Balancing of joint gap is a prerequisite in total knee arthroplasty (TKA). Recently, the tensor has been developed which can measure the joint gap with the patellofemoral joint reduced for more physiological assessment, and the results for osteoarthritis (OA) patients indicated that the flexion gap is larger than the extension gap during posterior-stabilized (PS) TKA. However with respect to the rheumatoid arthritis (RA) patients, the soft tissue balance in TKA is still unknown. Therefore, the purpose of this study was toinvestigate thecharacteristics of thejoint gap during TKAsurgeryforpatients with RA. We implanted 90 consecutive knees with a PS TKA using a NexGen LPS-flex (Zimmer, Warsaw, IN). OA was the underlying disease in 60 knees and RA was the disease in30 knees.Introduction
Methods
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 joint laxity exists in mid-range to deep knee flexion, postoperatively. We hypothesized that retaining the PCL or not during TKA has an influence on the postoperative joint laxity from mid-range to deep knee flexion. The purpose of this study was to investigate the postoperative coronal joint laxity throughout the full range of motion by the 3-dimensional in vivo analysis, both in PS and CR TKA. We implanted 5 knees with a PS TKA using a NexGen LPS-flex and 5 knees with a CR TKA using a NexGen CR-flex. All of them were the osteoarthritis patients. We performed all operations with a measured resection technique. Four weeks after TKA, the valgus- and varus-stress radiographic assessments were performed at the five flexion angles from full extension to maximum flexion. The patients sat on the radiolucent chair with their lower legs hanging down. The examiner held their thigh, and a force of 50N was applied 30 cm distal to the tibiofemoral joint. The series of static fluoroscopic images via a flat panel detector were stored digitally. A 3-dimentional to 2-dimentional techniqueusing an automated shape-matching algorithm was employed to determine the relative 3-dimentional positions of the femoral component and tibial component in each fluoroscopic image (KneeMotion; LEXI, Tokyo). On the coronal plane of the tibial component, the angle between the tangent line of the condyles of the femoral component and the tibial plateau was measured as the joint laxity for valgus (α valgus) or varus (α varus). The flexion angle between the femoral component and tibial component was also measured.Introduction:
Methods:
We measured the serum concentration of C-reactive protein (CRP) by a high-sensitive method in patients with lumbar disc herniation. There were 48 patients in the study group and 53 normal controls. The level and type of herniation were evaluated. The clinical data including the neurological findings, the angle of straight leg raising and post-operative recovery as measured by the Japanese Orthopaedic Association (JOA) score, were recorded. The high-sensitive CRP (hs-CRP) was measured by an ultrasensitive latex-enhanced immunoassay. The mean hs-CRP concentration was 0.056 ± 0.076 mg/dl in the patient group and 0.017 ± 0.021 mg/dl in the control group. The difference was statistically significant (p = 0.006). There was no other correlation between the hs-CRP concentration and the level and type of herniation, or the pre-operative clinical data. A positive correlation was found between the concentration of hs-CRP before operation and the JOA score after. Those with a higher concentration of hs-CRP before operation showed a poorer recovery after. The significantly high concentration of serum hs-CRP might indicate a systemic inflammatory response to impingement of the nerve root caused by disc herniation and might be a predictor of recovery after operation.
