More than 20° posterior tilt of the femoral head in undisplaced femoral neck fractures results in a four times higher risk of treatment failure

Abstract

Purpose In this study, we aimed to determine the correlation between the preoperative posterior tilt of the femoral head and treatment failure in patients with a Garden type I and II femoral neck fracture (FNF) treated with the dynamic locking blade plate (DLBP). Methods Preoperative posterior tilt was measured in a prospective documented cohort of 193 patients with a Garden type I and II FNF treated with the DLBP. The correlation between preoperative posterior tilt and failure, defined as revision surgery because of avascular necrosis, non-union, or cut-out, was analyzed. Results Patients with failed fracture treatment (5.5%) had a higher degree of posterior tilt on the initial radiograph than the patients with uneventful healed fractures: 21.4° and 13.8°, respectively (p = 0.03). The failure rate was 3.2% for Garden type I and II FNF with a posterior tilt < 20° and 12.5% if the preoperative posterior tilt was ≥ 20°. A posterior tilt of ≥ 20° was associated with an odds ratio of 4.24 (95% CI 1.09–16.83; p = 0.04). Conclusion Garden type I and II FNFs with a significant preoperative posterior tilt (≥ 20°) seem to behave like unstable fractures and have a four times higher risk of failure. Preoperative posterior tilt ≥ 20° of the femoral head should be considered as a significant predictor for failure of treatment in Garden type I and II FNFs treated with the DLBP.

Validation of direct CT measurement of malrotation in femoral neck fractures: A bone model study

“…Consequently, no threshold for correction has been defined regarding basicervical FNFs. In FNFs, a posterior tilt exceeding the threshold of 20° in Garden type I and II fractures increases the failure rate of osteosyntheses fourfold [ 27 ]. Kalsbeek et al report a rate of treatment failure for FNF Garden type I and II with posterior tilt over 20° being similar to displaced FNFs (Garden type III/IV) [ 27 ].…”

Evaluation of the Posterior Tilt Angle in Predicting Failure of Nondisplaced Femoral Neck Fractures After Internal Fixation: A Systematic Review

“…9 All studies involved cases using only internal fixation with either 2 or 3 screws, except for one study which also included cases involving a sliding hip screw 9 and one that used a dynamic locking blade plate. 11 Twelve studies divided cohorts into those with preoperative PTA above or below 20 degrees. The remaining 5 either used a different PTA cutoff 15,19,22 or reported a raw value for PTA alone.…”

“…6 It is important to note that there can be fractures classified as "incomplete" or "nondisplaced" Garden I or II with a PTA greater than 20-degrees because the classification is based on an AP radiograph while the angle measurement is based on a lateral radiograph. 2,[9][10][11] The purpose of this systematic review and meta-analysis was to assess the association between preoperative PTA and risk of treatment failure after internal fixation of nondisplaced femoral neck fractures.…”

Sagittal deformity of Garden type I and II geriatric femoral neck fractures is frequently misclassified by lateral radiographs

“…Previous studies have found that a femoral neck posterior tilt greater than or equal to 20 degrees and an anterior tilt greater than 10 degrees were associated with 1.7–4.7 times higher risk of fixation failure. [ 1 , 2 , 8 , 9 ] By contrast, 2 other studies found no association between sagittal tilt on the lateral view and postoperative complications. [ 7 , 10 ] One possible explanation for the discrepant findings is that the described methods for assessing sagittal deformity may have limited reliability, particularly when dichotomizing fractures as “low-risk” and “high-risk.” Posterior tilt on the lateral radiograph is influenced by rotation and flexion of the femur.…”