Comparison of three different internal fixation methods in the treatment of femoral neck fracture.

Objective: This study aimed to assess the efficacy of three different fixation methods in treating femoral neck fractures in young patients. Methods: A retrospective analysis was conducted on 35 young patients with femoral neck fractures who underwent surgical treatment. Among them, 16, 12, and 7 patients underwent fixation with three cannulated compression screws (3CS), the femoral neck system (FNS), and the compound compression system (CCS), respectively. Data, including fracture classification, injury-to-surgery time, surgery duration, intraoperative blood loss, fluoroscopy instances, fracture healing time, complications, and Harris score at the final follow-up, were collected and analyzed to compare clinical outcomes among the three fixation methods. Results: All patients were followed for at least 6 months, exhibiting no significant differences in age, gender, injury side, fracture type, or injury-to-operation time among the three groups (P > 0.05). The FNS and CCS groups exhibited shorter operation durations and fewer intraoperative fluoroscopy instances compared to the 3CS group (P < 0.01). Despite the minimally invasive nature of 3CS, the FNS and CCS groups experienced higher intraoperative blood loss (P < 0.01). During follow-up, only one patient with 3CS fixation developed nonunion. Additionally, patients treated with 3CS demonstrated a higher incidence of femoral head necrosis and severe femoral neck shortening than the FNS and CCS groups. Excluding patients with combined nonunion, no significant difference in mean fracture healing time was observed among the three groups (P > 0.05). At the last follow-up, the FNS and CCS groups showed higher Harris scores (P < 0.05). Conclusions: Both FNS and CCS are effective internal fixation systems for the treatment of femoral neck fractures in young patients, yielding more satisfactory clinical functional outcomes than 3CS. Comparatively, the CCS system presents a higher risk of iatrogenic rotation of the proximal fracture segment. Therefore, we advocate the insertion of two to three 2.5 mm Kirschner wires from the upper edge of the femoral neck along the axial direction before CCS lag screw insertion to resist iatrogenic rotational stress.

Does the management of osteofibrous dysplasia of the tibia and fibula in children should be tailored to the extent and location of the lesion? A case control study investigating different surgical options.

BACKGROUND: Osteofibrous dysplasia (OFD) is a rare non neoplastic, self-limited intracortical fibro-osseous lesion that most commonly affects the diaphysis of the tibia and fibula of children, the best treatment is still debated. Therefore we performed a retrospective study in children mostly under 10 years old with OFD aiming to determine whether early surgery is necessary and which is the best treatment. HYPOTHESIS: Symptomatic OFD lesions should be treated proactively, and appropriate treatment can achieve favorable outcome. METHODS: We retrospectively reviewed 23 patients with OFD of the tibia (n=22) and fibula. Management varied according to the severity of symptoms (deformity, pain or pathological fracture) and the extent of the lesion. Cases were divided into four groups (Gr.): Gr. 1: observation (n=4); Gr. 2: curettage and allograft (n=6); Gr. 3: curettage, allograft and elastic stable intramedullary nailing (ESIN) fixation (n=9); Gr. 4: extra-periosteal resection and bone transport (n=5). One patient received two different treatments successively (23 patients and 24 cases). All patients had regular clinical and radiographic follow-up to assess bone consolidation and complications. RESULTS: In Gr. 1, four asymptomatic patients underwent observation after open biopsy. Gr. 4 had the lowest local recurrence rate: 0 cases (0%) vs. 4 (66.7%; Gr. 2) vs. 1 (11.1%; Gr. 3) (p=0.002), incidence of deformity: 0 case (0%) vs. 0 (0%; Gr. 2) vs. 3 (50%; Gr. 3) (p=0.023), and pathological fracture: 0 case (0%) vs. 0 (0%; Gr. 2) vs. 1 (16.7%; Gr. 3) (p=0.006), although the consolidation time was longer: 6.8 vs. 2 (Gr. 2) vs. 2.7 months (Gr. 3) (p=0.017) and the rate of complication was higher than those of Gr. 2 and Gr. 3 (p<0.05). Gr. 3 had a lower local recurrence rate: 1 case (11.1%) vs. 4 cases (66.7%) (p=0.002), incidence of deformity: 0 case (0%) vs. 3 cases (50%) (p=0.023), and pathological fracture: 0 case vs. 1 case (16.7%) (p=0.006) than Gr. 2. DISCUSSION: Open biopsy is an important step in the management of patients with imaging suggestive of OFD in order to rule out Adamantinoma and other bone tumors or infection. Observation should be reserved for asymptomatic patients, while surgical treatment is indicated in patients with persistent pain, pathological fracture or significant deformity of the tibia. ESIN is a valid option to preserve the anatomical axis of the tibia in symptomatic patients with lesions of limited size; large circumferential lesions or recurrence can be managed by extra-periosteal resection and bone transport, although the complication rate can be relatively high. LEVEL OF EVIDENCE: III; case control study.

Transitional ankle fracture management using a new joystick technique.

PURPOSE: To investigate the feasibility and short-term clinical efficacy of the arthrography-assisted joystick technique for the treatment of adolescent transitional ankle fracture. METHODS: A retrospective analysis was performed in 10 adolescent transitional ankle fracture patients treated with the arthrography-assisted joystick technology. There were 7 male patients and 3 female patients with a mean age of 12.80 ± 1.81 years (range: 10-16 years). All cases were closed fractures, and the operation was performed after the failure of manual reduction [X-ray or computed tomography (CT) showed that the fracture gap was > 2 mm]. After the operation, X-ray or CT examination was performed to assess reduction of the fracture. Ankle function and fracture healing were evaluated by assessing the imaging indexes and evaluating the American Orthopedic Foot and Ankle Society (AOFAS) ankle score system. RESULTS: All patients were followed up for an average period of 12.00 ± 3.40 months (range: 8-20 months). The operation time was 40.50 ± 16.90 min (range: 25-80 min), the number of intraoperative fluoroscopy sessions was 18.70 ± 5.91 (range: 10-30 sessions), and the intraoperative blood loss was 5.90 ± 3.38 ml (range: 2-10 ml). X-ray examination showed that all cases achieved bone healing. The fracture healing time was 11.00 ± 2.45 weeks (range: 8-16 weeks). Four cases showed early closure of the epiphysis. The AOFAS scoring system evaluation results of these 10 pediatric cases were excellent. CONCLUSION: The arthrography-assisted joystick technique for the treatment of adolescent transitional ankle fracture offers advantages, such as minimal trauma, simple operation, ideal reduction effect, and the recent curative effect is satisfactory.

Free Fracture Fragment Predicts Poorer Outcomes in Adolescents With Delbet II Femoral Neck Fracture.

BACKGROUND: This retrospective multicenter study investigated whether the presence of free fracture fragments is associated with the clinical outcome of adolescents with Delbet II femoral neck fracture (FNF). MATERIALS AND METHODS: The study population comprised 74 adolescents with Delbet II FNF, with an average age of 13.31 y (range, 10-17 y). There were 19 and 55 patients, respectively, with and without (control) free fracture fragments. The patients underwent open (n = 41) or closed (n = 33) fracture reduction and then cannulated screw internal fixation. Postoperative functional evaluation was performed using Ratliff's criteria, and complications such as femoral head necrosis, premature epiphyseal closure, and coxa vara were recorded. RESULTS: All patients achieved bony union during the mean follow-up period of 15.6 mo (range, 12-78 mo). By Ratliff's criteria, the clinical outcomes of the patients with free fracture fragment (three excellent, eight good, eight poor) were significantly worse compared with the control group (26 excellent, 20 good, and nine poor). The rate of complications (femoral head necrosis, premature epiphyseal closure, and coxa vara) of patients with free fracture fragments was significantly higher than that of the control patients. CONCLUSIONS: In adolescents with Delbet II FNF, the presence of free fracture fragments is associated with poorer clinical outcomes. Delbet II FNF in adolescents with free fracture fragment may be a special clinical entity with a poorer outcome.

Design of High-Reliability Micro Safety and Arming Devices for a Small Caliber Projectile.

With the development of micro technology, the fuse for small-caliber projectiles tends to be miniaturized and intelligent, the traditional fuse no longer meets the requirements. In this paper, we demonstrate a micro safety and arming (S & A) device with small volume and high reliability in small caliber projectile platforms. The working principle of S & A devices is that a centrifugal insurance mechanism could deform under a centrifugal load and thus cause fuse safety arming. The centrifugal insurance mechanism is designed theoretically, verified by simulation and experimental methods. The experimental results show that, when the rotary speed is over 36,000 rpm, the fuse was armed safely. In addition, the experimental, simulation, and theoretical results are basically consistent, and indicate that the centrifugal insurance mechanism meets the expected criteria.

Altered sinoatrial node function and intra-atrial conduction in murine gain-of-function Scn5a+/ΔKPQ hearts suggest an overlap syndrome.

Mutations in SCN5A, the gene encoding the pore-forming subunit of cardiac Na(+) channels, cause a spectrum of arrhythmic syndromes. Of these, sinoatrial node (SAN) dysfunction occurs in patients with both loss- and gain-of-function SCN5A mutations. We explored for corresponding alterations in SAN function and intracardiac conduction and clarified possible mechanisms underlying these in an established mouse long QT syndrome type 3 model carrying a mutation equivalent to human SCN5A-ΔKPQ. Electrophysiological characterizations of SAN function in living animals and in vitro sinoatrial preparations were compared with cellular SAN and two-dimensional tissue models exploring the consequences of Scn5a+/ΔKPQ mutations. Scn5a+/ΔKPQ mice showed prolonged electrocardiographic QT and corrected QT intervals confirming long QT phenotypes. They showed frequent episodes of sinus bradycardia, sinus pause/arrest, and significantly longer sinus node recovery times, suggesting compromised pacemaker activity compared with wild-type mice. Electrocardiographic waveforms suggested depressed intra-atrial, atrioventricular node, and intraventricular conduction in Scn5a+/ΔKPQ mice. Isolated Scn5a+/ΔKPQ sinoatrial preparations similarly showed lower mean intrinsic heart rates and overall slower conduction through the SAN to the surrounding atrium than did wild-type preparations. Computer simulations of both single SAN cells as well as two-dimensional SAN-atrial models could reproduce the experimental observations of impaired pacemaker and sinoatrial conduction in terms of changes produced by both augmented tail and reduced total Na(+) currents, respectively. In conclusion, the gain-of-function long QT syndrome type 3 murine Scn5a+/ΔKPQ cardiac system, in overlap with corresponding features reported in loss-of-function Na(+) channel mutations, shows compromised SAN pacemaker and conduction function explicable in modeling studies through a combination of augmented tail and reduced peak Na(+) currents.

TGF-ß1-mediated fibrosis and ion channel remodeling are key mechanisms in producing the sinus node dysfunction associated with SCN5A deficiency and aging.

BACKGROUND: Mutations in the cardiac Na(+) channel gene (SCN5A) can adversely affect electric function in the heart, but effects can be age dependent. We explored the interacting effects of Scn5a disruption and aging on the pathogenesis of sinus node dysfunction in a heterozygous Scn5a knockout (Scn5a(+/-)) mouse model. METHODS AND RESULTS: We compared functional, histological, and molecular features in young (3 to 4 month) and old (1 year) wild type and Scn5a(+/-) mice. Both Scn5a disruption and aging were associated with decreased heart rate variability, reduced sinoatrial node automaticity, and slowed sinoatrial conduction. They also led to increased collagen and fibroblast levels and upregulated transforming growth factor-ß(1) (TGF-ß(1)) and vimentin transcripts, providing measures of fibrosis and reduced Nav1.5 expression. All these effects were most noticeable in old Scn5a(+/-) mice. Na(+) channel inhibition by Nav1.5-E3 antibody directly increased TGF-ß(1) production in both cultured human cardiac myocytes and fibroblasts. Finally, aging was associated with downregulation of a wide range of ion channel and related transcripts and, again, was greatest in old Scn5a(+/-) mice. The quantitative results from these studies permitted computer simulations that successfully replicated the observed sinoatrial node phenotypes shown by the different experimental groups. CONCLUSIONS: These results implicate a tissue degeneration triggered by Nav1.5 deficiency manifesting as a TGF-ß(1)-mediated fibrosis accompanied by electric remodeling in the sinus node dysfunction associated with Scn5a disruption or aging. The latter effects interact to produce the most severe phenotype in old Scn5a(+/-) mice. In demonstrating this, our findings suggest a novel regulatory role for Nav1.5 in cellular biological processes in addition to its electrophysiologic function.