TS27: NONUNION OF OSTEOPOROTIC DISTAL FEMORAL FRACTURES AFTER FIXATION WITH THE LISS: OUR EXPERIENCE AND A REVIEW OF THE LITERATURE.

Abstract

The Less Invasive Stabilisation System (LISS) was introduced with the aim to decrease the incidence of fracture nonunion and the need for primary bone grafting. We aim to describe the cases of nonunion of osteoporotic distal femoral fractures treated with the LISS at our institution and to review the cases of nonunion published in the literature.

Three cases of nonunion of osteoporotic distal femoral fractures treated with the LISS at our institution were identified. A thorough retrospective analysis of the available clinical information was performed. To identify all published papers on LISS, an exhaustive literature search was performed. The Medline and PubMed databases were searched for the following keywords: femoral fractures, distal femoral fractures, supracondylar, LISS, less invasive stabilization system and femoral no nunions. The search period was 1996 to 2008. All relevant studies were analysed.

Low energy trauma was responsible for the closed fractures encountered in our patients. Two patients sustained fractures around a joint arthroplasty: one fracture above a total knee arthroplasty and one fracture below a total hip arthroplasty. The operative technique consisted of indirect reduction on the traction table and minimally invasive percutaneous osteosynthesis. The postoperative radiographic alignment was satisfactory for all fractures. Aseptic nonunion was diagnosed in all patients. Implant failure occurred in two patients with fracture of the proximal screws in one case and fracture of the distal screws in the second case. No case s of failure of distal locking screws have previously been described in the literature. No other complications were identified. The literature search identified 21 cases of fracture nonunion. Six of these fractures occurred in osteoporotic bones as a result of low energy trauma. All 6 fractures were above a total knee arthroplasty.

The LISS is a new implant who has shown good results in the management of difficult distal femoral fractures. Its use is however not without problems: concerns with regards to inadequate or excessive rigidity and a demanding surgical technique are just some of the issues.