The role of elbow positioning on arthroscopic assessment of the long head of biceps tendon in the beach chair position.

Background: Tendinopathy of the long head of biceps (LHB) tendon is a common cause of anterior shoulder pain and dysfunction. The extra-articular portion within the bicipital groove undergoes frequent load and friction during shoulder movements and pathology within this area is frequently missed during arthroscopic assessment.

Methods: We quantified the arthroscopically assessable length of tendon within the shoulder in 14 consecutive patients undergoing subpectoral biceps tenodesis.

Characterization of the Proximal Long Head of Biceps Tendon Anatomy Using Magnetic Resonance Imaging: Implications for Biceps Tenodesis.

Background: Biceps tenodesis is a common treatment for proximal long head of biceps (LHB) tendon pathology. To maintain biceps strength and contour and minimize cramping, restoration of muscle-length tension and appropriate positioning of the tenodesis is key. Little is known about the biceps musculotendinous junction (MTJ) anatomy, especially in relation to the overlying pectoralis major tendon (PMT), which is a commonly used landmark for tenodesis positioning.

Minimizing Propionibacterium acnes contamination in shoulder arthroplasty: use of a wound protector.

Background: Propionibacterium acnes may be transmitted from the subdermal tissues to the deeper tissues during shoulder arthroplasty surgery, resulting in deep infection. The aim of this prospective, clinical study was to determine whether the use of a wound protector drape can lower the incidence of P. acnes in the wound during shoulder arthroplasty surgery.

Cohesion fatigue induces chromatid separation in cells delayed at metaphase.

Background: Chromosome instability is thought to be a major contributor to cancer malignancy and birth defects. For balanced chromosome segregation in mitosis, kinetochores on sister chromatids bind and pull on microtubules emanating from opposite spindle poles. This tension contributes to the correction of improper kinetochore attachments and is opposed by the cohesin complex that holds the sister chromatids together.

Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited.

Mitosis requires precise coordination of multiple global reorganizations of the nucleus and cytoplasm. Cyclin-dependent kinase 1 (Cdk1) is the primary upstream kinase that directs mitotic progression by phosphorylation of a large number of substrate proteins. Cdk1 activation reaches the peak level due to positive feedback mechanisms.