%) in the PSI group (p = 0.032). Operating time and the median three-month OKS were similar (p = 0.218 and p = 0.472, respectively). Physical and mental SF-12 scores were not significantly different at three months (p = 0.418 and p = 0.267, respectively) or at one year post-operatively (p = 0.114 and p = 0.569). The median one-year Oxford knee score was two points higher in the PSI group (p = 0.049). CONCLUSION: Compared with standard intramedullary jigs, the use of PSI did not significantly reduce the number of outliers or the mean operating time, nor did it clinically improve the accuracy of alignment or the median Oxford Knee Scores. Our data do not support the routine use of PSI when undertaking TKA.
Knee Surgery, Sports Traumatology, Arthroscopy, 2014
two groups. Mean HKA-deviation from the targeted neutral mechanical axis (CVI: 2.2° ± 1.7°; PSI: 1.5° ± 1.4°; p < 0.001), rates of outliers (CVI: 22.2 %; PSI: 9.6 %; p = 0.016), and 3D-component positioning outliers were significantly lower in the PSI group. Non-outliers (HKA: 180° ± 3°) showed better clinical results than outliers at the 2-year follow-up. Conclusions CT-based PSI compared with CVI improves accuracy of mechanical alignment restoration and 3D-component positioning in primary TKA. While clinical outcome was comparable between the two instrumentation groups at early follow-up, significantly inferior outcome was detected in the subgroup of HKA-outliers. Level of evidence Prospective comparative study, Level II. Keywords Patient-specific instrumentation • Total knee arthroplasty • MyKnee • CT-based cutting block • Clinical and radiological outcome • 3D-component positioning ene wear with decreased overall implant survival [17, 49]. Mechanical malalignment and component malpositioning have also been identified as influencing factors for unsatisfactory clinical outcome [3, 34]. Although the impact of neutral mechanical alignment on implant longevity is still a
A Comparative Study Between Patient-Specific Instrumentation and Conventional Technique in TKA
Orthopedics, 2016
T otal knee arthroplasty (TKA) is one of the most frequently performed surgeries in the field of orthopedics, due to the extension of the average life span. Total knee arthroplasty has a high success rate in relieving pain and improving knee function. 1 Important factors for successful TKA are proper patient selection, surgical technique, instrumentation and rehabilitation. Among these various factors, the surgical technique, and in particular an ideal underlying arrangement owing to accurate bone resection, is the most important factor. Improper alignment and imbalance can lead to increased and early polyethylene wear, early loosening, and decreased survival of implants. 2-4 Better resection methods to meet the anatomical characteristics of the patients were proposed, but it is a fact that it is difficult to standardize such methods for all patients. Computer-assisted TKA has been developed to achieve more precise and accurate postoperative alignment, but this technique involves time-consuming registration, increased surgical time, risk for pin site infection, and fracture. 1
Acta Orthop, 2016
Background and purpose — Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) has been introduced to improve alignment and reduce outliers, increase efficiency, and reduce operation time. In order to improve our understanding of the outcomes of patient-specific instrumentation, we conducted a meta-analysis. Patients and methods — We identified randomized and quasi-randomized controlled trials (RCTs) comparing patient-specific and conventional instrumentation in TKA. Weighted mean differences and risk ratios were determined for radiographic accuracy, operation time, hospital stay, blood loss, number of surgical trays required, and patient-reported outcome measures. Results — 21 RCTs involving 1,587 TKAs were included. Patient-specific instrumentation resulted in slightly more accurate hip-knee-ankle axis (0.3°), coronal femoral alignment (0.3°, femoral flexion (0.9°), tibial slope (0.7°), and femoral component rotation (0.5°). The risk ratio of a coronal plane outlier (> 3° deviation of chosen target) for the tibial component was statistically significantly increased in the PSI group (RR = 1.64). No significance was found for other radiographic measures. Operation time, blood loss, and transfusion rate were similar. Hospital stay was significantly shortened, by approximately 8 h, and the number of surgical trays used decreased by 4 in the PSI group. Knee Society scores and Oxford knee scores were similar. Interpretation — Patient-specific instrumentation does not result in clinically meaningful improvement in alignment, fewer outliers, or better early patient-reported outcome measures. Efficiency is improved by reducing the number of trays used, but PSI does not reduce operation time.