Objective To investigate the detailed biomechanics of TiNi shape-memory sawtooth-arm embracing plate (TiNi SMA) by comparing with l imited-contact dynamic compression plate (LC-DCP) and static interlocking intramedullary nail (SIiN), so as to provide theoretical evidence for cl inical appl ication. Methods Eight paired cadaveric femurs immersed in formaldehyde were harvested from eight specimens of adults. After making X-ray films and modeling midpiece transverse fracture, one side randomly was fixed by TiNi SMA (group A) and SIiN (group C) orderly, the other side was fixed by LC-DCP (group B). The axial compression, three-point bending (pressed from plate side and opposite side both of group A and group B, from inside of group C), and torsion were tested, and the stress shielding rate was compared. Results At every classified axial compression load, the strains of group A were greater than those of group B and group C (P lt; 0.05), the displacements of group A were greater than those of group B and group C (P lt; 0.05) except 100 N. At every classified three-point bending moment, the displacement of group A were greater than those of group B and group C pressed both from two sides, but there was no difference when pressing from two sides under the same load of group A (P gt; 0.05). At every torsion moment, the torsion angels of group A were greater than those of group B (P lt; 0.05), but equal to those of group C (P gt; 0.05). At 600 N of axial compression load, the stress shielding rates of groups A, B, C were 48.30% ± 22.99%, 89.21% ± 8.97%, 95.00% ± 3.15%, respectively, group A was significantly less than group B and group C (P lt; 0.01). Conclusion The anti-bending abil ity of TiNi SMA is weaker than LC-DCP and SIiN; the anti-torsion abil ity of TiNi SMA is weaker than SIiN, but TiNi SMA is a center-type internal fixation, the superior stress shielding rate and micromovement promote the stress stimulation of fracture, which makes it an ideal internal fixation device.
Objective To find out an ideal method of internal fixation for the treatment of fractures of proximal radius. Methods From August 2001 to April 2004, 24 patients suffering from fractures of proximal radius were treated with NiTi shape memory alloy embracing fixator. Of 24 patients, there were 19 males and 5 females, aging from 16 to 48 years; there were 9 cases of wrestling injury, 5 cases of crush injury, 4 cases of traffic accident injury, 3 cases of direct violence impact injury and 3 cases of high falling injury. All patients were given operation according to fix method of the shape memory alloy embracing fixator. All cases were regularly followed up to observe the fracture healingand functional recovery. Results All cases were followed up postoperatively from 4 months to 21 months with an average of 10 months. No complication occurred during operation and after operation. Healing by first intention was achieved. X－ray showed that all cases achieved clinical union 8－12 weeks after operation. According to Anderson’scriteria and the results were excellent in 18 cases, good in 5 cases, and fairin 1 case. The excellent and good rate was 95.83 %. Conclusion The internal fixation with shape memory alloy embracing fixator has as follows adventages: less trauma, esay－to－do, stable fixation, better tissue compatibility and less complication in treating fractures of proximal radius. This method can enhance the fracture healing and functional recovery. So it is a better method to treat fractures of proximal radius.
Objective To compare clinical outcomes between the performed titanium locking plate and nickel-titanium memory alloy embracing fixator for the treatment of multiple rib fractures, and to select a better internal fixator for multiple rib fractures. Methods A total of 206 consecutive patients with multiple rib fractures were admitted to Department of Cardiothoracic Surgery in Beijing Luhe Hospital of Capital Medical University from October 2011 to September 2016. According to different treatment strategies, the patients were divided into 2 groups: a performed titanium locking plate group (a titanium plate group, n=105) and a nickel-titanium memory alloy embracing fixator group (an embracing fixator group, n=101). There were 82 males and 23 females with a mean age of 46.5±9.7 years ranging from 23 to 65 years in the titanium plate group, and 83 males and 18 females with a mean age of 44.7±10.3 years ranging from 19 to 63 years in the embracing fixator group. The preoperative data, curative outcomes, visual analogue scale (VAS) and postoperative complications were compared between the two groups. Results There was no statistical difference in the preoperative data between the two groups, and all patients successfully completed the operation. Compared with the embracing fixator group, the incision length and operation time were shorter, intraoperative bleeding and VAS score were less, and curative outcome was better in the titanium plate group. Conclusion The performed titanium locking plate has a great advantage in the clinic, which can be preferred.
Objective To analyze the correlation between the polymorphism on interleukin 6 (IL-6) gene promoter region-174 locus and adolescent idiopathic scoliosis (AIS), including the susceptibility, the bracing effectiveness, and the possible mechanism. Methods The 182 AIS patients and 210 healthy controls who met the inclusion criteria between January 2013 and January 2016 were collected as research objects. The genotype of IL-6 gene promoter region-174 locus, the serum IL-6, the bone mineral density (BMD) of femoral neck and vertebrae (L1–4), and the bone metabolism parameters, including bone alkaline phosphatase (BALP), bone gla protein (BGP), tartrate resistant acid phosphatase 5b (TRACP-5b), urine Ca, and urine Ca/Cr, were detected. All research objects were divided into the AIS group and the control group according to whether they had AIS, the GG, CG, CC groups according to their genotype, and progression-free group and progression group according to the therapeutic effectiveness of 1-year bracing treatment. Statistical analysis for the indexes were conducted respectively. Results There were significant differences in AIS history, BMD of femoral neck and lumbar vertebrae between the AIS group and control group (P<0.05). According to the therapeutic effecitveness of 1-year bracing treatment, 182 AIS patients were divided into progression-free group in 110 cases and progression group in 72 cases. The results of single factor analysis showed that there were significant differences in the genotype and allele distribution of IL-6 gene promoter region-174 locus, BMD of femoral neck and lumbar vertebrae, IL-6, TRACP-5b, urine Ca, and urine Ca/Cr between the progression-free group and progression group (P<0.05). The results of multivariable analysis showed that the BMD of lumbar vertebrae, TRACP-5b, and urine Ca were the influencing factors of bracing efficacy (P<0.05). According to the results of genotype detection, all research objects were divided into GG group in 264 cases, CG group in 104 cases, and CC group in 24 cases. The IL-6, TRACP-5b, urine Ca, and urine Ca/Cr of GG type carriers were higher and BMD of femoral neck and lumbar vertebrae were lower when compared with the CG and CC type carriers (P<0.05). The BMD of lumbar vertebrae of CG type carriers was lower than that of CC type carriers (P<0.05). Conclusion The polymorphism of IL-6 genepromoter region-174 locus wasn’t correlated with the AIS susceptibility, but it was correlated (not independently correlated) with the scoliosis progression under bracing treatment, and the risk for G-carried patients was higher. The mechanism may be that the polymorphism affected the IL-6 expression level and eventually affected the BMD of AIS patients through the bone metabolism.
Objective To review the research progress of internal tension relieving technique in assisting anterior cruciate ligament (ACL) reconstruction with tendon grafts. MethodsThe in vivo and in vitro biomechanical tests, animal experiments, and clinical studies on the use of internal tensioning relieving technique assisted ACL reconstruction in recent years were extensively reviewed, the impact of this technology on the biomechanics, histological changes of grafts, and the clinical effectiveness were analyzed and summarized. Results The internal tensioning relieving technique based on non-absorbable high-strength sutures can reduce the risk of relaxation and rupture by enhancing the biomechanical strength of tendon grafts in vitro and in vivo, it shows good biocompatibility and support for the ligamentation of the tendon grafts and the establishment of the direct tendon-bone interface in terms of histology. This technique improves postoperative initial joint stability, range of motion, and functional scores in clinical practic, when combining with the enhanced recovery after surgery can effectively promote patients to return to pre-injury exercise level without serious complications. Conclusion The preliminary research results have confirmed the efficacy and safety of the internal tension relieving technique on assisting ACL reconstruction, then showes some degree of significance and prospect, but more research is needed to further optimize tension-relieving devices and related surgical techniques, and clarify the specific effects of this technique on graft’s structure remodeling, biomechanical function, and long-term clinical results.
Objective To analyze the effectiveness of shape memory alloy embracing device in the treatment of Vancouver B2 periprosthetic femoral fracture after primary hip arthroplasty. Methods The clinical data of 30 patients (30 hips) with Vancouver B2 periprosthetic femoral fracture after primary hip arthroplasty between January 2019 and January 2021 were analyzed retrospectively. Among them, 15 cases were treated with shape memory alloy embracing device for fracture fixation (group A) and 15 cases with titanium cable cerclage (group B). There was no significant difference in general data such as gender, age, body mass index, the cause of primary arthroplasty and surgical method, prosthesis type, the cause and side of femoral fracture, the time from injury to operation, and comorbidities between the two groups (P>0.05). The operation time, intraoperative blood loss, and hospital stay of the two groups were recorded. The fracture healing was examined by X-ray film, and the hip joint function was evaluated by Harris score. Results The operations in both groups were completed successfully, and the incisions healed by first intention after operation with no vascular or nerve injury. The operation time and hospital stay in group A were significantly shorter than those in group B (P<0.05), but there was no significant difference in intraoperative blood loss between group A and group B (t=−0.518, P=0.609). Patients were followed up 12-20 months (mean, 16.3 months) in group A and 12-22 months (mean, 16.7 months) in group B. X-ray film showed that all fractures healed, the healing time was (14.73±2.05) weeks in group A and (17.27±2.60) weeks in group B, and there was a significant difference between the two groups (t=−2.960, P=0.006). During follow-up, there was no complication such as prosthesis loosening, periprosthetic infection, joint stiffness, or internal fixator loosening. The Harris score of group A was significantly better than that of group B at 3, 6, and 12 months after operation (P<0.05). Conclusion Compared with titanium cable cerclage, using shape memory alloy embracing device to fix Vancouver B2 periprosthetic femoral fracture can accelerate fracture healing, shorten operation time, and reduce intraoperative blood loss. Patients can perform functional exercise earlier and restore joint function better.