Histologische und histomorphometrische Veränderungen bei Plattenosteosynthesen nach Osteotomien an der Tibia des Kaninchens

Abstract

In all specimens the cross-sections of bone taken at 4 marked points showed atrophy of the cortical bone which had occured in a typical manner. In the 1-week specimens no qualitative changes could be observed by normal light microscopy. In the 2nd week, however, a vivacious bone remodelling with wide Haversian canals and vessels starts from the medial cortex as could be seen identically in every series of our experiments. In the 4th week and especially in the 6th week it becomes also apparent on the lateral, dorsal and ventral wall. In the 12th week bone remodelling is still active but obvious diminishing of the osteons can be observed between internal and external lamellae. In the 24th week only solitary enlarged sinus and few osteons are found medially and laterally. Alltogether the cortical bone has become very thin. The bone remodelling has stopped and this state is characterized by loss of osteons and abundance of intermediate lamellae. Already in the 1st week polarisation microscopy shows a certain demascating of the collagenous fibres opposite to the plate. The control specimens do not show changes of the collagenous structure in this area. In addition to these results histomorphometric investigations of 1-week specimens revealed a quantitative increase of Haversian canals which are located closer to the medullary space as well as to the side opposite the plate. This result is due to the fact that the bone remodelling starts from the cortex opposite to the metal implant.

Changes in Calcium and Hydroxyproline Content of Cortical Bone after Compression and Neutral Plate Fixation

“…The mineral loss was less profound than that reported by Gordes et al (1975b). This may be because mineral loss is greater in the plated osteotomized bone these authors studied than in plated intact bone.…”

“…Gordes et al (1975b) observed that during the first 24 weeks after neutral rigid plate fixation of rabbit tibio-fibular bone cancellous transformation was progressive and profound. In our laboratory, the rigid plate fixation of intact rabbit tibio-fibular hone induced similar changes.…”

“…However, while providing conditions conducive to fracture repair, the attachment of rigid plates to cortical bone simultaneously calls forth a structural derangement of the underlying bone. Uhthoff & Dubiic (1971) drew attention to the profound cancellous transformation that occurred after plating of osteotomized canine femora, and Gordes et al (1975b) reported similar changes after plate fixation of osteotomized rabbit tibio-fibular bones. Recent reports suggest that the cancellous transformation of plated cortical hone is accompanied by a decrease in t h e mineral content of the bone.…”

Studies on Mechanical Strength of Bone: II.Torsional Strength of Cortical Bone after Rigid Plate Fixation with and without Compression

“…Refractures have been reported after removal of the plates (Richon et al 1967, Dietschi & Zenker 1973 Both adverse effects on bone tissue as a structure (Schenk & Willenegger 1967, Uhthoff & Dubuc 1971, Gordes et al 1975a, 1976 and reduction of the bone mineral mass 1974). (Gordes et al 1975b, Stromberg & Dalen 1976 have been reported in cortical hone after immobilization with a rigid plate.…”

Radiographic Changes in Cortical Bone after Intramedullary Nailing

“…Cancellous transformation of both fractured and intact cortical bone has been observed following rigid plate fixation (6,11). Similarly external fixation and intramedullary nailing cause porotic transformation of the cortical bone (9,12), the extent of which seems to be less than after application of rigid plates.…”