Role of preoperative posterior tilt on the outcomes of internal fixation of non-displaced femoral neck fractures: A systematic review and meta-analysis.
INTRODUCTION
There has been an increased interest in the role of preoperative posterior tilt, as measured on lateral radiographs, on the outcomes of internal fixation of non-displaced femoral neck fractures (FNF). The goal was to assess the available evidence for this in the literature.


PATIENTS AND METHODS
PRISMA guidelines were followed. PubMed, Embase and Cochrane were searched on June 10th, 2020 for studies assessing the role of posterior tilt on outcomes of internal fixation of non-displaced FNF. Primary outcomes were non-union and fixation failure, avascular necrosis (AVN), treatment failure, and reoperation (excluding symptomatic hardware removal). Outcomes were reported in Odds Ratio (OR) with 95% confidence intervals [CI].


RESULTS
Fourteen studies and 3729 patients were included (mean age 76 years, 72% female, mean follow-up 25 months). Moderate evidence was noted for the following: patients with greater preoperative posterior tilt had an increased risk of non-union and fixation failure (OR 2.4 [1.3 - 4.3]; p = 0.006), no increased risk of AVN (p = 0.550), an increased risk of treatment failure (OR 6.0 [2.2 - 15.9]; p<0.001) and reoperation (OR 2.5 [1.4 - 4.4]; p = 0.002). Furthermore, a greater preoperative tilt of 9.0° [4.1° - 13.9°] for treatment failure and 6.1° [3.7° - 8.5°] (p<0.001) for reoperation were noted in the unsuccessfully treated groups when compared to the successfully treated groups. Four studies found a threshold for posterior tilt ranging from 7° to 20° CONCLUSION: There is moderate evidence that patients with non-displaced FNF and greater tilt have an increased risk of unsuccessful outcomes following internal fixation. Older patients with a preoperative tilt of ≥20° might benefit from arthroplasty surgery, although studies assessing the optimal threshold are needed.
['van der List|Jelle P|JP|', 'El Saddy|Salih|S|', 'Vos|Stan J|SJ|', 'Temmerman|Olivier P P|OPP|']
D000368:Aged D001178:Arthroplasty D005260:Female D005265:Femoral Neck Fractures D005593:Fracture Fixation, Internal D006801:Humans D008297:Male D011859:Radiography D012086:Reoperation D012189:Retrospective Studies D016896:Treatment Outcome
Posterior tilt Internal fixation Failure Avascular necrosis Fracture displacement Hip fractures