40 patients with non-inflammatory arthrosis and minor preoperative deformity (< or =5 degrees ) were operated on with an AMK type (DePuy, Johnson & Johnson) total knee arthroplasty (TKA). The posterior cruciate ligament was retained. The patients were divided into those with a flat (terminology of the manufacturer: standard) or a concave (terminology of the manufacturer: constrained) polyethylene insert (20 in each group). Radiostereometric (RSA) examinations were done postoperatively and after 3,12 and 24 months. The median absolute rotations of the tibial inserts varied between 0.12 and 0.24 (range 0.00-1.54) degrees, with no differences between the 2 groups. The median maximum total-point motions (flat/concave = 0.41/0.42 mm), the maximum subsidence or lift-off did not differ. The Hospital for Special Surgery knee score and the patients' opinion about the operation, based on their preoperative expectations, showed little, if any, differences. At 2 years, 10 of 20 patients with flat and 13 of 19 with concave inserts regarded their knee function as normal or almost so.

Download full-text PDF

Source
http://dx.doi.org/10.1080/00016470152846583DOI Listing

Publication Analysis

Top Keywords

flat concave
8
total knee
8
knee arthroplasty
8
terminology manufacturer
8
concave tibial
4
tibial joint
4
joint surface
4
surface total
4
knee
4
arthroplasty randomized
4

Similar Publications

Difficult-to-cut titanium matrix composites (TMCs) are widely used in the aerospace, automotive, and defense sectors due to their excellent physical properties. Electrochemical mill grinding (ECMG) can achieve the processing effects of electrochemical milling and electrochemical grinding using the same tool, which has the potential to complete the rough and finish machining of TMCs in succession. However, in the rough machining stage, the bottom of the slot becomes concave due to the inevitable stray corrosion, leading to poor flatness, which increases the machining allowance for subsequent finish machining.

View Article and Find Full Text PDF

Objective: Profileplasty traditionally involves improving a nasal hump or an underprojected chin. However, this procedure can correct other facial defects like saddle nose or prognathism. To establish the best overall profile, the nose, the midface, and the chin should be considered altogether.

View Article and Find Full Text PDF

People with an outward peristomal body profile can experience difficulties obtaining a secure seal with a flat baseplate to the peristomal skin. Baseplates with a concave contour have been designed to provide a better fit to curved body profiles and reduce the risk of leakage. In this 4-week product evaluation, 110 individuals with an outward peristomal body profile using flat one-piece pouching systems were enrolled to evaluate the impact of a concave one-piece pouching system on wear time, unplanned changes of pouching systems and use of accessories.

View Article and Find Full Text PDF

The spin Hall effect of light, a phenomenon characterized by the transverse and spin dependent splitting of light at an optical interface, is highly promising for collecting precise quantitative data from interfaces and stands as an appealing option for improving precision metrology. This high level of precision is attributed to the principles of weak measurement. Since its conceptual introduction, the spin Hall effect of light has been empirically observed through weak measurement techniques, adhering closely to the initially proposed experimental configuration.

View Article and Find Full Text PDF
Article Synopsis
  • The study explores how thermal bonding and concave end faces impact the performance of 795 nm laser diodes (LD) when used to pump Tm:YAP crystals.
  • Concave end faces help to counteract thermal lensing effects, allowing for higher power output, reaching 42.5 W with a slope efficiency of 47.4% and optical-optical conversion efficiency of 41.6%.
  • Compared to flat bonding rods, the concave design improves the maximum output power and efficiencies, demonstrating its effectiveness in enhancing heat dissipation and laser performance.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!