Hiromichi Hama

Arthroscopic multiple osteochondral transplantation to the chondral defect in the knee associated with anterior cruciate ligament disruption

Treatment of a chondral lesion in the knee, associated with anterior cruciate ligament disruption, is known to be difficult and controversial. This article presents an arthroscopic technique for transplantation of multiple osteochondral fragments, harvested from the same knee, to this chondral lesion. A 3-year follow-up shows excellent results with good cartilage repair confirmed by second-look arthroscopy.

Experimental Studies on Connective Tissue of the Capsular Ligament: Influences of Aging and Sex Hormones

Influences of aging and sex hormones on connective tissue metabolism in the hip joint capsule of Wistar rats were analyzed both biochemically and morphologically. As age advanced, collagen content and collagen fibril diameter of the hip joint capsule tended to increase gradually in both sexes until sexual maturation was reached. Collagen content was significantly greater in males than in females after sexual maturation. The collagen content and fibril diameter were considerably increased by ovariectomy and significantly decreased by the administration of estrogen, or estrogen combined with progesterone, whereas they were significantly increased by the administration of testosterone in orchiectomized male rats.

A new strategy for treatment of suprascapular entrapment neuropathy in athletes: Shaving of the base of the scapular spine

A study of three volleyball teams comprising 40 players demonstrated the frequent occurrence of infraspinatus muscle atrophy. Anatomic studies of the suprascapular nerve in 20 cadavers revealed the possibility of entrapment of the nerve at the spinoglenoid notch. Four athletes with suprascapular neuropathy were followed up after surgical treatment. Shaving of the lateral edge of the base of the scapular spine proved effective. However, it is suggested that preventive measures such as strengthening of the infraspinatus muscle are important because suprascapular neuropathy in athletes is combined to at least some degree with damage to the muscle itself.

The mechanical strength of the growth plate under the influence of sex hormones.

: As sex hormones are considered to play a role in the etiology of the slipped upper femoral epiphysis, the influence of sex hormones on the mechanical strength of the epiphyseal plate was investigated in 310 female and 70 male rats. Ovariectomy weakened the strength of the growth plate while orchiectomy strengthened it. Estrogen given after ovariectomy, markedly strengthened the plate. Histologic examination revealed that the width of the growth plate was narrower in the mechanically stronger group. Hydroxyproline content increased and hexosamine content decreased in the epiphyseal plates of the mechanically stronger group. These observations confirm the view that sex hormones, especially estrogen, regulate the mechanical, morphologic, and biochemical functions of the growth plate.