Reconstruction of distal femoral fractures with fixed-angled or polyaxial technology; a prospective randomised controlled trial.

The management of fractures of the distal femur varies depending on the patient’s functional demands, fracture pattern, the availability of appropriate implants and the skill-set of the operating surgeon. It is widely accepted that the treatment of these fractures are challenging due to its prevalence amongst the elderly, a group with confounding co-morbidities, a high percentage of joint prosthesis and osteoporosis, which increase the technical demands on the surgeon and the selected implant. Locking osteosynthesis devices have been shown to provide superior stability to axial loading compared with traditional, unlocked osteosynthesis plate-screw constructs, blade plates and intra-medullary nails.. However, the outcome following fixation with first-generation, fixed-angle, locking plates and the newer, poly-angled locking plates remains obscure. This prospective multi-centre prospective pilot study was undertaken to investigate this issue. Forty patients with distal femoral fractures were randomised into two locking osteosynthesis device groups, the fixed-angled, Less Invasive Stabilisation System (LISS) group and the multi-angled, POLYAX plate group, in a 1:1 ratio. Operative, functional and radiological outcomes including; operation time, length of hospital stay, radiological union rates, Oxford knee scores and Quality of life measures (EQ-5D) were investigated and analysed within a 12 month follow-up period. The results showed an overall mortality rate of 12.5%. The rate of fracture union was 72.5 % at 6 months and 77.5% there after, with 3 patients requiring secondary procedures for non-union. One patient in the LISS group and 1 patients in the Polyax group required revision surgery for implant failure. Statistically analysis of the data showed no significant differences in both primary (fracture union) and secondary outcomes between either plating system. Based on our findings, we conclude that patient factors and surgical technic carry more weight in determining the outcome of these injuries rather than the choice of locking osteosynthesis implant, be it mono or poly-angled.