Morphometrical examinations of the mandibular ramus for the indication of lag screw osteosynthesis described by Eckelt in mandibular condylar fractures.

For several years, lag screw osteosynthesis as described by ECKELT has been used for the surgical treatment of condylar fractures with predominantly positive results. However anatomical variations occasionally do not permit the use of the lag screw. The aim of the present study was to re-examine the anatomical requirements for using ECKELT's lag screw osteosynthesis. Based on a detailed structural analysis of 140 isolated cadaver rami mandibulae, it can be seen that they principally meet the anatomical requirements for the treatment of mandibular condylar fractures with lag screw osteosynthesis using 2.0 mm diameter screws. Rare, extreme anatomical variants emphasize the need for a stricter preoperative determination of the indications. Using spiral computerized tomography, it is possible to exactly assess preoperatively the existing anatomical situation of the ascending mandibular ramus on the planned frontal plane of the lag screw.