Background:. We studied the effect of
Purpose. The purpose of this study was to evaluate the postoperative maximal flexion of Robotic assisted TKA which does not increase the
Purpose. We sought to determine whether there was a difference in the
Background. Posterior referencing (PR) total knee arthroplasty (TKA) aims to restore
Background. Joint line, patellar height and
Introduction:. One of the important criteria of the success of TKR is achievement of the Flexion ROM. Various factors responsible to achieve flexion are technique, Implant and patient related. Creation of the
Proper restoration of
Introduction. The effect of the implant
Introduction. One of the important criteria of the success of TKR is achievement of the Flexion ROM. Various factors responsible to achieve flexion are technique, Implant and patient related. Creation of the
Total Knee Arthroplasty (TKA) has a tendency to change the individual anatomy of the patient within the limits of today used arthroplasty designs. Femoral external rotation will lead to mediolateral overhang by upsizing to avoid lateral notching and downsizing will lead to loss of
Introduction. Stiffness after total knee arthroplasty (TKA) has been reported to occur due to component malpositioning and/or oversizing, improper femoral component (FC) flexion and tibial component (TC) slope, tight extension gap, inaccurate joint line placement, deficient posterior osteophyte resection, heterotopic ossification (HO), poor patellofemoral joint reconstruction, poor
Introduction. CT based systems that are used to create custom components and custom cutting guides in total knee arthroplasty (TKA) have variable methods for accounting for the thickness of remaining cartilage that may influence component sizing and bone resection. Little information has been published about the thickness of this cartilage, especially on the posterior femoral condyles. Failure to account for this cartilage may lead to under-sizing of the femoral component, or a reduction in the
Background. Total knee arthroplasty (TKA) was primarily considered a successful procedure, several new knee implants were introduced in recent years that seek to obtain improved stability and higher flexion. One of the implant, Vanguard XP. TM. BiCruciate retaining (BCR), Zinmmer-Biomet, USA recreates a specific kinematic model through the principle of normal joint. Patients and Method. An unselected consecutive series of sixty-two patients undergoing primary TKA using the cemented total knee system between August 2016 and April 2018 were studied. Twenty-seven knees was operated using Vanguard XP, subsequently thirty-five knees were received a TKA using cruciate retaining cemented total knee system FINE. TM. CR, Nakashimamedical, Japan. Postoperatively standing AP hip-to-ankle radiographs were obtained, from which the lower extremity mechanical axis, component angle were measured. The alignment goals were a neutral mechanical axis defined as a hip-to-ankle angle of 0°with the femoral and tibial components aligned perpendicular to the mechanical axis. The total operating time were quantified utilising an operating room database. The total operating time between TKAs performed with Vanguard XP BCR and those performed with FINE CR was compared in each group. All patients postoperatively was evaluated of clinical results the Japan Orthopedics Association(JOA) Knee scores. We evaluated femoral component posterior offset (PFCO) in both of two group. The maximal protrusion of the posterior condyle, posteriorly to the extension line parallel to the tibial shaft from the edge of the posterior tibial component was measured on true lateral radiographs. Results. The JOA Knee score of Vanguard XP BCR group was 86.5±4.7 points, and the score of FINE group was 82.7±5.9 points, there was no statistical significance between the two groups on the clinical score. The operative time in Vanguard XP BCR was 137.2±14.6 minutes and significantly more compared to the time of FINE group 111.3±11.9 minutes. The mechanical axis angle in Vanguard XP BCR group was −1.3°±2.7, while FINE CR group was −0.7°±3.2, there was no statistical significance. The number of outliers for mechanical axis angle was Vanguard XP BCR group 25%, the FINE group 24%, between the two groups there was no statistical significance. The mean value of the femoral component posterior offset ratio of Vanguard XP BCR was 14.4%±0.1. The mean value of the posterior offset ratio of FINE group was 16.7%±0.1, between the two groups there was statistical significance. Discussion. Bellemans et al. first defined the concept of
INTRODUCTION. Femur is one of the bones in humans that exhibit ethnic, racial, and gender difference. Several basic and clinical studies were conducted to explore these variations. Clinical anthropological studies have dealt with the compatibility of femoral prostheses and osteosythesis and materials with the femur. If there is a misalignment between the Total Knee Arthroplasy (TKA) femoral comportment installation position, Range of Motion (ROM) failure and several problems may arise. The aim of this study was to evaluate anterior bowing of the Japanese femur and to assess the adequacy of TKA femoral comportment installation position. METHODS. We analyzed 76 normal Japanese and 97 TKA patients. (June 2014-June 2015) The average age of the normal subjects was 62.0±20.90 (24–88) years old and the average of TKA subjects was 73.6±7.9 (53–89) years old. First we defined and measured the anterior curvature and the
IN THE PAST success of TKA has been measured by ROM with maximum flexion as a bench mark, along with good stability of the knee joint MAINLY IN EXTENSION. Due to changing demographics our TKA population has shifted to more active and demanding patients which want to return to normal daily living, including professional and recreational sports activities. With the patella in place, we define a ligament “balanced resection” technique using the elibra device, and are able to optimize our results and meet younger, more active patient's expectations. Our workflow consists of a flexion gap first technique, maximizing
The natural knee allows multi-planar freedoms of rotation and translation, while retaining stability in the antero-posterior direction. It allows flexion with roll back, and medial, lateral and central rotation movements. The natural femoral condyles of the knee are spiral, therefore inducing a side to side translatory movement during flexion and extension. Incorporating all these features is vital in successful knee replacement design. The different knee designs currently in use demonstrate different deficiencies in knee function. A study of 150 Posterior Cruciate (PCL) Retaining Total Knee Replacements [1] has shown that in 72% of knees direct impingement of the tibial insert posteriorly against the back of the femur was responsible for blocking further flexion. The mean pre-operative range of flexion was 105° and post-operative was 105.9°. For every 2mm decrease in
Introduction. Two principal targets are dominating the spectrum of goals in total knee arthroplasty: first of all the orthopedic surgeon aims at achieving an optimal pain-free postoperative kinematic motion close to the individual physiologic range of the individual patient and secondly he aims for a concurrent high ligament stability within the entire range of movement in order to establish stability for all activities of daily living. This study presents a modified surgical procedure for total knee replacement which is ligament-controlled in order to put both component into the “ligamentous frame” of the patients individual kinematics. Methods. The posterior femero-condylar index (PFC-I) is defined as being the
Objective. We performed total knee arthroplasty (TKA) without patella resurfacing in patients with osteoarthritis (OA) of the knee. The purpose of the present study was to evaluate the clinical results and the appropriateness TKA without patella resurfacing. Methods. A total of 61 patients (61 affected knees) who had undergone a Low Contact Stress mobile − bearing knee arthroplasty (LCS− TKA) (Depuy, Warsaw, IN. USA) 10 years or more before the present study were enrolled. The LCS− TKAs did not include patella resurfacing. The patients' mean age was 77.7 ± 6.1 years (range: 59−94 years). The mean follow-up period was 121 ± 2.4 months (range: 120−129 months). The clinical evaluation used the scoring system for OA of the knees issued by the Japanese Orthopaedic Association (JOA score). We defined patellofemoral (PF) pain, crepitation, patellar clunk syndrome, spin-out, and reoperation as complications. We also used X-Ray imaging to measure the component angle, patella height, lateral shift ratio, tilting angle, femorotibial angle,
Objective:. Patient-specific or “custom” total knee replacements have been designed to fit the arthritic knee in primary total knee arthroplasty (TKA) better than “off-the-shelf” implants. Using computer technology, patient-specific cutting-blocks and custom-made implants are created to more accurately fit the contour of the knee and reproduce the anatomic J-curve with the hope of providing a better functional outcome. Purpose:. This retrospective, matched-pair study evaluates manipulation under anesthesia (MUA) rates in cemented patient-specific cruciate-retaining (PSCR) TKA compared to that in both cemented posterior-stabilized (PS) and non-cemented cruciate-retaining rotating-platform (NC CR RP) TKA. Materials and Methods:. From 2010 through November of 2012, 21 PSCR TKAs were performed in 19 patients. Using medical records from our patient database, these patients were matched for age, side, deformity, diagnosis, Charnley Class, and preoperative range of motion (ROM) with 42 PS TKAs performed during the same time period by the same surgeon using the same intra- and post-operative protocols. Additionally, 11 NC CR RP TKA were performed and evaluated based on the same criteria. Pre- and postoperative radiographs were performed using criteria as described by The Knee Society. Results:. Preoperatively the custom CR RP TKA cohort had a larger average ROM compared to the PS TKA cohort (P-value = 0.006). Postoperatively, however, the custom CR RP TKA cohort overall was found to have a significantly decreased average ROM compared to both the PS and NC CR RP TKA cohorts (2.0°–110.6° P-value = 0.0002 and 2.4°–117.3° P-value = 0.0003, respectively). 6 of the 21 (28.6%) PSCR TKAs performed underwent MUA to improve postoperative ROM. One manipulation was unsuccessful and the patient is scheduled for revision for arthrofibrosis. No patients in either the matched PS group or the CR RP group underwent postoperative MUA. Clinical and radiographic analysis including pre-operative ROM, deformity, side, Charnley Class, posterior tibial slope angle, epicondylar axis and
Introduction. Computed tomography (CT) can be utilized to design patient specific instruments (PSI) for total knee arthroplasty (TKA). The PSI preoperative plans predict bone resection, anterior-posterior implant position, implant rotation and implant size. The purpose of this study was to compare preoperatively predicted implant sizes (tibia and femur) to the actual implanted sizes. Data were compiled from two surgeons, one in the United Kingdom (Surgeon 1, cruciate retaining) and one in the United States (Surgeon 2, posterior stabilizing). Both used the same primary TKA implant systems (Sigma® and Attune®; DePuySynthes®, Warsaw, Indiana). This is the largest comparison of CT-based PSI size accuracy between two implant systems. Methods. An international cohort of 396 CT-based PSI-TKA preoperative plans (TruMatch®)were compared to postoperative implant records. Data were retrospectively analyzed for Sigma®(n=351) and Attune® (n=45), both as separate cohorts and as a combined cohort (Sigma® + Attune®). Three analyses were performed: Tibia and femur plan accuracy, major size changes (femoral size change or tibial size change resulting in a femoral size change) and minor size changes (tibial size change not impacting femoral size). Inter-rater reliability analyses using ICC (intra-class correlation) and the Kappa statistic were performed to determine reliability and agreement among the groups. Combined TKA implant data (Sigma® + Attune®) for surgeons 1 and 2 were compared for accuracy between users utilizing different implant designs, cruciate retaining (CR) versus posterior stabilized (PS). Results. In the combined system analysis (Sigma® + Attune®) femoral implant prediction was 97.0% accurate and combined tibial implant size accuracy was 79.5%. There were no significant differences between the systems for tibial or femoral accuracy. See Table 1. There were 12 major size changes, 11 downsized femoral implants and 1 upsized femoral implant (all femoral changes were with Sigma® system). There were 81 minor size changes. Per Kappa, the plans were in excellent agreement with the femoral implant size and had substantial agreement with tibial implant size (p<.01). See Table 2. Comparing size accuracy between Surgeon 1 and Surgeon 2, Surgeon 1 had significantly greater tibial accuracy (p<.01), while femoral accuracy showed no significant difference (p=0.49). See Table 3. Discussion. In this combined data set of two surgeons, we report high implant sizing accuracy overall. This accuracy was noted across implant systems (Sigma® and Attune®) and across surgeons (1 and 2) utilizing different implant designs (CR vs. PS) using TruMatch® PSI. In all cohorts, the femur was more accurately predicted than the tibia. Accurate size reconstitution and reconstruction of the femur is critical for maintenance of