CLINICAL-RESULTS USING THE TROCHANTER STABILIZING PLATE (TSP) - THE MODULAR EXTENSION OF THE DYNAMIC HIP SCREW (DHS) FOR INTERNAL-FIXATION OF SELECTED UNSTABLE INTERTROCHANTERIC FRACTURES

Objective: To evaluate whether the implantation of the modular trochan ter stabilizing plate (TSP) in addition to the dynamic hip screw (DHS) prevents excessive telescoping and Limb shortening in four-pad and se lected three-part trochanteric fractures. Design: Prospective clinical study. Setting: The study was conducted at the trauma unit of the Sur gical Department of the University of Basel, Switzerland. Patients: Fo rty-six consecutive patients with unstable intertrochanteric fractures were treated with an additional TSP superimposed on the regular DHS a t our institution between July 1991 and July 1993. Five patients died before the first follow-up, one patient was lost to follow-up, and ano ther patient refused followup. Thus, thirty-nine patients were followe d for at least twelve months (mean 14 months, range 12 to 20 months). Intervention: The fractures treated were classified according to the O TA classification, which is based on the AO classification. Seventeen were 31-A2.2, seven were 31-A2.3, and fourteen were 31-A3.3 fractures. Results: Lateralization of the greater trochanter was successfully pr evented in all fractures. Limited fracture impaction was found in 90 p ercent (n = 35) of the patients with telescoping of 9.5 millimeters (r ange 0 to 30 millimeters), resulting in mean limb shortening of 5.37 m illimeters (range 0 to 14.9 millimeters). Four patients suffered limb shortening exceeding fifteen millimeters (range 15.6 to 21.3 millimete rs). Functional results were excellent and good in 87 percent of patie nts and fair in 13 percent according to the Salvati-Wilson score. All fractures had healed six months after the operation. Three complicatio ns required a secondary procedure: one from not inserting a second scr ew parallel to the gliding hip screw to prevent rotation of the head-n eck fragment (''antirotation screw''), one because of deep infection, and one because of a refracture after premature implant removal. Concl usion: In unstable pertrochanteric fractures with small or missing lat eral cortical buttress, the addition of a TSP to the DHS effectively s upports the unstable greater trochanter fragment and can prevent rotat ion of the head-neck fragment. Excessive fracture impaction and consec utive limb shortening was prevented by this additional implant in 90 p ercent of these patients.