Treatment Of Femoral Neck Fractures Research Articles

Biomechanical analysis of a new cannulated screw for unstable femoral neck fractures.

The treatment of unstable femoral neck fractures (FNFs) remains a challenge. In this study, a new cannulated screw for unstable FNFs was designed to provide a new approach for the clinical treatment of these injuries, and its biomechanical stability was analyzed using finite element analysis and mechanical tests. An unstable FNF model was established. An internal fixation model with parallel inverted triangular cannulated screws (CSs) and a configuration with two superior cannulated screws and one inferior new cannulated screw (NCS) were used. The biomechanical properties of the two fixation methods were compared and analyzed by using finite element analysis and mechanical tests. The NCS model outperformed the CSs model in terms of strain and stress distribution in computer-simulated reconstruction of the inverted triangular cannulated screw fixation model for unstable FNFs. In the biomechanical test, the NCS group showed significantly smaller average femoral deformation (1.08 ± 0.15mm vs. 1.50 ± 0.37mm) and fracture line displacement (1.43 ± 0.30mm vs. 2.01 ± 0.47mm). In the NCS group, the mean stiffness was significantly higher than that in the CSs group (729.37 ± 82.20N/mm vs. 544.83 ± 116.07N/mm), and the mean compression distance was significantly lower than that in the CSs group (2.87 ± 0.30mm vs. 4.04 ± 1.09mm). The NCS combined with two ordinary cannulated screws in an inverted triangle structure to fix unstable FNFs can provide better biomechanical stability than CSs and exhibit a length- and angle-stable construct to prevent significant femoral neck shortening.

Biomechanical changes in the proximal femur before and after removal of femoral neck system

BackgroundAs an innovative internal fixation system, FNS (femoral neck system) is increasingly being utilized by surgeons for the treatment of femoral neck fractures. At present, there have been numerous finite element analysis experiments studying the immediate stability of FNS and CSS in treating femoral neck fractures. However, there is scarce mechanical analysis available regarding the effects post internal fixation removal. This study aimed to investigate the alterations in mechanical parameters of the proximal femur before and after the removal of FNS (femoral neck system), and to assess potential distinctions in indicators following the extraction of CSS (Cannulated Screws).MethodsA proximal femur model was reconstructed using finite element numerical techniques. The models for CSS and FNS were formulated utilizing characteristics and parametric definitions. The internal fixation was combined with a normal proximal femur model to simulate the healing state after fracture surgery. Within the framework of static analysis, consistent stress burdens were applied across the entirety of the models. The total deformation and equivalent stress of the proximal femur were recorded before and after the removal of internal fixation.ResultsUnder the standing condition, the total deformation of the model before and after removing CSS was 0.99 mm and 1.10 mm, respectively, indicating an increase of 12%. The total deformation of the model before and after removing FNS was 0.65 mm and 0.76 mm, respectively, indicating an increase of 17%. The equivalent stress for CSS and FNS were 55.21 MPa and 250.67 MPa, respectively. The average equivalent stress on the cross-section of the femoral neck before and after removal of CSS was 7.76 MPa and 6.11 MPa, respectively. The average equivalent stress on the cross-section of the femoral neck before and after removal of FNS was 9.89 MPa and 8.79 MPa, respectively.ConclusionsThe retention of internal fixation may contribute to improved stability of the proximal femur. However, there still existed risks of stress concentration in internal fixation and stress shielding in the proximal femur. Compared to CSS, the removal of FNS results in larger bone tunnels and insufficient model stability. Further clinical interventions are recommended to address this issue.

Treatment of femoral neck fractures using actis stem: complication rate in 188 uncemented hemiarthroplasties.

Cemented hemiarthroplasty (HA) is preferred in treating dislocated femoral neck fractures in elderly, osteoporotic patients, since uncemented HA was associated with mechanical complications more frequently. Cementation can conversely cause cardiopulmonary complications, leading to demand on safe, uncemented implants addressing osteoporosis. This study is set up as a retrospective feasibility study on the use of an uncemented, collared wedge implant (Actis®, DePuy Synthes, Warsaw, IN), for HA in elderly patients, focusing on complication rate. From 1,194 patients, treated with HA in two study centers between 2017-2022, 188 received Actis® uncemented stem with bipolar head. Complete follow-up were retrospectively collected in all patients. In 188 patients (f: 64.9%; age: 83.1 ± 7.7a) included, no case of intra-operative mortality was recorded. 2day mortality was 1.1%, 30day mortality was 7.4% and 1year mortality was 28.2%. 2 (1.1%) intra-operative fractures did not receive surgical revision, 3 (1.6%) post-operative periprosthetic fractures caused separate admission and revision. 2 cases (1.1%) of early infection required surgical revision. Our data provide proof of concept, that Actis® Stem allows an alternative, uncemented treatment option for displaced femoral neck fractures with HA. In case of preoperative or intraoperative medial cortical bone defects, stability of this implant is deteriorated.

The Impact of China's Healthcare Reforms on Promoting Early Treatment for Femoral Neck Fractures.

The Impact of China's Healthcare Reforms on Promoting Early Treatment for Femoral Neck Fractures.

Clinical efficacy of Femoral Neck System for treatment of unstable femoral neck fractures in young adults.

This study was performed to evaluate the mid-term clinical efficacy of the Femoral Neck System (FNS) (DePuy Synthes, Zuchwil, Switzerland) in treating young patients with unstable Pauwels type III femoral neck fractures. We performed a retrospective observational analysis of 21 young adults treated with the FNS. Clinical outcomes were assessed based on fracture reduction quality, Harris hip scores, and postoperative complication rates. The study comprised 21 patients with a mean age of 35 years (range, 20-50 years) who were followed for a mean duration of 22.8 months (range, 16-30 months). Closed reduction was unfeasible in three (14.3%) patients, each of whom required open reduction. Notable postoperative complications were avascular necrosis in two (9.5%) patients, nonunion in one (4.7%), and implant failure in one (4.7%). Each of these complications led to the requirement for total hip arthroplasty. The favorable mid-term clinical outcomes of this study indicate that the FNS is a potentially effective treatment modality for young individuals with unstable Pauwels type III femoral neck fractures.

Femoral Neck Fractures with Concomitant Ipsilateral Femoral Shaft Fractures in Young Adults <50 Years Old: A Multicenter Comparison of 80 Cases vs. Isolated Femoral Neck Fractures

OBJECTIVES: To analyze patients, injury pattern, and treatment of femoral neck fractures in young patients with femoral neck fractures associated with shaft fractures (assocFNFs) to improve clinical outcomes. The secondary goal was to compare this injury pattern to that of young patients with isolated femoral neck fractures (isolFNFs). METHODS: Design: Retrospective multicenter cohort series Setting: 26 North American Level-1 trauma centers Level of Evidence: Level III Patient Selection Criteria: Skeletally mature patients, <50 years old, treated with operative fixation of a femoral neck fracture with or without an associated femoral shaft fracture. Outcome Measures and Comparisons: The main outcome measurement was treatment failure defined as nonunion, malunion, avascular necrosis, or subsequent major revision surgery. Odds ratios for these modes of treatment were also calculated. RESULTS: Eighty assocFNFs and 412 isolFNFs evaluated in the study were different in terms of patients, injury patterns, and treatment strategy. AssocFNF patients were younger (33.3±8.6 vs. 37.5±8.7 years old, p<0.001), greater in mean BMI (29.7 vs. 26.6, p<0.001), and more frequently displaced (95% vs. 73%, p<0.001), “vertically oriented” Pauwels’ type 3, p<0.001 (84% vs. 43%) than for isolFNFs, with all p values <0.001. AssocFNFs were more commonly repaired with an open reduction (74% vs. 46%, p<0.001) and fixed angle implants (59% vs. 39%) (p<0.001). Importantly, treatment failures were less common for assocFNFs compared to isolFNFs (20% vs. 49%, p<0.001) with lower rates of failed fixation/ nonunion and malunion (p<0.001 and p=0.002, respectively). Odds of treatment failure (OR=0.270, 95% CI=0.15-0.48, p<0.001), nonunion (OR=0.240, 95% CI=0.10-0.57, p<0.001), and malunion (OR=0.920, 95% CI=0.01-0.68, p=0.002) were also lower for assocFNFs. Excellent or good reduction was achieved in 84.2% of assocFNFs reductions and 77.1% in isolFNFs (p=0.052). AssocFNFs treated with fixed angled devices performed very well, with only 13.0% failing treatment compared to 51.9% in isolFNFs treated with a fixed angle constructs (p=<0.001) and 33.3% in assocFNFs treated with multiple cannulated screws (p=0.034). The study also identified the so-called “shelf sign”, a transverse ≥6mm medial-caudal segment of the neck fracture (forming an acute angle with the vertical fracture line) in 54% of assocFNFs and only 9% of isolFNFs (p<0.001). AssocFNFs with a shelf sign failed in only 5 of 41 (12%) of cases. CONCLUSIONS: AssocFNFs in young patients are characterized by different patient factors, injury patterns, and treatments, than for isolFNFs, and have a relatively better prognosis despite the need for confounding treatment for the associated femoral shaft injury. Treatment failures among assocFNFs repaired with a fixed angled device occurred at lower rate compared to isolFNFs treated with any construct type, and assocFNFs treated with multiple cannulated screws. The radiographic “shelf sign” was found as positive prognostic sign in more than half of assocFNFs and predicting a high rate of successful treatment. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Contralateral Neck-shaft Angle Lower Than 130° Is Associated With Clinical Failure in Nongeriatric Individuals: Analysis of the National Femoral Neck Fracture Database of 1066 Patients.

Treatment of femoral neck fractures in patients who are nongeriatric (≤ 60 years) is challenging because of high failure rates. Anatomic parameters influence the biomechanical environment for fracture healing, but their associations with clinical prognosis remains unclear. (1) Which anatomic parameter that is identifiable on pelvic radiographs shows a statistical correlation with a higher risk of clinical failure defined as nonunion, avascular necrosis (AVN), reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference) in the screw fixation of femoral neck fractures among nongeriatric patients? (2) How does the influence of anatomic parameters on clinical prognosis manifest: directly or mediated by additional mechanisms? This retrospective, multicenter study used a nationwide database in China. Between January 2014 and December 2020, we evaluated 1066 patients with femoral neck fractures with a median age of 53 years (interquartile range 46 to 56) and median follow-up period of 62 months. Anatomic parameters including femoral neck-shaft angle (NSA), femoral head radius, femoral neck width, femoral offset, acetabular center-edge angle, and acetabular sharp angle were variables of interest. The primary outcome was clinical failure including nonunion, AVN, reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference). Risk factors for failure were first filtered using the Bayesian information criterion and then assessed with multiple regression adjusting for confounders. The mediation effect was further explored using model-based causal mediation analysis with a quasi-Bayesian Monte Carlo method. Of all anatomic parameters we assessed, the contralateral NSA was associated with clinical failure, after adjusting for all potential covariates and confounding variables (adjusted odds ratio 0.92 [95% confidence interval 0.89 to 0.95]; p < 0.001). The optimal threshold for the NSA was 130°, with the highest Youden index of 0.27. Patients with an NSA < 130° (41% [441 of 1066]) demonstrated an increased occurrence of nonunion (15% [68 of 441] versus 5% [33 of 625]; p < 0.001), AVN (32% [141 of 441] versus 22% [136 of 625]; p < 0.001), functional failure (25% [110 of 441] versus 15% [93 of 625]), and reoperations (28% [122 of 441] versus 13% [79 of 625]). The impact of an NSA less than 130° on clinical failure was direct and substantially mediated by the type of displaced fracture (mediation proportion: 18.7%). In our study of screw fixations for femoral neck fractures among nongeriatric patients, we identified that a contralateral NSA < 130° correlates with an increased risk of clinical failure including nonunion, AVN, functional failure, and reoperation. The effect is either direct or mediated through displaced fracture types. This is important for surgeons in order to recognize the elevated rate of clinical failure and nature of the challenging biomechanical environment, which should guide them in refining surgical details and selecting appropriate fixation and rehabilitation plans. Approaches to managing these fractures require further validation with large-scale clinical trials. Level III, prognostic study.

Revision rate following unipolar versus bipolar hemiarthroplasty.

There has been much debate on use of bipolar or unipolar femoral heads in hemiarthroplasty for the treatment of femoral neck fractures. The outcome of these implants should be studied in the America Joint Replacement Registry (AJRR). All primary femoral neck fractures treated with hemiarthroplasty between January 2012 and June 2020 were searched in the AJRR. All cause-revision of unipolar and bipolar hemiarthroplasty and reasons for revision were assessed for these patients until June of 2023. There were no differences in number and reason for all cause revisions between unipolar and bipolar hemiarthroplasty (p = 0.41). Bipolar hemiarthroplasty had more revisons at 6 months postoperatively (p = 0.0281), but unipolar hemiarthroplasty had more revisions between 2 and 3 years (p = 0.0003), and after 3-years (p = 0.0085), as analysed with a Cox model. Patients with older age (HR = 0.999; 95% CI, 0.998-0.999; p = 0.0006) and higher Charlson Comorbidity Index (HR = 0.996; 95% CI, 0.992- 0.999; p = 0.0192) had a significant increase in revision risk. We suggest that surgeons should consider using bipolar prosthesis when performing hemiarthroplasty for femoral neck fracture in patients expected to live >2 years post injury.

Comparison of rehabilitation outcomes between robot-assisted and freehand screw placement in treatment of femoral neck fractures: a systematic review and meta-analysis

PurposeTo compare the postoperative rehabilitation of femoral neck fractures treated with robot-assisted nailing and freehand nailing.MethodsWe systematically searched the PubMed, EMBASE, Cochrane, China National Knowledge Infrastructure(CNKI), WanFang database, China Science and Technology Journal Database (VIP) and Web of Science databases to identify potentially eligible articles. Indispensable data such as the year of publication, country, study type, robot type, age, number of patients, sex distribution, study design, and outcome indicators were extracted. The outcome indicators of interest included healing rate, length of healing time, Harris score, operation time, frequency of X-ray fluoroscopy, frequency of guide pin insertion, and intraoperative blood loss. RevMan 5.4.1 was used for the meta-analysis.ResultsFourteen studies with 908 participants were included in this meta-analysis. The results showed that in terms of healing rate (SMD = 2.75, 95% CI, 1.03 to 7.32, P = 0.04) and Harris score (SMD = 2.27, 95% CI, 0.79 to 3.75, P = 0.003), robot-assisted screw placement technique scores were higher than the traditional freehand technique. Additionally, operative time (SMD = -12.72, 95% CI, -19.74 to -5.70, P = 0.0004), healing time (SMD = -13.63, 95% CI, -20.18 to -7.08, P < 0.0001), frequency of X-ray fluoroscopy (SMD = − 13.64, 95% CI, − 18.32 to − 8.95, P < 0.00001), frequency of guide pin insertion (SMD = − 7.95, 95% CI, − 10.13 to − 5.76, P < 0.00001), and intraoperative blood loss (SMD = − 17.33, 95% CI, − 23.66 to − 11.00, P < 0.00001) were lower for patients who underwent robotic-assisted screw placement than those for patients who underwent the conventional freehand technique.ConclusionCompared to the freehand nailing technique, robot-assisted nailing helps improve postoperative healing rates in patients with femoral neck fractures; shortens healing times; better restores hip function; reduces the number of intraoperative fluoroscopies, guides pin placements; reduces intraoperative bleeding; and increases perioperative safety.

The Fragility of Statistical Findings in the Femoral Neck Fracture Literature: A Systematic Review of Randomized Controlled Trials.

Randomized controlled trials (RCTs) in the femoral neck fracture literature frequently report P -values for outcomes, which have substantial implications in guiding surgical management. This study used the fragility index (FI), reverse fragility index (rFI), and fragility quotient (FQ) to assess the statistical stability of outcomes reported in RCTs evaluating the management and treatment of femoral neck fractures. PubMed, Embase, and MEDLINE were queried for RCTs (January 1, 2010 to February 28, 2023). RCTs that evaluated surgical management or treatment of femoral neck fractures were included. RCTs with 2 treatment arms reporting categorical dichotomous outcomes were included. Non-RCT studies, RCTs with greater than 2 treatment arms, and RCTs without a femoral neck fracture cohort were excluded. The FI and rFI were calculated as the number of outcome event reversals required to alter statistical significance for significant ( P < 0.05) and nonsignificant ( P ≥ 0.05) outcomes, respectively. The FQ was calculated by dividing the FI by the sample size for the study. Nine hundred eighty-five articles were screened, with 71 studies included for analysis. The median FI across a total of 197 outcomes was 4 [interquartile range (IQR) 2-5] with an associated FQ of 0.033 (IQR 0.017-0.060). Forty-seven outcomes were statistically significant with a median FI of 2 (IQR 1-4) and associated FQ of 0.02 (IQR 0.014-0.043). One hundred fifty outcomes were statistically nonsignificant with a median rFI of 4 (IQR 3-5) and associated FQ of 0.037 (IQR 0.019-0.065). Statistical findings in femoral neck fracture RCTs are fragile, with reversal of a median 4 outcomes altering significance of study findings. The authors thus recommend standardized reporting of P -values with FI and FQ metrics to aid in interpreting the robustness of outcomes in femoral neck fracture RCTs. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Revision ratio after Femoral Neck System implantation for hip fracture treatment: a retrospective cohort analysis.

The aim of the study is to determine the revision ratio after implantation of the femoral neck system (FNS) for the treatment of femoral neck fractures. A retrospective single center cohort analysis with a total of 71 patients who underwent the implantation of the FNS between December 2019 and December 2021, was performed. 31 males and 40 females were included. There was no exclusion based on BMI, ASA score, Garden classification or Pauwels classification. Primary outcome was the revision rate after FNS implantation. Secondary outcomes comprise the reason for revision surgery as well as the time toward revision surgery and the 30-day mortality. The revision ratio was 11 out of 71 patients (15.5%) with an average time to revision surgery of 10 months. Most common reason for revision was avascular necrosis (AVN) in 45.5%. Other reasons for revision surgery were implant failure due to a secondary fall on to the hip with the FNS implant in place, cut-out, cut-through and malunion in respectively 27.3%, 9%, 9% and 9% of the revision patients. The one- hole plate was used in 72% of the patients. Mean follow-up was 18.07 months (range 6-30 months). Full weight bearing instruction was given to 85.9% of the patients. Partial weight bearing in 14.1% of the patients. In conclusion, the FNS has similar revision ratio when used for femoral neck fractures compared to cannulated screw fixation in literature. The predominant reason for revision is AVN and implant failure with no difference between the use of the one- or-two-hole plate in this study.

Sagittal Angulation and the Treatment of Geriatric Femoral Neck Fractures: Time to Update our Classification Systems.

Inconsistent outcomes have been reported for percutaneous fixation of Garden I/II femoral neck fractures in geriatric patients. It was hypothesized that accounting for variable follow-up would better estimate the failure rate of percutaneous fixation with and without significant sagittal angulation. Retrospective. Single academic healthcare system. Patients ≥50 years of age treated with percutaneous screw fixation of Garden I/II (OTA/AO B1.1/B1.2) femoral neck fractures from 2010 to 2020 were identified. Pathologic fractures and open approaches were excluded. Sagittal angulation was measured using a previously described method. 11 Treatment failure was defined as early fixation failure (within 6 weeks), nonunion, and/or avascular necrosis. Potential associations between treatment failure and patient, injury, and treatment variables were assessed. Cox proportional hazard analysis accounted for variable follow-up when assessing for event-free survival. Of the 240 fractures that met inclusion criteria, there were 20 treatment failures (8%) and 33 fractures with sagittal angulation ≥20 degrees on lateral radiographs (14%). Failure-free survival at 2 years was 91% for patients with <20 degrees of posterior angulation and 52% for patients with ≥20 degrees of posterior angulation ( P < 0.0001). The hazard ratio, which incorporates variable follow-up, for failure with ≥20 degrees of posterior angulation was 6.36 ( P < 0.0001). No other factors were associated with treatment failure. Significant posterior angulation (≥20 degrees) of Garden I/II femoral neck fractures is associated with a high failure rate after screw fixation. The authors suggest characterizing fractures with ≥20 degrees of sagittal angulation as Garden III fractures to better support surgical decision making. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Outcome of dynamic locked plate in treatment of intracapsular femur neck fracture

Background: The ideal surgical treatment of femoral neck fractures is still debatable. When internal fixation is used, many implants are available. This study aimed to evaluate the outcome following fixation of intracapsular femur neck fractures using the Targon-FN system (B. Braun, AG. Melsungen, Germany) comparing the results with a similar study done by the manufacturer and to assess risk factors associated with complications. Methods: A prospective interventional case series involved 30 consecutive patients aged from 23 to 82 (Mean 49 years) treated at Al-Jalaa trauma hospital in Benghazi- Libya in period from January 2016 to July 2017, for an intracapsular femur neck fracture with Targon-FN system. According to Garden classification 9 fractures (30%) undisplaced and 21 (70%) were displaced fractures, with 2 patients (6.7%) had type I, 7 patients (23.3%) had type II, 7 patients (23.3%) had type III and 14 patients (46.7%) had type IV fracture. Epidemiological data were collected. Patients were followed-up for 2 years (average 16 months). Joint function was assessed clinically by using Harris hip score (HHS) and fracture healing by radiological assessment at sex weeks, 3 months, 6 months, 1 year and finally at 2 years. Complications were recorded. Statistical analysis done to predict risk factors associated with reoperation and complications. Results: Sixteen patients (53.3%) developed one or more complications. Complications were higher than those of manufacturer’s study and included avascular necrosis (53.3%, n=16), nonunion (30%, n=9), blown out implant (16.66%, n=5), loosening screw (3.3%, n=1), and deep infection (3.3%, n=1). In total, 5 patients required total hip replacements. At end of 2 years 19 patients (63%) had poor result, one patient (3.3%) had fair result, 1 patient (3.3%) had good result and 9 patients (30%) had excellent result according to HHS. Delayed surgery, fracture displacement, surgeon’s experience, age ≥40 years and time to postop weight bearing recognized as risk factors for complications. Conclusions: A minimally-invasive surgery of Targon FN justifies use of this system for the preservation of the patient’s hip joint, early rehabilitation and mobilization. Complications and re-operation could be minimized by performing surgery within 24-48 hours, provision of skillful surgeons, and proper timing of postoperative weight bearing. The main limitation is the small number of cases and short follow-up averaged at 16 months.

Orthopaedic robot assisted femoral neck dynamic cross fixation system for the treatment of femoral neck fractures

To explore and compare the clinical efficacy of orthopedic robot assisted femoral neck system （FNS） and traditional manual FNS in the treatment of femoral neck fractures in middle-aged and young people. The clinical data of 62 consecutive patients with femoral neck fracture and age less than 65 years old admitted to the Intelligent Orthopaedic Department of Beijing Jishuitan Hospital from June 2021 to June 2022 were retrospectively analyzed. According to whether orthopedic robot-assisted surgery the patients were divided into two groups：30 patients aged 34 to 56 years old were treated with orthopedic robot assisted FNS internal fixation after closed or limited open reduction（experimental group）； 32 patients aged 33 to 54 years old underwent FNS internal fixation after closed or limited open reduction（control group）. The age, gender, time from injury to admission, average hospital stay, surgical duration, intraoperative bleeding volume, and intraoperative fluoroscopy frequency of two groups of patients were analyzed and compared. The hip joint function in both groups of patients was evaluated using the Harris hip joint scoring standard at 6 months after surgery. All 62 patients with femoral neck fractures successfully completed the surgery. There was no significant difference（P>0.05） between the experimental group and the control group in terms of baseline data such as age, gender, time from injury to admission, time from admission to surgery and the intraoperative bleeding. The surgical duration of the experimental group was significantly shorter than that of the control group [42.1（28.5, 50.7）min vs. 53.4（36.9, 62.5） min, Z=-2.338, P=0.019]. The intraoperative X-ray fluoroscopy frequency of the experimental group was significantly lower than that of the control group[8.0 （6.0, 11.0） times vs. 15.0（13.0, 17.0） times, Z=-5.960, P<0.001]. In terms of postoperative hip joint function, there was no significant difference in Harris score between the two groups of patients at 6-month follow-up（P>0.05）. Compared with manual operation of FNS, orthopedic robot assisted FNS in the treatment of femoral neck fractures can help shorten surgical time, reduce intraoperative fluoroscopy frequency, and have similar therapeutic effects on long-term hip joint function recovery.

Comparison of the efficacy of TiRobot orthopaedic robot assisted F screw technique and inverted triangle parallel nail internal fixation in the treatment of unstable femoral neck fractures

To compare the effectiveness of TiRobot assisted F screw technique and inverted triangle parallel nail internal fixation in the treatment of unstable femoral neck fractures. A retrospective analysis was conducted on 72 patients with unstable femoral neck fractures who were treated with percutaneous cannulated screw fixation assisted with TiRobot Orthopaedic robot from December 2019 to April 2021. Among them, 37 patients were treated with F screw internal fixation, including 16 males and 21 females, aged 47 to 64 years old with an average of （53.87±5.28） years old；According to Pauwels classification, there were 1 case of type Ⅰ, 19 cases of type Ⅱ, 17 cases of type Ⅲ；8 cases of combined medical diseases；17 cases of falling, 8 cases of traffic accident and 12 cases of falling from height；The time from injury to operation was 29 to 49 hours with average of （35.00±7.34） hours. Another 35 cases used internal fixation with an inverted triangle parallel nail, including 13 males and 22 females with an average age of 46 to 63 years old （52.36±5.05） years old；According to the Pauwels injury classification：there were 2 cases of type Ⅰ, 21 cases of type Ⅱ, 12 cases of type Ⅲ；6 cases of medical diseases, 15 cases of falling injury, 9 cases of traffic accident, 11 cases of falling injury；The time from injury to operation was 30 to 45 hours with an average of （33.00±6.83） h. The intraoperative blood loss, operation time, intraoperative fluoroscopy times, follow-up time, fracture healing time, postoperative complications were observed and compared between the two groups. The hip joint function was evaluated by Harris score at 6 months and 12 months after operation. There was no significant difference in operation time, intraoperative blood loss, intraoperative fluoroscopy times and other intraoperative data between two groups（P>0.05）. Both groups were followed up regularly, and the follow-up time was 12 to 16 months. The fracture healing time and Harris score of the F screw internal fixation group were better than those of the inverted triangle parallel nail internal fixation group （P<0.05）. There was 1 case of femoral neck shortening in the F screw internal fixation group, 1 case of nonunion, 1 case of nail withdrawal, and 1 case of lower extremity deep vein thrombosis in the inverted triangle internal fixation group. The incidence of complications in the F screw internal fixation group was lower than that in the inverted triangle parallel nail internal fixation group（P<0.05）. Percutaneous cannulated F screw technique using Tirobot navigation positioning system is a safe and effective treatment for patients with unstable femoral neck fractures. It can significantly shorten the fracture healing time, reduce the incidence of postoperative complications, significantly improve hip joint function, and improve the quality of life.

Orthopaedic robot assisted closed reduction and cannulated screw internal fixation for the treatment of femoral neck fractures

To investigate the preliminary clinical effect of closed reduction and cannulated nail internal fixation for femoral neck fracture assisted by robot navigation and positioning system. From July 2019 to January 2020, 16 cases of femoral neck fracture （navigation group） were treated with closed reduction and internal fixation guided by robot system, including 7 males and 9 females, aged 25 to 72 years old with an average of （53.61±5.45） years old；Garden classification of fracture：3 cases of typeⅠ, 3 cases of typeⅡ, 8 cases of type Ⅲ, 2 cases of type Ⅳ. Non navigation group （control group）：20 cases of femoral neck fracture were treated with closed reduction and hollow nail internal fixation, 8 males and 12 females, aged 46 to 70 years old with an average of （55.23±4.64） years old；Garden typeⅠin 2 cases, typeⅡin 4 cases, type Ⅲ in 11 cases, type Ⅳ in 3 cases. The operation time, fluoroscopy times, guide needle drilling times, screw adjustment times, intraoperative bleeding volume and other indicators of two groups were evaluated. Both groups were followed up for 12 to 18 months with an average of （15.6±2.8） months. The fractures of both groups were healed without delayed union and nonunion. There was no significant difference in healing time between two groups（P=0.782）. There was no significant difference in Harris scores between two groups at the last follow-up（P=0.813）. There was no significant difference in operation time between two groups（P>0.05）. There were significant differences between two groups in fluoroscopy times, guide needle drilling times, hollow screw replacement times, and intraoperative bleeding volume（P<0.05）. Closed reduction and hollow screw internal fixation assisted by robot navigation system for femoral neck fracture has the advantages of minimally invasive operation, precise screw placement, and reduction of X-ray radiation damage during operation.

Real-time traking and virtual reality technology-assisted trauma orthopaedic surgery robot for femoral neck fractures

To investigate the effectiveness of real-time tracking and virtual reality technology（RTVI） used to assist the intraoperative alignment of the trauma orthopaedic surgery robot for the treatment of femoral neck fractures and its impact on the treatment outcome. A retrospective analysis was conducted on 60 patients with femoral neck fractures treated with trauma orthopedic robotic surgery from September 2020 to September 2022. Patients were divided into two groups according to whether RTVI technology was used during surgery to assist robotic surgery. There were 28 patients in the RTVI group （12 males and 16 females）, with an average age of （46.2±9.3） years old ranging from 28 to 60 years old. There were 32 patients in the simple Tianji surgical robot group, including 15 males and 17 females, aged （48.2±7.8） years old ranging from 32 to 58. The number of registered fluoroscopy, operation time, total number of intraoperative fluoroscopy, intraoperative blood loss, and hospitalization time of the two groups of patients were observed and recorded. All patients received regular follow-up after surgery, and hip X-rays were routinely reviewed to record Garden alignment index, fracture healing time, postoperative complications, and Harris score. All 60 patients were followed up. The RTVI group was followed up for 9 to 16 months with an average of （13.0±1.2） months, and the Tianji surgical robot group alone was followed up for 10 to 14 months with an average of （12.0±1.3） months. During the follow-up period, the femoral neck fractures of both groups of patients healed well, and no complications such as internal fixation loosening and incision infection occurred. The number of registered fluoroscopy, operation time, and number of intraoperative fluoroscopy of patients in the RTVI group were significantly better than those in the simple Tianji surgical robot group（P<0.01）. There was no statistically significant difference in intraoperative blood loss, hospital stay, Garden alignment index, fracture healing time, and hip Harris score between two groups（P>0.05）. Although RTVI technology assisted by the surgical robot for femoral neck fracture surgery has little impact on its postoperative outcome, it can effectively reduce the operating time, the number of intraoperative X-ray projections, and the risk of intraoperative radiation exposure to patients. It also shortened the learning curve of the operator and better reflected the precision and efficiency of the trauma orthopaedic surgery robot.

Fully automated measurement of femoral neck axis line in anatomical coordinate system using CT images.

The femoral neck is the most vulnerable site for fractures within the hip joint. Due to its complex three-dimensional structure and special blood supply mechanism, the treatment of femoral neck fractures is difficult and the healing probability is low. Using computers to accurately and automatically locate the femoral neck axis can detect the density of femoral neck, the neck-shaft angle and the anteversion angle, which effectively assists in the prevention and treatment of femoral neck fractures. Additionally, the traditional femoral neck axis positioning schemes have limitations in accuracy, automation and assistance to bone density measurement. Therefore, this paper proposes a new fully automatic femoral neck axis positioning method. First, the coronal plane's three-dimensional reconstruction highlights the details of the target bone, and then designs a coarse localization module based on multi-scale template matching to obtain the rough range of the femoral neck axis. Then, a detailed localization module based on the femoral neck virtual slices is used to obtain the contour centers and accurately locates the three-dimensional femoral neck axis. This method has been validated in comparison with the manual measurement method. Experimental results revealed that the extracted femoral neck axis in this study can achieve automation, ensure accuracy, and avoid subjective effects effectively and has the potential value to be applied in the prevention and treatment of femoral neck fractures.

Treatment of old femoral neck fractures in young adults with a medial buttress plate combined with three cannulated screws and iliac autograft: Surgical technique and preliminary results

ObjectivesWhether the application of MBP plus cannulated screws works for old femoral neck fractures (OFNF) is unknown. The purpose of this study is to present a case series of OFNF in young adults using calcar buttress plate and three cannulated screws with autologous iliac bone grafts. MethodsWe conducted a retrospective study of eleven young patients (6 males and 5 females) with femoral neck fractures who were treated with open reduction and internal fixation at a single center between 2013 and 2021. The subjects had trauma-to-surgery intervals longer than 3weeks and all were fixed with a calcar buttress plate combined with three cannulated screws, which were supplemented by autologous iliac bone grafts. ResultsAll eleven cases achieved radiological union under the surgery technique, which occurred on average at 4.46±1.29months after surgery. Complications included femoral neck shortening in all cases, heterotopic ossification in three cases, and osteonecrosis of the femoral head in two cases. One patient with osteonecrosis of the femoral head received total hip arthroplasty. In follow-ups of 24–52months, the median Harris hip score was 81.64±15.39. ConclusionsThe medial buttress plate in combination with three cannulated screws and iliac autograft may be a good choice for treating old femoral neck fractures in young adults. Level of evidenceIV, case series.

Experimental analysis of femoral head intraosseous vascular anastomosis in the treatment of porcine subcapital femoral neck fractures

IntroductionFemoral neck fractures are challenging injuries associated with a compromised blood supply to the femoral head, leading to a high risk of avascular necrosis and poor clinical outcomes. This study aimed to investigate the efficacy of femoral head intraosseous vascular anastomosis in the treatment of porcine sub-capital femoral neck fractures. MethodsTen Landrace pigs were used as experimental animal models. The femoral head was completely removed after femoral neck sub-cephalic fracture. It was fixed on the medial side of the knee joint, and the blood supply to the femoral head was reconstructed by anastomosing the femoral head vessels. One week later, blood flow in the femoral head was observed by borehole, digital subtraction angiography examination, and hematoxylin and eosin staining. Further, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling tests were performed to detect pathological changes in the femoral head. ResultsAfter one-week, digital subtraction angiography of the femoral head revealed a blood circulation rate of 70 %, and the blood seepage rate of the borehole was 80 %. Hematoxylin and eosin staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling test results showed that necrosis of bone marrow cells in the experimental group was significantly improved compared to that in the control group. DiscussionThis study highlights the potential benefits of femoral head intraosseous vascular anastomosis in the treatment of porcine sub-capital femoral neck fractures. Further research and clinical trials are warranted to validate these findings and to explore the translational potential of this technique in human patients.