Effect of lymphedema on the recovery of fractures

Background. Lymphedema delays the healing of any wound by negatively affecting its inflammatory period. Whether it affects bone healing in a similar negative manner is unknown. Therefore, we experimentally investigated the effect of lymphedema on fracture recovery. Methods. We used thirty 200- to 250-g Sprague-Dawley rats for the experiment. The rats were randomly divided into two groups of 15 rats each for the experimental lymphedema and control groups. Lymphedema development was confirmed by measuring the circumference and diameter of the extremities together with lymphoscintigraphy. Twenty days after the development of lymphedema, a fracture model was created in both groups in the right tibia with mid-diaphyseal osteotomy and fixing with an intramedullary Kirschner wire. After 6 weeks, all rats were sacrificed and the callus tissue that formed along the osteotomy was compared between groups with respect to radiographic, histological, and biomechanical characteristics. Results. The three-point bending test yielded an average stiffness value of 1227 N/mm (n = 6) in the control group and 284 N/mm (n = 7) in the experimental lymphedema group (P < 0.05). At the end of week 6, radiographic evaluation showed that solid knitting was obtained in the control group, whereas in the lymphedema group delayed or no knitting was observed. In the control group, histological investigation revealed normal callus morphology. Trabecular bone was normal and osteoblast and osteoclast activity was clearly evident. The bone was stained homogeneously with hematoxylin and eosin, and ossification was within normal limits. In the lymphedema group, however, the histological appearance was mostly that of scar tissue. In addition, osteoblast and osteoclast activity was much less visible or absent. Conclusions. Lymphedema negatively affected bone healing in rats. However, the mechanism of this negative effect and its occurrence in humans are still unknown. Further experimental and clinical studies are needed to support and extend our findings.