Standard Approaches to the Acetabulum Part 1: Kocher-Langenbeck Approach.

Historically, standard approaches for surgical treatment of displaced acetabular fractures were the KocherLangenbeck approach, the ilioinguinal approach and the extended iliofemoral approach (12). Presently, several modifications of these approaches are accepted alternatives, especially anterior modifications based on the intrapelvic approach described by Hirvensalo (8). Single access approaches allowing visualization of one acetabular column are the posterior Kocher-Langenbeck approach and the anterior ilioinguinal approach (12) and the use of a single approach is favoured (9, 24). For more complex situations, in the 80s and 90s extended approaches (extended iliofemoral approach according to Letournel (12), its modification to Reinert (19) (Baltimore approach), and the Triradiate approach according to Mears (14)) were introduced. These approaches are presently rarely choosen due to the extensive soft tissue dissection and higher complication rates (28). Alternatively, the combination of an anterior and posterior standard approach was recommended (7, 21, 22) having the disadvantage of longer operating time and blood loss and showed no superior results compared to a single approach. The meta-analysis by Giannoudis et al. stated that 48,7% of patients were treated using the Kocher-Langenbeck approach, followed by 21,9% ilioinguinal approaches and 12,4% extended approaches (6). More recent data from the years 2005-2007, showed that anterior approaches are now predominantly used according to a higher number of acetabular fractures with anterior column involvement. Overall, more than 40% of all patients with acetabular fractures are still approached via the Kocher-Langenbeck approach (18). Therefore, the Kocher-Langenbeck approach is still a "working horse" in approaching displaced acetabular fractures. The Kocher-Langenbeck approach consists of two parts. In 1874 von Langenbeck described a longitudinal incision starting from above the greater sciatic notch to the greater trochanter, dissecting the gluteal muscles for treating hip joint infections (11). Theodor Kocher in 1911 described a curved incision starting from the posterior-inferior corner of the greater trochanter, running across the postero-superior tip of the greater trochanter passing oblique in line with the fibres of the gluteus maximus muscle in direction to the posterior superior iliac spine (10). The aim of the present analysis is the detailed anatomi - cal analysis of this standard approach, focusing on fracture indication, positioning of the patient, exposure, dissection, reduction techniques of special fracture types, approach modifications/extensions, complications and approach-specific results.