Postoperative computed tomography assessment of anteromedial cortex reduction is a predictor for reoperation after intramedullary nail fixation for pertrochanteric fractures

Anteromedial Cortical Support in Reduction of Trochanteric Hip Fractures: From Definition to Application

➤ The concept of anteromedial cortical support (AMCS) serves as valuable guidance for the intraoperative reduction of trochanteric hip fractures.➤ Positive medial cortical support (MCS) and positive or neutral anterior cortical support (ACS) are desirable. Some evidence has suggested that positive MCS is potentially superior to neutral MCS.➤ Experimental studies underscore the vital importance of the anteromedial wall and reveal why positive MCS potentially outperforms neutral MCS.➤ Incorporating the AMCS concept, the Chang reduction quality criteria (CRQC) are a reliable alternative approach to evaluate the reduction quality of trochanteric hip fractures.

Residual lateral wall width predicts a high risk of mechanical complications in cephalomedullary nail fixation of intertrochanteric fractures: a retrospective cohort study with propensity score matching

PURPOSE

The purpose of this study is to determine whether the integrity of the entry portal of head-neck implant is related to postoperative mechanical complications.

METHODS

We retrospectively reviewed consecutive patients with pertrochanteric fractures in our hospital treated from January 1, 2018, to September 1, 2021. Based on the integrity of the entry portal for head-neck implants on the femoral lateral wall, patients were divided into two groups, including the ruptured entry portal (REP) group and the intact entry portal (IEP) group. After 4:1 propensity score-matched analyses were used to balance the baseline of the two groups, a total of 55 patients were extracted from the original participants, including 11 patients in the REP group and 44 matched patients in the IEP group. The anterior to posterior cortex width on the mid-level of the lesser trochanter was measured and defined as the residual lateral wall width (RLWW).

RESULTS

Compared with the IEP group, the REP group was correlated with postoperative mechanical complications (OR = 12.00, 95% CI 1.837-78.369, P = 0.002) and hip-thigh pain (OR = 26.67, 95% CI 4.98-142.86). RLWW ≤ 18.55 mm indicated a high likelihood (tau-y = 0.583, P = 0.000) of becoming the REP type postoperatively and being more likely to suffer from mechanical complications (OR = 30.67, 95% CI 3.91-240.70, P = 0.000) and hip-thigh pain (OR = 14.64, 95% CI 2.36-90.85, P = 0.001).

CONCLUSION

Rupture of entry portal is a high-risk factor for mechanical complications in intertrochanteric fractures. RLWW ≤ 18.55 mm is a reliable predictor of the postoperative REP type.

Coronal shear fractures of the femoral neck: a comparison with basicervical fractures

PURPOSE

We propose coronal shear fracture of the femoral neck (CSFF) as a new type of fracture that differs from a basicervical fracture. This study aimed to present the incidence of CSFF and compare its clinical characteristics and outcomes with those of basicervical fractures.

METHODS

In this multicenter retrospective cohort study, 2207 patients with hip fractures were identified using computed tomography (CT), 17 and 27 patients were diagnosed with CSFF (CSFF group) and basicervical fractures (basicervical fracture group), respectively. The primary outcome was reoperation, while the secondary outcomes were postoperative radiographic findings, ambulatory ability, and 1-year mortality rate. These outcomes were compared between the two groups. We also conducted diagnostic reliability tests for these fractures using the Cohen's kappa coefficient.

RESULTS

The incidence of CSFF and basicervical fractures in the 2207 patients were 0.77% and 1.22%, respectively. The inter-and intra-observer agreements for the diagnosis were almost perfect. The comorbidity score was significantly higher in the CSFF group than in the basicervical fracture group. No reoperations occurred in both groups. There were no significant intergroup differences in the postoperative radiographic findings. The 1-year mortality rate was higher in the CSFF group than in the basicervical fracture group (38.5% vs. 5.3%; odds ratio: 11.9, 95% CI: 1.2-118.5; p = 0.025).

CONCLUSION

This study presents the definition and incidence of CSFF with a high diagnostic reliability. Patients with CSFF had similar reoperation rate postoperative radiographic outcomes to basicervical fractures, while 1-year mortality rate was high.

Predictors of and predictive nomogram for cut-out of proximal femur nail anti-rotation device in intertrochanteric fractures

PURPOSE

This study determined independent predictors and developed a predictive nomogram for failed correction of intertrochanteric fractures due to cut-out of the proximal femur nail anti-rotation (PFNA) device.

METHODS

Demographic and radiological data of 592 adult patients with intertrochanteric fractures (AO 31A) treated by PFNA were collected retrospectively. Independent predictors of cut-out were obtained through univariate and multivariate analyses, and a predictive nomogram was established. The discrimination, calibration, and clinical utility of the nomogram were based on receiver operating characteristic curve (AUC), concordance index (C-index), calibration curve, and decision curve analysis, respectively.

RESULTS

Overall, 18 (3.04%) cases of cut-out occurred. Independent predictors according to the multivariate analysis were body mass index (BMI), poor-to-acceptable quality of reduction, PFNA blade position, and tip-apex distance (TAD). AUC of the nomogram was 0.849, and C-index was 0.849 (95% CI [0.844-0.854]). Bootstrapping yielded a corrected C-index of 0.849. The calibration and decision curves indicated good agreement and clinical benefit of the nomogram.

CONCLUSION

A reliable predictive nomogram was developed for cut-out of the PFNA in intertrochanteric fractures, based on BMI, quality of reduction, blade position, and TAD.

Association between Immediate Postoperative Radiographic Findings and Failed Internal Fixation for Trochanteric Fractures: Systematic Review and Meta-Analysis

Failed internal fixations for trochanteric fractures have a strong negative impact owing to increased postoperative mortality and high medical costs. However, evidence on the prognostic value of postoperative radiographic findings for failed internal fixations is limited. We aimed to clarify the association between comprehensive immediate postoperative radiographic findings and failed internal fixation using relative and absolute risk measures. We followed the meta-analysis of observational studies in epidemiology guidelines and the Cochrane handbook. We searched specific databases in November 2021. The outcomes of interest were failed internal fixation and cut-out. We pooled the odds ratios and 95% confidence intervals using a random-effects model and calculated the number needed to harm for each outcome. Thirty-six studies involving 8938 patients were included. The certainty of evidence in the association between postoperative radiographic findings and failed internal fixation or cut-out was mainly low or very low except for the association between intramedullary malreduction on the anteromedial cortex and failed internal fixation. Moderate certainty of evidence supported that intramedullary malreduction on the anteromedial cortex was associated with failed internal fixation. Most postoperative radiographic findings on immediate postoperative radiographs for trochanteric fractures were uncertain as prognostic factors for failed internal fixations.

In response to letter to the editor: calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures

We appreciate the interest by Drs. Hagiyama and coauthors in our work entitled "Calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures". They discussed several pertinent points and it is our pleasure to respond their concerns in order. Firstly, we agree that calcar fracture gap and anteromedial cortical support are different concepts, though both of them were used to evaluate the displacement of fracture reduction quality. Secondly, our primary outcome parameter was the threshold distance of calcar fracture gapping in anteroposterior and lateral fluoroscopies, which was calculated based on sensitivity and specificity by receiver operating characteristic curves. Thirdly, we took immediate post-operative fluoroscopic images in 3 views to describe the initial reduction quality as baseline to compare and calculate the changes with three-dimensional computed tomography, which was taken about one week after operation for confirming secondary stability after head-neck sliding and impaction. Lastly, the parameters selected in multivariable analysis. Future work with better study-design is needed to improve the prediction of patient outcomes.

Letter to the editor: Calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures

A recently published article by Song H et al. investigated the risk factors for anteromedial cortical support loss in pertrochanteric fractures treated with cephalomedullary nails. In this Correspondence, we would like to raise some concerns. Specifically, calcar fracture gap and anteromedial cortical support are different concepts in evaluating reduction quality. In addition, calcar fracture gap using immediate postoperative radiographic images has measurement bias. Lastly, explanatory variables selected for multivariable analysis are inappropriate. We would like to discuss and suggest solutions for these problems.

Low filling ratio of the distal nail segment to the medullary canal is a risk factor for loss of anteromedial cortical support: a case control study

Background

Anteromedial cortical support apposition (positive and/or neutral cortical relations) is crucial for surgical stability reconstruction in the treatment of trochanteric femur fractures. However, the loss of fracture reduction is frequent in follow-ups after cephalomedullary nail fixation. This paper aimed to investigate the possible predictive risk factors for postoperative loss of anteromedial cortex buttress after nail fixation.

Methods

A retrospective analysis of 122 patients with AO/OTA 31A1 and A2 trochanteric femur fractures treated with cephalomedullary nails between January 2017 and December 2019 was performed. The patients were classified into two groups according to the postoperative status of the anteromedial cortical apposition in 3D CT images: Group 1 with contact “yes” (positive or anatomic) and Group 2 with contact “No” (negative, loss of contact). The fracture reduction quality score, tip-apex distance (TAD), calcar-referenced TAD (Cal-TAD), Parker ratio, neck-shaft angle (NSA), and the filling ratio of the distal nail segment to medullary canal diameter in anteroposterior (AP) and lateral fluoroscopies (taken immediately after the operation) were examined in univariate and multivariate analyses. Mechanical complications were measured and compared in follow-up radiographs.

Results

According to the postoperative 3D CT, 84 individuals (69%) were categorized into Group 1, and 38 individuals (31%) were classified as Group 2. The multivariate logistic regression analysis showed that the poor fracture reduction quality score (P < 0.001) and decreasing filling ratio in the lateral view (P < 0.001) were significant risk factors for the loss of anteromedial cortical contact. The threshold value for the distal nail filling ratio in lateral fluoroscopy predicting fracture reduction re-displacement was found to be 53%, with 89.3% sensitivity and 78.9% specificity. The mechanical complication (varus and over lateral sliding) rate was higher in Group 2.

Conclusions

The fracture reduction quality score and the decreasing filling ratio of the distal nail to the medullary canal in the lateral view (a novel parameter causing pendulum-like movement of the nail) were possible risk factors for postoperative loss of anteromedial cortical support.