Preoperative Posterior Tilt Increases the Risk of Later Conversion to Arthroplasty After Osteosynthesis for Femoral Neck Fracture

Comparable results for the Femoral Neck System and three-screw fixation in femoral neck fracture treatment

Objectives

To report outcomes of femoral neck fractures (FNFs) treated with Femoral Neck System (FNS) and to compare the risks of later conversion to arthroplasty for FNS and fixation with cannulated screws (CNSs).

Design

A retrospective study.

Setting

A single-center study (Turku University Hospital, Finland).

Patients

Data on 51 patients with FNFs treated with FNS between January 1, 2019, and May 31, 2021, were retrospectively reviewed. In addition, data on 301 patients treated with cannulated screws were collected and analyzed in a previous study.

Intervention

Patients with FNFs underwent osteosynthesis with FNS.

Main Outcome Measurements

Patients' preoperative and postoperative radiographs were analyzed and measured to determine preoperative displacement, preoperative posterior tilt, and quality of reduction. Later conversion to arthroplasty and other reoperations were recorded. The risk of later conversion to arthroplasty was compared between the FNS group and CNS group.

Results

The overall reoperation rate in the FNS group was 20%, and 16% of the patients treated with FNS underwent later conversion to arthroplasty. In the multivariate analysis, age, sex, and fracture displacement were not associated with increased risk of later conversion to arthroplasty. In comparison with fixation with cannulated screws, there was no statistically significant difference in the probability of later conversion to arthroplasty between the groups.

Conclusion

FNS seems to have a comparable reoperation rate and conversion-to-arthroplasty rate compared with the gold standard treatment.

Level of Evidence

III.

What is the Fate of Undisplaced Femoral Neck Fractures Treated With Cannulated Screws?

BACKGROUND

We aimed to report implant survival in Garden type I and II femoral neck fractures treated with cannulated screws in elderly patients.

METHODS

We retrospectively studied 232 consecutive unilateral Garden I and II patients (232 fractures) treated with cannulated screws. Mean age was 81 years (range, 65 to 100), and a body mass index of 25 (range, 15.8 to 38.3). No between-group differences were found in demographic variables and/or baseline measurements (P > .05). Mean follow-up was 36 months (range, 1 to 171). Two observers measured baseline radiographic variables with good-to-excellent interobserver reliability. The posterior tilt angle, measured on a cross-table lateral x-ray, was used to classify the cohort into <20° (n = 183) and ≥20° (n = 49). The cumulative incidence with competing risk analysis was used to predict association between posterior tilt and subsequent conversion to arthroplasty. Patient survival was calculated with the Kaplan-Meier estimate.

RESULTS

Implant survival was 86.3% (95% confidence interval (CI) 80 to 90) at 12 months and 77.3% (95% CI 64 to 86) at 70 months. The 12-month cumulative incidence failure was 12.6% (95% CI 8 to 17). After controlling for confounders, posterior tilt ≥20° had higher risk of subsequent arthroplasty when compared to posterior tilt <20° (38.8 [95% CI 25 to 52] versus 5% [95% CI 2.8 to 9], subhazard ratio 8.3, 95% CI 3.8 to 18), without any other radiologic or demographic factor being associated with failure. Patient survival was 88.2% (95% CI 83 to 91.7) at 12 months, 79.5% (95% CI 73 to 84) at 24 months, and 57% (95% CI 48 to 65) at 70 months.

CONCLUSION

Cannulated screws were a reliable treatment for Garden I and II fractures, except when there was posterior tilt ≥20°, where arthroplasty should be considered.

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.

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.

Clinical outcomes of patients with Garden I and II femoral neck fractures as verified on MRI: a retrospective case series

Background

Between 2 to 10% of non-displaced femoral neck fractures (nFNF) cannot be diagnosed on plain radiographs and require further imaging investigation to be detected or verified. These fractures are referred to as occult hip fractures. This study aimed to report treatment failures, reoperations and mortality in a consecutive series of occult femoral neck fractures (FNF) treated with internal fixation (IF).

Methods

A retrospective multicenter study was performed based on a consecutive series of patients aged ≥ 60 years with an occult magnetic resonance imaging (MRI) verified Garden I and II FNF sustained after a trauma and treated with primary IF. We included 93 patients with a minimum 2-year follow-up. Radiographic assessment encompassed pre- and postoperative tilt, implant inclination, MRI and treatment failure. Data on reoperation and mortality were collected. Treatment failure was defined as fixation failure, nonunion, avascular necrosis or posttraumatic osteoarthritis.

Results

The study comprised of 93 patients (72% women, 67/93) with a mean age of 82 (range, 60–97) years. Overall, 6 (6%) patients had major reoperations. 2 (2%) had minor reoperations. One-month mortality was 7%, 1-year mortality was 20% and 2-year mortality was 31%.

Conclusion

This multicenter cohort study identifies a subgroup of elderly patients with MRI verified Garden I and II FNFs sustained after trauma, i.e. occult fractures. These fractures seem to have a lower complication rate compared to nFNF identified on plain radiographs.

Level of evidence

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

Nomogram for predicting reoperation following internal fixation of nondisplaced femoral neck fractures in elderly patients

OBJECTIVE

We aimed to evaluate risk factors and develop a nomogram for reoperation after internal fixation of nondisplaced femoral neck fractures (FNFs) in elderly patients.

METHODS

We conducted a retrospective study involving a total of 255 elderly patients who underwent closed reduction and internal fixation with cannulated screw system for nondisplaced FNFs between January 2016 and January 2019. We collected data on demographics, preoperative radiological parameters, surgery, serum biochemical markers, and postoperative rehabilitation. In addition, we performed univariate and multivariate logistic regression analyses to determine independent risk factors for reoperation, and then developed a nomogram to assess the risks of reoperation. Besides, discriminative ability, calibration, and clinical usefulness of the nomogram were evaluated using the concordance index (C-index), the receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA), respectively. We employed bootstrap method to validate the performance of the developed nomogram.

RESULTS

Our analysis showed that among the 255 patients, 28 (11.0%) underwent reoperation due to osteonecrosis of the femoral head (14 cases), mechanical failure (8 cases) or nonunion (6 cases). All of the 28 patients underwent conversion surgery to arthroplasty. The multivariate logistic regression analysis demonstrated that preoperative posterior tilt angle ≥ 20°, Pauwel's III type, younger patients, preoperative elevated levels of alkaline phosphatase (ALP), preoperative hypoalbuminemia, and early postoperative weight-bearing were independent risk factors for reoperation. In addition, the C-index and the bootstrap value of the developed nomogram was 0.850 (95% CI = 0.803-0.913) and 0.811, respectively. Besides, the calibration curve showed good consistency between the actual diagnosed reoperation and the predicted probability, while the DCA indicated that the nomogram was clinically valuable.

CONCLUSIONS

Our analysis showed we successfully developed and validated a nomogram for personalized prediction of reoperation after internal fixation of nondisplaced FNFs in elderly patients. This model would help in individualized evaluation of the need for reoperation and inform strategies aimed at eliminating the need for the reoperation.