title: Outcome analysis of retrograde nailing and less invasive stabilization system in distal femoral fractures: A retrospective analysis.
abstract: BACKGROUND
  TWO MAJOR THERAPEUTIC PRINCIPLES CAN BE EMPLOYED FOR THE TREATMENT OF DISTAL FEMORAL FRACTURES: retrograde intramedullary (IM) nailing (RN) or less invasive stabilization on system (LISS). Both operative stabilizing systems follow the principle of biological osteosynthesis. IM nailing protects the soft-tissue envelope due to its minimally invasive approach and closed reduction techniques better than distal femoral locked plating. The purpose of this study was to evaluate and compare outcome of distal femur fracture stabilization using RN or LISS techniques.
  
  
  METHODS
  In a retrospective study from 2003 to 2008, we analyzed 115 patients with distal femur fracture who had been treated by retrograde IM nailing (59 patients) or LISS plating (56 patients). In the two cohort groups, mean age was 54 years (17-89 years). Mechanism of injury was high energy impact in 57% (53% RN, 67% LISS) and low-energy injury in 43% (47% RN, 33% LISS), respectively. Fractures were classified according to AO classification: there were 52 type A fractures (RN 31, LISS 21) and 63 type C fractures (RN 28, LISS 35); 32% (RN) and 56% (LISS) were open and 68% (RN) and 44% (LISS) were closed fractures, respectively. Functional and radiological outcome was assessed.
  
  
  RESULTS
  Clinical and radiographic evaluation demonstrated osseous healing within 6 months following RN and following LISS plating in over 90% of patients. However, no statistically significant differences were found for the parameters time to osseous healing, rate of nonunion, and postoperative complications. The following complications were treated: hematoma formation (one patient RN and three patients LISS), superficial infection (one patient RN and three patients LISS), deep infection (2 patients LISS). Additional secondary bone grafting for successful healing 3 months after the primary operation was required in four patients in the RN (7% of patients) and six in the LISS group (10% of patients). Accumulative result of functional outcome using the Knee and Osteoarthritis Outcome (KOOS) score demonstrated in type A fractures a score of 263 (RN) and 260 (LISS), and in type C fractures 257 (RN) and 218 (LISS). Differences between groups for type A were statistically insignificant, statistical analysis for type C fractures between the two groups are not possible, since in type C2 and C3 fractures only LISS plating was performed.
  
  
  CONCLUSIONS
  Both retrograde IM nailing and angular stable plating are adequate treatment options for distal femur fractures. Locked plating can be used for all distal femur fractures including complex type C fractures, periprosthetic fractures, as well as osteoporotic fractures. IM nailing provides favorable stability and can be successfully implanted in bilateral or multisegmental fractures of the lower extremity as well as in extra-articular fractures. However, both systems require precise preoperative planning and advanced surgical experience to reduce the risk of revision surgery. Clinical outcome largely depends on surgical technique rather than on the choice of implant.
authors.affiliation: Department of Trauma Surgery, Trauma Center Murnau, Murnau, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Hierholzer
authors.forename: Christian
authors.initials: C
authors.lastname: von Rüden
authors.forename: Tobias
authors.initials: T
authors.lastname: Pötzel
authors.forename: Alexander
authors.initials: A
authors.lastname: Woltmann
authors.forename: Volker
authors.initials: V
authors.lastname: Bühren