Three-dimensional analyses to predict surgical outcomes in non-displaced or valgus impaction fractures of the femoral neck: A multicenter retrospective study

Preoperative posterior tilt can be a risk factor of fixation failure in nondisplaced femoral neck fracture: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to identify whether posterior tilt increases the risk of treatment failure in nondisplaced femoral neck fractures.

METHODS

We searched the databases of the PubMed, Embase, and Cochrane Library from 1980 to 2022. The search strategy was based on the combination of keywords "nondisplaced," "hip fracture," "femoral neck fracture," and "internal fixation." Cohort studies enrolled patients with nondisplaced (Garden I and Garden II) femoral neck fractures were included. Two investigators independently extracted data and the other two assessed the methodological quality. Data were analyzed using Review Manager software.

RESULTS

We analyzed 13 cohort trials with a pooled sample of 4818 patients, with posterior tilt ≥ 20° in 698 patients and < 20° in 3578 patients in 11 trials, and posterior tilt ≥ 10° in 483 patients and < 10° in 496 patients in 4 trials. All studies were of high quality based on Newcastle-Ottawa Scale evaluation. Treatment failure was reported in 24.4% (170/698) of patients with posterior tilt ≥ 20° and 10.9% (392/3578) of patients with posterior tilt < 20°, indicating that posterior tilt ≥ 20° was significantly associated with a higher risk of treatment failure (Risk ratio, 2.73; 95% confidence interval [CI], 1.77-4.21). Posterior tilt ≥ 10° was not found to be a risk factor for fixation failure (risk ratio, 1.92; 95% CI 0.76-4.83).

CONCLUSION

Nondisplaced femoral neck fractures with posterior tilt ≥ 20° were associated with an increasing rate of failure when treated with internal fixation. LEVEL OF EVIDENCE : III, Systematic review and meta-analysis.

The association between three-dimensional measurement of posterior tilt angle in impacted femoral neck fractures and osteonecrosis of the femoral head

BACKGROUND

Hollow screw internal fixation is commonly used in clinical treatment of impacted femoral neck fractures. Previous studies have demonstrated a correlation between the preoperative posterior tilt angle of the femoral head and failure of internal fixation, but there are fewer studies related to the occurrence of postoperative femoral head necrosis and the posterior tilt angle.

METHODS

To examine the relationship between three-dimensional posterior tilt angle measurements in affected femoral neck fractures and postoperative osteonecrosis of the femoral head and related risk variables. We retrospectively examined 130 Yantaishan Hospital patients with affected femoral neck fractures from 2019 to 2022. Three-dimensional reconstruction technology assessed the posterior tilt angle of the femoral head and separated patients into necrosis and non-necrosis groups based on postoperative femoral head necrosis. Univariate analysis compared clinical data between groups, and multivariate logistic regression analyzed risk variables for femoral head necrosis. Postoperative femoral head necrosis was predicted by posterior tilt angle using Receiver operating characteristic (ROC) curve analysis.

RESULTS

Out of 130 patients who were followed up for 16-68 months postoperatively, 20 developed femoral head necrosis. Multivariate logistic regression analysis indicated that the posterior tilt angle and reduction quality level C were risk factors for the occurrence of femoral head necrosis. The ROC curve analysis showed that the three-dimensional measurement of the posterior tilt angle had predictive value for postoperative femoral head necrosis, with a cut-off value of 20.6°.

CONCLUSIONS

These results suggest that, for patients with impacted femoral neck fractures, the posterior tilt angle and reduction quality level C are risk factors for femoral head necrosis following closed reduction and internal fixation surgery. Fracture patients with a posterior tilt angle ≥ 20.6°are more likely to experience postoperative femoral head necrosis.

A three-dimensional measurement study of fracture displacement in Garden I femoral neck fracture: a retrospective study

BACKGROUND

Garden I femoral neck fractures are nondisplaced femoral neck fractures. Nonoperative treatment and in situ fixation are the preferred treatments. However, the postoperative outcome is not satisfactory and the incidence of complications remains high, which raises doubts about the accuracy of the diagnosis of nondisplaced Garden I fractures. Recently, three-dimensional (3D) reconstruction has been reported as a mature technology for reconstructing the bone structure of patients. We further extended this technique in the measurement of the fracture spatial displacement to verify the accuracy of Garden I femoral neck fractures.

METHODS

This was a retrospective study of patients with Garden I femoral neck fractures from January 2013 to December 2018 at our institution, who were included according to specified criteria. A bilateral proximal femur model of each patient was established based on computed tomography (CT) data. The displacement of the deepest portion of the femoral head fovea, the displacement of the center of the femoral head and the rotation of the femoral head were measured in the bilateral model.

RESULTS

A total of 102 patients diagnosed with Garden I fractures were included in this study. The cohort included 32 men and 70 women, with an average age of 55.88 ± 15.32 years. In these patients, the average displacement of the deepest portion of the femoral head fovea was 16.43 ± 7.69 mm. The minimum and maximum displacement was 3.58 and 44.32 mm, respectively. The average displacement of the center of the femoral head was 10.39 ± 5.47 mm and ranged from 2.16 to 34.42 mm. The rotational angle was 23.81 ± 10.15 ° and ranged from 3.71 ° to 61.19 °.

CONCLUSIONS

Garden I fractures have large spatial displacement and cannot be considered incomplete or nondisplaced fractures. Therefore, we suggest that anatomical reduction should be considered during treatment.

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

OBJECTIVE

To evaluate the posterior tilt angle (PTA) in predicting treatment failure after internal fixation of nondisplaced femoral neck fractures as graded by the Garden classification, which is based solely on anterior-posterior radiographic evaluation.

DATA SOURCES

A search was conducted of all published literature in the following databases from inception to December 20, 2021: PubMed, Embase, Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov .

STUDY SELECTION

We included English-language randomized controlled trials, prospective and retrospective cohort studies that reported malunion/nonunion, avascular necrosis, fixation failure, or reoperations in patients with nondisplaced femoral neck fractures treated with internal fixation who were evaluated for PTA using either lateral radiograph or computed tomography.

DATA EXTRACTION

All abstract, screening, and quality appraisal was conducted independently by 2 authors. Data from included studies were extracted manually and summarized. The Methodological Index for Non-Randomized Studies criteria was used for quality appraisal.

DATA SYNTHESIS

Odds ratios with 95% confidence intervals were calculated for treatment failure, defined as nonunion/malunion, avascular necrosis, fixation failure, or reoperation, in cases involving preoperative PTA ≥20-degrees and <20-degrees. Statistical significance was set at P < 0.05.

RESULTS

Nondisplaced femoral neck fractures with PTA >20-degrees had a 24% rate of treatment failure compared with 12% for those <20-degrees [odds ratios, 3.21 (95% confidence intervals, 1.95-5.28); P < 0.001].

CONCLUSION

PTA is a predictor of treatment failure in nondisplaced femoral neck fractures treated with internal fixation. Nondisplaced femoral neck fractures with a PTA >20-degrees may warrant alternative treatment modalities.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Incidence and risk factors for failure of conservative treatment for valgus impacted femoral neck fractures in elderly patients with high-risk comorbidities-A bi-center retrospective observational study

BACKGROUND

-Establishing the ideal indications for conservative treatment for elderly patients with valgus impacted femoral neck fractures is difficult because few studies have identified predictive factors for the failure of this treatment method. This study aimed to report the outcomes of conservative treatment for elderly patients with valgus impacted femoral neck fractures and determine risk factors that lead to treatment failure.

METHODS

-From January 2009 to December 2018, 206 patients with valgus impacted femoral neck fracture were identified at two institutions. Elderly patients with valgus impacted femoral neck fractures corresponding to an Orthopedic Trauma Association/AO Foundation (OTA/AO) classification of 31-B1.1 or 31-B1.2 who were treated conservatively were included in the study. The following data was collected to compare the preoperative characteristics of patients with valgus impacted femoral neck fractures: age, sex, bone mineral density, medical comorbidities (hypertension, diabetes mellitus, ischemic heart disease, arrhythmia, chronic kidney disease [CKD], and stroke), medial cortex displacement, valgus angle, posterior tilt, and retroversion. These data were used to assess the independent predictors for failure of conservative treatment using multiple logistic regression analysis.

RESULTS

-The failure rate after conservative treatment for valgus impacted femoral neck fracture in the enrolled patient group was 27.3% (15 of 55). CKD, presence of medial cortex displacement, high posterior tilt, and high retroversion were all identified as independent predictors for failure. The cut-off values for retroversion and posterior tilt that predicted treatment failure were 12.5° (area under curve [AUC] 0.768, p = 0.002, 95% confidence interval [CI] 0.632-0.903, sensitivity 0.733, 1-specificity 0.300) and 7.5° (AUC 0.712, p = 0.016, 95% CI 0.542- 0.881, sensitivity 0.667, 1-specificity 0.325), respectively.

CONCLUSIONS

-The present study showed that a high union rate could be obtained if the indications for conservative treatment in for elderly patients with valgus impacted femoral neck fractures are well-defined. Thus, we believe that conservative treatment can be a viable option for valgus impacted femoral neck fractures when elderly patients with high-risk comorbidities have acceptable fracture angulation, no medial cortex displacement, and no CKD.

LEVEL OF EVIDENCE

-Level III, retrospective cohort study.

A three-dimensional measurement based on CT for the posterior tilt with ideal inter-and intra-observer reliability in non-displaced femoral neck fractures

Posterior tilt is associated with prognosis of non-displaced femoral neck fractures (FNFs). Knowledge of their association is critical and informs surgeons whether to choose internal fixation or arthroplasty in treatment of non-displaced FNFs. This study aimed to design a novel three-dimensional (3D) posterior tilt measurement and evaluate the intra- and inter-observer variability compared to two-dimensional (2D) measurement proposed by Palm. We hypothesized that 3D measurement would be more accurate and realistic with higher reliability. To test the hypothesis, three observers measured the posterior tilt on the radiographs of 50 non-displaced FNFs, twice with both methods. Intra- and inter-observer reliability for each measurement method used were determined. The measured angle was divided into two categories, at the cut-off of 20° for clinical practice simulation. Intra- and inter-observer reliability were identified for clinical effectiveness. The results indicated that inter- and intra-observer reliability for 3D measurement and its classification was almost perfect with an intraclass coefficient of 0.995 (0.994) and a kappa value of 0.927(0.947), respectively. Conversely, a substantial inter- and intra-observer reliability for the 2D measurement was obtained with an interclass coefficient of 0.764 as well as an intraclass coefficient of 0.773. The clinical validity for 2D measurement showed slight inter-reliability and moderate intra-reliability with a kappa value of 0.192 and 0.587, respectively. Hence, the novel 3D measurement appears to be more reliable with a strong inter- and intra-observer reliability measurement. Further clinical studies are needed to carry out to validate this hypothesis.

Deep learning for the radiographic diagnosis of proximal femur fractures: Limitations and programming issues

INTRODUCTION

Radiology is one of the domains where artificial intelligence (AI) yields encouraging results, with diagnostic accuracy that approaches that of experienced radiologists and physicians. Diagnostic errors in traumatology are rare but can have serious functional consequences. Using AI as a radiological diagnostic aid may be beneficial in the emergency room. Thus, an effective, low-cost software that helps with making radiographic diagnoses would be a relevant tool for current clinical practice, although this concept has rarely been evaluated in orthopedics for proximal femur fractures (PFF). This led us to conduct a prospective study with the goals of: 1) programming deep learning software to help make the diagnosis of PFF on radiographs and 2) to evaluate its performance.

HYPOTHESIS

It is possible to program an effective deep learning software to help make the diagnosis of PFF based on a limited number of radiographs.

METHODS

Our database consisted of 1309 radiographs: 963 had a PFF, while 346 did not. The sample size was increased 8-fold (resulting in 10,472 radiographs) using a validated technique. Each radiograph was evaluated by an orthopedic surgeon using RectLabel™ software (https://rectlabel.com), by differentiating between healthy and fractured zones. Fractures were classified according to the AO system. The deep learning algorithm was programmed on Tensorflow™ software (Google Brain, Santa Clara, Ca, USA, tensorflow.org). In all, 9425 annotated radiographs (90%) were used for the training phase and 1074 (10%) for the test phase.

RESULTS

The sensitivity of the algorithm was 61% for femoral neck fractures and 67% for trochanteric fractures. The specificity was 67% and 69%, the positive predictive value was 55% and 56%, while the negative predictive value was 74% and 78%, respectively.

CONCLUSION

Our results are not good enough for our algorithm to be used in current clinical practice. Programming of deep learning software with sufficient diagnostic accuracy can only be done with several tens of thousands of radiographs, or by using transfer learning.

LEVEL OF EVIDENCE

III; Diagnostic studies, Study of nonconsecutive patients, without consistently applied reference "gold" standard.

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.

Long-Term Efficacy of Screw Fixation vs Hemiarthroplasty for Undisplaced Femoral Neck Fracture in Patients over 65 Years of Age: A Systematic Review and Meta-Analysis

Objective

To compare the long‐term efficacy of screw fixation and hemiarthroplasty in elderly patients with undisplaced femoral neck fractures.

Methods

We searched Cochrane Library, EMBASE, and MEDLINE from inception to 10 June 2020 to identify studies about undisplaced femoral neck fracture in elderly patients over 65 years of age. The included studies were assessed by two researchers according to the Cochrane risk‐of‐bias criteria and Newcastle–Ottawa Scale. Meta‐analysis was performed with Revman 5.3 software. The odds ratios (OR) and mean differences (MD) were used to compare dichotomous and continuous variables.

Results

A total of 750 patients were included in this meta‐analysis. In elderly patients, undisplaced femoral neck fracture treated with hemiarthroplasty had a lower implant‐related complication rate (OR, 4.05 [95% CI, 2.38 to 6.89]; P < 0.00001; I² = 0), lower reoperation rate (OR, 4.88 [95% CI, 2.84 to 8.38]; P < 0.00001; I² = 0), and superior Harris score (WMD, −5.05 [95% CI, −7.30 to −2.80]; P < 0.0001; I² = 0) in the early postoperative period. Although screw fixation was associated with shorter operative time (WMD, −36.22 [95% CI, −50.72 to −21.73]; P < 0.00001; I² = 98%) and less blood loss (WMD, −165.84 [95% CI, −209.29 to −122.38]; P < 0.00001; I² = 96%), there was no significant difference in long‐term mortality (OR, 0.65 [95% CI, 0.28 to 1.48]; P < 0.31; I² = 75%) between these two treatments.

Conclusion

In elderly patients with undisplaced femoral neck fractures, hemiarthroplasty provided a lower implant‐related complication rate, lower reoperation rate, superior hip function without increased long‐term mortality. Hemiarthroplasty should be recommended as a better alternative in such patients compared with multiple cannulated screws.

Poor results of functional treatment of Garden-1 femoral neck fracture in dependent patients

INTRODUCTION

Variable results are reported after functional treatment for Garden-1 femoral neck fracture, with no definite factors for failure, particularly in the absence of selection for risk. It seems well indicated in frail and/or dependent patients with comorbidities, but this has not been specifically assessed, and failure is frequent in this target population. We therefore performed a retrospective study to: (1) assess results of functional treatment for Garden-1 impacted femoral neck fracture in dependent patients, and (2) analyze survival in terms of complications and death, and related factors.

HYPOTHESIS

Functional treatment for Garden-1 fracture in dependent patients gives poor results, with a high rate of surgical revision.

MATERIAL AND METHODS

A retrospective analysis was made of Garden-1 femoral neck fracture in dependent patients (Parker score≤5), with a minimum 2 years' follow-up. One hundred and forty-six patients were included: mean age, 81.3±8.7 years (range, 55.7-99.6 years). The endpoint was survival in terms of complications requiring surgery, secondary displacement requiring surgery, excessive pain requiring surgery, non-union or femoral head osteonecrosis. Secondary endpoints were overall mortality and mortality related to complications.

RESULTS

Mean follow-up was 4.2±2.6 years (range, 2.0-10.3 years). Ninety-one of the 146 patients (62.3%) required secondary surgery: 79 (54.1%) early (<3 months post-fracture), with 77 (52.7%) secondary displacements and 2 cases (1.4%) of excessive pain; and 12 (8.2%) late (162.2±132.3 days; range, 90-454 days), with 8 (5.4%) non-unions and 4 (2.7%) osteonecroses. Mean time to onset of secondary displacement was 13.6±11.8 days (range, 0-67.0 days). Two-year survival in terms of revision surgery was 34.1% [95% CI: 26.0-42.4]. At last follow-up, 91 patients (62.3%) had died; 2-year survival in terms of death was 69.9% [95% CI: 62.4-77.3]. Survival analysis in terms of complications revealed greater mortality in absence of complications: 42 of the 55 patients (76.3%) without complications requiring surgery died, versus 49 of the 91 (53.8%) with complications requiring surgery (p=0.012); relative risk of death in absence of complications requiring surgery was 1.42 [95% CI: 1.33-5.77].

DISCUSSION

Functional treatment for Garden-1 fracture in dependent patients gave poor short- and medium-term results. Surgery is therefore recommended in this specific population; the present findings should improve survival.

LEVEL OF EVIDENCE

IV, retrospective study.