Component In Total Knee Arthroplasty Research Articles

Socioeconomic Disadvantage Predicts Decreased Likelihood of Maintaining a Functional Knee Arthroplasty Following Treatment for Prosthetic Joint Infection

BackgroundProsthetic joint infection (PJI) carries major morbidity and mortality as well as a complicated and lengthy treatment course. In patients who have high degrees of socioeconomic disadvantage, this may be a particularly devastating complication. Our study sought to evaluate the impact of socioeconomic deprivation on outcomes following treatment for PJI of the knee. MethodsWe conducted a retrospective review of revision total knee arthroplasty (TKA) procedures performed for the treatment of initial PJI between 2008 and 2020 at a single tertiary care center in the United States. The Area Deprivation Index (ADI) was used to quantify socioeconomic deprivation. The primary outcome measure was presence of a functional knee joint at the time of most recent follow-up defined as TKA components or an articulating spacer. A total of 96 patients were included for analysis. The median follow-up duration was 26.5 months. ResultsThere was no significant difference in the rate of treatment failure (P = .63). However, the proportion of patients who had a functional knee arthroplasty (in contrast to having undergone arthrodesis, amputation, or retention of a static spacer) declined significantly with increasing ADI index (81.8% for the least disadvantaged group, 58.7% for the middle group, 42.9% for the most disadvantaged group, P = .021). ConclusionsPatients who have a higher socioeconomic disadvantage as measured by ADI are less likely to maintain a functional knee arthroplasty following treatment for TKA PJI. These findings support continued efforts to improve access to care and optimize treatment plans for patients who have socioeconomic disadvantage.

Prediction of knee biomechanics with different tibial component malrotations after total knee arthroplasty: conventional machine learning vs. deep learning.

The precise alignment of tibiofemoral components in total knee arthroplasty is a crucial factor in enhancing the longevity and functionality of the knee. However, it is a substantial challenge to quickly predict the biomechanical response to malrotation of tibiofemoral components after total knee arthroplasty using musculoskeletal multibody dynamics models. The objective of the present study was to conduct a comparative analysis between a deep learning method and four conventional machine learning methods for predicting knee biomechanics with different tibial component malrotation during a walking gait after total knee arthroplasty. First, the knee contact forces and kinematics with different tibial component malrotation in the range of ±5° in the three directions of anterior/posterior slope, internal/external rotation, and varus/valgus rotation during a walking gait after total knee arthroplasty were calculated based on the developed musculoskeletal multibody dynamics model. Subsequently, deep learning and four conventional machine learning methods were developed using the above 343 sets of biomechanical data as the dataset. Finally, the results predicted by the deep learning method were compared to the results predicted by four conventional machine learning methods. The findings indicated that the deep learning method was more accurate than four conventional machine learning methods in predicting knee contact forces and kinematics with different tibial component malrotation during a walking gait after total knee arthroplasty. The deep learning method developed in this study enabled quickly determine the biomechanical response with different tibial component malrotation during a walking gait after total knee arthroplasty. The proposed method offered surgeons and surgical robots the ability to establish a calibration safety zone, which was essential for achieving precise alignment in both preoperative surgical planning and intraoperative robotic-assisted surgical navigation.

Can Isolated Tibial Component Revision Be an Alternative to Isolated Aseptic Loosening of the Tibial Component in Total Knee Arthroplasty?

This article reviews the information on isolated tibial component revision for isolated aseptic loosening of the tibial component in total knee arthroplasty (TKA). It summarizes the results of recent major studies published in PubMed since the beginning of the search engine until 28 March 2023. Sixty-five articles were found, of which only five were analyzed because they were directly related to the title of this article. At 5-year follow-up isolated tibial revision and both-component (femoral and tibial) revision for aseptic loosening did not differ with regard to failures of the implant, adverse events, and clinical outcomes.

Accuracy and reproducibility of two-dimensional computed tomography-based positioning of femoral component rotational alignment in preoperative planning for total knee arthroplasty

BackgroundPoor rotation of the femoral component in total knee arthroplasty (TKA) can result in various postoperative complications, underscoring the critical importance of preoperative planning.PurposeTo improve the accuracy of femoral component positioning during TKA, this study compared the accuracy and repeatability of different two-dimensional (2D) computed tomography (CT) measurement methods for measuring the posterior condylar angle (PCA) in preoperative TKA planning.MethodsA retrospective analysis was conducted on 75 patients (150 knees) who underwent bilateral lower extremity computed tomography angiography (CTA) at Fuyang People's Hospital from January 2021 to July 2021. Three different methods were used to measure the PCA based on 2D CT images (axial CT slices) and three-dimensional(3D) models (femoral models reconstructed from CT data) in this study. Method 1: Single-plane 2D CT measurement, measuring PCA in the most obvious single-plane CT slice of the surgical transepicondylar axis (sTEA); Method 2: multi-plane 2D CT measurement, identifying and locating anatomical landmarks in multiple 2D CT slices and measuring PCA; Method 3: 3D model measurement, measuring PCA in the reconstructed femur 3D model. Compare the differences in PCA measurements between the three measurement methods. A positive PCA measurement was recorded when the sTEA was externally rotated relative to the posterior condylar line (PCL). Any difference exceeding 3° between the PCA measurement in the 2D CT and the PCA reference value in the 3D model was classified as an outlier. The intraclass correlation coefficient (ICC) and Bland–Altman method were utilized to assess the intra- and inter-observer reproducibility of the three measurement methods.ResultsThe PCA measurement in the single-plane 2D CT was 1.91 ± 1.94°, with a measurement error of − 1.22 ± 1.32° and 12.7% of outlier values. In the multi-plane 2D CT, the PCA measurement was 2.96 ± 1.68°, with a measurement error of -0.15 ± 0.91° and 6.0% of outlier values. The PCA measurement in the 3D model was 3.12 ± 1.69°. The PCA measurement in single-plane 2D CT was notably smaller than that in multi-plane 2D CT and 3D models, with no significant difference between the latter two. The multi-plane 2D CT showed significantly lower measurement error and outlier values than the single-plane 2D CT. All three PCA measurement methods exhibited high reproducibility (ICC: 0.93 ~ 0.97).ConclusionsUsing of multi-plane 2D CT for measuring PCA in preoperative planning of TKA has high reproducibility and accuracy, with fewer outlier values. We recommend preoperative measurement of PCA using muti-plane 2D CT to improve the accuracy of positioning the femoral component rotational alignment during surgery.

Uncemented trabecular metal high-flex posterior-stabilized monoblock total knee arthroplasty in patients aged 60 years or younger

BackgroundUncemented trabecular metal (TM) monoblock tibial components in total knee arthroplasty (TKA) have shown excellent clinical results for up to 10 years. However, these studies were performed in highly specialized units, with few surgeons and often excluding knees with secondary osteoarthritis (OA), severe malalignments and previous surgery. The purpose of this study was to investigate implant survivorship and clinical and radiological outcome of the uncemented TM high-flex posterior stabilized (PS) monoblock tibial component in routine clinical practice. MethodsA retrospective study of 339 knees (282 patients) operated with the implant in routine clinical practice at two hospitals on patients aged 60 years or younger between 2007 and 2015. The operations were performed by 12 surgeons and there were no specific contraindications for use of the implant. Follow up ended in 2020. The status of the implant of deceased patients at death and those not attending follow up was checked with the Swedish Knee Arthroplasty Register. Clinical follow up consisted of clinical investigation, PROMs, and knee X-ray. ResultsFollow up was mean (range) 8.5 (5–13.8) years, and the 8-year survival rate was 0.98 (standard error 0.007). Five patients five knees) were deceased, five knees were revised (none due to aseptic loosening), and 16 patients did not attend the clinical follow up.Forty-four percent of the knees had secondary OA and 45% had had previous operations. 93% were satisfied or very satisfied with the operation and forgotten joint score (FJS) was median (interquartile range) 81 (44–94). Radiographic analysis revealed bone in close contact with the tibial tray and pegs in most cases, and in only 2% of the knees were potential radiolucent lines found. ConclusionThe results indicate that this uncemented implant performs excellently in routine clinical practice and also in younger patients with secondary OA or previous knee operations.

Cementless metal-backed patellar components in primary total knee arthroplasty using an implant of modern design.

The use of cementless total knee arthroplasty (TKA) components has increased during the past decade. The initial design of cementless metal-backed patellar components had shown high failure rates due to many factors. The aim of this study was to evaluate the clinical results of a second-generation cementless, metal-backed patellar component of a modern design. This was a retrospective review of 707 primary TKAs in 590 patients from a single institution, using a cementless, metal-backed patellar component with a mean follow-up of 6.9 years (2 to 12). A total of 409 TKAs were performed in 338 females and 298 TKAs in 252 males. The mean age of the patients was 63 years (34 to 87) and their mean BMI was 34.3 kg/m2 (18.8 to 64.5). The patients were chosen to undergo a cementless procedure based on age and preoperative radiological and intraoperative bone quality. Outcome was assessed using the Knee Society knee and function scores and range of motion (ROM), complications, and revisions. A total of 24 TKAs (3.4%) in 24 patients failed and required revision surgery, of which five were due to patellar complications (0.71%): one for aseptic patellar loosening (0.14%) and four for polyethylene dissociation (0.57%). A total of 19 revisions (2.7%) were undertaken in 19 patients for indications which did not relate to the patella: four for aseptic tibial loosening (0.57%), one for aseptic femoral loosening (0.14%), nine for periprosthetic infection (1.3%), one for popliteus impingement (0.14%), and four for instability (0.57%). Knee Society knee and function scores, and ROM, improved significantly when comparing pre- and postoperative values. Survival of the metal-backed patellar component for all-cause failure was 97.5% (95% confidence interval 94.9% to 100%) at 12 years. The second-generation cementless TKA design of metal-backed patellar components showed a 97.5% survival at 12 years, with polyethylene dissociation from the metal-backing being the most common cause of patellar failure. In view of the increased use of TKA, especially in younger, more active, or obese patients, these findings are encouraging at mean follow-up of seven years.

Osteometric Dimension of Lower End of Femoral Bone among Bangladeshi Population

Introduction: The osteometric dimensions of the lower end of the femur have significant clinical implications, particularly in the context of total knee arthroplasty (TKA). Accurate measurements are crucial for the design of femoral components in TKA, which can influence surgical outcomes. This study aims to determine the measurements of different variables of the lower end of the femur, including femoral condylar width, intercondylar width and depth, and the depth of the medial and lateral condyles, in a Bangladeshi population. Methods: This cross-sectional study was conducted on 50 dried femurs collected from three medical colleges in Dhaka, Bangladesh. Measurements were obtained using digital sliding calipers and were rounded to two decimal places. Data analysis was performed using SPSS. Result: Statistical analysis revealed that 56% of the femurs were right-sided and 44% were left-sided. The mean femoral bicondylar width was 69.78 ± 5.38 mm, falling mostly in the "Above Average" range (30%). The mean intercondylar width was 23.77 ± 1.55 mm, with 50% falling in the "Medium" range. Other variables like femur medial condylar width had a mean of 31.05 ± 1.74 mm. Conclusion: Observationally, the study successfully delineates the osteometric dimensions of the lower end of the femur in a Bangladeshi cohort. The statistical results not only fulfill the study's initial aim but also provide a nuanced understanding of the osteometric variations. These findings are instrumental for clinicians in the design and customization of femoral components in TKA, thereby potentially enhancing surgical outcomes and patient satisfaction. The data also lay the groundwork for future research in this area.

The influence of cross shear and contact pressure on the wear of UHMWPE-on-PEEK-OPTIMA™ for use in total knee replacement

PEEK-OPTIMA™ polymer is being considered as an alternative material to cobalt chrome in the femoral component of total knee arthroplasty to give a metal-free knee replacement system. Simple geometry pin-on-plate wear simulation can be used to systematically investigate and understand the wear of materials under many different conditions. The aim of this study was to investigate the wear of UHMWPE-on-PEEK-OPTIMA™ under a range of contact pressure (2.1–80 MPa) and cross-shear ratio (0–0.18) conditions.With increasing contact pressure, there was a trend of decreasing UHMWPE wear factor with a significant difference (p<0.001) in the wear factor of UHMWPE under the different contact pressure conditions of interest. Under uniaxial motion (cross-shear ratio = 0), the wear of UHMWPE was low, introducing multi-axial motion increased the wear of the UHMWPE. There was a significant difference (p<0.01) in the wear factor at different cross-shear ratios however, post hoc analysis showed only the study carried out under unidirectional motion to be significantly different from the other conditions.With varying contact pressure and cross-shear ratio, the wear of UHMWPE against PEEK-OPTIMA™ polymer showed similar trends to previous studies of UHMWPE-on-cobalt chrome.

No Benefit of Robotic-Assisted over Computer-Assisted Surgery for Achieving Neutral Coronal Alignment in Total Knee Arthroplasty.

The use of robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming increasingly popular due to better precision, potentially superior outcomes and the ability to achieve alternative alignment strategies. The most commonly used alignment strategy with RAS is a modification of mechanical alignment (MA), labeled adjusted MA (aMA). This strategy allows slight joint line obliquity of the tibial component to achieve superior balancing. In the present study, we compared coronal alignment after TKA using RAS with aMA and computer-assisted surgery (CAS) with MA that has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) were compared for both techniques. In 140 patients, 68 CASs and 72 RASs, we observed no difference in postoperative measurements (median 90 degrees for all, LDFA p = 0.676, MPTA p = 0.947) and no difference in outliers <2 degrees (LDFA p = 0.540, MPTA p = 0.250). The present study demonstrates no benefit in eliminating outliers or achieving neutral alignment of both the femoral and the tibial components in robotic-assisted versus computer-assisted TKA if MA is the target. To utilize the precision of RAS, it is recommended to aim for more personalized alignment strategies. The level of evidence is level III retrospective study.

In Total Knee Arthroplasty, Cementless and Hybrid Tibial Components Did Not Differ from Cemented Components for Revision-Free Survival and Had No Aseptic Loosening at 10 Years.

In Total Knee Arthroplasty, Cementless and Hybrid Tibial Components Did Not Differ from Cemented Components for Revision-Free Survival and Had No Aseptic Loosening at 10 Years.

Preoperative carbohydrate drink in fast-track primary total knee arthroplasty: a randomized controlled trial of 168 patients.

A key component in fast-track total knee arthroplasty (TKA) is early mobilization. Preoperative fasting might cause orthostatic hypotension and -intolerance which both can interfere with early mobilization. It was hypothesized that consuming a carbohydrate drink 2-3 hours prior to surgery is a viable option to reduce orthostatic hypotension, and as a result, improve rehabilitation. In this randomized controlled trial, all consecutive unilateral primary TKA patients were reviewed for eligibility. Exclusion criteria were American Society of Anesthesiologists (ASA) class above 3, older than 80 years of age, Diabetes Mellitus, and an insufficient comment of Dutch language. Patients were distributed in two groups. The control group was allowed to eat till 6 hours and drink clear fluids till 2 hours before surgery (standard treatment). The intervention group consumed, additionally to the standard treatment, a carbohydrate drink 2-3 hours before surgery. Blood pressure was measured both lying and standing as a measure for orthostatic hypotension during first time postoperative mobilization on day of surgery. A total of 168 patients were included. Prevalence of orthostatic hypotension in the control- and intervention group was 24 patients (34%) and 14 patients (19%) respectively, (p=0.05). Prevalence of orthostatic intolerance was 13 patients (19%) in the control group and 9 patients (13%) in the intervention group (p=0.32). No drink related adverse events occurred. In conclusion, taking a carbohydrate drink 2-3 hours before TKA significantly lowers the number of patients with orthostatic hypotension in early mobilization. However, the clinical relevance of the carbohydrate drink has to be studied further.

Preoperative predictors of implant size in patients undergoing total knee arthroplasty: a retrospective cohort study

BackgroundTraditionally, the size of total knee arthroplasty (TKA) components is predicted by preoperative radiographic templating, which is of limited accuracy. This study aimed to evaluate the role of demographic data and ankle volume in predicting implant size in TKA candidates.MethodsIn a retrospective study, 415 patients who underwent TKA at a single institution were included. The mean age of the patients was 67.5 ± 7.1 years. The mean BMI of the patients was 31.1 ± 4.7 kg/m2. TKA implants were Zimmer Biomet NexGen LPS-Flex Knee in all cases. The demographic data included age, sex, height, weight, BMI, ethnicity, and ankle volume. Ankle volume was assessed with the figure-of-eight method. Multivariate linear regression analysis was used for predicting factors of implant size.ResultsMultivariate linear regression analysis showed that the Sex (β:1.41, P < 0.001), height (β:0.058, P < 0.001), ankle volume (β:0.11, P < 0.001), and Age (β:0.017, P = 0.004) were significant predictors of tibial component size. Sex (β:0.89, P < 0.001), height (β:0.035, P < 0.001), and ankle volume(β:0.091, P < 0.001) were significant predictors of femoral component size in the multivariate analysis.ConclusionDemographic data, adjunct with the ankle volume, could provide a promising model for preoperative prediction of the size of tibial and femoral components in TKA candidates.

Accuracy and outcome of a handheld accelerometer-based navigation device compared to conventional alignment method in total knee arthroplasty in a Chinese population

Background Total knee arthroplasty (TKA) is a successful procedure in treatment of degenerative disease of the knee, and optimal component placement is essential for long-term implant survival. The purpose of this study was to compare the accuracy of the accelerometer-based KneeAlign 2 (KA2) navigation system against conventional methods for accurate positioning of the femoral and tibial components in TKA in a Chinese population. Methods A total of 123 (37 conventional and 86 KA2) cases of elective primary TKA were reviewed. Hip-knee-ankle (HKA) angle, mechanical lateral distal femoral angle (mLDFA), and anatomical lateral distal femoral angle (aLDFA) were measured from hip-to-ankle EOS radiographs. Accuracy of conventional alignment and KA2 navigation system was assessed by measuring the difference between intraoperative goal and postoperative radiographic measurements of the components for each respective case. Results There was no significant difference between conventional alignment methods and KA2 navigation in achieving a neutral mechanical alignment of the lower limb. KA2 navigation was significantly more accurate than conventional alignment methods for optimal positioning of the tibial component in both the coronal and sagittal plane, while no significant difference between the two groups was appreciated in the positioning of the femoral component in the coronal plane. Conclusions TKA using the accelerometer-based KA2 system was found to offer a high degree of accuracy in component alignment, and in particular, significantly improved tibial component alignment in comparison with conventional alignment methods in a Chinese population. However, no significant improvements were observed in neutral mechanical axis of the lower limb alignment and femoral component placement in the coronal plane.

A 15-YEAR SURVIVAL ANALYSIS OF OXIDIZED ZIRCONIUM TOTAL KNEE ARTHROPLASTY

AbstractBackgroundOxidized zirconium (OxZr) has been introduced as an alternative bearing for femoral components in Total Knee Arthroplasty (TKA). It has a ceramic-like zirconium oxide outer layer with a low coefficient of friction. Early studies have found OxZr TKA to have a low incidence of early failure in young high demand patients. Currently no study has reported on the outcome of these implants beyond ten years.ObjectivesThe purpose of our study was to present an in-depth 15-year survival analysis of cemented Profix II OxZr TKA.Study Design &amp; MethodsData was collected prospectively and survival analysis undertaken with multiple strict end points. Complication rates were recorded and patient reported outcomes were measured.Results617 Profix II OxZr TKAs were performed over four years. Forty-nine patients underwent reoperation. Aseptic tibial loosening was the most common cause of failure (32.7%) on average occurring 2.8 years post primary procedure. There was one recorded failure due to loosening of the zirconium femoral component. Revision rate at 15-years was 6.38%. Cumulative survivorship was 91.52% with failure considered to be reoperation for any reason. WOMAC score improved in 86% of patients by year 1. The average score improved by 21.2 points and met the standard for minimum clinically important difference.ConclusionsThis study presents the first 15-year survival analysis of cemented Profix II OxZr TKA. Our data supports current literature on the long-term survivorship of oxidised zirconium total knee replacements.

Combined femoral and tibial component total knee arthroplasty device rotation measurement is reliable and predicts clinical outcome

BackgroundThe optimal total knee arthroplasty (TKA) rotational alignment and how best to obtain and measure it are debatable. The aim was to analyse the reliability of the Berger femoral, three different tibial and four different combined two-dimensional computer tomography (2D-CT) TKA component rotation measurements, and to ascertain which rotational values best predict a successful clinical outcome.MethodsThe 2D-CT scans were obtained post-operatively on 60 patients who had TKA. We determined one femoral [Berger’s femoral angle (BFA)], three tibial [Berger’s tibial angle (BTA), anatomical tibial angle (ATA) and bimalleolar posterior tibial component angle (BM_PTCA)] and four combined [transepicondylar posterior tibial component angle (TE_PTCA), bicondylar posterior tibial component angle (BC_PTCA, transepicondylar bimalleolar angle (TE_BM) and bicondylar bimalleolar angle (BC_BM)] TKA rotation angles. We made all measures in 23 patients twice by three observers and determined inter- and intra-observer agreement using the Bland–Altman plot method. We analysed measures of 55 patients using the area under the ROC curve (AUC) analysis to ascertain the discriminative capacity of BFA, ATA, TE_PTCA and BC_PTCA for predicting a successful clinical outcome according to the Knee Society Score (KSS) threshold.ResultsATA showed the smaller inter- and intra-observer average of differences (−0.1° and 1.6°, respectively) of the studied methods followed by BFA (−0.9° and 1.4°), TE_PTCA (−2.1° and 2.7°) and BC_PTCA (−0.5° and 1.8°). BFA (−4° to 2.1° and −6.1° to 8.8°) and BC_PTCA (−4.4° to 3.4° and −7.9° to 4.4°) showed the narrower inter- and intra-observer limits of agreement. A TKA device rotation (BC_PTCA) < 0.8° of external rotation (ER) predicted a KSS and KSS knee successful outcome, and < 3.8° ER for KSS functional (AUC = 0.889; 0.907 and 0.764, respectively). BFA and ATA < 0.9° ER and < 3.9° internal rotation (IR) predicted a successful KSS knee outcome (AUC = 0.796 and 0.889, respectively).ConclusionThe ATA tibial component rotation measurement was the most reliable of those studied. BFA, TE_PTCA and BC_PTCA were reliable measures for TKA femoral and combined rotation. The presence of a minimal rotation between the TKA components (BC_PTCA) and a small femoral ER or tibial IR predicted a successful KSS outcome.Level of evidence II.

The influence of retropatellar fat preservation on the positioning of the tibial component of total knee arthroplasty

Background: The good clinical-functional outcomes of total knee arthroplasty (TKA) depend on several factors, such as the surgical time and the adequate positioning of the prosthesis components. The present study aims to evaluate whether the preservation of retropatellar fat pad during the surgical act influences the rotational alignment of the tibial component and the surgical time of the procedure. Methods: The study was carried out with 50 patients operated on by the main author, who were randomly divided into two groups, experimental and control. For the evaluation of the positioning of the tibial component, the patients underwent computed tomography (CT) four weeks after the surgery, on average. Casuistry was determined by pilot study with the first five patients of each group. For the sample calculation, the t-student test was used for two independent samples. Results: All patients presented internal rotation of the tibial component, with no statistical difference in mean rotation between the experimental and control groups. When there was complete detachment of the fat in the experimental group, the tibial component showed greater external rotation, with a statistical difference. Surgical time was shorter in the experimental group, varying in this group according to the degree of osteoarthrosis. Conclusions: Maintenance of retropatellar fat pad did not influence the rotational alignment of the tibial component; however, in patients with advanced osteoarthrosis, such maintenance increases the surgical time.

Treatment of neuropathic unstable knee osteoarthritis by a condylar, rotating-hinge prosthesis with cementless pentagonal stem: a case series

Total knee arthroplasty (TKA) in the neuropathic unstable knee (NUK) setting is classically a challenging orthopedic problem due to intraoperative technical difficulties and a higher frequency of periprosthetic complications. More recently, satisfactory results have been reported using improved constraints, stems and revision-type TKA components. The study aims to present long-term results of a small case series with NUK osteoarthritis reconstructed by a condylar, semi-constrained prosthesis with a polygonal, hydroxyapatite-coated (HA-coated) press-fit stem. From 2009 through 2010, three knees in three patients with advanced NUK arthropathy underwent TKAs in our institution using the PENTA® prosthesis. The average age at surgery was 44 years (32–58). The patients were followed up for a mean period of 124 months (120–128). The etiology of NUK was determined to be poliomyelitis sequela in 2 cases and spinal cord injury in one case. Functional outcomes were assessed with Knee Society (KS) Knee and Function Scores, and radiological outcomes were evaluated with ISOLS radiographic implant scores. Patients were monitored for complications clinically and radiologically. KS knee scores improved from a mean of 12,3 (0–37) preoperatively to 71,3 (65–77) and KS function scores improved from a mean of 1,7 (0–5) preoperatively to 68,3 (55–80) at the latest follow-up. Radiological outcomes were excellent according to ISOLS scores, and no complications were observed. Although this is a small case series, the significant improvement in functional scores, excellent radiological outcome, and implant survival at the end of a long follow-up period warrants TKA with a semi-constrained hinged implant in the setting of NUK. PENTA® prosthesis offers a good choice of implant with its hydroxyapatite-coated, press-fit, pentagonal stem and precisely designed rotating hinge.

Functional assessment of all polyethylene tibial monoblock component in total knee arthroplasty

Background: In a developing country like India the cost effectiveness of all polyethylene tibial components is a major boon, without compromising the functional outcome. In this study we have attempted to evaluate the functional outcome of all polyethylene tibial monoblock component in total knee arthroplasty. Methodology: The study was carried out on 86 patients who are operated for total knee arthroplasty with all polyethylene tibial monoblock component. Demographic, surgical and follow up data was collected from case sheets of patients and copied in Performa. The patients were called for five years follow up and examined in the outpatient department. Results: The mean age of study population was 62.8 years (range 50 – 72 years) with mean BMI of 27.6 kg/m2. Statistically significant improvement was seen in the range of movements in all the age groups. Both male and female patients had insignificant difference in knee scoring. Assessment of clinical functional abilities of knee scoring have observed to be higher in patients with lower BMI. Conclusion: Significant improvement in range of motion as well as knee score in all age range, emphasizes the fact that total knee arthroplasty with all polyethylene design in osteoarthritis is an excellent surgery to restore near normal life style.

Functional assessment of all polyethylene tibial monoblock component in total knee arthroplasty

Background: In a developing country like India the cost effectiveness of all polyethylene tibial components is a major boon, without compromising the functional outcome. In this study we have attempted to evaluate the functional outcome of all polyethylene tibial monoblock component in total knee arthroplasty. Methodology: The study was carried out on 86 patients who are operated for total knee arthroplasty with all polyethylene tibial monoblock component. Demographic, surgical and follow up data was collected from case sheets of patients and copied in Performa. The patients were called for five years follow up and examined in the outpatient department. Results: The mean age of study population was 62.8 years (range 50 – 72 years) with mean BMI of 27.6 kg/m2. Statistically significant improvement was seen in the range of movements in all the age groups. Both male and female patients had insignificant difference in knee scoring. Assessment of clinical functional abilities of knee scoring have observed to be higher in patients with lower BMI. Conclusion: Significant improvement in range of motion as well as knee score in all age range, emphasizes the fact that total knee arthroplasty with all polyethylene design in osteoarthritis is an excellent surgery to restore near normal life style.

Proximal tibial aspect ratio and matching of tibial component in total knee arthroplasty: a narrative review

Proximal tibial aspect ratio (PTAR) is closely related to age, disease status and cutting parameters with considerable inter-individual variation independent of gender and race, nevertheless the aspect ratio of tibial components from different manufacturers remains relatively constant from smallest to largest size. As a result, component mismatching is an unavoidable dilemma during tibia preparation in total knee arthroplasty (TKA). Various prosthesis systems all can achieve more than 80% coverage on proximal tibia, whereas their optimal fit rates are generally not more than 50%. It is difficult for symmetrical components to avoid anteroposterior mismatch, internal malrotation tends to occur when maximum coverage is pursued on the resected surface with a medial dominant plateau or lower PTAR. Although it is easier to achieve a balance of rotation and coverage with anatomical components, significant anteromedial overhang tends to appear on the resected surface with a symmetrical or lateral dominant plateau. Further researches should focus on the law of inter-individual variability of proximal tibial morphology, the quantitative definition of "ideal matching" safety zone of key morphological parameters on different areas of proximal tibia and the methodology of realizing"ideal matching"in the majority patients with the least amount of component sizes. In addition, with the rapid development of additive manufacturing and digital orthopedic technology, individual customized implant is expected to become a breakthrough point in the field of TKA component fitting.