Effect of the Number, Size, and Location of Cannulated Screws on the Incidence of Avascular Necrosis of the Femoral Head in Pediatric Femoral Neck Fractures: A Review of 153 Cases

Is there an alternative to the Delbet-Colonna classification? Introduction and reliability assessment of a new classification system for paediatric femoral neck fractures: preliminary results

PURPOSE

The purpose of this study was to introduce a new classification system for paediatric femoral neck fractures (PFNFs) and to evaluate its reliability.

METHODS

Two hundred and eight unilateral PFNFs (mean patient age: 9.0 ± 4.8 years) were included. Based on preoperative radiographs, the new classification system distinguished PFNFs without anterior or posterior translation (Type I), PFNFs with anterior (Type II) or posterior (Type III) translation, PFNFs with a comminuted medial or posterior column (Type IV), and subtrochanteric femoral fractures (SFFs; Type V). Radiographs were evaluated twice with an interval of two weeks by 19 raters with different specialties, experiences and geographical origins. The results were compared with a selection of 50 patient age-matched unilateral PFNFs and SFFs (mean patient age: 9.1 ± 4.9 years). These were graded twice by the same graders according to the Delbet-Colonna (D-C) classification.

RESULTS

Four radiologists and 15 paediatric orthopaedic surgeons from Europe and Asia graded the radiographs. Fair agreement was found between radiologists (κ = 0.296 ± 0.01) and surgeons (κ = 0.3 ± 0.005) (P = 0.17), although more experienced surgeons performed better than less experienced ones; a similar fair assessment was found for raters from Europe (κ = 0.309 ± 0.021) and Asia (κ = 0.3 ± 0.006) and for type II, III and IV fractures; the κ value in the first evaluation (0.309) was similar to that in the second evaluation (0.298). The overall κ value of the D-C classification subtypes was significantly higher (0.599 ± 0.217) than that of the new classification, 0.326 ± 0.162 (t = 3.190 P = 0.005).

CONCLUSIONS

The new classification system showed fair reliability relative to the D-C classification. The reliability of the new classification system was not affected by the specialty or geographic origin of the rater or the evaluation round, only by rater experience level. The concordance was worse for PFNFs with anterior or posterior translation or with a comminuted medial or posterior columns.

Outcome of early versus delayed presentation of proximal femur fractures in children: A prospective cohort study

OBJECTIVE

We hypothesized that the exact time of fixation of paediatric proximal femur fractures will have an effect on the ultimate clinical and radiological outcome. This article aimed to compare the clinical-radiological outcomes in paediatric proximal femur fractures having early and delayed presentation.

METHODOLOGY

A prospective cohort study was conducted from January 2019 to November 2022 in patients of age of 5 to 16 years presented with proximal femur fracture and divided into two groups: group A: early presentation, presented <48hours of injury; group B: delayed presentation, presented >48hours of injury. Patients underwent internal fixation treatment modality and followed up to assess clinical outcomes and radiological outcomes, and final outcome was assessed as per Ratliff's criteria.

RESULTS

In the study of 44 patients, 72.72% were male, and 27.27% were female, with male-to-female ratio to be 2.6:1. The commonest mode of injury was fall from height accounting for 52.27% followed by road traffic accidents (RTA) in 38.63%. The most common fracture type observed was Delbet type II, which was observed in 43.18%. There was significant shorter duration of surgery in group A (p-value=0.013), VAS score (p=0.045), and limb length discrepancy (p=0.022). Also, there was a statistical difference in AVN (p-value=0.0295) and growth disturbance (p-value=0.0394) between two groups. Also, there was statistically significant difference between Ratliff's criteria two groups (p-value=0.030).

CONCLUSION

Early presentation has shorter duration of surgery, less VAS score at final follow-up, and less limb length discrepancy, less development of complications like avascular necrosis of the femoral head, and growth disturbance.

LEVEL OF EVIDENCE

III.

The Duration of Hardware Retention After Radiologic Union of Surgically Treated Femoral Neck Fractures in Children May Predict the Aggravation or Occurrence of Avascular Necrosis of the Femoral Head or Neck After Hardware Removal

BACKGROUND

The incidence of aggravation or occurrence of avascular necrosis (AVN) following hardware removal in surgically treated pediatric femoral neck fractures who achieved radiologic consolidation is unknown. This study aimed to investigate the risk factors for this complication.

METHODS

Seventy-one pediatric (mean age: 9.8±3.9 y) were retrospectively analyzed. Risk factors (age, sex, laterality, severity of initial displacement, type of fracture, time from trauma to reduction, reduction and fixation method, quality of reduction, time required to achieve radiologic union, duration of hardware retention, presence of AVN before hardware removal and follow-up time) were recorded. The severity of AVN was assessed based on radiographs with Ratliff's classification.

RESULTS

Following hardware removal, the aggravation/occurrence of AVN was detected in 11 hips (15.5%). Among the 5 hips (7%) with aggravation of AVN, 1 (1.4%) with type II AVN and 3 (4.2%) with type III AVN exhibited aggravation of type I AVN, while the remaining hip (1.4%; type I) showed enlargement of the involved AVN area. Six hips (8.5%) developed AVN following hardware removal: 2 (2.8%) were classified as type I and 4 (5.6%) as type III. Receiver operating characteristic curve analysis indicated that hardware retention >7 months after union is associated with a decreased rate of aggravation or occurrence of AVN of the femoral neck or head following hardware removal.

CONCLUSIONS

The incidence of aggravation or occurrence of AVN following hardware removal in surgically treated pediatric femoral neck fractures is 15.5%; hardware retention >7 months after radiologic union may reduce the risk of aggravation or occurrence of AVN of the femoral neck or head postimplant removal.

LEVEL OF EVIDENCE

Level III.

Risk factors related with avascular necrosis after internal fixation of femoral neck fractures in children: a systematic review and meta-analysis

Background

Less than 1% of children develop femoral neck fractures (FNF), making them uncommon. However, they may have dangerous side effects, like avascular necrosis. Even though several risk factors for postoperative avascular necrosis have been identified, there is still debate regarding them. In this investigation, a meta-analysis was performed to examine the potential causes of postoperative avascular necrosis in children with FNF.

Methods

We conducted a thorough literature search to find risk factors for avascular necrosis (AVN) after internal fixation of pediatric FNF. Until December 2022, we searched several databases, including PubMed, Embase, Cochrane Library, Web of Science, CNKI, Orthosearch, and Sinomed. Software Zotero 6.0 and Stata 17.0 were used to organise and synthesise the data. Finally, a sensitivity and publication bias test was carried out.

Results

Our study includes a total of 15 case-control studies involving 814 patients. The risk of postoperative AVN increased with age at fracture encounter (95% CI: 0.64-1.88, P = 0.0003), initial fracture displacement (95% CI: 1.87-9.54, P = 0.0005), and poor fracture reduction (95% CI:1.95-22.34, P = 0.0024) were risk factors for postoperative AVN. There was no significant relationship between gender and postoperative AVN (95% CI: 0.52-1.31, P = 0.41). Conversely, Postoperative AVN and reduction methods have no connection with each other (95% CI: 0.77-2.66, P = 0.25), procedure time (95% CI: 0.43-2.99, P = 0.16), or injury mechanism (95% CI: 0.32-2.26, P = 0.75). The incidence of post-operative AVN varies between Delbet fracture types (95% CI: 0.15-0.31, P < 0.0001), with the overall trend being that the incidence of post-operative AVN is highest for type II, lowest for type IV, and close for types I and III, but it is not clear which type of fracture is the independent risk factor. Funnel plots indicate no significant publication bias.

Conclusions

In line with this study, About 26% of children who underwent surgery for a femoral neck fracture suffered postoperative AVN. The main risk factors for AVN were the child's age, the initial displacement of the fractures, and poorly reduced fractures. The risk of AVN did not significantly correlate with gender, the time of the procedure, reduction methods or the mechanism of injury. The overall trend in the incidence of postoperative AVN for the different Delbet types of fracture is that the incidence of postoperative AVN is highest for type II, lowest for type IV, and close for types I and III, but it is not clear which type of fracture is the independent risk factor.

Do the Number, Size, and Position of Partially Threaded Screws Affect the Radiological Healing of Surgically Treated Displaced Femoral Neck Fractures? A Review of 136 Children

Background and Objectives: The quantity, size, and position of implants might affect the fracture healing process of surgically treated displaced pediatric femoral neck fractures (PFNFs). The aim of this retrospective multicenter study was to evaluate the correlation between the time needed to achieve radiological union and the number, size, and location of the partially threaded cannulated screws (PTCSs) in children with displaced PFNFs. Materials and Methods: A retrospective review of 136 children (mean age: 10.6 ± 3.8 years) with displaced PFNFs treated by two (n = 103) or three (n = 33) PTCSs was carried out. Student’s t-tests, one-way ANOVA, Cox regression analysis, and multiple linear regression analyses were performed to investigate the variables affecting the time needed to achieve radiological fracture healing according to the number, size, and position of PTCSs, as assessed on plain radiographs. Results: A total of 132 hips achieved union at an average of 3.2 ± 1.6 months after the initial surgery. The time needed to achieve union in the patients treated with two or three PTCSs was comparable (p = 0.36). Among the fractures treated by two PTCSs, the time needed to achieve union did not correlate with the size of the implant (p = 0.122), or with the angulation between the PTCSs on anterior–posterior (p = 0.257) and lateral radiographs (p = 0.547). The time needed to achieve union in the fractures that were fully compressed by the implants was similar to the partially compressed fractures (p = 0.08). Conclusions: The number, size, and position of the PTCSs do not affect the radiological healing in the children with displaced PFNFs treated surgically.

Is Femoral Neck System a Valid Alternative for the Treatment of Displaced Femoral Neck Fractures in Adolescents? A Comparative Study of Femoral Neck System versus Cannulated Compression Screw

Background and Objectives: The femoral neck system (FNS) is a new minimally invasive internal fixation system for femoral neck fractures (FNFs), but its use has not been reported in adolescents. The aim of this study was to compare the clinical and radiographic outcomes of displaced FNF in adolescents treated with FNS or a cannulated compression screw (CCS). Materials and Methods: A retrospective study of 58 consecutive patients with displaced FNF treated surgically was performed; overall, 28 patients underwent FNS and 30 CCS fixation. Sex, age at injury, type of fracture, associated lesions, duration of surgery, radiation exposure, and blood loss were collected from the hospital database. The clinical and radiographic results, as well as complications, were recorded and compared. Results: The patients were followed up for 16.4 ± 3.1 months on average after index surgery (range, 12 to 24). Consolidation time among patients treated with FNS was significantly lower than those managed by CCS (p = 0.000). The functional scores of patients treated with FNS were significantly higher than those managed by CCS (p = 0.030). Unplanned hardware removal in patients treated with FNS was significantly lower than in those managed by CCS (p = 0.024). Conclusions: FNS has a lower complication rate and better functional outcome than CCS. It may be a good alternative to treat femoral neck fractures in adolescents.