The influence of intermittent external dynamic pressure and tension forceson the healing of an epiphyseal fracture

Breburda, E Wirth, T Leiser, R Griss, P

E. Breburda et al., The influence of intermittent external dynamic pressure and tension forceson the healing of an epiphyseal fracture, ARCH ORTHOP, 121(8), 2001, pp. 443-449

30

INGLESE

Article

Ortopedics, Rehabilitation & Sport Medicine

ARCHIVES OF ORTHOPAEDIC AND TRAUMA SURGERY

0936-8051 → ACNP

121

8

2001

443 - 449

ISI

0936-8051(200109)121:8<443:TIOIED>2.0.ZU;2-L

In vitro studies about the regenerative capacity of chondrocytes located in the growth plate of long bones revealed a potential for reparation. A meas urable advance in the understanding of the physiologic processes in the bon e growth plate and their modifications after defined lesions is based on th e recognition of the role of the vascular architecture. Newly formed bridgi ng arteries crossing from the metaphysis to the epiphysis through the growt h plate are thought to be responsible for the cell proliferation observed a fter Salter-Harris I and II lesions. We aimed to examine the influence of m echanical microstimulations on the growth or inhibition of the proliferatio n of the chondrocytes in the tibial growth plate. We studied 22 tibial bone fractures, which were stabilized with a dynamic or a stable external fixat eur. Proliferative changes in the bone tissue were examined by immunohistoc hemical classification using bromodeoxyuridine (BUdR), a thymidine analogue . Radiologic studies, computer tomography, and magnetic resonance imaging d ocumented the results in comparison with histological examination. Cell pro liferation in the growth plate was not stimulated in the I st week after di straction. The histological studies revealed an initial increase in prolife ration of chondrocytes, especially between the 2nd and the 4th week. This w as more clearly seen with the use of the dynamic fixator. We conclude that a temporary ischemia with a reactive hyperemia takes place, which we could document by histological analysis and MRI. These results could modify the c urrent clinical therapy of growth plate fractures.