Enhancement of tendon-bone healing with the use of bone morphogenetic protein-2 inserted into the suture anchor hole in a rabbit patellar tendon model

Background aimsSuture anchor fixation failure has been reported as a result of anchor loosening and migration during the tendon-bone repair. The aim of this study was to evaluate the effects of bone morphogenetic protein-2 (BMP-2) inserted into the suture anchor hole on bone formation and the tendon-bone healing.MethodsBoth back legs of 24 New Zealand White rabbits (n = 48) were used in this study. A metal suture anchor was then placed 5 mm below the cortex. In the control group, the space over the eyelet of the anchor (suture anchor hole) was not filled. In the experimental group, the suture anchor hole was filled with 0.1 mL of fibrin glue (group 2) or collagen gel (group 3) with 1 μg BMP-2. Histologic analysis, real-time-polymerase chain reaction, bone density and failure load measurement were performed, and differences were analyzed at 4 and 8 weeks.ResultsHistologic analysis revealed more abundant new bone, mature bone and organized fibrocartilage at the tendon-bone interface at 4 and 8 weeks in groups in which BMP-2 was applied. At 8 weeks, the failure load of groups 1, 2 and 3 was significantly different among the three groups (P = 0.01). After post hoc Tukey test, the failure load of group 2 was significantly higher than that of group 1 (P = 0.01).ConclusionsBMP-2, administrated as described in this study, improved tendon-bone healing and bone formation, resulting in improved biomechanical strength of the tendon-bone junction.     

An intersegmental reflex between the copulatory swimmerets of the male squat lobster,Galathea strigosa

The structure of the sexually modified 1st 2 pairs of swimmerets of the male squat lobster Galathea strigosa are described, and a reflex involving these swimmerets is characterised. The endopodite of the 1st swimmeret forms a partially rolled lamina which hooks around the “bottle brush” end of the endopodite of the 2nd swimmeret. Mechanical stimulation of a sensitive region on the endopodite of each 1st swimmeret causes retraction of both 2nd swimmerets, inducing the “bottle brush” to push up within the endopodite of the 1st swimmeret. The reflex is thought to be involved in sperm transfer during copulation. Neural information travels between the 1st and 2nd swimmerets in the interganglionic connective ipsilateral to the stimulus.