INTRODUCTION. During TKA surgery, the usual goal is to achieve equal balancing between the lateral and medial side, which can be achieved by ligament releases or “pie crusting”. However little is known regarding a relationship between the balancing forces on the medial and lateral plateaus during TKA surgery, and the varus and valgus and rotational
Preoperative ligament laxity can be characterized intraoperatively using digital robotic tensioners. Understanding how preoperative knee joint laxity affects preoperative and early post-operative patient reported outcomes (PROMs) may aid surgeons in tailoring intra-operative balance and
Inverse Kinematic Alignment (iKA) and Gap Balancing (GB) aim to achieve a balanced TKA via component alignment. However, iKA aims to recreate the native joint line versus resecting the tibia perpendicular to the mechanical axis. This study aims to compare how two alignment methods impact 1) gap balance and
Introduction. Surgeons commonly resect additional distal femur during primary total knee arthroplasty (TKA) to correct a flexion contracture to restore range of motion and knee function. However, the effect of joint line elevation on the resulting TKA kinematics including frontal plane
The aim of an anterior cruciate ligament (ACL) reconstruction is to regain functional stability of the knee following ACL injury, ideally allowing patients to return to their pre-injury level of activity. The purpose of this study was to assess clinical, functional and patient-reported outcomes following primary ACL reconstruction with hamstring autograft. A prospective case-series design (n=1610) was used to gather data on post-operative ACL graft
The primary purpose of this study was to assess whether patients presenting with clinical graft
Introduction. When performing total knee arthroplasty (TKA), surgeons often utilize a posterior-stabilized (PS) design which compensates for the loss of the posterior cruciate ligament (PCL). These designs attempt to replicate normal knee kinematics and loading using a cam and post to provide posterior restraint of the tibia during flexion. However, these designs may not be able to compensate for the increase in flexion space or the inherent loss of coronal stability after PCL release compared to a cruciate retaining (CR) design. This study aimed to compare stability of PS and CR TKA designs by assessing
Postero-lateral rotator instability (PLRI) is the most common pattern of recurrent elbow instability. Unfortunately, current imaging to aid PLRI diagnosis is limited. We have developed an ultrasound (US) technique to measure ulnohumeral joint gap with and without stress of the lateral ulnocollateral ligament. We sought to define lateral ulnohumeral joint gap measurements in the resting and stressed state to provide insight into how US may aid diagnosis of PLRI. Sixteen elbows were evaluated in eight healthy volunteers. Lateral ulnohumeral gap was measured on US in the resting position and with posterolateral drawer stress test maneuver applied.
Introduction. Total knee arthroplasty (TKA) is a successful procedure for end stage arthritis of the knee that is being performed on an exponential basis year after year. Most surgeons agree that soft tissue balancing of the TKA is a paramount to provide a successful TKA. We utilized a set of retrieved lower extremities with an existing TKA to measure the
Introduction. Total knee arthroprasty (TKA) is an excellent treatment with osteoarthritis of the knee joint. The acquisition of joint stability after TKA is one of the most important factors to improve the patient's quality of life. Deep flexion of knee joint is often demanded in daily life, and stability in flexed knee position is also important. But there were few papers reporting about
Introduction. The aim of this study was to quantify mid-flexion
INTRODUCTION. There are many factors which contribute to function after TKA. In this study we focus on the effect of varus-valgus (VV) balancing measured externally. A loose knee can show instability (Sharkey 2014) while too tight, flexion can be limited. Equal lateral-medial balancing at surgery leads to a better result (Unitt 2008; Gustke 2014), which is generally the surgical goal. Indeed similar varus and valgus
Functional joint stability and accurate component alignment are crucial for a successful clinical outcome after TKA. However, there are few methods to evaluate joint stability during TKA surgery. Activities of daily living often cause mechanical load to the knee joint not only in full extension but also in mid-flexion. Computer navigation systems are useful for intra-operative monitoring of joint positioning and movements. The purpose of this study was to compare the varus-valgus stability between knees treated with cruciate-retaining (CR) and posterior-stabilized (PS) TKA at different angles in the range of motion (ROM) especially in mid-flexion, using the navigation technique. Thirty two knees that underwent TKA with computer navigation technology (precisionN Knee Navigation Software version 4.0, Stryker, Kalamazoo, MI) were evaluated (CR:16; PS:16). The investigator gently applied physiologically allowable maximal manual varus-valgus stress to the knee without angular acceleration, while moving the leg from full extension to flexion, and the mechanical femoral-tibial angle was measured automatically by the navigation system at every 10 degrees throughout the ROM. This measurement cycle was repeated for 3 to 4 times, and maximal varus-valgus
Introduction:. One of the important factors for success in TKA is to achieve proper stability of the knee joint. It is currently unknown that how much
Introduction. The aim of this study was to quantitatively analyze the amount coronal plane
Introduction. The aim of this study was to quantitatively analyze the amount coronal plane
The aim of an anterior cruciate ligament (ACL) reconstruction is to regain functional stability of the knee following ACL injury, ideally allowing patients to return to their pre-injury level of activity. The purpose of this study was to assess clinical, functional and patient-centered outcomes a minimum of 1-year following ACL reconstruction. This study assessed for relationships between post-operative ACL graft
Knee laxity following anterior cruciate ligament (ACL) injury is a complex phenomenon influenced by various biomechanical and anatomical factors. The contribution of soft tissue injuries – such as ligaments, menisci, and capsule – has been previously defined, but less is known about the effects of bony morphology. (Tanaka et al, KSSTA 2012) The pivot shift test is frequently employed in the clinical setting to assess the combined rotational and translational
This study was performed to measure intra-operative varus-valgus
Background. To improve implant positioning in total knee arthroplasty (TKA) patient-specific instrumentation (PSI) has been introduced as alternative for conventional instrumentation (CI). Though the PSI technique offers interesting opportunities in TKA, there is no consensus about the effectiveness of PSI in comparison with CI and results concerning soft-tissue balancing remain unclear. Therefore, the primary aim of the present study was to investigate the varus-valgus