Angular Stability Plate System (LCP) - the new AO standard for plate osteosynthesis

Abstract

Locking Compression Plate (LCP) represents the latest development of AO plates, combining the features of conventional plates and internal fixators. This is achieved by a so-called combi-hole merging the Dynamic Compression Unit (DCU) of the DCP and the threaded hole of locked plates. Therefore all kinds of conventional screws as well as threaded locking head screws (LHS) can be inserted through the plate depending on the specific local requirements. However, LCP represents not a new plate per se, but rather a plate/screw system to enrich the well known АО-plate designs with the option of interlocking. As the mechanical characteristics have not changed by adding a combi-hole the complete set of small (3,5 mm) and broad (4,5/5,0 mm) АО-plates is available. Additionally LCP-systems adapted to certain anatomic regions, like the proximal humerus and distal radius as well as Tomofix2 plates for osteotomies have been developed. We report about our first experience in clinical use of LCP. Prom April 2000 till December 2002,310 LCP systems have been implanted in 274 patients. 303 plates (97,7%) were implanted for fixation of 285 fractures with different localization in 267 patients, including 17 pediatric fractures (5,9%),9 periprosthetic fractures (3,2%),5 delayed-unions (1,8%) and 4 pathologic fractures (1,4%). Seven plates (2,3%) were implanted to fix osteotomies. Of all plates 111 (35,8%)) implants were fixed with locking head screws,194 (62,6%) with both types of screws and only in 5 plates (l,6%o) conventional screws were used. 73 (23,5%o) of all plates were inserted using a minimal-invasive approach and 237 (76,5%) via an open procedure. Postoperative complications occurred in 14/267 patients (5,2%) exclusively treated for fractures, representing a complication rate of 5,2%o in 15/285 fractures. Loosening of implants were seen in 1,4%), deep wound infection in 1,05%), osteomyelitis, refracture and postoperative hematoma in 0,7%o, respectively. Secondary malalignment and problems with implant removal occurred in 1 patient (0,35%), respectively. No delayed or non-unions were observed. In LCP all options of plate osteosynthesis are included, so fixation can be adapted more accurately to the local situation and operative procedure is facilitated.