Retaining Total Knee Arthroplasty Research Articles

Better Flexion but Unaffected Satisfaction After Treatment With Posterior Stabilized Versus Cruciate Retaining Total Knee Arthroplasty – 2-year Results of a Prospective, Randomized Trial

BackgroundBoth the cruciate-retaining (CR) and posterior-stabilized (PS) implant systems are commonplace in modern total knee arthroplasty (TKA) practice. However, there is controversy regarding functional outcomes and survivorship. The aim of the underlying study was to evaluate differences between CR and PS TKA regarding knee function, patient-reported outcome measures (PROMs) as well as complication rates. Methods140 patients with knee osteoarthritis scheduled for an unconstrained TKA were enrolled in a prospective, randomized study. Patients received either a CR or PS implant. Range of motion and PROMs (Oxford Knee Score, Knee Society Score, European Quality of Life 5 Dimensions 3 Level, University of California Los Angeles Activity scale and subjective satisfaction) were assessed prior to, 3 months, 1 and 2 years after surgery. ResultsWe found minor differences between treatment groups regarding demographic factors. Within the PS group duration of surgery was longer (mean PS 81.4 min vs CR 76.0 min, P = .006). We observed better flexion (median PS 120.0° vs CR 115°, P = .017) and an overall better range of motion (median PS 120.0° vs CR 115.0°, P = .008) for the PS group. PROMs did not differ between groups. At 2-year follow-up there were no revisions in either cohort. Five patients needed reoperations. Three patients needed manipulation under anesthesia, 2 in the CR and one in the PS group. ConclusionWhile PS TKA achieved a better flexion capability, PROMs were similar in CR and PS TKA. The CR implant design continues to be a reliable option for patients with an intact posterior cruciate ligament.

Equal bony resection of distal and posterior femur will lead to flexion/extension gap inequality in robot-assisted cruciate-retaining TKA.

Joint imbalance has become one of the main reasons for early revision after total knee arthroplasty (TKA) and it is directly related to the surgical technique. Therefore, a better understanding of how much bone has to be removed to obtain a balanced flexion/extension gap could improve current practice. The primary objective of this study was to analyse the amount of bone that needed to be removed from the distal and posterior femoral joint surfaces to obtain an equal flexion/extension gap in robot-assisted TKA. The second objective of this study was to evaluate whether the size of the knee joint influenced the amount of bony resection needed to achieve an equal flexion/extension gap in robot-assisted TKA. A retrospective analysis was performed on all patients receiving a robot-assisted TKA (Cruciate Retaining (n = 268)) by six surgeons from April 2018 to September 2019. The robot was used consecutively when available in all patients receiving Cruciate Retaining TKA. Gap assessment, bony resections, femoral implant size and hip-knee-ankle angle were evaluated with the robot. Femoral implant size was categorized into small (size 1-2), medium (size 3-5) and large (size 6-8). The difference between the posterior and distal resection needed to obtain equal flexion and extension gap was on average 2.0mm (SD 1.6) and 1.5mm (SD 2.2) for the medial and lateral compartment, respectively. The discrepancy was smaller in the large implant group compared to the small implant group (p < .05 medial and lateral) and medium implant group (p < .05 medial). Varus knees required a larger differential resection compared to neutral and valgus knees (only laterally) (medial compartment: p < .05 (varus-neutral), p = .051 (varus-valgus); lateral compartment: p < .05 (varus-neutral and varus-valgus). Removing an equal amount of bone from the distal and posterior femur will lead to flexion/extension gap imbalance in TKA. It was required to remove 1.5-2mm more bone from the posterior femur compared to the distal femur to equalize flexion and extension gap. This effect was size dependent: in larger knees, the discrepancy between the distal and posterior resections was smaller. IV.

A short-term radiological and clinical comparison between the bi-cruciate and cruciate retaining total knee arthroplasty A retrospective case controlled study

PurposeThe aim of this study was to provide a short term comparison in radiological and clinical outcome between Bi-Cruciate Retaining (BCR)- and Cruciate Retaining (CR) Total Knee Arthroplasty (TKA). MethodsThe cohort consists of 122 patients undergoing a TKA with PSI, equally distributed over the BCR- and CR-TKA group. Perioperative conditions were observed and radiological images were analysed pre-, 6-weeks, and 1-year postoperative to quantify alignment differences between BCR- and CR-TKA. Preoperatively predicted templates were compared with the implanted size to determine predictive value. In addition mean range of motion and revision rates were determined in both groups. ResultsNo significant difference was observed in amount of outliers in component alignment between BCR- and CR-TKA. Outliers of the Hip-Knee-Ankle-Axis (HKA-axis) occurred significantly more frequent (P = 0.009) in the BCR-group (37.7%) compared to CR-TKA (18.0%). No clinically relevant differences regarding the predictive sizing of implant components was obtained. No significant differences were observed in revision rates (P = 1.000) and ROM (p = 0.425) between the BCR-groep and CR-group at 2-years FU. ConclusionThis study illustrates that although the HKA-axis was not fully restored, bi-cruciate retaining surgical technique for BCR-TKA is safe and effective with comparable radiological and clinical outcome as CR TKA. Randomized controlled trials with longer follow up on the HKA-axis alignment and clinical parameters are needed to confirm the presented results and should focus on possible cut off values concerning leg axis in order to define in what patients a BCR-TKA can safely be used. Level of evidence IVRetrospective Case Controlled Study.

The Effect of Joint Line Elevation on In Vivo Knee Kinematics in Bicruciate Retaining Total Knee Arthroplasty.

Prior studies have reported a negative effect on both clinical outcomes and patient-reported outcome measures (PROMS) following joint line elevation (JLE) in cruciate-retaining (CR) total knee arthroplasty (TKA) and posterior stabilized (PS) TKA designs. This experimental study was aimed to quantify the effect of JLE on in vivo knee kinematics in patients with bicruciate retaining (BCR) TKA during strenuous activities. Thirty unilateral BCR TKA patients were evaluated during single-leg deep lunge and sit-to-stand using a validated combined computer tomography and dual fluoroscopic imaging system. Correlation analysis was performed to quantify any correlations between JLE and in vivo kinematics, as well as PROMS. There was a significant negative correlation between JLE and maximum flexion angle during single-leg deep lunge (ρ = -0.34, p = 0.02), maximum varus joint angles during single-leg deep lunge (ρ = -0.37, p = 0.04), and sit-to-stand (ρ = -0.29, p = 0.05). There was a significant negative correlation between JLE and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score (ρ = -0.39, p = 0.01) and knee disability and osteoarthritis outcome score physical function (KOOS-PS; ρ = -0.33, p = 0.03). The JLE that yields a significant loss in PROMS and maximum flexion angles were 2.6 and 2.3 mm, respectively. There was a linear negative correlation of JLE with both in vivo knee kinematics and PROMS, with changes in JLE of greater than 2.6 and 2.3 mm, leading to a clinically significant loss in PROMS and maximum flexion angles, respectively, suggesting an increased need to improve surgical precision to optimize patient outcomes following BCR TKA.

Bicruciate Retaining Total Knee Arthroplasty: Short-Term Clinical Outcomes Using a Novel Prosthesis.

There is renewed interest in bicruciate retaining (BCR) total knee arthroplasty (TKA), which preserves anatomy and more closely replicates native kinematics, theoretically allowing for improved functional results when compared to posterior stabilized (PS) TKA or cruciate retaining (CR) TKA. The purpose of this study is to report early clinical and radiographic results for a novel BCR TKA design.

Higher Component Malposition Rates with Patient-Specific Cruciate Retaining TKA than Contemporary Posterior Stabilized TKA

Customized individually manufactured total knee arthroplasty (CIM-TKA) was developed to improve kinematic total knee arthroplasty (TKA) performance. Component placement accuracy may influence the success of CIM-TKA designs. We performed this study to compare radiographic component alignment and revision rates of a cruciate retaining (CR) CIM-TKA and a contemporary posterior stabilized TKA (PS-TKA). After obtaining Institutional Review Board approval, we identified 94 CR CIM-TKAs (76 patients) and 91 PS-TKAs (82 patients) performed between July 1, 2013 and December 31, 2014 with a minimum 2-year follow-up (mean 41.1 months, range 24-59 months). We performed a retrospective electronic medical record review to identify patient demographic characteristics and revision procedures performed. Postoperative plain radiographs were reviewed to assess component alignment including cruciate ligament imbalance, femoral overhang, and femoral notching. Demographic characteristics, component malalignment, and revision surgery rates were assessed using a student's t-test or two-tailed Fisher's exact test, with a p-value < 0.05 designating significance. Technical errors were more commonly identified with CR CIM-TKA (29.8 vs. 9.9%, p < 0.001), including higher rates of tibiofemoral instability (13.8 vs. 1.1%, p < 0.01), femoral notching (12.8 vs. 3.3%, p = 0.03), and patellofemoral malalignment (20.2 vs. 7.7%, p = 0.02). CR CIM-TKA had more frequent coronal plane malposition (26.6 vs. 9.9%, p < 0.01) or sagittal plane reconstruction > 3 degrees outside of an optimized range (20.2 vs. 9.9%, p = 0.06). Aseptic revisions occurred more frequently with the CR CIM-TKA design (9.6 vs. 3.3%, p = 0.13). Demographic characteristics were not significantly different between the treatment groups. CR CIM-TKA may improve kinematic performance for patients undergoing knee replacement surgery. However, our study observations suggest that careful attention to surgical technique is important for optimizing implant survivorship with the CR CIM-TKA design. Additional study is needed to determine whether higher revision rates identified during this study are related to patient selection, surgical technique, or implant design.

Clinical outcome, functional outcome and patient satisfaction after cruciate retaining total knee arthroplasty for stiff arthritic knee - A short term outcome study

BackgroundVarious authors have shown that Cruciate Retaining (CR) Total Knee Arthroplasty (TKA) has better long-term survivorship compared to Posterior Stabilized (PS), however most arthroplasty surgeons tend to use PS knees in patients with severe deformity and stiffness. There is limited data correlating stiffness and CR versus PS design. The aim of our study was to assess the outcome of CR TKA for patients with stiff arthritic knee. Materials & methodsWe evaluated the results of 30 knees with osteoarthritis and inflammatory arthritis and preoperative stiffness (ROM 15-90°), who had been treated with CR TKA with a mean follow up of 2 years. The primary outcome variable measures were improvement in the flexion, flexion deformity (FFD) and overall improvement in the arc of motion. Patients were also evaluated by Knee Society Score (KSS), WOMAC score and 5-point Likert scale for patient satisfaction. ResultAt the time of final follow-up, the mean arc of motion improved from 75° preoperatively to 108° postoperatively and it was statistically significant (p < 0.001). Similar improvement was noted for FFD (15.43° to 0.83° (p < 0.001)), maximum flexion from 90.9° to 109.1° (p < 0.001), KSS clinical from 37.67 to 87.47 (p < 0.001), KSS functional from 58.5 to 93.83 (p < 0.001), WOMAC from 76.73 to 7.63 (p < 0.001). Further, the Likert Scale for patient satisfaction was excellent for 90% of the patients. ConclusionThis study clearly shows that the routine use of PS design for complex stiff knees has questionable scientific intent and standard CR TKA design in stiff knees can produce excellent outcome. Since there is slight preponderance of data pointing towards improved longevity with CR design, it would be a better option for the patients with longer life expectancy.

Does Component Alignment Affect Patient Reported Outcomes following Bicruciate Retaining Total Knee Arthroplasty? An In Vivo Three-Dimensional Analysis.

This is an experimental study. Anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) retaining bicruciate retaining (BCR) total knee arthroplasty (TKA) have the potential to restore normal knee kinematics and thus improve patient outcome. Limited studies have examined the relationship between component alignment and patient-reported outcome measures (PROM). This study aims to determine (1) accurate three-dimensional (3D) component alignment of BCR TKA and (2) whether the component alignment of BCR TKA affects PROMs. The 3D modeling analysis was performed based on computed tomography images from 29 BCR TKAs. Component orientations were quantified for femoral and tibial components in the sagittal, axial, and coronal planes. The knee society scores (KSS) were collected preoperatively and postoperatively at 1-year follow-up. Multiple comparisons were performed to analyze the relationship between component alignment and patient outcomes. High variability was observed in the tibial component alignment (root-mean-square values: axial plane 6.6 degrees, sagittal plane 5.1 degrees, and coronal plane 4.0 degrees). At 1-year follow-up, significant improvement in KSS was noted in BCR TKA patients (p < 0.001). However, regression analysis adjusting for baseline KSS demonstrated the postoperative KSS was negatively associated with the posterior tibial slope (B [slope of the output of the regression analysis] = 2.597, p = 0.006). Patients with greater posterior tibial slopes were reported poorer postoperative functions at 1-year follow-up. Excessive posterior tibial slope may generate greater posterior force on the femur that leads to continuous overloading of the preserved ACL, suggesting optimal sagittal plane alignment of the tibial component may be important for the optimization of postoperative functions of BCR TKA patients.

Does Contemporary Bicruciate Retaining Total Knee Arthroplasty Restore the Native Knee Kinematics? A Systematic Review of In-vitro Cadaveric Investigations.

Does Contemporary Bicruciate Retaining Total Knee Arthroplasty Restore the Native Knee Kinematics? A Systematic Review of In-vitro Cadaveric Investigations.

Conservative Bone Cuts and Technical Hints In cruciate Retaining Total Knee Arthroplasty, a 20 Years Experience.

Total knee arthroplasty (TKA) is one of the most successful procedures in modern orthopedic surgery, providing high patient satisfaction rate. As a result, the number of patients undergoing TKA is increasing in number every year and more patients would be inclined to have the operation in near future . The demand for TKA is expected to grow 673% between 2005 and 2030. Knee surgeons are using more advanced techniques of arthroplasty and apply their experience to improve the outcome of the operation and achieving better results. Understanding of the knee biomechanics , introduction of better techniques together with more modern prosthesis design and instrumentation plus good experience are reasons for success and popularity of this surgery. In this paper we aim to share our experience of total knee arthroplasty patients with other knee surgeons.

Midterm Results of Cementless Total Knee Arthroplasty: A Retrospective Case Series.

Background:There is an ongoing debate about whether to use cementless or cemented fixation for Total Knee Arthroplasty (TKA).Objective: The study aimed to assess midterm survivorship of the Vanguard cementless system, and to demonstrate the utility of the Bone Hardness Test (BHT) for the selection of cementless fixation TKA.Methods:From September 2009 through November 2014, 123 total knee arthroplasties were completed, with cementless Vanguard Cruciate Retaining TKA in 110 knees (102 patients) and cemented Vanguard in 13 cases (12 patients). Implant fixation was based on intraoperative assessment of posterior cruciate ligament stability, bone quality, and BHT. All patients with a cementless Vanguard implant were eligible for this retrospective study. Preoperative and postoperative Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index were obtained. Standardized standing anteroposterior and lateral radiographs were taken.Results:Three patients (4 TKAs) were lost to follow-up. The mean follow-up time was 5.5 ± 1.4 years. All scores significantly improved postoperatively. No radiographic failures were observed. Five-year implant survival, with revision of any component for any reason as an endpoint, was 97.2% (95% confidence interval, 91.7 - 99.1%). Five-year survival with revision for aseptic loosening was 100%. Only one knee required revision due to an isolated unrelated bearing exchange, and two additional knees required secondary resurfacing of the patella for retropatellar pain.Conclusion:Good midterm results were obtained with the cementless Vanguard Cruciate Retaining TKA for the treatment of osteoarthritis. The Bone Hardness Test appears to be an effective way to determine the selection of cementless TKA.

Kinematics and Mechanical Properties of Knees following Patellar Replacing and Patellar Retaining Total Knee Arthroplasty.

Knee injury is a common medical issue. A full understanding of the kinematics and mechanical properties of knees following total knee arthroplasty (TKA) repair utilizing patellar replacement (only the base of the patella is replaced) versus patellar retaining surgical techniques is still lacking. In the current paper, we investigated magnetic resonance (MR) imaging data from knees repaired by these two methods and evaluated total knee models created using imaging reconstruction technology that simulated gait conditions. Results revealed that patellar replacement had little influence on tibiofemoral kinematics, although the tibia-surface equivalent stress increased slightly. By contrast, patellar replacement had a significant influence on the patellofemoral joint; patellar internal rotation, external rotation, and medial-lateral translation were all increased. Moreover, the stress distribution on patellar prostheses was altered, resulting in an increased surface maximal equivalent stress on the corresponding area. Moreover, during the gait cycle, we found that the area with maximal equivalent stress shifted its position. Finally, the patellofemoral joint showed decreased motion stability. From the view of kinematics and mechanics, this paper suggests that patella should be retained during TKA if it is possible. The present study presented approaches and technologies for evaluating kinematics and mechanical properties of total knee joint after TKA under gait loads.

Tibiofemoral Contact Behavior Is Improved in High-flexion Cruciate Retaining TKA

Recently, total knee arthroplasty (TKA) designs have been modified to prevent edge loading on the posterior tibial articular surface and increase the tibiofemoral contact area at high degrees of flexion. The expected improvement in contact behavior of high-flexion TKA over conventional design is not well documented. We ascertained peak contact locations and contact areas of a conventional and a high-flexion cruciate-retaining TKA design. Both TKAs showed similar kinematics throughout the range of flexion although their contact behaviors differed: the peak contact point for the high-flexion TKA was located more anteriorly than the conventional TKA for flexion angles greater than 90 degrees. The tibiofemoral contact of both TKAs reached the polyethylene posterior edge at 150 degrees. The contact on conventional TKA reached the polyethylene posterior edge approximately 15 degrees to 30 degrees before the high-flexion TKA. The high flexion TKA exhibited similar contact areas to conventional TKA. While the clinical relevance is unclear, these data suggest high flexion TKA might improve tibiofemoral contact biomechanics if high flexion is achievable.

Functional and Radiological Outcomes of Patella Retaining Total Knee Arthroplasty: Minimun 5-Year Follow-up Results

Purpose : Conflicting results have been reported for patellar resurfacing in total knee arthroplasty. We reviewed the clinical and radiological results of patella retaining total knee arthroplasties retrospectively. Materials and Methods : Patella retaining total knee arthroplasty using a press-fit condylar (PFC) model by the hybrid technique was reviewed retrospectively in 27 knees (22 patients). Clinical evaluation was done according to HSS knee and patella scores. Radiographic assessment was made by measuring the patellofemoral joint space (mild, moderate, and severe loss), patellar sclerosis, patellar tilt, and patellar subluxation. Results : The mean HSS knee score improved from 58 to 87 and the patellar score was found to be good or excellent in 85% (23/27) of cases. Patellar sclerosis was found in 10 cases (9 lateral and 1 medial) and patellar tilting was found in 4 cases (15%). Correlation between the radiographic findings and the clinical scores was statistically indifferent (p>0.05). Conclusion : Patella retaining total knee arthroplasty may reduce patellofemoral complications but long term radiographic and clinical follow-up including patellar sclerosis, patellar tilting, and patellar subluxation is recommended.