according to fig1 a and 1 b , a device r 1 according to the invention for lengthening bones or bone parts , in particular for transport of segments , comprises a guide element 1 and a drive unit 2 . the guide element 1 can , for example , be designed as a medullary nail and is provided at each end area 3 . 1 , 3 . 2 with through - openings 4 . 1 , 4 . 2 , respectively , which serve for fixing , in particular locking , the guide element 1 in or to a bone 5 or bone part . securing elements ( not shown in more detail here ) fix the guide element 1 releasably in the bone 5 . moreover , a preferably continuous and elongate guide slot 6 is provided in the axial direction in the guide element and has , at one end , a bearing recess 7 , if appropriate designed also as a through - bore . at the other end , the guide slot 6 is adjoined by a passage 8 and , preferably following the latter in the end area 3 . 2 , a receiving opening 9 . the drive unit 2 is preferably made up of a motor element 10 and , if appropriate , upstream gear 11 and downstream control unit 12 . the motor element 10 and / or gear 11 are adjoined by a drivable spindle element 13 on which at least one locking element 14 . 1 sits . the spindle element 13 can be designed , for example , as a threaded rod or the like and extends through the locking element 14 . 1 or engages with an internal thread of the locking element 14 . 1 . the plan view according to fig2 shows the device r 1 with the drive unit 2 inserted into the guide element 1 . the drive unit 2 can be inserted without locking element 14 . 1 through the receiving opening 9 of the guide element 1 and into the latter , the locking element 14 . 1 being pushed in through the guide slot 6 and being taken up by the suitably advanced spindle element 13 , the end area of the spindle element 13 then coming to bear in the bearing recess 7 . the drive unit 2 can be fixed releasably in this position , in particular the motor element 10 in the receiving opening 9 of the guide element 1 , and the drive unit 2 can be powered or controlled via connecting cables ( not shown here ), inductive adapters or the like . in this position of use , the spindle element 13 can be driven in rotation by suitable actuation of the motor element 10 or gear 11 , so that , in this way , the locking element 14 . 1 can be driven or moved in or counter to an indicated direction x , the locking element 14 . 1 being guided through the guide slot 6 and executing only an axial movement in the indicated direction x . as is shown in particular in the diagrammatic side view , the locking element 14 . 1 can be moved axially to and fro along the guide slot 6 depending on the driving direction of the spindle element 13 . the length of the guide slot 6 determines a stroke h by which the locking element 14 . 1 can be moved and driven . as is shown in fig4 , the device r 1 according to the invention is fitted , for example , into two end bones 5 or bone parts 5 which are intended to fuse back together by means of transport of a bone segment 15 . a bone segment 15 is separated from one bone 5 in the area of a separating site 16 shown here . the bone segment 15 is then connected to the lock 14 . 1 or engages in the latter or is fixed thereon by means of securing elements . it is also conceivable that the locking element 14 . 1 for transport of the bone segment 15 is arranged in the area of the separating site 16 and engages behind the bone segment 15 . the spindle element 13 is then activated , for example at selected time intervals , by means of the drive unit 2 via the motor element 10 and slowly moves the locking element 14 . 1 and thus the bone segment 15 to the opposite bone 5 , for example at 0 . 5 mm to 1 . 5 mm a day , preferably at 1 mm a day . in this way , the bone 5 can be lengthened again or can be fully restored by segment transport . in a further illustrative embodiment of the present invention according to fig5 , a device r 2 is used which corresponds substantially to the aforementioned type . the difference here is that the locking element 14 . 1 sits on the spindle element 13 near the end area 3 . 1 and a further locking element 14 . 2 sits on it near the end area 3 . 2 . the thread turns of the spindle element are preferably designed in one half as right - hand threads , for example , and in the other half as left - hand threads , for example , so that the locking elements 14 . 1 , 14 . 2 , which are preferably at an identical distance from a middle m , can be moved uniformly toward one another or away from one another by the driving movement of the spindle element 13 . in this way , for example , segments 15 from each bone 5 or bone part can be moved toward one another , so that , for example , with an advance movement of 1 mm a day , a segment transport of two bone parts can be considerably accelerated . this is also intended to lie within the scope of the present invention .
a device which lengthens bones or bone parts , especially for segmental transportation , comprising at least two elements which can be displaced in relation to each other . at least one locking element can be axially displaced in or along a guiding element .