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Summary The reactions of the epiphyseal growth plates to physiological and pathophysiological stimuli, in particular after injuries are described, and the appropriate treatment including the form and the consequences of the injuries are presented. There then follows a comparison of the treatment of growth plate injuries and growth abnormalities obtained from the literature. Between 1997 and 1999, 252 dogs with an orthopaedic illnes occurring during the growth phase were presented at the clinic and out-patient's clinic. 60 of these patients developed in the cours of time a shortening or deformity of the affected limb. In 53 dogs the front limb was effected an in 7 the hind limb. As well as examining the growth behaviour of the shortened bone, the growth of the primarily unaffected section of limb was also examined. 39 patients with a shortening of the ossa antebrachii and 6 patients with a shortening of the tibia, or the os femoris, demonstrated a lengthening of the ipsilateral humerus or tibia/os femoris by 0,2 - 1,8cm. It was examined how the growth activity of the neighbouring section of limb was influenced. Of the 39 patients with a lengthening of the ipsilateral humerus, 13 patients displayed a radial and ulnar diaphyseal fracture as the cause of the resulting shortening of the limb. The same amount of lengthening of the humerus was measured in both the male and the female dogs. Patients with an expected final weight of >30kg developed most commonly a lengthening of the humerus >_ 5%. When the radial or ulnar shortening was compared with the lengthening of the humerus, it became clear that the increased traction forces have an influence on the growth activitiy of the humerus. Therefore in 56% of the measurements the humerus was asymmetrically lengthened. The same amount of lengthening could be measured, independent of the age of the patient at the time of the trauma. Lengthenings of the humerus >_5% were first measured after limb shortening of 9% had been reached. The size of the axis deviation had influence on the growth actitivity of the humerus. Lengthening of the humerus of >_0,9cm were measured in 69% (11/16) of he patients with a valgus deviation of 6-20°. In both the hind and fore limb anatomical changes were measured in the compensatively lengthened section of limb, in the form of a reduction in the diameter of the bone of up to 0,7cm. It was able to be shown in this study that, particularly in the front limb, an increase in growth rate of the ipsilateral uninjured section of limb is a commonly-occurring compensatory mechanism. In the process, the limb shortening of up to 11% was compensated for by the lengthened humerus.