summaryThe development of a bone-bonding calcia-phosposilicate glass-ceramic is discussed. A theoretical model to explain the interfacial bonding is based upon in-vitro studies of glass-ceramic solubility in interfacial hydroxyapatite crystallization mechanisms, compared with in-vivo rat femur implant histology and ultrastructure results.

No abstract

The snapping hip syndrome is a symptom complex characterized by hip pain and an audible snapping of the hip with exercise typically seen in young individuals. "External" and "internal" etiologies have been described, although the "internal" etiology is poorly understood. A clinical, radiographic, and anatomical study of eight patients with this disorder, secondary to an internal etiology, was undertaken to aid in the diagnosis and surgical treatment. Iliopsoas bursography with cineradiography revealed subluxation of the iliopsoas tendon to be an apparent cause of the snapping hip. The anatomy of the hip in relationship to the iliopsoas tendon is defined with the anterior inferior iliac spine, iliopectineal eminence, and lesser trochanter assuming a significant role in the syndrome. An operative approach involving a partial release and lengthening of the iliopsoas tendon, with minimal resection of a lesser trochanteric bony ridge, if involved, is described.

Eighteen patients with 20 symptomatic hips underwent lengthening of the iliopsoas tendon for persistent painful snapping of this "internal" variety of snapping hip. We referred to the pathologic, painful snapping of the iliopsoas in the deep anterior groin as the "internal" snapping hip. This is in contrast to the more common and better-known "external" snapping that involves the greater trochanter and its overlying soft tissues. The results of our iliopsoas lengthening procedure are presented here. Lengthening of the iliopsoas tendon was accomplished by step cutting of the tendinous portion of the iliopsoas. The pathoanatomy of this poorly understood symptom complex was described in 1984 paper from this institution and is reviewed here. Iliopsoas bursography demonstrated a sudden jerking movement of the iliopsoas tendon between the anterior inferior iliac spine and iliopectineal eminence, synchronous with the patient's pain and often accompanied by an audible snap. The average preoperative duration of symptoms was 2.9 years, and the average length of postoperative followup was 25 months. All patients, except one, had a marked reduction in the frequency of snapping after tendon lengthening, and 14 of 20 hips had no snapping postoperatively. Of the six patients who had recurrence of snapping, all but one stated that this occurred much less frequently and was much less painful compared to the preoperative state. Two hips required reoperation. Postoperatively, only three patients complained of subjective weakness, and most patients were unlimited in physical activity with return to activities such as competitive football, pole vaulting, and long-distance running.(ABSTRACT TRUNCATED AT 250 WORDS)

In this series, primary iliopsoas tendon lengthening in patients with internal coxa saltans was without any complication in only 60% of patients; however, overall patient satisfaction was 89%.