1.  Field of the Invention
The present invention relates to surgical instruments generally, and in particular to devices used for joining, tensioning, fixing and severing sutures.  This invention finds application, for example, with stainless steel sutures in sternotomy closure. 
2.  Description of the Prior Art
The prior art includes manual techniques in which suture wires are crossed, twisted, tightened and cut.  The twisted segment, measuring approximately 1 cm.  in length, is then further tightened, trimmed and bent into adjacent tissue.  Although this method is widely employed, occasional difficulties are encountered relating to the manual technique for suture wire application and approximation.  Asymmetric twisting of the wire may cause wire buckling, metal fatigue and possible wire fracture.  Incomplete wire fixation can result in motion between the approximated sides of the sternum with resultant post-operative pain and possible dehiscence. 
Nylon bands have been used for closure, but these were found unacceptable by some workers because of an increased incidence of complications and sternal infection. 
Small stainless steel plates have also been utilized for fixation of wire sutures, but this technique requires three additional instruments and components in addition to the wire sutures, and cutting and trimming of the wire sutures is still necessary.  The principle of applying controlled tension to close the sternum has led to satisfactory sternal approximation in a small series of patients, however.