The aim of this study was to compare a bicruciate-retaining (BCR) total knee arthroplasty (TKA) with a posterior cruciate-retaining (CR) TKA design in terms of kinematics, measured using fluoroscopy and stability as micromotion using radiostereometric analysis (RSA). A total of 40 patients with end-stage osteoarthritis were included in this randomized controlled trial. All patients performed a step-up and lunge task in front of a monoplane fluoroscope one year postoperatively. Femorotibial contact point (CP) locations were determined at every flexion angle and compared between the groups. RSA images were taken at baseline, six weeks, three, six, 12, and 24 months postoperatively. Clinical and functional outcomes were compared postoperatively for two years.Aims
Methods
Aims. The removal of the cruciate ligaments in total knee arthroplasty (TKA) has been suggested as a potential contributing factor to patient dissatisfaction, due to alteration of the in vivo biomechanics of the knee. Bicruciate retaining (BCR) TKA allows the preservation of the cruciate ligaments, thus offering the potential to reproduce healthy kinematics. The aim of this study was to compare in vivo kinematics between the operated and contralateral knee in patients who have undergone TKA with a contemporary
To address the current challenge of anterior cruciate ligament (ACL) reconstruction, this study is the first to fabricate a braided collagen rope (BCR) which mimics native hamstring for ACL reconstruction. The study aims to evaluate the biological and biomechanical properties of
Introduction. A bicruciate retaining (BCR) TKA is thought to maintain a closer resemblance to the native knee kinematics compared to a posterior cruciate retaining (CR) TKA. With
Introduction. Inability to reproduce 6-degrees of freedom (6DOF) kinematics, abnormal “paradoxical” anterior femoral translation and loss of normal medial pivot rotation are challenges associated with contemporary posterior cruciate retaining and posterior stabilized total knee arthroplasty (TKA). The removal of the anterior and/or both cruciate ligaments in CR/PS TKA, leading to significant kinematic alteration of the knee joint, has been suggested as one of the potential contributory factors in patients remaining dissatisfied after TKA. Bi-cruciate retaining (BCR) TKA designs allow preservation of both anterior and posterior cruciate ligaments with the potential to replicate normal knee joint kinematics. Physically demanding tasks such as sit-to-stand (STS), and deep lunging may be more sensitive tools for investigating preserved kinematic abnormalities following TKA. This study aims to compare in-vivo kinematics between the operated and the contralateral non-operated knee in patients with contemporary
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
Background. While posterior cruciate retaining (PCR) implants are a more common total knee arthroplasty (TKA) design, newer bi-cruciate retaining (BCR) TKAs are now being considered as an option for many patients, especially those that are younger. While PCR TKAs remove the ACL, the
Bi-cruciate-retaining (BCR) total knee arthroplasty (TKA), which retains both the anterior (ACL) and posterior cruciate (PCL) ligaments, serves as an alternative to the traditional TKA procedure. Despite the difficulty of ensuring the structural integrity of the prosthesis, the
Introduction. Preservation of the anterior cruciate ligament (ACL), along with the posterior cruciate ligament, is believed to improve functional outcomes in total knee replacement (TKR). The purpose of this study was to examine gait differences and muscle activation levels between ACL sacrificing (ACL-S) and bicruciate retaining (BCR) TKR subjects during level walking, downhill walking, and stair climbing. Methods. Ten ACL-S (Vanguard CR) (69±8 yrs, 28.7±4.7 kg/m2) and eleven
Introduction. Many fluoroscopic studies on total knee arthroplasty (TKA) have identified kinematic variabilities compared to the normal knee, with many subjects experiencing paradoxical motion patterns. The intent of this study was to investigate the results of a newly designed PCR TKA to determine kinematic variabilities and assess these kinematic patterns with those previously documented for the normal knee. Methods. The study involves determining the in vivo kinematics for 80 subjects compared to the normal knee. 10 subjects have a normal knee, 40 have a Journey II PCR TKA and 40 subjects with the Journey II XR TKA (BCR). Although all PCR subjects have been evaluated, we are continuing to evaluate subjects with a
INTRODUCTION. In native knees anterior cruciate ligament (ACL) and asymmetric shape of the tibial articular surface with a convex lateral plateau are responsible for differential medial and lateral femoral rollback. Contemporary ACL retaining total knee arthroplasty (TKA) improves knee function over ACL sacrificing (CR) TKA; however, these implants do not restore the asymmetric tibial articular geometry. This may explain why ACL retention addresses paradoxical anterior sliding seen in CR TKA, but does not fully restore medial pivot motion. To address this, an ACL retaining biomimetic implant, was designed by moving the femoral component through healthy in vivo kinematics obtained from bi-planar fluoroscopy and sequentially removing material from a tibial template. We hypothesized that the biomimetic articular surface together with ACL preservation would better restore activity dependent kinematics of normal knees, than ACL retention alone. METHODS. Kinematic performance of the biomimetic
Purpose. Total knee replacement is the one of the most performed surgeries. However, patient's satisfaction rate is around 70–90 % only. The sacrifice of cruciate ligament might be the main reason, especially in young and active patients. ACL stabilizes the knee by countering the anterior displacing and pivoting force, absorbs the shock and provides proprioception of the knee. However, CR knees has been plagued by injury of PCL during the surgery and preservation of the ACL is a demanding technique. Stiffness is more common comparing to PS designed knee. To insert a tibial baseplate with PE is usually thicker than 8 mm comparing to 2–4 mm of removed tibial bone. The stuffing of joint space may put undue tension on preserved ACL and PCL. Modern designed
Background. Total knee arthroplasty (TKA) is an effective surgical procedure to alleviate excruciating pain and correct dysfunction due to severe knee deformity. The satisfaction rate with current TKA is 80%, While 20% of the patients report uncomfortable feeling during stair descending and deeply knee bending. Preserving the ligaments might allow a restoration close to the natural function, although sacrifice of the ACL is common with the conventional TKA technique. The current bicruciate-retaining (BCR) TKA would be a way to go concerning this issue. This study aimed at evaluating the intraoperative kinematics and joint laxity on
INTRODUCTION. ACL retaining (BCR) Total Knee Arthroplasty (TKA) provides more normal kinematics than ACL sacrificing (CR) TKA. However, in the native knee the ACL and the asymmetric shape of the tibial articular surface with a convex lateral plateau are responsible for the differential medial/lateral femoral rollback (medial pivot). Therefore, the hypothesis of this study was that an asymmetric biomimetic articular surface together with ACL preservation would better restore native knee kinematics than retention of the ACL alone. Normal knee kinematics from bi-planar fluoroscopy was used to reverse engineer the tibial articular surface of the biomimetic implant. This was achieved by moving the femoral component through the healthy knee kinematics and removing material from a tibial template. METHODS. LifeModeler KneeSIM software was used to analyze a biomimetic
Aim. In cases of prosthetic joint infections the sensitivity of bacterial cultivation of tissue samples is not 100%. In fact, the reported sensitivity based on standardized criteria and rigorous tissue sampling technique probably differs between 86 to 89%. It has been claimed that sonication of explanted prostheses with subsequent culturing of sonication fluid can increase the sensitivity of the test compared to culturing of tissue samples. To what degree bacteria embedded in biofilm is dislodged during the sonication process has to our knowledge not been fully elucidated. We studied the effect of sonication as a method to dislodge biofilm embedded Staphylococcus epidermidis in vitro. Method. 46 steel plates were colonized with biofilm forming S. epidermidis ATCC 35984 in TSB with 1% glucose aerobically at 37°C for 24 hours. Plates were cleansed for non-adherent bacteria before microscopy. Biofilm embedded bacteria were stained with LIVE/DEAD ™ BacLight ™ Bacterial Viability Kit for microscopy and visualized under vital conditions using EVOS™ FL Auto 2 Imaging System (epifluorescence) and an inverse confocal laser scanning microscope LSM510 (CLSM). All steel plates were subjected to epifluorescence microscopy before and after sonication. CLSM and SEM were used to confirm the presence of biofilm embedded bacteria after sonication. Pictures from epifluorescence microscopy were processed for image analysis with help of a macro application (Fiji) and the data was expressed as biofilm coverage rate (BCR). The sonication was performed using a BactoSonic® Bandolin sonicator and the applied effect in each glass test tube (40 kHz, 800W) was measured with a Bruel og Kjær 8103 hydrophone. The amount of bacteria in the sonication fluid was quantified by counting the number of colony forming units (CFU). Three steel plates acted as negative controls. Results. The
The bi-cruciate retaining (BCR) total knee arthroplasty (TKA) is based on sound biomechanics to produce kinematics close to normal, which is the goal of
The goal was to evaluate tibiofemoral knee joint kinematics during stair descent, by simulating the full stair descent motion in vitro. The knee joint kinematics were evaluated for two types of knee implants: bi-cruciate retaining and bi-cruciate stabilized. It was hypothesized that the bi-cruciate retaining implant better approximates native kinematics. The in vitro study included 20 specimens which were tested during a full stair descent with physiological muscle forces in a dynamic knee rig. Laxity envelopes were measured by applying external loading conditions in varus/valgus and internal/external direction.Aims
Methods
Multiple contemporary TKA designs that sacrifice the anterior cruciate ligament and then either retain or substitute for the posterior cruciate ligament have demonstrated-records of good durability and good function across joint registries worldwide. In recent years there has been an emphasis on improving function in TKA and to that end various strategies including changes in surgical alignment targets (kinematic alignment), the addition of advanced technologies such as computer navigation and sensors in trial components, the expansion of indications for unicompartmental knee arthroplasty and the re-introduction of total knee implants that preserve both the ACL and PCL have been championed. Early ACL/PCL retaining total knee implants had mixed results with some designs failing while others championed by Cloutier and by Pritchett have had some success in regard to reasonable durability. Unfortunately those early designs, despite decent durability, did not conclusively demonstrate better function. More recently a new bi-cruciate retaining TKA was introduced with some substantial fanfare. Unfortunately, the widely touted theoretical or potential benefits of bi-cruciate preservation (in regard to better function) have failed to materialise or have been offset by a higher than expected re-operation rate. Even some of the initial proponents of the bi-cruciate implants have noted that the short-term findings are not very encouraging. The largest report to date shows 5% vs. 1.6% all-cause revision at 1 year (BCR vs. CR, respectively) and no improvement in standardised patient reported outcome measures. Some have placed their hopes for
Lumbar spinal stenosis (LSS) is a common skeletal system disease that has been partly attributed to genetic variation. However, the correlation between genetic variation and pathological changes in LSS is insufficient, and it is difficult to provide a reference for the early diagnosis and treatment of the disease. We conducted a transcriptome-wide association study (TWAS) of spinal canal stenosis by integrating genome-wide association study summary statistics (including 661 cases and 178,065 controls) derived from Biobank Japan, and pre-computed gene expression weights of skeletal muscle and whole blood implemented in FUSION software. To verify the TWAS results, the candidate genes were furthered compared with messenger RNA (mRNA) expression profiles of LSS to screen for common genes. Finally, Metascape software was used to perform enrichment analysis of the candidate genes and common genes.Aims
Methods
Purpose: Complete distal biceps tendon ruptures (DBTRs) require prompt surgical management for optimal functional and aesthetic outcome. Waiting for confirmatory diagnostic imaging can often delay timely surgical referral of these injuries. The need exists for a valid and reliable diagnostic tool to expedite appropriate referrals for surgery. Method: Based on the hypothesis that complete distal biceps tendon rupture leads to an objectively measurable increase in the “biceps crease interval” (BCI) due to proximal retraction of the musculotendinous complex, three independent examiners established “normal” biceps crease intervals (N-BCI) for 80 males (average age = 43 years) with no history of biceps injury. Given acceptable inter-rater reliability (ICC >
0.70), a mean N-BCI value was established and a normal biceps crease ratio (N-BCR) between right and left arms was calculated. Correlations with arm dominance, biceps circumference, and age were determined. Diagnostic N-BCI and N-BCR thresholds were applied to 23 consecutive patients presenting with a possible complete DBTR to determine the diagnostic value of the BCI Test. A definitive diagnosis was confirmed at surgery and/or by radiographic imaging. Results: The BCI Test had acceptable inter-rater reliability (ICC= 0.794, p = <
0.001). The mean N-BCI for both dominant and non-dominant arms was 4.8 +/− 0.6 cm. The mean N-BCR was 1.0 +/− 0.1. Applied to an injured population, using a diagnostic threshold of two standard deviations above “normal” values (BCI >
6.0 cm,