Vascularized Growth-Plate Transplantation: A Comparative Study in the Rat

Abstract

The purpose of this study was to evaluate the influence of hormonal milieu on endochondral growth. This was achieved by transplanting hind limbs of juvenile rats to syngeneic adult rats. Because there is no potential for rejection, the limb can be transplanted between animals of different ages, to study the influence of hormonal maturity on stimulation and cessation of physeal growth and maturation. Tibial length and the histologic appearance of the physis were recorded. Whole vascularized hind-limb transplantation in syngeneic Lewis rats was used. Group 1: Thirty-five transplants between animals of the same age (three weeks old) were performed (isochronografts). Group 2: In 35 procedures, the age of the donor was three weeks old and of the recipient, 15 weeks (heterochronografts). In the first two study groups, the transplanted limb was placed on the dorsal flank of the recipient animal without nerve reconstruction. Controls were the contralateral hind limb of the donor animal. Because the limb was transplanted with loss of femoral and sciatic nerve supply to the dorsal flank position, the effects of denervation and lack of weight bearing were also evaluated. Group 3: Thirty-five limbs in three-week-old animals were transposed to the dorsal flank position, after severing the femoral and sciatic nerves. Analysis of variance of tibial length was used to compare study groups. Limbs transplanted to older animals (heterochronografts--Group 2) achieved the greatest length, 91 percent of normal, and significantly more when compared to Groups 1 (84 percent) and 3 (83 percent) (p less than .005). Growth of the limb was adversely affected by limb position and denervation.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone quality and growth characteristics of growth plates following limb transplantation between animals of different ages - Results of an experimental study in male syngeneic rats

“…Chiu et al [12], in a similar study involving limb transplantation between animals of different ages, observed that the transplanted bone achieved only 70% of the normal growth in length. This finding was corroborated by Drzewiecki et al [11] who also found that after limb transplantation the transplanted bone could not achieve normal growth potential, but noted that the maximum growth (91% of normal) was observed in heterochronografts. However, in both of these studies the nerves of the transplanted limbs were not sutured, and the animals were non-weight bearing, so the failure to achieve full growth could be attributed to the effects of denervation and lack of external stress.…”

“…However, they yield conflicting results; some report that juvenile growth plates attain full growth potential in the adult body[1,10] while others report that juvenile growth plates attain only partial growth potential in the adult hormonal environment[11,12]. Vascularized growth plate transplants are now feasible alternatives for the management of growth plate damage by tumor, infection, trauma or congenital anomalies.…”

Expression of delta‐like 1 homologue and insulin‐like growth factor 2 through epigenetic regulation of the genes during development of mouse molar

“…Organ development therefore requires a coordinated regulation of growth and is governed by regulatory mechanisms that remain essentially unknown. Data from previous studies suggest that the growth rates of transplanted organs are defined by the age of the donor rather than by the age of the recipient . This leads to the suggestion that termination of organ development is not under systemic control (e.g.…”