Treatment of the Fixation Surface Improves Glenoid Prosthesis Longevity in vitro.

Unlabelled: Many commercial cemented glenoid components claim superior fixation designs and increased survivability. However, both research and clinical studies have shown conflicting results and it is unclear whether these design variations do improve loosening rates. Part of the difficulty in investigating fixation failure is the inability to directly observe the fixation interface, a problem addressed in this study by using a novel experimental set-up.

Failure mechanism of the all-polyethylene glenoid implant.

Fixation failure of glenoid components is the main cause of unsuccessful total shoulder arthroplasties. The characteristics of these failures are still not well understood, hence, attempts at improving the implant fixation are somewhat blind and the failure rate remains high. This lack of understanding is largely due to the fundamental problem that direct observations of failure are impossible as the fixation is inherently embedded within the bone.

The structural properties of the lateral retinaculum and capsular complex of the knee.

Unlabelled: Although lateral retinacular releases are not uncommon, there is very little scientific knowledge about the properties of these tissues, on which to base a rationale for the surgery. We hypothesised that we could identify specific tissue bands and measure their structural properties. Eight fresh-frozen knees were dissected, and the lateral soft tissues prepared into three distinct structures: a broad tissue band linking the iliotibial band (ITB) to the patella, and two capsular ligaments: patellofemoral and patellomeniscal.

Loss of rotator cuff tendon-to-bone interface pressure after reattachment using a suture anchor.

The purpose of this study was to examine the tendon-to-bone interface pressure, contact area, and force after reattaching a tendon to bone by use of a suture and suture anchor. Repairs were made in 8 ovine shoulders in vitro, by use of 3 suture types in each: Ethibond, polydioxanone, or Orthocord. A Tekscan pressure sensor was placed between the tendon and bone and monitored for 1 hour after the repair.

Definition of the capsular insertion plane on the proximal humerus.

The aim of this work was quantitatively to establish the relationship between the plane that hosts the humeral head lateral margin (anatomical neck) and that of the capsular insertion. Eight cadaveric shoulders were used. These were dissected, exposing the humeral head margin and the root of the capsular humeral insertion to extract digitally their outlines using a mechanical 3-d digitizer.