concave member disposed between and continuous with two convex members a first convex member 66 that is adjacent the distal edge 58 and a second convex member 68 that is located at a free end of the hook tip 60 if a plurality of hook tips 60 are present they can be arranged in a spaced and selectively determined order so that the hook assembly can be used in conjunction with a corresponding needle assembly 20 for example if the needle assembly 20 employs six needle tips 26 then hook assembly 54 should similarly provide six hook tips 60 the spacing between hook tips 60 preferably also coincides with the spacing of the prongs 44 on the frame 42 and the spacing of the needle tips 26 of needle assembly 20 in a preferred embodiment handle 56 comprises a plurality of handle portions 57 with each independent handle portion 57 having means e g 62 for detachably connecting adjacent independent handle portions the connecting means 62 preferably comprise corresponding interlocking portions of the handle portions similar to those described above for the needle assembly preferably the interlocking portions of connecting means 62 include an elongated recess and a corresponding flange.