[Clinical outcomes of reverse shoulder arthroplasty for the treatment of failed fixation of proximal humeral fracrtures in the elderly patients].

OBJECTIVE: To evaluate the clinical outcomes of reverse total shoulder arthroplasty as a revision procedure for the failed fixation of proximal humeral fractures in the elderly patients. METHODS: A retrospective analysis was performed on 8 patients with failed internal fixation of proximal humeral fractures from May 2014 to March 2020, including 3 males and 5 females, aged from 65 to 75 years old. All 8 patients underwent reverse total shoulder arthroplasty, and the mean time between initial fixation and reverse total shoulder arthroplasty ranged from 8 to 16 months. Range of motion(ROM), University of California at Los Angeles(UCLA) shoulder score, visual analogue scale (VAS), self-rating anxiety scale(SAS), and Constant-Murley score of shoulder function were assessed pre-operatively and at the last follow-up. Complications relating to the surgery were recorded. RESULTS: All 8 patients successfully followed up. The mean follow-up after reverse total shoulder arhroplasty ranged from 16 to 28 months. The range of motion (forward flexion, external rotation, abduction and internal rotation) of the affected shoulder was significantly improved after surgery, and the post-operative VAS, SAS and UCLA scores were also significantly improved. For the Constant-Murley score of shoulder joint function, the total scores and the subscores of pain, daily activities, range of motion and strength test at the last follow-up were all significantly improved. Scapular glenoid notch was observed in patient, which was evaluated as grade 1 on imaging. All the other patients did not develop specific or non-specific complications. CONCLUSION: Reverse total shoulder arhroplasty is an appropriate treatment as a revision surgery for failed fixation of proximal humeral fractures. It has shown satisfactory clinical outcomes, accelerating the rehabilitation of shoulder function and improving the quality of life.

[High strength wire under arthroscopy combined with outside anchor nail in treating Meyers McKeever II, III avulsion fracture of anterior cruciate ligament tibial check point].

OBJECTIVE: To explore clinical effect of high strength wire under arthroscopy combined with outside anchor nail in treating Meyers McKeever II, III anterior cruciate ligament tibial check point. METHODS: From March 2014 to June 2016, 21 patients with Meyers McKeever II, III avulsion fracture of anterior cruciate ligament tibial check point were treated by high strength wire under arthroscopy combined outside anchor nail. There were 13 males and 8 females aged from 18 to 48 years old with an average of (26.40±5.42) years old. There were 9 cases injured on the left side, and 12 cases on the right side. The courses of disease included sports injuries of 12 cases, falling down injuries of 6 cases, and accident injuries of 3 cases. According to Meyers-McKeever classification, 16 patients were type II and 5 patients were type III. All fractures were fresh, closed and simple injury. The time from injury to operation ranged from 2 to 15 days with an average of (6.20±2.63) d. Lysholm score, IKDC score and the changes of knee mobility were observed and compared before operation and 6 months after operation. RESULTS: Twenty-one patients were followed up for 12 to 24 months with an average of (14.30±3.01) months. Operation time ranged from 40 to 65 min with an average of (45.10±4.82) min, Blood loss ranged from 5 to 15 ml with an average of (10.05±2.75) ml. Lysholm score was improved from 50.29±6.67 before operation to 92.48±2.18 at 6 months after operation. IKDC scores was increased from 47.19±4.57 before operation to 90.71±2.22 at 6 months after operation. Knee joint activity was respectively (83.05±5.33)° and (132.05±7.15)° before operation and 6 months after operation. CONCLUSIONS: High strength wire under arthroscopy combined outside anchor nail in treating Meyers McKeever II, III ACL tibial check point has the advantages of less trauma, firm fixation, and satisfactory clinical effect.

[Case-control study on minimally invasive percutaneous plate osteosynthesis for the treatment of distal tibial comminuted fractures at different operation times].

OBJECTIVE: To compare clinical outcomes of minimally invasive percutaneous plate osteosynthesis (MIPPO) in treating distal tibial comminuted fractures at early and delayed stage. METHODS: From January 2006 to January 2012,66 patients with distal tibial comminuted fractures were treated by MIPPO. All patients were divided into primary group and delayed group according to operation time. There were 31 patients in primary group, including 18 males and 13 females aged 21 to 57 years old with an average of (39.0 +/- 17.8), treated by MIPPO at primary stage,according to Tscherne soft tissue injury, 18 cases were grade I ,12 cases were grade II and 1 case were grade III. Thirty-five patients were treated by MIPPO at delayed stage, including 16 males and 19 females aged 24 to 55 years old with an average of (39.5 +/- 15.2), according to Tscherne soft tissue injury, 6 cases were grade I, 26 cases were grade II and 3 cases were grade III. Operation time, blood loss, hospital stay, fracture healing time and complications of two groups were recorded and observed, Lowa scoring of ankle joint were used to evaluated therapeutic effects at final following and AP and lateral X-rays were used to evaluated fracture reduction and alignment. RESULTS: All patients were followed up, the time of following-up of primary group was (13.5 +/- 3.5) months, (15.2 +/- 3.8) months in delayed group, there was no significant meaning between two groups (t = 1.882, P = 0.064). There was no significant differences between two groups in operation time and blood loss (P > 0.05), but hospital stay in primary group was shorter than that of delayed group(P<0.05). There was no significant meaning between primary group (5.5 +/- 2.8) and delayed group (6.2 +/- 3.1) in fracture healing time (t = 0.958, P = 0.342); there was no significant meaning between primary group (87.6 +/- 6.8) and delayed group (89.6 +/- 5.2) in Lowa scores at final following-up (t = 1.351, P = 0.182). Two cases occurred postoperative superficial inflammatory reaction around fibular incision in primary group, 1 case occurred postoperative superficial inflammatory reaction around fibular incision and 1 case occurred delayed deep incision infection in delayed group at four months after operation. There was no significant differences in incidence of postoperative soft tissue complications between primary group (6.5%) and delayed group (5.7%) (t = 0.016, P = 0.900). CONCLUSION: For distal tibial comminuted fractures with grade I and II of Tscherne soft tissue injury, MIPPO at primary stage can not increase incidence of soft tissue complications, also can obtain the same clinical outcomes just like delayed MIPPO.

[Effect of elongated-needle penetration intervention on spinal apoptosis and cell signal transduction in acute spinal cord injury rabbits].

OBJECTIVE: To observe the effect of elongated-needle penetration (ENP) stimulation of "Zhibian" (BL 54), "Shuidao" (ST 28), "Qihai" (CV 6) and "Zhongji" (CV 3) on spinal nerve cell apoptosis and cellular signal transduction in spinal cord injury rabbits, so as to reveal its mechanism underlying improvement of spinal injury. METHODS: A total of 80 adult Newzealand rabbits were randomized to control, model, ENP, ENP + LY 294002 (PI3K antagonist), ENP + PD 98059 (MEK antagonist) groups, with 16 rabbits in each group. The spinal cord injury model was established by using modified Allen's method (Gravity-drop device). Elongated-needle penetration was applied to bilateral BL 54, ST 28, CV 3 and CV 6, once daily for 3 times. For rabbits of the ENP+ LY 294002 and ENP+ PD 98059 groups, LY 294002 (10 microg, 20 microL), PD 98059 (3 microg, 20 microL) were separately given by intrathecal injection. Pathomorphological changes of the injured spinal cord (T13-L1) were observed after H.E. stain. Spinal cell apoptosis was detected by TUNEL,and phosphorylated (p)-Akt and p-ERK1/2 immunoactivity was detected by immunohistochemistry, and the expression levels of p-Akt, p-ERK1/2, cytochrome C (Cyt C) and Caspase-3 proteins were determined by Western blot (WB), and serum TNF-alpha content was assayed by ELISA. RESULTS: H. E. staining showed apparent structural changes as hemmorrhage, inflammatory cell infiltration, cellular edema and necrosis, and formation of vacuolation in the spinal cord in the model group, which was marked milder in the ENP group. TUNEL assay showed that the rate of apoptotic cells was notably increased in the model group than in the control group (P < 0.05), obviously decreased in the ENP group when compared with the model group (P < 0.05). Immunohistochemistry, WB and ELISA results showed that compared with the control group, spinal p-Akt and p-ERK1/2 protein expression levels in the model group were significantly decreased (P < 0.05), and Cyt C and Caspase-3 expression levels and serum TNF-a content were significantly increased in the model group (P < 0.05). Compared with the model group, the expression levels of p-Akt, p-ERK1/2 were significantly increased in the ENP group (P < 0.05), while Cyt C and Caspase-3 expression levels and TNF-alpha content were significantly down-regulated in the ENP group (P < 0.05). After intrathecal injection of PI3K and MEK antagonists, the effects of ENP were significantly weakened in reducing apoptosis rate, upregulating p-Akt and p-ERK1/2 expression and in down-regulating Cyt C and Caspase-3 expression and TNF-alpha content (P < 0.05), suggesting important roles of ERK1/2 mediated extracellular and PI3K/Akt mediated intracellular apoptotic signal transduction pathways in ENP induced repair of the traumatic tissues. CONCLUSION: ENP stimulation can decrease spinal injury and cell apoptosis in spinal injury rabbits, which may be closely related to its effects in up-regulating p-Akt and p-ERK1/2 and down-regulating Cyt C and Caspase-3 expression levels in the spinal cord and serum TNF-alpha content.

[The role of the expression of PPAR-gamma gene in the adipogenesis in hemangioma evolution].

OBJECTIVE: To investigate the role of the expression of PPAR-gamma gene in the adipogenesis in hemangioma evolution. METHODS: Routine immunohistochemistry staining of Perilipin A, the marker antigen of adipocytes, was performed to observe the adipogenesis in hemangioma. Immunofluorescence staining of PPAR-gamma, the important transcription factor in promoting adipogenesis, was carried out to observe its location in hemangioma tissue, with the co-staining of alpha-SMA and CD31. And RT-PCR was used to examine the expression of PPAR-gamma gene in hemangioma in different stages. RESULTS: In the evolution of hemangioma, the number of adipocytes increased continuously. And the tumor was replaced by fibrofatty tissue finally. PPAR-gamma was located in the nuclei of perivascular cell in hemangioma tissue. The expression of PPAR-gamma gene in hemangioma increased in the evolution of hemangioma, but still was lower than that in normal fat tissue from children. CONCLUSION: The expression of PPAR-gamma in the perivascular cells suggests that they may contribute to the adipogenesis in hemangioma involution.

[Awn needle therapy on the impact of urinary retention after spinal cord injury].

OBJECTIVE: To investigate the therapeutic mechanism of point 8L54-through-point ST2S acupuncture with elongate needles in treating urinary retention after spinal cord injury. METHODS: Thirty-five healthy Japanese rabbits (weight 2.5 +/- 0.25 kg, 3 months old, male or female), used as experimental subjects, were divided into 4 groups involving blank group, model group, acupuncture group, elongate needles group (5 rabbits in blank group, 10 rabbits in each of the other group 10). Modified Allen's method was used to cause spinal cord injury model for the model group, the acupuncture group and the elongate needles group, the blank group was only sham surgery. Immediately after spinal cord injury model,the elongated needle group was given the bilateral acupoints of the elongated needle penetration needling and electric stimulation, electrical stimulation 15 mm stimulation frequency of 20 to 40 times/mm, intensity 1.5 to 3 V the acupuncture group immediately was given ordinary electric needle acupuncture, given other disposals as the elongated needle group; model group was not given electric needle acupuncture, waiting 15 minutes, started to detect and record the observed indicator as the elongated needle group; the blank group was only sham surgery. The following indicators including the Tarlov score ,urinary bladder pressure point, the threshold urination, voided volume, were observed in the first day and the fifth day after surgery. RESULTS: Three groups of animals which modeled were urinary retention after operation. Compared to 1 d, Tarlov score of model group, acupuncture group and elongate needles group significantly improved at postoperative 5 d (P < 0.05). Compared with acupuncture group, the Tarlov score of elongate needles group had no significant difference at postoperative 5 d (P > 0.05). Compared with model group, values of urinary bladder pressure point decreased with varying degrees in the acupuncture group and elongate needles group at postoperative 5 d (P < 0.05); relative to the acupuncture group, the point of the bladder voiding pressure in the elongate needles group decreased more significantly at postoperative 5 d (P < 0.05); compared with model group, micturition threshold of acupuncture group and elongate needles group had been significantly improved at the fifth day after surgery (P < 0.05); relative to the acupuncture group, the improvement is more obvious in the elongate needles group. Compared with model group, voided volume of acupuncture group and elongate needles group had increased significantly at the fifth day after surgery (P < 0.05); relative to the acupuncture group, the increment is more evident in the elongate needles group (P < 0.05). CONCLUSION: To treat urinary retention after spinal cord injury, the method, which was point-through-point acupuncture with elongate needles in the "Zhibian" and "Shuidao", was better than general acupuncture method. The therapeutic mechanism may be related to stimulate peripheral nerve of bladder, and to rectify the dysfunction between detrusor and sphincter.

Mesenchymal stem cells in infantile hemangioma reside in the perivascular region.

Infantile hemangioma grows quickly in the first year of life and regresses slowly to fibrofatty tissue during childhood; mesenchymal stem cells (MSCs) have been reported to contribute to this adipogenesis. Recent studies have shown the perivascular origin of MSCs in multiple organs. We hypothesized that MSCs in hemangioma might also reside in the perivascular region. We isolated MSCs from proliferating hemangioma by their selective adhesion to plastic culture dishes. Mesenchymal stem cells from bone marrow (BM-MSCs) and foreskin-derived fibroblasts were used as controls. Flow cytometry and immunofluorescence staining were used to examine their antigen profiles; in vitro induction of multi-lineage differentiation was performed to test their pluripotency. Platelet-derived growth factor R-ß (PDGFR-ß), CD133, and peroxisome-proliferator-activated receptor gamma (PPAR-γ) were selected as the markers to observe MSCs in hemangioma by immunohistochemistry staining, with costaining of CD31 and alpha-smooth muscle actin (α-SMA). Hemangioma-derived MSCs (Hem-MSCs) had fibroblast-like morphology; they expressed the MSC markers CD105, CD90, CD29, and vimentin and did not express the hematopoietic/endothelial markers CD45, CD34, CD31, and flt-1; Hem-MSCs also expressed CD133 and PPAR-γ. Most Hem-MSCs expressed PDGFR-ß and α-SMA; in contrast, the expression of PDGFR-ß and α-SMA in BM-MSCs was very weak. The Hem-MSCs differentiated into adipocytes, osteoblasts, and chondroblasts in vitro. This confirmed their pluripotency. Immunohistochemistry showed the colocalization of PDGFR-ß/α-SMA, CD133/α-SMA, and PPAR-γ/α-SMA in the perivascular region. MSCs were successfully obtained from proliferating hemangioma, revealing the perivascular origin of MSCs in hemangioma.

Electroacoustic analysis of an electret loudspeaker using combined finite-element and lumped-parameter models.

An unconventional type of electrostatic loudspeaker is presented in this paper. The loudspeaker made of thin, light, and flexible electret material lends itself well to the space-concerned applications. Electrical impedance measurement reveals that the coupling between the electrical system and the mechanical system is weak, which renders conventional parameter identification based on electrical impedance measurement impractical. A different approach is thus employed to model the electret loudspeaker. To predict the loudspeaker's dynamic response, finite-element analysis (FEA) is conducted on the basis of a simple model and a full model. In the simple model, FEA is applied to model the electret membrane, leaving the rest of system as rigid parts. In the full model, FEA is applied to model the entire membrane-spacer-back plate assembly. Velocity response of the membrane subject to a uniformly distributed force is calculated using FEA harmonic analysis. Mechanical impedance is then calculated with the velocity response. The acoustical impedance due to the back cavity, pores, and the radiation loading at the front side is calculated by theoretical formulas. The volume velocity of the membrane and the resulting on-axis sound pressure level are predicted with electrical-mechanical-acoustical analogous circuits. The response data predicted by the simulation compare very well with experimental measurements.

Optimal design of resonant piezoelectric buzzer from a perspective of vibration-absorber theory.

In this paper, an optimization technique is presented for the design of piezoelectric buzzers. This design technique aims at finding the optimal configuration of the coupled cavity and diaphragm structure to maximize the sound pressure output. Instead of measuring the material constants of the piezoelectric ceramic and the metal diaphragm, an "added-mass method" is developed to estimate the equivalent electromechanical parameters of the system on which an analogous circuit can be established. The electrical impedance and on-axis sound pressure level of the piezoelectric buzzer can be simulated by solving the loop equations of the electromechanoacoustical analogous circuit. An interesting finding of this research is that the nature of the piezoelectric buzzer bears remarkable resemblance to that in the dynamic vibration absorber theory. Much physical insight can be gained by exploiting this resemblance in search of the optimal configuration. According to the system characteristic equation, a design chart was devised to "lock" the critical frequency at which the system delivers the maximal output. On the basis of the analogous circuit and the vibration absorber theory, an optimal design was found with constrained optimization formalism. Experiments were conducted to justify the optimal design. The results showed that the performance was significantly improved using the optimal design over the original design. Design guidelines for the piezoelectric buzzers are summarized.