High Reliability of a Scoring System for Implant Position in Undisplaced Femoral Neck Fractures

Nonanatomical Reduction of Femoral Neck Fractures in Young Patients (≤65 Years Old) with Internal Fixation Using Three Parallel Cannulated Screws

Purpose

The study is aimed at investigating the association between different reduction classifications (anatomic reduction, positive buttress position reduction, and negative buttress position reduction) and two end points (complications and reoperations).

Methods

The study retrospectively analyzed 110 patients undergoing internal fixation with three parallel cannulated screws from January 2012 to January 2019 in Huashan Hospital. Based on the principles of the “Gotfried reduction,” all enrolled patients were divided into three groups: anatomic reduction, positive buttress position reduction, and negative buttress position reduction intraoperatively or immediately after surgery. Clinical characteristics including age, sex, side, Garden classification, Pauwels classification, fracture level, reduction classification, Garden alignment index angles, cortical thickness index (CTI), tip-caput distance (TCD), angle of the inferior screw, and the two ending points (complications and reoperations) were included in the statistical analysis. The Mann-Whitney U-test, the chi-square test, Fisher's exact test, and multiple logistic regression analysis were used in the study.

Results

Of the 110 patients included in our study, the mean ± standard deviation (SD) of age was 51.4 ± 10.4 years; 41 patients showed anatomic reduction, 35 patients showed positive buttress position reduction, and 34 patients showed negative buttress position reduction. For the outcomes, 24 patients (anatomic reduction: 6 [14.6%]; positive buttress position reduction: 5 [14.3%]; negative buttress position reduction: 13 [38.2%]) had complications, while 18 patients (anatomic reduction: 5 [12.2%]; positive buttress position reduction: 3 [8.6%]; negative buttress position reduction: 10 [29.4%]) underwent reoperations after surgery. In the multivariate logistic regression analysis of complications, negative buttress position reduction (negative buttress position reduction vs. anatomic reduction, OR = 4.309, 95%CI = 1.137 to 16.322, and p = 0.032) was found to be correlated with higher risk of complications. The same variable (negative buttress position reduction vs. anatomic reduction, OR = 5.744, 95%CI = 1.177 to 28.042, and p = 0.031) was also identified as risk factor in the multivariate logistic regression analysis of reoperations. However, no significant difference between positive reduction and anatomical reduction was investigated in the analysis of risk factors for complications, not reoperations.

Conclusion

Positive buttress position reduction of femoral neck fractures in young patients showed a similar incidence of complications and reoperations compared with those of anatomic reduction. For irreversible femoral neck fractures, if positive buttress position reduction has been achieved intraoperatively, it is not necessary to pursue anatomical reduction; however, negative reduction needs to be avoided.

Implant positioning (IMPO) in undisplaced femoral neck fractures: Association to reoperation and development of an IMPO scoring system

INTRODUCTION

This study aims to investigate whether implant positioning is associated to risk of reoperation following internal fixation of undisplaced femoral neck fractures (FNF) with a posterior tilt < 20° in patients > 65 years.

METHOD

Patients were retrieved from the Danish Multidisciplinary Hip Fracture Register in the period 2009-2013. The patients' health records and x-rays were reviewed for age, sex, implant, Charlson Comorbidity Index, mortality, reoperation, fracture classification and implant positioning. X-rays were measured for implant positioning using a pre-existing scoring system (the Schep score) as well as some additional measurements. Primary outcome was reoperation within 2 years. The study included 406 patients, 75% females and the median (range) age was 82 (65-99) years. Odds ratios (OR) are shown with 95% confidence interval.

RESULTS

There were 45 (11%) reoperations. Six measurements were individually associated to risk of reoperation: 1) Distance to inferior calcar < 1 or ≥ 6 mm, OR 2 (1.1-4), 2) Distance to superior cortex 10 mm, OR 2(1.1-5), 3) Tip-head distance < 3 or ≥ 20 mm, OR 2 (1.1-4), 4) Placement in the superior or inferior 15 mm, OR 2 (1.1-5), 5) Placement in the anterior 25 %, OR 6 (1.8-20), 6) Inter-implant angle ≥ 5°, OR 3 (1.4-8). The Schep score had no associated to reoperation, and therefore a new implant positioning (IMPO) score was developed. The IMPO score consists of 6 items; 1 point given for each acceptable implant placement. An IMPO score less than 5 had an increased risk of reoperation; 0-2 points OR 22 (7-71) and OR 5 (2-11) for 3-4 points, compared to a score of 5-6. Among the 207 patients with a score of 5-6, the reoperation frequency was 4%.

CONCLUSIONS

This study identified implant positioning as a predictor to an increased risk of reoperation in undisplaced FNF. The newly developed IMPO score seems promising for identifying risk of reoperation.

Reproducibility of the stability-based classification for ankle fractures

BACKGROUND

Classification of ankle fracture is important when deciding for operative or conservative treatment. This study rates the reproducibility of ankle stability assessment and compares it with the classification by Lauge-Hansen and Arbeitsgemeinschaft für Osteosyntesefragen (AO) in adult patients with primary ankle fractures.

METHODS

A total of 496 consecutive ankle fractures were included, and the X-ray images were reviewed 2 times by 2 medical students, 2 residents, and 1 consultant in orthopedic traumatology. The raters were blinded to each other and to their own results. Unweighted Kappa statistics were used to assess reproducibility.

RESULTS

Overall mean (95% CI) interrater Kappa results were 0.65 (0.64; 0.68) for Lauge-Hansen, 0.62 (0.60; 0.63) for AO and 0.61 (0.57; 0.62) for the stability assessment. The intrarater results ranged from a mean Kappa of 0.64-0.80 for the medical students, 0.65-0.81 for the residents and 0.82-0.84 for the consultant.

CONCLUSION

The stability assessment has substantial to almost-perfect agreement which is comparable to the Lauge-Hansen and AO classifications.

Osteosynthesis with Parallel Implants in the Treatment of Femoral Neck Fractures: Minimal Effect of Implant Position on Risk of Reoperation

BACKGROUND

The purpose of this study was to estimate the incidence of reoperation and the effect of implant position on the risk of reoperation within 12 months following osteosynthesis with use of parallel implants for femoral neck fractures.

METHODS

From cases registered in the Danish Fracture Database, 1,206 consecutive surgeries for a primary femoral neck fracture treated with use of parallel implants during the period of December 2011 to November 2015, and having available radiographs and follow-up data, were reviewed. Data included age, sex, time to surgery, fracture classification, and American Society of Anesthesiologists (ASA) score. Fracture displacement, posterior tilt, the number of implants, posterior distance, calcar distance, tip-cartilage distance, and angulation of implants were measured on pre- and postoperative radiographs. Data on secondary surgeries were collected from the Danish Civil Registration System. The effects of the included variables on the risk of reoperation were evaluated using Cox regression analysis.

RESULTS

The median age was 73 years (range, 21 to 102 years); in 69% of the cases, the patient was female. Two implants were used in 997 cases and 3 implants were used in 209. In 157 cases, the patient underwent reoperation within 1 year; in 228 cases, the patient died within 1 year. The median time to reoperation was 116 days. Patients <70 years of age were more likely to undergo reoperation (18.0% compared with 9.8%) but less likely to die (7.4% compared with 26.3%) than were patients ≥70 years of age. Female sex, higher ASA score, and displaced fractures were associated with increased risk of reoperation. Time to surgery was associated with increased risk of reoperation for displaced fractures only. Of the variables pertaining to the osteosynthesis, only insufficient fracture reduction, placement of the implants with an angle to the shaft of ≤125°, and femoral head perforation significantly increased the risk of reoperation. We found no effect of the posterior distance, the calcar distance, the tip-caput distance, or whether or not the implants were parallel.

CONCLUSIONS

Insufficient reduction, varus position of the implants, and perforation of the femoral head cartilage were the only surgical factors influencing the risk of reoperation. Sufficient fracture reduction is perhaps more important than focusing on an optimal position of the implants.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.