Stable and unstable trochanteric fractures. Differentiated indication for the dynamic hip screw

The aim of all surgical procedures in the treatment of trochanteric fractur es in elderly and even geriatric patients is achievement of initial stabili ty. We examined in a clinical trial whether primary stability was achieved in all types of trochanteric fractures following osteosynthesis with the Dy namic Hip Screw (DHS). From 1994 to 1996, 122 patients with trochanteric fr actures had osteosynthesis by dynamic hip screw. Patient records were evalu ated and all data got registered with a standardized protocoll; clinical an d radiological outcome was analysed after an average period of 1,9 years af ter injury according to the Traumatic Hip Rating Score. 22% of all patients died meantimes, 51,6% of the remaining 95 patients could get examined. The average age was 75,5 years, the patient population showed an increased pre operative morbidity (2,5 points) according to ASA-Score. 81% showed progres sive osteoporosis. According to the AD-classification 47% stable fractures (type A-1) and 53% instable trochanteric fractures (type A-2 and A-3) occur ed. Surgery lasted 77 minutes average in osteosynthesis of stable fractures . The duration of 108 minutes in instable fractures was significantly highe r, as well as the blood loss was 43% increased in these complex fractures. Complications closely associated to the osteosynthesis appeared only in ins table fractures (7%). Also common complications (24,6%) predominated with 1 5,6% in type A-2 and A-3 fractures versus 9% in type A-1 fractures; mortali ty was also different with 5,7% versus 1,6%. Assesment of the functional ou tcome according to THRS showed a significant deterioration of 20 points in 71% of all patients compared with the preoperative score. The results show that dynamic hip screw osteosynthesis in instable trochanteric fractures is associated to a higher incidence of complications. While the dynamic hip s crew still represents the standard implant in stable fractures of the troch anteric region, beeing aware of improved intramedullary implants regarding biomechanical features and surgical technique, the results justify to criti cal consider the use of DHS for osteosynthesis in instable fractures of the trochanteric region.