Navigation In Total Knee Arthroplasty Research Articles

Alineación frontal en la artroplastia total de rodilla. Estudio comparativo entre medición radiográfica y con navegación quirúrgica

ObjectiveTo establish the concordance between angulation of the femoro-tibial mechanical axis measured with x-rays and surgical navigation in both the pre and postoperative period after a total knee arthroplasty (TKA) was implanted. Material and methodPre and postoperative measurements were analyzed in 88 TKA of the same model and all performed with the same surgical navigation system. The mechanical frontal angle (MFA) and femoro-tibial anatomic angle were measured before and after the TKA. The angulation was digitally measured with a teleradiography. In the navigation, the femoro-tibial angle at rest, forced varus and valgus were registered and the average of these three measurements was calculated. ResultsThe mean preoperative MFA measured on the radiograph was 4.55°. The mean of the same angle measured on the postoperative radiograph was 1.72°, (p=0.05). The mean of the MFA measured with navigation before TKA was 3.12° and after the implant with navigation was 0.53 (P=.013). The concordance coefficient between the MFA in teleradiography and in navigation was 0.869 (P<.001) preoperatively and 0.709 postoperatively (P=.017). ConclusionsWe found a strong concordance between radiographic and surgical navigation measurements of the MFA. This may imply that teleradiography is not necessary when using surgical navigation in TKA.

Navigation in Total Knee Arthroplasty: A Procedure Whose Time Has Not Come: Commentary on an article by Young-Hoo Kim, MD, et al.: "The Clinical Outcome of Computer-Navigated Compared with Conventional Knee Arthroplasty in the Same Patients. A Prospective, Randomized, Double-Blind, Long-Term Study".

Navigation in Total Knee Arthroplasty: A Procedure Whose Time Has Not Come: Commentary on an article by Young-Hoo Kim, MD, et al.: "The Clinical Outcome of Computer-Navigated Compared with Conventional Knee Arthroplasty in the Same Patients. A Prospective, Randomized, Double-Blind, Long-Term Study".

Incurvation frontale des os longs du membre inférieur : son influence sur l’axe frontal et le positionnement des implants dans les arthroplasties du genou sans navigation et ancillaire conventionnel

BackgroundCoronal alignment is an important factor for the function and longevity of total knee arthroplasty (TKA). Coronal bowing of the lower extremity is common among Asians and it may pose a risk for malalignment of the lower leg and malposition of component. HypothesisWe hypothesized that coronal bowing itself has a risk for malalignment of the lower leg and malposition of femoral/tibial components and that navigation TKA is beneficial for patients with coronal bowing. We investigated the incidence of femoral/tibial bowing in patients treated with TKA and compared the radiographic parameters between the navigation group and the conventional group. Additionally, the influence of coronal bowing on these radiographic parameters was investigated. Materials and methodsWe enrolled 35 patients with knee osteoarthritis and 70 bilateral simultaneous TKAs. The patients underwent TKA with the use of a computer tomography-free navigation in one knee and conventional TKA in the contralateral knee. Preoperative coronal bowing were measured, and the subjects were divided into 2 subgroups, i.e. the bowing group and the non-bowing group. Lateral bowing was expressed as plus (+) and medial bowing was expressed as minus (–). Various radiographic parameters, including coronal bowing, lower leg alignment, component position, and outliers were compared between the navigation group and the conventional group. ResultsFemoral bowing varied from –7.4° to 10.9° with an average of 3.0°. Tibial bowing varied from –4.1° to 4.6° with an average of 0.4°. The femoral component was placed more properly in the navigation group. Number of outlier regarding to the coronal femoral component angle to the femoral mechanical axis was 14 cases (37.8 %) in the bowing group and 6 cases (18.2 %) in the non-bowing group (P=0.04). DiscussionIn conclusion, coronal femoral bowing has an important effect on femoral bone cut in TKA. The navigated TKA was more consistent than conventional TKA in aiding proper alignments of femoral component. Level of evidenceLevel II, comparative prospective study.

Gyroscope Based Two Pod Pinless Navigation in Total Knee Arthroplasty

Gyroscope Based Two Pod Pinless Navigation in Total Knee Arthroplasty

Robotics and navigation in total knee arthroplasty

Robotics and navigation in total knee arthroplasty

Total knee arthroplasty with computer-assisted navigation more closely replicates normal knee biomechanics than conventional surgery

BackgroundComputer-assisted navigation in total knee arthroplasty (TKA) reduces variability and may improve accuracy in the postoperative static alignment. The effect of navigation on alignment and biomechanics during more dynamic movements has not been investigated. MethodsThis study compared knee biomechanics during level walking of 121 participants: 39 with conventional TKA, 42 with computer-assisted navigation TKA and 40 unimpaired control participants. ResultsStanding lower-limb alignment was significantly closer to ideal in participants with navigation TKA. During gait, when differences in walking speed were accounted for, participants with conventional TKA had less knee flexion during stance and swing than controls (P<0.01), but there were no differences between participants with navigation TKA and controls for the same variables. Both groups of participants with TKA had lower knee adduction moments than controls (P<0.01). ConclusionsIn summary, there were fewer differences in the biomechanics of computer-assisted navigation TKA patients compared to controls than for patients with conventional TKA. Computer-assisted navigation TKA may restore biomechanics during walking that are closer to normal than conventional TKA.

Comparison of patient-specific instruments with the computer-assisted navigation in total knee arthroplasty for osteoarthritis in a patient with femoral fracture malunion

Extra-articular femoral deformity in total knee arthroplasty (TKA) is a challenge the surgeon must face when using the conventional cutting devices to perform distal femoral intra-articular resection. A variety of new instruments have sprung up to overcome this problem, including patient-specific instruments (PSI) and computer-assisted navigation (CAN). We compared these two instruments in guiding the coronal resection in TKA for osteoarthritis in a 58-year-old woman with a femoral fracture malunion. The patient demonstrated a satisfactory functional outcome and neutral lower limb alignment. Both of PSI and CAN are promising alternatives to conventional devices in the present of extra-articular deformity. The preoperative preparation of PSI is time-consuming but the resection procedure is simple. CAN has the contrary characteristics and it is more reliable than the PSI.

Computer Navigated Total Knee Arthroplasty: Rates of Adoption and Early Complications

BackgroundWhen new technologies are introduced, it is important to evaluate the rate of adoption and outcomes compared with preexisting technology. The purpose of this study was to determine the adoption rate of computer-assisted navigation in total knee arthroplasty (TKA), to determine if the short-term complication rate changed over time with navigation, and to compare short-term complication rates of navigated and traditional TKA. MethodsThe American College of Surgeons National Surgical Quality Improvement Program database was used to identify 108,277 patients undergoing primary TKA between 2010 and 2014, of which 3573 cases (3.30%) were navigated. Rates of adoption of navigated TKA were determined. Differences in short-term complications by year were compared using propensity score matching. ResultsNavigation utilization decreased from 4.96% in 2010 to 3.06% in 2014. Blood transfusion rates for the entire cohort decreased from 19% in 2011 to 6% in 2014, and was not decreased with navigation compared with traditional TKA in 2014 (P = .1309). Operative time was not increased by navigation, and average 94.2 minutes. There were no significant differences in all-cause complications, reoperation rate, unplanned readmission, or length of stay for any year. ConclusionsThere was a 38.3% decrease in TKA navigation utilization from 2010-2014. Blood transfusion rates decreased 68% over the 5-year study, and were not decreased with navigation in 2014. Navigation was not found to increase operative time. There were no significant differences in short-term complications, readmission rate, or length of stay between navigated and traditional TKA.

Influence of coronal bowing on the lower alignment and the positioning of component in navigation and conventional total knee arthroplasty

BackgroundCoronal alignment is an important factor for the function and longevity of total knee arthroplasty (TKA). Coronal bowing of the lower extremity is common among Asians and it may pose a risk for malalignment of the lower leg and malposition of component. HypothesisWe hypothesized that coronal bowing itself has a risk for malalignment of the lower leg and malposition of femoral/tibial components and that navigation TKA is beneficial for patients with coronal bowing. We investigated the incidence of femoral/tibial bowing in patients treated with TKA and compared the radiographic parameters between the navigation group and the conventional group. Additionally, the influence of coronal bowing on these radiographic parameters was investigated. Materials and methodsWe enrolled 35 patients with knee osteoarthritis and 70 bilateral simultaneous TKAs. The patients underwent TKA with the use of a computer tomography-free navigation in one knee and conventional TKA in the contralateral knee. Preoperative coronal bowing were measured, and the subjects were divided into 2 subgroups, i.e. the bowing group and the non-bowing group. Lateral bowing was expressed as plus (+) and medial bowing was expressed as minus (−). Various radiographic parameters, including coronal bowing, lower leg alignment, component position, and outliers were compared between the navigation group and the conventional group. ResultsFemoral bowing varied from −7.4° to 10.9° with an average of 3.0°. Tibial bowing varied from −4.1° to 4.6° with an average of 0.4°. The femoral component was placed more properly in the navigation group. Number of outlier regarding to the coronal femoral component angle to the femoral mechanical axis was 14 cases (37.8%) in the bowing group and 6 cases (18.2%) in the non-bowing group (P=0.04). DiscussionIn conclusion, coronal femoral bowing has an important effect on femoral bone cut in TKA. The navigated TKA was more consistent than conventional TKA in aiding proper alignments of femoral component. Level of evidenceLevel II, comparative prospective study.

Software and instrument improvements reduced significantly navigation acquisition time in computer assisted TKA: A cadaveric study

Purpose: Computer navigation in total knee arthroplasty (TKA) has proven to significantly reduce the number of outliers in prosthesis positioning and to improve mechanical leg alignment. Despite th...

Similar migration in computer-assisted and conventional total knee arthroplasty

Background and purpose — Computer-assisted surgery (CAS) in total knee arthroplasty (TKA) has been used in recent years in the hope of improving the alignment and positioning of the implant, thereby achieving a better functional outcome and durability. However, the role of computer navigation in TKA is still under debate. We used radiostereometric analysis (RSA) in a randomized controlled trial (RCT) to determine whether there are any differences in migration of the tibial component between CAS- and conventionally (CONV-) operated TKA.Patients and methods — 54 patients (CAS, n = 26; CONV, n = 28) with a mean age of 67 (56–78) years and with osteoarthritis or arthritic disease of the knee were recruited from 4 hospitals during the period 2009–2011. To estimate the mechanical stability of the tibial component, the patients were examined with RSA up to 24 months after operation. The following parameters representing tibial component micromotion were measured: 3-D vector of the prosthetic marker that moved the most, representing the magnitude of migration (maximum total point motion, MTPM); the largest negative value for y-translation (subsidence); the largest positive y-translation (lift-off); and prosthetic rotations. The precision of the RSA measurements was evaluated and migration in the 2 groups was compared.Results — Both groups had most migration within the first 3 months, but there was no statistically significant difference in the magnitude of the migration between the CAS group and the CONV group. From 3 to 24 months, the MTPM (in mm) was 0.058 and 0.103 (p = 0.1) for the CAS and CON groups, respectively, and the subsidence (in mm) was 0.005 and 0.011 (p = 0.3).Interpretation — Mean MTPM, subsidence, lift-off, and rotational movement of tibial trays were similar in CAS- and CONV-operated knees.

Variation in Optimal Sagittal Alignment of the Femoral Component in Total Knee Arthroplasty.

Accurate sagittal alignment of the femoral component in total knee arthroplasty is crucial for prosthesis longevity, improved function, and patient satisfaction. However, there is variation in the techniques used to attain optimal sagittal femoral component placement in total knee arthroplasty. Femoral component flexion in imageless navigation is based on the mechanical axis rather than the distal femoral anatomy, and there is significant variability in the anatomy of the distal femur. The purpose of this study was to accurately determine the mean distal femoral flexion angle of a representative population and whether variability of the distal femoral flexion angle correlates with race, femur length, or radius of curvature. The mean degree of distal femoral flexion was determined by assessing distal femoral anatomy on computed tomography scans of paired femurs of 1235 patients without evidence of previous fracture, deformity, or surgical implants. The mean±SD distal femoral flexion angle was 2.90°±1.52°, with 80.2% of knees within 3°±2°. Therefore, placing the component in 3° of flexion from the mechanical axis would attain a satisfactory position in most cases. However, further analysis of the patient data revealed 11.4% of Asians, 7.3% of African Americans, and 8.3% of whites had a distal femoral flexion angle greater than 5°. Additionally, the data revealed a moderately strong negative correlation between the distal femoral flexion and the overall radius of curvature of the femur. This preliminary study highlights the need for improved methods for selecting femoral component position in the sagittal plane when using navigation for total knee arthroplasty. [Orthopedics. 2017; 40(2):102-106.].

Conventional versus computer-navigated TKA: a prospective randomized study.

The purpose of this study was to assess the midterm results of total knee arthroplasty (TKA) implanted with a specific computer navigation system in a group of patients (NAV) and to assess the same prosthesis implanted with the conventional technique in another group (CON); we hypothesized that computer navigation surgery would improve implant alignment, functional scores and survival of the implant compared to the conventional technique. From 2008 to 2009, 225 patients were enrolled in the study and randomly assigned in CON and NAV groups; 240 consecutive mobile-bearing ultra-congruent score (Amplitude, Valence, France) TKAs were performed by a single surgeon, 117 using the conventional method and 123 using the computer-navigated approach. Clinical outcome assessment was based on the Knee Society Score (KSS), the Hospital for Special Surgery Knee Score and the Western Ontario Mac Master University Index score. Component survival was calculated by Kaplan-Meier analysis. Median follow-up was 6.4years (range 6-7years). Two patients were lost to follow-up. No differences were seen between the two groups in age, sex, BMI and side of implantation. Three patients of CON group referred feelings of instability during walking, but clinical tests were all negative. NAV group showed statistical significant better KSS Score and wider ROM and fewer outliers from neutral mechanical axis, lateral distal femoral angle, medial proximal tibial angle and tibial slope in post-operative radiographic assessment. There was one case of early post-operative superficial infection (caused by Staph. Aureus) successfully treated with antibiotics. No mechanical loosening, mobile-bearing dislocation or patellofemoral complication was seen. At 7years of follow-up, component survival in relation to the risk of aseptic loosening or other complications was 100%. There were no implant revisions. This study demonstrates superior accuracy in implant positioning and statistical significant better functional outcomes of computer-navigated TKA. Computer navigation for TKAs should be used routinely in primary implants. II.

Navigated vs Conventional Total Knee Arthroplasty: Is There a Difference in the Rate of Respiratory Complications and Transfusions?

BackgroundProponents of navigation in total knee arthroplasty (TKA) report lower rates of systemic embolization and perioperative bleeding compared to conventional TKA given that breeching the intramedullary canal is not required. MethodsWe queried the National Surgical Quality Improvement Program to compare perioperative respiratory complications and transfusions between navigated and conventional TKA. We identified 2008 patients who underwent navigated TKA. These patients were matched 4:1 to a control group of 8026 patients. ResultsConventional TKA resulted in similar odds of having a respiratory complication compared to navigated TKA (odds ratio = 1.35, P = .44). However, conventional TKA was found to be an independent predictor for requiring a transfusion perioperatively (odds ratio = 1.90, P < .001). ConclusionUse of navigation in TKA results in less perioperative transfusions but has no influence on the rate of respiratory complications.

Radiographic outcomes in the coronal plane with iASSIST™ versus optical navigation for total knee arthroplasty: A preliminary case-control study

BackgroundThe new navigation system iASSIST™ for total knee arthroplasty (TKA) relies on accelerometers and gyroscopes. The objective of this prospective study was to compare the accuracy of iASSIST™ to that of the conventional optical navigation system Navitrack™ by determining the rate of mechanical axis restoration (±3°), postoperative mean mechanical alignment, rate of adequate femoral and tibial component positioning, mean operative time, and occurrence of navigation-related adverse events. HypothesisThe rate of mechanical axis restoration (±3°) is not lower with iASSIST™ than with the conventional navigation system Navitrack™. Material and methodsOf 40 patients who underwent primary TKA between October 2013 and March 2014, 20 had navigation using iASSIST™ and 20 using Navitrack™. Six months after TKA, an independent observer measured three parameters on coronal radiographs: the hip-knee-ankle angle (HKA), the mechanical lateral distal femoral angle (mLDFA), and the mechanical medial proximal tibial angle (mMPTA). ResultsThe two groups showed no significant differences for the rates of HKA restoration (P=0.3), adequate coronal positioning of the femoral component (P=0.12) and tibial component (P=0.12), or optimal success (P=0.09). Significant differences in favour of iASSIST™ were demonstrated for the values and angular deviations of the HKA (P=0.02) and mMPTA (P=0.01), whereas no significant difference was found for mLDFA. There were no significant differences regarding the mean operative time (P=0.06) or the occurrence of navigation-related adverse events (P=0.18). DiscussionThe iASSIST™ system provides a neutral mechanical axis and optimal component position in the coronal plane in 95% of cases, indicating that it is as accurate as the optical navigation system Navitrack™. Level of evidenceIII, prospective case-control study.

Computer navigation is effective in reducing blood loss but has no effect on transfusion requirement following primary total knee arthroplasty: a meta-analysis.

This meta-analysis was designed to evaluate the effects of computer navigation on blood conservation after total knee arthroplasty (TKA) by comparing postoperative blood loss and need for allogenic blood transfusion in patients undergoing computer navigation and conventional primary TKAs. Studies were included in this meta-analysis if they compared change in haemoglobin concentration before and after surgery, postoperative blood loss via drainage or calculated total blood loss, and/or allogenic blood transfusion rate following TKA using computer navigation and conventional methods. For all comparisons, odds ratios and 95% confidence intervals (CI) were calculated for binary outcomes, while mean difference and 95% CI were calculated for continuous outcomes. Twelve studies were included in this meta-analysis. The change in haemoglobin concentration was 0.39g/dl lower with computer navigation than with conventional TKA (P=0.006). Blood loss via drainage was 83.1ml (P=0.03) lower and calculated blood loss was 185.4ml (P=0.002) lower with computer navigation than with conventional TKA. However, the need for blood transfusion was similar for the two approaches (n.s.). The primary TKA with computer navigation was effective in reducing haemoglobin loss and blood loss, but had no effect on transfusion requirement, compared with conventional primary TKA. These findings suggest the importance of analysing several blood loss parameters, because each may not always accurately reflect true postsurgical bleeding. Meta-analysis, Level III.

Kinematically aligned TKA can align knee joint line to horizontal

The joint line of the native knee is horizontal to the floor and perpendicular to the vertical weight-bearing axis of the patient in a bipedal stance. The purposes of this study were as follows: (1) to find out the distribution of the native joint line in a population of normal patients with normal knees; (2) to compare the native joint line orientation between patients receiving conventional mechanically aligned total knee arthroplasty (TKA), navigated mechanically aligned TKA, and kinematically aligned TKA; and (3) to determine which of the three TKA methods aligns the postoperative knee joint perpendicular to the weight-bearing axis of the limb in bipedal stance. To determine the joint line orientation of a native knee, 50 full-length standing hip-to-ankle digital radiographs were obtained in 50 young, healthy individuals. The angle between knee joint line and the line parallel to the floor was measured and defined as joint line orientation angle (JLOA). JLOA was also measured prior to and after conventional mechanically aligned TKA (65 knees), mechanically aligned TKA using imageless navigation (65 knees), and kinematically aligned TKA (65 knees). The proportion of the knees similar to the native joint line was calculated for each group. The mean JLOA in healthy individuals was parallel to the floor (0.2°±1.1°). The pre-operative JLOA of all treatment groups slanted down to the lateral side. Postoperative JLOA slanted down to the lateral side in conventional mechanically aligned TKA (-3.3°±2.2°) and in navigation mechanically aligned TKA (-2.6°±1.8°), while it was horizontal to the floor in kinematically aligned TKA (0.6°±1.7°). Only 6.9% of the conventional mechanically aligned TKA and 16.9% of the navigation mechanically aligned TKA were within one SD of the mean JLOA of the native knee, while the proportion was significantly higher (50.8%) in kinematically aligned TKA. The portion was statistically greater in mechanically aligned TKA group than the other two. Postoperative joint line orientation after kinematically aligned TKA was more similar to that of native knees than that of mechanically aligned TKA and horizontal to the floor. Kinematically aligned TKA can restore pre-arthritic knee joint line orientation, while mechanically aligned TKA is inefficient in achieving the purpose even if navigation TKA is employed. III.

Comparative study between the pinless navigation and the articular surface mounted (ASM) navigation in total knee arthroplasty: Radiographic results and early clinical outcomes

Introduction: There were reports showed pinless navigation and articular surface mounted navigation in total knee arthroplasty (TKA) produces better results in term of radiographic outcomes when compared to conventional techniques. However, there was no comparative study between these two systems. Objective: To compare the radiographic results and early clinical outcomes between two systems. Methods: We collect data from all patients underwent TKA using either system from 1 January 2014 to 30 September 2014. We excluded the patient whom underwent navigation on tibia or femur only; the patients with pre-op deviation of mechanical axis more than 15 degrees, and the patients with extra-articular deformity. Radiographic outcomes included pre and post-operative alignment, and post-operative prosthesis alignment in coronal and sagittal plane. Clinical outcomes included demographic data, knee score and functional score, tourniquet time, blood loss, and complications. Results: 83 patients were included (43 pinless group, 40 ASM group). There was no statistical significant difference in the mean of age, BMI, pre-operative deformity, and pre-operative knee score, functional score, blood loss, and post-operative knee score and functional score. However in term of radiographic results, the mean post-operative correction of mechanical axis of pinless navigation was varus 1.1+/-2.16 degree while mean of ASM navigation was varus 0.01+/-1.88 degree. The difference was statistically significant with p-value less than 0.05. Percentage of radiographic outlier of pinless group was 13.95% while ASM group was 2.5%. Conclusion: The ASM navigation showed better result in term of post-operative correction of mechanical axis, which due to the ability to verify bone resection after the bone was resected. This feature could be beneficial in future development of this simple CAS system.

Does Computer Assisted Navigation Improve Functional Outcomes and Implant Survivability after Total Knee Arthroplasty?

The objective of this study was to determine whether computer assisted navigation in total knee arthroplasty (TKA) improves functional outcomes and implant survivability using data from a large national database. We analysed 9054 primary TKA procedures performed between 2006 and 2012 from the New Zealand National Joint Registry. Functional outcomes were assessed using Oxford Knee Questionnaires at six months and five years. On multivariate analysis, there was no significant difference in mean Oxford Knee Scores between the navigated and non-navigated groups at six months (39.0 vs 38.1, P=0.54) or five years (42.2 vs 42.0, P=0.76). At current follow-up, there was no difference in revision rates between navigated and non-navigated TKA (0.46 vs 0.43 revisions 100 component years, P=0.8).

Manual Navigation in Total Knee Arthroplasty

Manual Navigation in Total Knee Arthroplasty