Dorr Classification Type C

In the late 1970s, cementless stems with osteogenic fixation capacities similar to the cementless stems of today began to be used because of concerns about cemented stem laxity and the concept of “cement disease” which was prevalent in the 1970s. The average age of patients who received cementless stems in North America at the end of 1980 was 45–55 years old [1]. At that time, it was believed that (1) morphological compatibility between the stem and supporting bone and (2) good bone quality of the femur were important for good fixation of the cementless stem. Further research in this field is urgently needed. Noble et al. used the canal flare index to classify proximal femurs by shape into champagne flute, normal, and stovepipe shapes (Fig. 79.1a) [1]. Dorr et al. studied the biochemical and histological characteristics of different proximal femur shapes and proposed a radiographic classification that also evaluated the bone quality of the femur [2]. This classification is still frequently used, particularly cementless stems.