Osseous anatomy of the scapula.

Detailed anatomy and morphometry of the scapula were obtained to provide information for surgical procedures such as hardware fixation, drill hole placement, arthroscopic portal placement, and prosthetic positioning. Twenty-six measurements were made in 15 pairs of scapulas from cadavers. The average length of the scapulas from the superior to the inferior angle was 155 +/- 16 mm (mean +/- standard deviation). The thickness of the medial border 1 cm from the edge was 4 +/- 1 mm. The superior border was sharp and thin, and the suprascapular notch was present as a foramen in two scapulas. The distance from the base of the suprascapular notch to the superior rim of the glenoid was 32 +/- 3 mm. The length of the spine from the medial edge of the scapula to the lateral edge of the acromion was 134 +/- 12 mm. The anteroposterior width of the spine at 1 and 4 cm from the medial edge was 7 +/- 1 and 18 +/- 3 mm, respectively; the width at the lateral edge (spinoglenoid notch) was 46 +/- 6 mm. The acromion measured 48 +/- 5 mm x 22 +/- 4 mm and was 9 +/- 1 mm thick. The acromial shape was flat in 23%, curved in 63%, and hooked in 14% of scapulas. The distance from the glenoid to the acromion was 16 +/- 2 mm. The glenoid dimensions were 29 +/- 3 mm (anteroposterior) x 36 +/- 4 mm (superoinferior) and faced posterior by 8 +/- 4 degrees. Anteroposterior thickness of the head of the scapula 1 cm from the surface was 22 +/- 4 mm. The thickness of the coracoid was 11 +/- 1 mm. The average length of the coracoacromial ligament was 27 +/- 5 mm. Scapulas from male cadavers were significantly larger than scapulas from female cadavers in 19 measurements.

Immunohistochemical localization of beta 1-integrins in anterior cruciate and medial collateral ligaments of human and rabbit.

The integrins are a family of adhesion-mediating cell surface receptors that play critical roles in cell-extracellular matrix interactions and have been shown to be important in the healing response in several tissues. We have studied integrin expression in normal human and rabbit anterior cruciate (ACL) and medial collateral (MCL) ligaments of the knee as a preamble to studies of beta 1-integrin expression in healing ligaments. Histologic sections of human and rabbit ACL and MCL were probed for integrin expression utilizing integrin-specific monoclonal antibodies (mAbs) followed by immunoperoxidase detection. Staining of human specimens with mAbs revealed the presence of beta 1-, alpha 1-, and alpha 5-integrin chains on the tissue fibroblasts of both ACL and MCL, while staining of rabbit specimens with rabbit integrin-reactive monoclonals revealed the presence of beta 1- and alpha 5-integrin on these ligaments. Equivalent amounts of the integrins studied were present on normal ACL and MCL. We conclude that the rabbit is an appropriate model for analyzing the expression and functional role of integrins in ligament wound healing.

Age-related properties of medial collateral ligament and anterior cruciate ligament: a morphologic and collagen maturation study in the rabbit.

The medial collateral ligament (MCL) and anterior cruciate ligament (ACL) from New Zealand white rabbits ages 2, 12, and 36 mos were resected and utilized for analysis by light microscopy and electron microscopy, as well as for determinations of water content, collagen concentration, collagen crosslink (i.e., reducible, nonreducible) analysis, and collagen synthesis rates in vitro. Both modes of microscopy revealed substantial differences between the various age groups. Water content, as well as collagen concentration, decreased significantly from the 2-mo to the 12- or 36- mo groups. The concentration of the reducible crosslinks, associated with less mature tissue, was significantly greater in the younger tissues relative to the aged tissues. The nonreducible crosslink increased with maturation of the collagen in the 36-mo rabbits. Collagen synthesis rates fell from a highest value in the 2-mo group to the lowest in the 36-mo group.