Distraction effects on the physis in rabbits

Abstract

Gradual physeal distraction by external fixation was performed on the distal femur in 19 growing rabbits. The rate of distraction was 0.5-1 mm once daily. Distraction was continued for 1-21 days until killing. Lengthening of the femur and latitudinal growth of the distraction area were measured in radiographs. Morphologic changes in the physes were studied in histologic preparations. The length gained by distraction was maximally 5 mm. Latitudinal overgrowth was noted in specimens distracted for more than 13 days. Hyperplasia of the hypertrophic chondrocyte zone was seen after 1 day of distraction. Separation of the epiphysis from the metaphysis, mostly through the hypertrophic zone, occurred in 11 specimens. Both hyperplasia and separation were often seen in the same physis. In the separation gap, early signs of bone formation into a collagen frame were seen from the 7th day on. An accessory physis, located in the metaphysis and apparently growing interstitially, was noted in 1 specimen.

Chondrodiatasis in a patient with spondyloepimetaphyseal dysplasia using the Ilizarov technique: successful correction of an angular deformity with ensuing ossification of a large metaphyseal lesion

“…De Pablos also noted that the lower the rate of distraction employed, the greater was the short-and long-term viability of the physis. Other reports have confirmed de Pablos' observations [1,2,5,19]. In addition, these studies have shown that the apparent thickening of the physis with distraction is caused by a decrease in the enchondral ossification rate with an ensuing accumulation and disorganization of hypertrophic chondrocytes.…”

Effects of distraction and compression on proliferation of growth plate chondrocytes: A study in rabbits

“…Physeal distraction leads to hyperplasia of the proliferative and hypertrophic zones , Connolly et al 1986, Alberty et al 1990, Kenwright et al 1990). This hyperplasia occurs whether or not physeal separation occurs Noble 1978, Alberty et al 1990).…”

“…Transient hyperplasia of the physis is common during physeal distraction , De Bastiani et al 1986, Elmer et al 1989, Alberty et al 1990, De Pablos and Canadell 1990. Fracture-separation of the growth plate occurs in rabbits, if the distraction force exceeds 2 kp , Nakamura et al 1991.…”

Physeal growth arrest after tibial lengthening in achondroplasia

“…The cause of growth inhibition and physeal damage after limb lengthening has been analyzed in animal models (Pennecot et al 1983, Alberty et al 1990, Albanese et al 1996). These studies demonstrated that continuous compressive forces on the physis result in either temporary or permanent cessation of growth (the Heuter-Volkmann principle).…”