Comparison of dynamic hip screw with anti-rotation screw and femoral neck system internal fixation for the treatment of garden II

Abstract

BACKGROUND:

OBJECTIVE:

To compare the efficacy and safety of dynamic hip screw (DHS) with anti-rotation screw and femoral neck system (FNS) internal fixation for the treatment of Garden II–IV type femoral neck fractures.

METHODS:

A total of 90 patients with Garden II–IV type femoral neck fractures were randomly assigned to either the control group ( $n=$ 45) treated with DHS and anti-rotation screw or the experimental group ( $n=$ 45) treated with FNS. Surgical outcomes, including incision size, blood loss, operation time, fluoroscopy frequency, and fracture healing time, were compared. Postoperative complication rates, reoperation rates, Harris scores, and visual analogue scale (VAS) scores were also assessed.

RESULTS:

The experimental group demonstrated significantly reduced incision length, blood loss, operation time, and fluoroscopy frequency compared to the control group ( $P<$ 0.01). No significant differences were observed in fracture healing time, Garden classification, or fracture reduction outcomes between the two groups ( $P>$ 0.05). At 6 months post-treatment, both groups showed significant improvements in Harris scores and VAS scores compared to pre-treatment ( $P<$ 0.05), with no significant differences between the groups ( $P>$ 0.05). The rates of internal fixation failure, nonunion, and avascular necrosis of the femoral head, as well as overall incidence of postoperative complications and reoperation rates, showed no significant differences between the two groups ( $P>$ 0.05).

CONCLUSIONS:

Both DHS with anti-rotation screw and FNS internal fixation demonstrated comparable efficacy and safety profiles in the treatment of Garden II–IV type femoral neck fractures. The experimental group showed advantages in terms of reduced incision length, blood loss, operation time, and fluoroscopy frequency, while maintaining similar clinical outcomes and complication rates.

Keywords

Femoral neck fractures Garden II–IV classification dynamic hip screw (DHS)anti-rotation screw femoral neck system (FNS)internal fixation

1. Introduction

Femoral neck fractures, which are fractures occurring from the femoral head to the base of the femoral neck, are prevalent in the elderly population. With the progression of societal aging, the incidence of femoral neck fractures has been steadily increasing, making it a significant global issue that urgently needs to be addressed. Studies have shown that the incidence of hip fractures is 18% in females and 6% in males, with the female incidence rate being three times higher than that of males [1]. The main clinical manifestations of these fractures include pain and deformity in the affected limb, functional impairment, and inability to stand or walk [2].

Currently, conservative treatment and surgical intervention are the two main approaches for managing femoral neck fractures in the elderly population. Conservative treatment often requires a prolonged duration and yields suboptimal results, leading to multiple complications associated with long-term bed rest [3]. Although traditional open reduction surgeries provide faster recovery for patients, some elderly individuals have multiple comorbidities and exhibit poor surgical tolerance, resulting in a higher rate of postoperative complications [4]. The biomechanical strength of dynamic hip screws combined with anti-rotation screws is higher than that of cannulated screws [5].

In an effort to reduce the incidence of screw back-out complications, an anti-rotation screw is added above the main screw of the dynamic hip screw system, enhancing the resistance to rotational shear forces. This modification effectively compensates for the inadequacy of the primary screw’s anti-rotational properties, providing strong internal fixation for the fracture [6]. Patients can initiate early non-weight-bearing ambulation with the assistance of crutches, reducing the incidence of deep vein thrombosis in the lower limbs. However, the operative procedure does not exhibit the characteristics of minimally invasive surgery [7].

The biomechanical properties of the femoral neck system (FNS) are comparable to those of the dynamic hip screw combined with anti-rotation screw, but the procedure is minimally invasive. A small incision of 4.0–5.0 cm on the lateral aspect of the thigh is sufficient to perform the surgical procedure, including the insertion of the femoral neck dynamic rod, placement of the lateral locking plate, locking of the locking screws, and insertion of the anti-rotation screw. This approach involves only partial incision of the vastus lateralis muscle and avoids injury to the iliopsoas tendon and irritation of the iliopsoas muscle, better reflecting the principles of minimally invasive surgery [8, 9].

This study aims to compare the short-term therapeutic efficacy of the dynamic hip screw with anti-rotation screw internal fixation and FNS internal fixation for the treatment of Garden II–IV type femoral neck fractures, providing valuable insights for clinicians in selecting the appropriate surgical technique.

2. Materials and methods

2.1 Study design

A total of 90 patients with femoral neck fractures treated at the 909th Hospital of Joint Logistic Support Force, Center for Orthopedics, from January 2021 to February 2022 were included in the study. Participants were randomly assigned to either the control group ( $n=$ 45) or the experimental group ( $n=$ 45) using a random digit table. The control group underwent fracture fixation and reduction with dynamic hip screw (DHS) and anti-rotation screw, while the experimental group underwent fracture fixation and reduction with the FNS. All patients provided informed consent for treatment. The study was approved by the Ethics Committee of the 909th Hospital of Joint Logistic Support Force, Center for Orthopedics.

Inclusion criteria: fresh closed femoral neck fractures; Garden II–IV classification; no history of long-term corticosteroid use for systemic diseases.

Exclusion criteria: pathological fractures; old femoral neck fractures; inability to comply with follow-up.

2.2 Sample size calculation

Based on the primary outcome of Harris scores at 6 months post-operation, equivalence statistical hypothesis calculations were performed. Literature review and past experience estimated Harris scores of 85 $\pm$ 10 for the experimental group and 80 $\pm$ 8 for the control group. Using t-distribution for approximation and pooled variance for sample size correction, a 1:1 allocation ratio was employed, with a two-sided test ( $\alpha=$ 0.05) and 80% power. The boundary value was set at 10, with approximately 42 patients per group.

2.3 Surgical procedures

All surgeries were performed by the same team of surgeons and the description of internal fixation materials is provided in Table 1. Preoperative routine X-rays and CT scans were performed. All patients received prophylactic antibiotics (cefazolin sodium 3 g, intravenous infusion) 30 minutes preoperatively until 24 hours postoperatively. Patients without contraindications to anticoagulants received low molecular weight heparin sodium (1 mg/kg, once daily) until 12 hours preoperatively, with anticoagulation therapy resumed 12 hours postoperatively.

Table 1
Introduction of internal fixation materials

Parameter	Dynamic hip screw	Femoral neck system	Anti-rotation screw
Manufacturer	Omega II	Tianjin Zhengtian	Tianjin Zhengtian
Approval number	2008-3461125	2017-3461038	2013-3460715
Material	Stainless steel	TC4 titanium alloy	TC4 Titanium alloy
Model number	GJYDV	GJYDV	GJYDV
Indications	Temporary stabilization of fracture ends or bone fragments until bony union. Indications include fracture fixation, osteotomy, arthrodesis, deformity correction, revision surgery after treatment or device failure, bone reconstruction. Compatible with dynamic hip screw plate and compression screw for internal fixation of femoral neck fractures.	Internal fixation of femoral neck fractures using femoral neck dynamic anti-rotation system, suitable for adult basal, transcervical and subcapital femoral neck fractures, as well as adolescent (12–21 years) femoral neck fractures with closed growth plates or fracture lines not crossing growth plates.
Adverse reactions	Allergic reaction, infection, breakage	Allergic reaction, infection, breakage	Allergic reaction, infection, breakage

Control group treatment: After lumbar and epidural combined anesthesia, patients were placed in the supine position. The surgical approach was through the proximal lateral femur. Under C-arm X-ray guidance, fracture reduction was performed using adduction and internal rotation maneuvers. After satisfactory reduction was achieved in both anteroposterior and lateral views, a two-hole DHS and an additional anti-rotation screw were used for fixation and reduction. The accuracy of internal fixation placement was ensured under fluoroscopy, and the incision was sutured.

Experimental group treatment: Anesthesia and reduction were performed as previously described. An anti-rotation guide wire was inserted to control femoral neck rotation. A longitudinal incision approximately 4 cm in length was made on the lateral femur. Under the assistance of a guide, a femoral neck dynamic rod guide wire was inserted. After measuring the depth, the lateral femoral cortex and medullary canal were expanded using a reamer. The dynamic rod was inserted through the canal, and the FNS was installed. With the assistance of a connecting rod, the system was gently hammered into the femoral neck medullary cavity. One or two locking screws were used for fixation, and the anti-rotation screw medullary cavity was opened along the guide. An appropriate anti-rotation screw was inserted. After satisfactory internal fixation placement and fracture reduction were confirmed under fluoroscopy, the incision was sutured.

Patients were allowed to sit up on postoperative day 1, and were instructed to perform lower limb, hip, and ankle muscle contraction exercises. Partial weight-bearing with crutches was initiated at 1 month postoperatively, with a gradual increase in load depending on individual healing progress. Full weight-bearing was determined based on the specific healing condition.

2.4 Primary outcome measures

The primary outcome measures included intraoperative incision size, blood loss, operation time, fluoroscopy frequency, and fracture healing time. Postoperative complication rates and reoperation rates were recorded for both groups. On postoperative day 3, routine X-rays and CT scans were performed to evaluate fracture reduction and internal fixation. Reduction was graded according to the Garden index: grade I, anteroposterior 160^∘ and lateral 180^∘; grade II, anteroposterior 155^∘ and lateral 180^∘; grade III, anteroposterior 155^∘ or lateral $>$ 180^∘; and grade IV, anteroposterior 150^∘ and lateral $>$ 180^∘. Follow-up visits were conducted monthly for the first 3 months post-discharge, monitoring fracture healing and complications. Patients with satisfactory healing had follow-up intervals adjusted to 3 months. At 6 months postoperatively, all patients underwent Harris scoring and visual analog scale (VAS) assessments. Harris scores were evaluated based on joint function (47 points), pain (44 points), joint deformity (4 points), and joint mobility (5 points), with a total score of 100 points. Higher scores indicated better function. VAS scores ranged from 0 to 10, with higher scores indicating more pain. Single-blind assessments were conducted, with the evaluator unaware of group allocation or treatment methods.

2.5 Statistical analysis

Data were analyzed using SPSS 22.0 software. Continuous data following a normal distribution were presented as mean $\pm$ standard deviation ( $\bar{x}\pm s$ ) and compared using independent $t$ -tests. Categorical data were presented as frequency or percentage (%) and compared using chi-square tests. Ordinal data were analyzed using rank-sum tests. Two-sided tests were performed, with $P<$ 0.05 considered statistically significant.

3. Results

3.1 Participant analysis

A total of 90 patients with Garden II–IV type femoral neck fractures participated in the study, completing a follow-up of 6 months or more after surgery. All patients were included in the outcome analysis to ensure a comprehensive evaluation of the treatment methods. The patients were divided into two groups: the experimental group, treated with dynamic hip screw with anti-rotation screw, and the control group, treated with FNS internal fixation.

3.2 Baseline comparisons between the two groups

The baseline characteristics, including age, injury factors, and Garden classification, were compared between the two groups. There were no significant differences ( $P>$ 0.05), indicating that the groups were comparable and well-matched for the study. Detailed baseline data are presented in Table 2.

Table 2
Comparison of baseline data between the two groups

Parameter	Control group ( $n=$ 45)	Experimental group ( $n=$ 45)	$P$ -value
Male/female ( $n$ )	25/20	26/19	$>$ 0.05
Age ( $\bar{x}\pm s$ , years)	55.19 $\pm$ 10.01	54.42 $\pm$ 9.62	$>$ 0.05
Injury factors ( $n$ )			$>$ 0.05
Fall/fall injury	15	18
Traffic accident	17	22
Other	10	7
Garden classification ( $n$ )			$>$ 0.05
Type II	14	16
Type III	23	24
Type IV	7	9

3.3 General surgical outcomes in both groups

In the experimental group, there was a significant reduction in incision Length, blood loss, operation time, and the number of fluoroscopy examinations compared to the control group ( $P<$ 0.01). Additionally, the incision length was significantly smaller in the experimental group ( $P<$ 0.01). However, there was no significant difference in fracture healing time or Garden classification between the two groups ( $P>$ 0.05). The surgical outcomes are summarized in Table 3.

Table 3
Comparison of general surgical conditions between the two groups

Parameter	Control group ( $n=$ 45)		Experimental group ( $n=$ 45)		$t$ -value	$P$ -value
Incision length (cm)	6.39	$\pm$ 0.78	5.20	$\pm$ 0.90	3.287	0.001
Blood loss (mL)	107.70	$\pm$ 35.97	82.67	$\pm$ 21.47	4.191	$<$ 0.001
Operation time (min)	49.16	$\pm$ 5.54	43.76	$\pm$ 8.01	3.958	$<$ 0.001
Fluoroscopy count	10.90	$\pm$ 3.28	9.59	$\pm$ 2.60	2.258	0.006
Fracture healing time (weeks)	16.68	$\pm$ 3.98	17.41	$\pm$ 3.68	0.967	0.336

3.4 Fracture reduction in both groups

The Garden index evaluation results demonstrated that both groups achieved satisfactory fracture reduction. No significant differences in reduction grade were observed between the groups ( $P>$ 0.05). A detailed comparison of the fracture reduction outcomes is provided in Table 4.

Table 4
Comparison of fracture reduction between the two groups

Group	$n$	Reduction grade
		Grade I	Grade II	Grade III	Grade IV
Control	45	21	22	2	0
Experimental group	45	20	23	2	0
$Z$ value	0.558
$P$ value	0.569

3.5 Pre- and post-treatment comparisons of harris scores and visual analogue scale scores in both groups

Before treatment, there were no significant differences in Harris scores or visual analogue scale scores between the two groups ( $P>$ 0.05), indicating similar baseline pain and functional status. At 6 months post-treatment, both groups showed significant improvements in Harris scores and visual analogue scale scores compared to pre-treatment ( $P<$ 0.05). However, there was no significant difference in the post-treatment scores between the two groups ( $P>$ 0.05). The pre- and post-treatment scores are presented in Fig. 1.

Table 5
Comparison of postoperative complication rate and reoperation rate between the two groups

Group	Internal fixation failure ( $n$ /%)	Nonunion ( $n$ /%)	Femoral head necrosis ( $n$ /%)	Total incidence (%)	Reoperation rate ( $n$ /%)
Control	3/6.67	4/8.89	2/4.44	21.67	8/17.78
Test	1/2.22	2/4.44	1/2.22	8.88	5/9.62
$\chi^{2}$ value	1.47	1.14	0.55	3.37	2.43
$P$ value	0.225	0.286	0.458	0.066	0.119

Figure 1.

Comparison of Harris and visual analogue scale scores between the two groups. (A) Harris scores. (B) Visual analogue scale scores. ^{* P <} 0.05 compared to pre-treatment.

3.6 Incidence of postoperative complications and reoperation rates in both groups

The rates of internal fixation failure, nonunion, and avascular necrosis of the femoral head were compared between the two groups. There were no significant differences ( $P>$ 0.05), indicating comparable safety profiles for both treatment methods. The overall incidence of postoperative complications and reoperation rates also showed no significant differences ( $P>$ 0.05). A comprehensive overview of complications and reoperation rates is provided in Table 5.

3.7 Biocompatibility of internal fixation materials

Throughout the follow-up period, no patients experienced any adverse reactions related to the fixation materials used in either group. This result suggests that both dynamic hip screw with anti-rotation screw and FNS internal fixation demonstrate good biocompatibility in the treatment of Garden II–IV type femoral neck fractures.

4. Discussion

Femoral neck fractures are a common orthopedic issue, accounting for over half of all hip fractures. With the aging population and an increase in various traumas, the incidence of these fractures is on the rise [1]. Surgical treatment is the primary approach in clinical practice, but postoperative complications such as femoral neck shortening, nonunion, varus and valgus deformities, and avascular necrosis of the femoral head frequently occur [10, 11]. Researchers continue to explore solutions for these problems, mainly attributing them to three aspects: blood supply to the femoral head, femoral neck reduction, and the choice of internal fixation [12, 13]. Multiple femoral neck internal fixation devices are available in clinical practice, with no unified standard for selection [14, 15].

The use of three cannulated screws for internal fixation offers the advantages of minimally invasive surgery and good anti-rotation resistance. However, in cases with a Pauwels angle $>$ 50^∘, the fracture becomes unstable, and the biomechanical performance of the three cannulated screws is suboptimal [16, 17]. Additionally, the placement requirements are high, and the number of intraoperative fluoroscopy examinations is greater. The biomechanical strength of dynamic hip screw (DHS) with an anti-rotation screw is superior to that of cannulated screws, but it does not adhere to the principles of minimally invasive surgery. The FNS is a minimally invasive technique for treating femoral neck fractures that results in fewer complications, improved postoperative stability, and better prognosis. It can reduce the incidence of complications such as internal fixation failure and fracture displacement, lower medical costs, and alleviate patient suffering [8].

The main characteristics of the FNS are minimal trauma and excellent stability. From a biomechanical perspective, the FNS is an effective method for treating unstable femoral neck fractures, providing stability comparable to DHS and superior to cannulated screws [8]. The FNS effectively addresses bending, tensile, rotational, and shear stresses originating from the fracture site. Furthermore, after fixation with the FNS, the compressive stress between fracture ends increases, resulting in a more even distribution of external forces. Consequently, the FNS provides strong and biomechanically stable internal fixation for femoral neck fractures, promoting more effective fracture healing [18, 19].

The goal of developing the FNS is to combine the advantages of existing techniques. This new concept in femoral neck fracture fixation still emphasizes biological principles, specifically, promoting fracture healing through initial fracture compression. The results of this study show that the experimental group had significantly less blood loss, shorter operation times, and fewer fluoroscopy examinations than the control group, and the incision length was significantly smaller than that in the DHS group ( $P<$ 0.05). During the insertion of the main screw in the FNS, adjusting the guide needle angle and insertion point using a correction guide avoids repeated adjustments and reduces the number of fluoroscopy examinations. This simplifies the surgical procedure, shortens operation time, and results in smaller incisions and less tissue trauma, adhering to the principles of minimally invasive surgery and reducing intraoperative blood loss.

The Garden index evaluation results show that both groups had satisfactory fracture reduction ( $P>$ 0.05), indicating that both FNS and DHS with an anti-rotation screw can achieve good reduction with higher reduction grades. The Harris and visual analog scale (VAS) scores in both groups improved significantly after treatment compared to before treatment ( $P<$ 0.05). However, there were no significant differences in the post-treatment Harris scores, VAS scores, total incidence of complications, or reoperation rates between the two groups ( $P>$ 0.05). DHS with an anti-rotation screw effectively stabilizes the fracture site, allowing local blood circulation to recover without damaging the joint capsule in the femoral neck region, thus reducing the risk of avascular necrosis of the femoral head. The stability provided by the plate in combination with the DHS aids in fracture healing, and the addition of an anti-rotation screw improves the fixation stability and biomechanical performance, reducing the risk of complications such as screw-plate fracture and varus deformity [20, 21]. Consequently, postoperative pain is significantly relieved, limb function is substantially improved, VAS scores are markedly reduced, and Harris scores are significantly elevated.

The FNS includes an anti-rotation screw, which forms a crossed fixation angle with the main screw, substantially enhancing its anti-rotation resistance and preventing screw back-out. Additionally, the FNS connects to a one or two-hole plate, which enhances its resistance to shear and sliding forces. Furthermore, the fracture ends can be compressed through the multifunctional connecting rod, facilitating fracture site healing. As a result, the FNS offers excellent biomechanical performance, increased minimally invasive characteristics, and significantly improved postoperative Harris scores and VAS scores for patients.

This study had several limitations. Firstly, it was conducted at a single center, and the sample size was small. Further investigation is warranted regarding age and garden classification grouping. Secondly, due to the short follow-up time, some important outcomes, such as avascular necrosis, were not evaluated. Thus, a definitive conclusion regarding the fracture healing rate could not be reached, highlighting the need for long-term research. Additionally, other internal fixation devices, such as the cannulated compression screw and gamma nail fixation, were not included in the trial control group for comparison. Finally, the study was unblinded, as the surgeons reviewing radiographs were aware of the type of implant allocated. Therefore, future research should prioritize multicenter randomized controlled studies with larger sample sizes and longer follow-up periods.

5. Conclusions

FNS and DHS with an anti-rotation screw exhibit robust biomechanical performance and clinical efficacy in femoral neck fracture treatment. Nevertheless, FNS offers minimally invasive features with smaller incisions and reduced blood loss, along with notably enhanced postoperative Harris scores and VAS scores for patients. Consequently, FNS system fixation can facilitate early rehabilitation of hip joint function in femoral neck fracture patients, with a high safety profile devoid of complications.

Footnotes

Conflict of interest

None to report.

References

Veronese

Maggi

. Epidemiology and social costs of hip fracture. Injury. 2018; 49(8): 1458-60.

Florschutz

Langford

Haidukewych

Koval

. Femoral neck fractures: Current management. J Orthop Trauma. 2015; 29(3): 121-9.

Fischer

Maleitzke

Eder

Ahmad

Stöckle

Braun

. Management of proximal femur fractures in the elderly: Current concepts and treatment options. Eur J Med Res. 2021; 26(1): 86.

Zelle

Salazar

Howard

Parikh

Pape

. Surgical treatment options for femoral neck fractures in the elderly. Int Orthop. 2022; 46(5): 1111-22.

Knobe

Altgassen

Maier

Gradl-Dietsch

Kaczmarek

Nebelung

, et al. Screw-blade fixation systems in Pauwels three femoral neck fractures: A biomechanical evaluation. Int Orthop. 2018; 42(2): 409-18.

Makki

Mohamed

Gadiyar

Patterson

. Addition of an anti-rotation screw to the dynamic hip screw for femoral neck fractures. Orthopedics. 2013; 36(7): e865-8.

Hackl

von Rüden

Weisemann

Klöpfer-Krämer

Stuby

Högel

. Internal Fixation of Garden Type III Femoral Neck Fractures with Sliding Hip Screw and Anti-Rotation Screw: Does Increased Valgus Improve Healing? Medicina (Kaunas). 2022; 58(11).

Stoffel

Zderic

Gras

Sommer

Eberli

Mueller

, et al. Biomechanical Evaluation of the Femoral Neck System in Unstable Pauwels III Femoral Neck Fractures: A Comparison with the Dynamic Hip Screw and Cannulated Screws. J Orthop Trauma. 2017; 31(3): 131-7.

Knobe

Bettag

Kammerlander

Altgassen

Maier

Nebelung

, et al. Is bone-cement augmentation of screw-anchor fixation systems superior in unstable femoral neck fractures? A biomechanical cadaveric study. Injury. 2019; 50(2): 292-300.

10.

Duffin

Pilson

. Technologies for young femoral neck fracture fixation. J Orthop Trauma. 2019; 33 Suppl 1: S20-s6.

11.

Slobogean

Stockton

Zeng

Wang

Pollak

. Femoral neck shortening in adult patients under the age of 55 years is associated with worse functional outcomes: Analysis of the prospective multi-center study of hip fracture outcomes in China (SHOC). Injury. 2017; 48(8): 1837-42.

12.

Cole

. Anatomical considerations in adult femoral neck fractures: How anatomy influences the treatment issues? Injury. 2015; 46(3): 453-8.

13.

Jones

Walker

. Diagnosis and management of ipsilateral femoral neck and shaft fractures. J Am Acad Orthop Surg. 2018; 26(21): e448-e54.

14.

Panteli

Rodham

Giannoudis

. Biomechanical rationale for implant choices in femoral neck fracture fixation in the non-elderly. Injury. 2015; 46(3): 445-52.

15.

Slobogean

Sprague

Scott

McKee

Bhandari

. Management of young femoral neck fractures: Is there a consensus? Injury. 2015; 46(3): 435-40.

16.

Zhao

Yin

Zhang

Tang

. Comparison of three different internal fixation implants in treatment of femoral neck fracture – a finite element analysis. J Orthop Surg Res. 2019; 14(1): 76.

17.

Yin

Zhao

Cui

, et al. Novel slide compression anatomic plates of the femoral neck for treating unstable femoral neck fracture: A biomechanical study. J Orthop Res. 2023; 41(5): 1088-96.

18.

Schopper

Zderic

Menze

Müller

Rocci

Knobe

, et al. Higher stability and more predictive fixation with the Femoral Neck System versus Hansson Pins in femoral neck fractures Pauwels II. J Orthop Translat. 2020; 24: 88-95.

19.

Wang

Yang

Feng

Guo

Chen

, et al. Biomechanical comparison of the femoral neck system versus InterTan nail and three cannulated screws for unstable Pauwels type III femoral neck fracture. Biomed Eng Online. 2022; 21(1): 34.

20.

Zhang

Peng

Zhang

Deng

, et al. Comparative study of Pauwels type III femoral neck fractures managed by short dynamic hip screw with fibula bone graft or cannulated screws in young adults. Ann Transl Med. 2020; 8(11): 681.

21.

Luo

Zou

Xian

Wang

Shen

, et al. Modified dynamic hip screw loaded with autologous bone graft for treating Pauwels type-3 vertical femoral neck fractures. Injury. 2017; 48(7): 1579-83.

Comparison of dynamic hip screw with anti-rotation screw and femoral neck system internal fixation for the treatment of garden II–IV type femoral neck fractures

Abstract

BACKGROUND:

OBJECTIVE:

METHODS:

RESULTS:

CONCLUSIONS:

Keywords

1. Introduction

2. Materials and methods

2.1 Study design

2.2 Sample size calculation

2.3 Surgical procedures

Table 1 Introduction of internal fixation materials

2.5 Statistical analysis

3. Results

3.1 Participant analysis

3.2 Baseline comparisons between the two groups

Table 2 Comparison of baseline data between the two groups

Table 3 Comparison of general surgical conditions between the two groups

Table 4 Comparison of fracture reduction between the two groups

Table 5 Comparison of postoperative complication rate and reoperation rate between the two groups

3.7 Biocompatibility of internal fixation materials

4. Discussion

5. Conclusions

Footnotes

Conflict of interest

References

Table 1
Introduction of internal fixation materials

Table 2
Comparison of baseline data between the two groups

Table 3
Comparison of general surgical conditions between the two groups

Table 4
Comparison of fracture reduction between the two groups

Table 5
Comparison of postoperative complication rate and reoperation rate between the two groups