GAMMA-NAIL OSTEOSYNTHESIS FOR PERTROCHANT ERIC AND SUBTROCHANTERIC FEMORAL FRACTURES - A 4-YEAR EXPERIENCE AND THE CONSEQUENCES FOR THE ONGOING IMPLANT DEVELOPMENT

The Gamma nail can be used in all types of per- and subtrochanteric fr actures because of its biomechanical characteristics. In this prospect ive evaluation of our 330 patients treated between November 1989 and N ovember 1993 the usefulness of the Gamma nail for the osteosynthesis o f all types of fracture was evaluated. The rate of intraoperative and postoperative complications but also gait function, postoperative weig ht bearing, general complications, and survival were analysed. We comp ared the results of four therapy periods to evaluate the importance of the expertise of the surgeon and the 'learning curve'. The Gamma nail osteosynthesis was performed in 72-98% in unstable per- and subtrocha nteric fractures. The nail diameters used shifted to the 12 mm nail (9 9%) and the 130-degrees angle (93%) in the fourth examination period. The intraoperative complication rate is highly dependent from the expe rtise of the surgeon and the experience with the system. The rate decr eased from 42.2% in the first to 17.2% in the fourth examination perio d. The most important complications were: additional fractures (1.7%), distal locking screw problems (7%), femoral head rotation (2,4%), and not sufficient fracture reduction (4.1%). Whereas in general these di d not influence the postoperative management the use of a too short fe moral neck screw lead to instability. Postoperative local complication s were: rotation of the femoral head and neck (0.6-5.5%), related to t he gliding of the neck screw (0.6-4%), fracture at the end of the nail (1.8-4%), fatigue break of the nail (1 case) and hematoma (1.2-8.3%). In all these cases reoperation was needed. To reduce the rate of intr a- and postoperative complications a new gliding nail (GN) is presente d. Due to the double T-profile of the femoral neck blade the implant i s stable for neck rotation. The blade has a collar which makes it impo ssible to implant the blade to deep in the femoral neck. The larger na il profile at the femoral neck perforation reduces the risk of implant failure. The implant can be used as dynamic compression as well as st atic implant both in the direction of femoral neck and shaft.