Incidence of mitral valve prolapse in adolescent scoliosis and thoracic hypokyphosis.

Seventy-four patients with adolescent scoliosis underwent cardiac examination and M-mode echocardiography to detect the presence of mitral valve prolapse (MVP). Twenty-one (28%) had echocardiographic evidence of MVP, whereas 18 had auscultatory findings of a nonejection click or late systolic murmur. A subset of 41 patients had a family history of scoliosis and 37% had MVP. The incidence of MVP increased to 41% when a first degree relative, such as a sibling, parent, or offspring, had scoliosis. Thirty-six patients with scoliosis had additional thoracic hypokyphosis (straight back) and 13 (36%) had MVP. The incidence of MVP was 48% when the scoliosis and hypokyphosis were hereditary and increased to 53% when a familial history of skeletal abnormality was present. This study indicates a high incidence of MVP in patients with scoliosis and hypokyphosis, especially when the cardiac and skeletal systems may be affected by a generalized soft-tissue defect.

Freeze-dried allogeneic segmental cortical-bone grafts in dogs.

Forty-four adult male mongrel dogs were used to compare segmental cortical freeze-dried allogeneic bone grafts with fresh autogenous, freeze-dried autogenous, and fresh allogeneic segmental cortical grafts. Group I consisted of bilateral fresh autografts as external controls; Group II, a fresh autograft on one side for internal control and a freeze-dried autogenous graft on the other side to evaluate the effect of freeze-drying on repair; Group III, a fresh autograft on one side and a fresh allograft on the other side to measure the differences between autogenous and allogeneic grafts; and Group IV, a fresh autograft on one side and a freeze-dried allogeneic graft on the other to see if freeze-drying altered the repair of allogeneic grafts. The grafts were analyzed qualitatively over a six-month period by the use of interval roentgenograms to determine the times of graft-host union and the incidence of fatigue fractures. Six months after operation, the repair processes in the four groups were compared quantitatively with respect to biological repair and physical strength using torsional stress-testing, tetracycline labeling, and microradiography. The results indicate both qualitatively and quantitatively that: (1) fresh bilateral segmental cortical autografts show reproducible characteristics, so that the canine fibula furnishes a satisfactory model (Group I); (2) freeze-drying does not inhibit the repair process per se (Group II); (3) fresh allografts are rejected in varying degrees of intensity (Group III); and (4) freeze-drying does not protect cortical allogeneic grafts from such rejection (Group IV).