Research progress on the immunological functions of Piezo1 a receptor molecule that responds to mechanical force.

The human immune system is capable of defending against, monitoring, and self-stabilizing various immune cells. Differentiation, proliferation, and development of these cells are regulated by biochemical signals. Moreover, biophysical signals, such as mechanical forces, have been found to affect immune cell function, thus introducing a new area of immunological research. Piezo1, a mechanically sensitive ion channel, was awarded the Nobel Prize for Physiology and Medicine in 2021. This channel is present on the surface of many cells, and when stimulated by mechanical force, it controls calcium (Ca2+) inside the cells, leading to changes in downstream signals and thus regulating cell functions. Piezo1 is also expressed in various innate and adaptive immune cells and plays a major role in the immune function. In this review, we will explore the physiological functions and regulatory mechanisms of Piezo1 and its impact on innate and adaptive immunity. This may offer new insights into diagnostics and therapeutics for the prevention and treatment of diseases and surgical infections.

Investigating the efficacy of vacuum sealing drainage versus traditional negative pressure drainage in treating deep incision infections following posterior cervical internal fixation-a retrospective cohort study.

BACKGROUND: Assessing the efficacy and safety of Vacuum Sealing Drainage (VSD) in treating deep incision infections (DII) following posterior cervical internal fixation. METHODS: We retrospectively studied the clinical effects of VSD and Traditional Negative Pressure Drainage (TND) on 12 patients with deep incision infection after posterior cervical fixation surgery who were treated in our department from 2012 to 2020. A comparison of patient-related factors (age, gender, BMI, comorbidities, initial internal fixation surgery segment, preoperative laboratory inflammation indicators) and surgical-related factors (postoperative duration of fever, positive rate of drainage fluid bacterial culture, Visual Analogue Scale (VAS) score at 3 days after surgery, laboratory indicators at 3 days after surgery, debridement frequency and drainage time, hospital stay, internal fixation retention rate, and infection recurrence rate) between the VSD group and the TND group was conducted using independent sample t tests to draw experimental conclusions. RESULTS: This study included 12 patients, with six cases of VSD (5 males and 1 female) and six cases of TND (4 males and 2 females). The VSD group had significantly lower postoperative fever time (1.50 ± 0.46 days vs. 4.28 ± 0.97 days, P < 0.05), a higher positive rate of bacterial cultures in drainage fluid (5/6 vs. 2/6, P < 0.05), lower 3 day VAS scores (3.13 ± 0.83 vs. 3.44 ± 0.88, P < 0.05), lower 3 day CRP levels (66.89 ± 23.65 mg/L vs. 57.11 ± 18.18 mg/L, P < 0.05), a shorter total drainage time (14.50 ± 2.98 days vs. 22.56 ± 3.01 days, P < 0.05), and a higher total drainage flow rate (395.63 ± 60.97 ml vs. 155.56 ± 32.54 ml, P < 0.05) than the TND group (the total drainage volume throughout the entire treatment process). In addition, the frequency of debridement (2.67 ± 0.52 times vs. 3.17 ± 0.41 times, P < 0.05) and average hospital stay (23.13 ± 3.27 days vs. 34.33 ± 6.86 days, P < 0.05) were significantly lower in the VSD group, although both groups retained internal fixation. CONCLUSIONS: VSD is a secure and effective treatment for deep incision infections that results from cervical posterior internal fixation surgery.

Effects of different sponge implantation methods of negative pressure wound therapy on wound healing of deep surgical site infection after spinal surgery.

PURPOSE: After spinal surgery, negative pressure wound treatment (NPWT) improves deep surgical site infection (DSSI) wound healing. This research compared the healing benefits of two sponge implantation strategies in NPWT for DSSI. METHODS: 21 patients with DSSI utilized NPWT to improve wound healing following spine surgery were followed from January 1, 2012 to December 31, 2021. After antibiotic treatment failure, all these patients with DSSI received extensive debridement and NPWT. They are grouped by sponge placement method: centripetal reduction and segment reduction. The two groups' hospital stays, NPWT replacement frequency, wound healing time, healing speed, and quality of wound healing (POSAS score) were compared. RESULTS: All patients had been cured by the end of December 2022, and the mean follow-up time was 57.48 ± 29.6 months. Surgical incision length did not vary across groups (15.75±7.61 vs. 15.46±7.38 cm, P = 0.747). The segmental reduction approach had shorter hospital stay and NPWT treatment times than the centripetal reduction method (39.25±16.04 vs. 77.38±37.24 days, P = 0.027). Although there is no statistically significant difference, the mean wound healing duration of segmental reduction group is faster than that of centripetal reduction group (0.82±0.39 vs 0.45±0.28 cm/d, P = 0.238), wound healing quality (POSAS) (33.54±8.63 vs 48.13±12.17, P = 0.408) is better in segmental reduction group, and NPWT replacement frequency (2.62 ± 1.04 vs 3.88 ± 1.25, P < .915) is smaller in segmental reduction group. CONCLUSIONS: NPWT heals wounds and controls infection. Segmental reduction method accelerates wound healing, reduces hospital stay, and improves wound quality compared to central reduction method.

A comprehensive clinical analysis of the use of percutaneous endoscopic debridement for the treatment of early lumbar epidural abscesses.

Objective: The purpose of this study is to evaluate the safety and efficacy of a percutaneous endoscopic debridement and drainage for lumbar infections with early epidural abscesses. Methods: Eight cases of early epidural abscess underwent lumbar intervertebral space debridement and drainage by percutaneous endoscopic. Laboratory indicators, pathogenic microorganisms and complications were documented, and the ASIA scores were used to assess preoperative and postoperative neurological function changes. Additionally, the VAS was used to evaluate the therapeutic effect. Results: The average duration of the drainage tube was 11.25 ± 3.96 days (7-20 days), and the epidural abscess was eliminated after the tube was taken out. Postoperative CRP (14.40 ± 12.50 mg/L) and ESR (48.37 ± 16.05 mm/1 h) were significantly lower than the preoperative CRP (62.5 ± 61.1 mg/L) and ESR (75.30 ± 26.20 mm/1 h). The VAS score after the operation (2.50 ± 0.92 points) was significantly lower than the one before the surgery (8.25 ± 0.83 points). 5 patients experienced lower extremity pain and neurological dysfunction prior to surgery, however, after drainage, the lower extremity pain dissipated and the lower extremity muscle strength improved in one patient. All 8 patients were followed up for a period of (28.13 ± 10.15) months, including 3 patients with spinal segmental instability who had lumbar bone graft and internal fixation for the second stage. At the end of the follow-up, all 8 patients were clinically cured without any progressive nerve injury, paraplegia or recurrence of infection. Conclusion: Percutaneous Endoscopic Debridement and Drainage is an effective way to drain intraspinal abscesses, thus avoiding any potential progressive harm to the spinal cord.

Case Report: A spinal infection with bilateral psoas abscesses was treated with NPWT to enhance the local infection by increasing the infiltration of neutrophil cells and draining the pus.

Treatment of spinal brucellosis with bilateral psoas abscess is a challenging clinical endeavor. We retrospectively evaluated a case of lumbar infection and bilateral psoas abscess, and was effectively managed through a unilateral extreme lateral approach with the aid of NPWT for bilateral drainage. We hypothesize that NPWT can influence the Piezo1 receptor of neutrophils and further influence the interaction between neutrophils and endothelial cells to promote the clearance of infected lesions, and this phenomenon is also observed in pathological slides. This proves that NPWT can rapidly enhance the recruitment of neutrophils in the infected area and improve the local immune response, and after a year of reassessment and tracking, Bilateral drainage using NPWT via a unilateral Extreme Lateral Approach could acquire satisfactory surgical outcomes, can be used as a treatment modality for lumbar infection with bilateral psoas abscesses.

Prostate Ultrasound Image Segmentation Based on DSU-Net.

In recent years, the incidence of prostate cancer in the male population has been increasing year by year. Transrectal ultrasound (TRUS) is an important means of prostate cancer diagnosis. The accurate segmentation of the prostate in TRUS images can assist doctors in needle biopsy and surgery and is also the basis for the accurate identification of prostate cancer. Due to the asymmetric shape and blurred boundary line of the prostate in TRUS images, it is difficult to obtain accurate segmentation results with existing segmentation methods. Therefore, a prostate segmentation method called DSU-Net is proposed in this paper. This proposed method replaces the basic convolution in the U-Net model with the improved convolution combining shear transformation and deformable convolution, making the network more sensitive to border features and more suitable for prostate segmentation tasks. Experiments show that DSU-Net has higher accuracy than other existing traditional segmentation methods.

Young thoracic vertebra diffuse idiopathic skeletal hyperostosis with Scheuermann disease: A case report.

BACKGROUND: Diffuse idiopathic skeletal hyperostosis (DISH) is a disorder characterised by the calcification and ossification of ligaments and entheses. It is a frequent occurrence in elderly males, but rarely encountered in younger individuals. CASE SUMMARY: A 24-year-old male was admitted to the hospital due to low back pain accompanied with numbness in both lower limbs for 10 d. Upon clinical examination and imaging tests, the patient was diagnosed with DISH with Scheuermann disease and thoracic spinal stenosis. Before the operation and medical treatment, the patient had hypoesthesia of the skin below the xiphoid process. Afterward, a standard laminectomy was conducted using ultrasonic bone curette and internal fixation was applied. Subsequently, the patient was given corticosteroids, neurotrophic drugs, hyperbaric oxygen and electric stimulation. As a result of the treatment, the patient's sensory level decreased to the navel level and there was no major change in the muscle strength of the lower limbs. During follow-up, the patient's skin sensation has returned to normal. CONCLUSION: This case is a rare instance of DISH co-existing with Scheuermann's disease in a young adult. This provides a valuable reference point for spine surgeons, as DISH is more commonly observed in middle-aged and elder adults.

A Comparison of Negative Pressure and Conventional Therapy in Spine Infections: A Single-Center Retrospective Study.

Purpose: To investigate the effectiveness and safety of negative-pressure wound therapy (NPWT) in treating primary spinal infections. Methods: Patients who underwent surgical treatment for primary spinal infection between January 2018 and June 2021 were retrospectively evaluated. They were divided into two groups based on the type of surgery: one that underwent negative-pressure wound therapy (NPWT) and another that underwent conventional surgery (CVSG-Posterior debridement, bone grafting, fusion, and internal fixation in one stage). The two groups were compared in terms of the total operation time, total blood loss, total postoperative drainage, postoperative pain score, time for the postoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to return to normal, postoperative complications, treatment time, and recurrence rate. Results: A total of 43 cases of spinal infection were evaluated, with 19 in the NPWT group and 24 in the CVSG group. The NPWT group had a superior postoperative drainage volume, antibiotic use time, erythrocyte sedimentation rate and CRP recovery times, VAS score at 3 months after the operation, and cure rate at 3 months after operation compared with the CVSG group. There were no significant variations in the total hospital stay and intraoperative blood loss between the two groups. Conclusions: This study supports the use of negative pressure in the treatment of a primary spinal infection and indicates that it has a notably better short-term clinical effect than conventional surgery. Additionally, its mid-term cure rate and recurrence rate are more desirable than those of conventional treatments.

Treatment of lumbar brucella spondylitis with negative pressure wound therapy via extreme lateral approach: A case report.

Brucella spondylitis (BS) is a specific spinal infection. Surgical treatment is required for Brucella spondylitis that has caused neurological symptoms in the lower extremities and developed an intraspinal abscess. The main purpose of surgery is to remove the lesion and restore the stability of the spine. However, both the anterior approach and the posterior approach cannot completely remove the lesions, resulting in a low cure rate and a certain recurrence rate. Although anterior or posterior debridement is more thorough, it is unbearable for some patients with poor general condition. In this study, for the first time, a negative pressure wound therapy (NPWT) device was introduced into the intervertebral space through the extreme lateral approach to treat a patient with Brucella spondylitis. We summarize the treatment process, and discuss the feasibility and effectiveness of this surgical approach through 1-year follow-up.

The Percutaneous Endoscopic Lumbar Debridement and Irrigation Drainage Technique for the First-Stage Treatment of Spontaneous Lumbar Spondylodiscitis: A Clinical Retrospective Study.

Background: Minimally invasive or open surgery is contentious in the treatment of spondylodiscitis, therefore finding a balance between the two is urgently needed. In this study, we propose a new treatment paradigm for treating spontaneous lumbar spondylodiscitis by percutaneous endoscopic lumbar debridement and irrigation drainage (PELDID). Then, the Pola classification was used to guide subsequent treatment. Methods: From November 2017 to April 2019, this study collected data on 16 patients with lumbar spondylodiscitis who were surgically treated utilizing this treatment paradigm in our department. Clinical effectiveness was determined using the visual analogue scale (VAS), the Oswestry Disability Index (ODI), the MOS 36-item short-form health survey (SF-36), and Kirkaldy-Willis criteria. Results: All 16 patients completed the treatment using the above paradigm and were followed up for 28.13 ± 10.15 months. The preoperative Pola classification is as follows: 7 cases of type A, 3 cases of type B, and 6 cases of type C. After the first-stage surgery, the evaluation results of Pola classification were as follows: 8 cases of type A, 8 cases of type B, and 0 cases of type C. Four patients received second-stage surgery with internal fixation through the paravertebral multifidus space approach and intervertebral bone graft fusion through the transforaminal approach, and the reoperation rate was 25% (4/16 cases). The Visual analogue scale (VAS), Oswestry Disability Index (ODI), and SF-36 score all improved significantly from 2.43 ± 0.89 to 0.18 ± 0.40, from 77.31% ± 11.15%to 16.93% ± 5.45%, and from 18.34 ± 7.47 to 80.3 ± 15.36. The CRP and ESR decreased dramatically from 49.61 ± 48.84 to12.50 ± 12.18 and from 65.56 ± 26.89 to 29.68 ± 20.68. There were no recurrences of infection in our study. Conclusions: The paradigm of the first-stage PELDID technique combined with the Pola classification system to guide the second-stage treatment for spontaneous spondylodiscitis is a novel and effective strategy for treating spontaneous spondylodiscitis.

Vacuum Sealing Drainage for Primary Thoracolumbar Spondylodiscitis: A Technical Note.

Primary spinal infection is a challenge for neurosurgeons. Here, for the first time, we introduced the vacuum sealing drainage (VSD) sponge into the intervertebral space for the primary thoracolumbar infection treatment. This study included 6 bedridden patients with thoracolumbar spondylodiscitis without deformity formation. All 6 patients were treated with the VSD in our hospital from June 30, 2018, to August 31, 2019. All 6 cases of thoracolumbar infection achieved clinical cure at 3-month follow-up, and no surgical-related mortalities occurred in our series. One patient died of acute cerebral infarction 5 months after surgery, and the remaining 5 patients completed a 12-month follow-up without recurrence. The JOA score of all 6 cases improved significantly after VSD treatment. VSD is feasible for safe and effective treatment for primary thoracolumbar infection. The short-term follow-up effect is definite.

Postoperative discal pseudocyst after percutaneous endoscopic transforaminal discectomy treated by drainage: Case report.

RATIONALE: This article reports 2 cases of symptomatic postoperative discal pseudocysts (PDP), a rare complication of percutaneous endoscopic transforaminal lumbar discectomy (PELD). In this report, we propose a possible mechanism of PDP and introduce an effective therapeutic strategy. To our knowledge, there have been no reports of the use of indwelling drainage techniques for the PDP treatment after PELD. PATIENT CONCERNS: Herein, we report 2 cases of PDP after PELD in our hospital. Both patients had disc herniation at the L4/5 level, and the symptoms of low back pain and radiculopathy were significantly relieved after PELD. However, the signs in both 2 cases recurred 20 days after surgery. MRI indicated PDP in both 2 patients with high intensity on T1- and T2-weighted imaging in the primary surgical area. INTERVENTIONS: Given the progressive symptoms in both cases, PELD was performed again and 3-lumen drainage catheters were placed at the surgical site for adequate drainage. OUTCOMES: The patient's symptoms were significantly relieved after adequate drainage and disappeared 3 months after surgery. There was no clinical or MRI recurrence at the 6-month follow-up. CONCLUSION: According to operative findings, we found that PDP symptoms may not be attributable mainly to cyst compression but to the excessive accumulation of local inflammatory factors. Treatment of PELD combined with indwelling drainage is feasible and effective in treating PDP.

Safety and efficacy of negative pressure wound therapy in treating deep surgical site infection after lumbar surgery.

PURPOSE: To evaluate the efficacy and safety of negative pressure wound therapy (NPWT) for post-operative deep surgical site infection (SSI) after posterior instrumented spinal surgery. METHODS: We retrospectively compared the clinical outcomes of NPWT with standard debridement for deep SSI after posterior instrumented spinal surgery from 2012 to 2020 in our department. The primary outcomes were peri-operative characteristics including positive organism results, duration of fever, and visual analogue scale (VAS) pain scores three days after re-operation. The secondary outcomes were post-operative characteristics including implant infection recurrence, implant retention rate, duration of hospitalization, and VAS at discharge. Pearson's chi-squared analysis (categorical) and Student's t test (continuous) were used to determine the differences. RESULTS: Thirty-four patients were included, of which 19 underwent NPWT, and 15 underwent standard debridement. Patients in the NPWT group all significantly improved primary outcomes including duration of fever after re-operation (0.95 ± 1.13 vs 4.07 ± 5.35, P = 0.001), positive organism results (14 of 19 vs 2 of 15, P < 0.01), and VAS at 3 days after re-operation (2.58 ± 0.69 vs 3.40 ± 1.06, P < 0.05). Patients in NPWT group exhibited significant decrease in implant infection recurrence (0 of 19 vs 5 of 15, P < 0.01), implant retention rate (19 of 19 vs 10 of 15, P < 0.01), duration of hospitalization (27.74 ± 10.95 vs 37.67 ± 13.67, P < 0.01). CONCLUSIONS: NPWT is a feasible and safe treatment option for deep SSI after posterior instrumented spinal surgery.

Construction and evaluation of a novel tissue-engineered bone device.

Tissue-engineered bones (TEB) are a promising strategy for treating large segmental bone defects. However, the application of TEB is greatly limited by technical and logistical issues caused by the viable cells used. The aim of the present study was to devise novel TEB, termed functional TEB (fTEB) using devitalized mesenchymal stem cells (MSCs) with the functional proteins retained. TEB were fabricated by seeding MSCs on demineralized bone matrix (DBM) scaffolds. fTEB were prepared with deep hyperthermia treatment. Total proteins were extracted from fTEB and conditioned media (CM) were prepared. The effects of fTEB-CM on the proliferation, differentiation and migration of host MSCs were assessed. Following lyophilization, the majority of the MSCs were devitalized, but the proteins within the TEB were retained in fTEB. Similar to TEB, fTEB outperformed the DBM in inducing migration, proliferation and osteogenic differentiation in MSCs. The abundance of cytokines in fTEB was also determined. fTEB were shown to be a promising alternative to TEB. Thus, they might serve as off-the-shelf tissue engineering products, meeting the high demands for bone substitutes in the clinical setting.

Percutaneous endoscopic discectomy in adolescent lumbar disc herniation: a 3- to 5-year study.

OBJECTIVEThe authors sought to investigate the efficiency of percutaneous endoscopic discectomy (PED) in adolescent patients with lumbar disc herniation (LDH), compare PED outcomes in adolescent patients with those in young adult LDH patients as controls, and discuss relevant technical notes.METHODSThis was a retrospective study involving 19 adolescent LDH patients (age > 13 and < 18 years, 20 discectomies) and 38 young adults (age < 40 years, 38 discectomies) who also had LDH and were matched to the adolescent group for sex and body mass index. The combined cohort included 51 male patients (89.5%) and 6 female patients (10.5%), with an average age of 26.7 years (range 14-39 years). The operated levels included L3-4 in 1 patient (1.7%), L4-5 in 22 patients (37.9%), and L5-S1 in 35 patients (60.4%). Two adolescents (10.5%) exhibited apophyseal ring separation and one (5.3%) had had previous PED. All patients underwent PED under local anesthesia. Outcomes were evaluated through a visual analog scale (VAS), the Japanese Orthopaedic Association (JOA) scoring system, and the modified MacNab grading system.RESULTSThe mean duration of follow-up was 41.7 months (range 36-65 months). The outcomes in adolescents were satisfactory and comparable with previously reported outcomes of microsurgical discectomy (MD) and conventional open discectomy (COD). The adolescent patients had a faster and better recovery course than the adult patients (p < 0.01). One adolescent patient (5.3%) exhibited recurrence and 2 adults (5.3%) experienced transient dysesthesia; the complication rates were comparable in the 2 age groups (p = 0.47). Prolonged duration of symptoms (p < 0.01) and disc degeneration (p = 0.01) were correlated with lower postoperative JOA values; patients with extrusions had higher postoperative JOA values than those with protrusions (p = 0.01).CONCLUSIONSPED may yield favorable results in the treatment of adolescent LDH in terms of short- to medium-term follow-up; restricted discectomy and a conservative rehabilitation program might be advisable. Further long-term studies are warranted to address this rare disease entity.

The posterior approach operation to treat thoracolumbar disc herniation: A minimal 2-year follow-up study.

Thoracolumbar disc herniation (TLDH) is a rare and progressively disabling disorder; surgical procedures predispose the subjects to high incidence of complications including recurrence, neurological aggravation, and adjacent segment degeneration.Ten patients with TLDH underwent posterior approach operation in our institution from January, 2006 to December, 2015. The mean preoperative duration of clinical symptoms was 16.5 months. The clinical data including operative time, blood loss, and hospitalization duration were investigated. Furthermore, pre and postoperative neurological status was evaluated by the modified Japanese Orthopedic Association (JOA) scoring system and pain by visual analog scale (VAS) scoring system.The mean operative time was 176.50 ±â€Š20.55 minutes, the mean blood loss was 435.00 ±â€Š89.58 mL, and the mean hospitalization length was 13.30 ±â€Š2.97 days. All patients were followed with a mean period of 35.1 months. The mean JOA score of all patients before operation, at discharge, 3 months after operation, and at last follow-up was 6.50 ±â€Š1.28, 7.60 ±â€Š1.22, 8.90 ±â€Š0.99, and 9.00 ±â€Š0.92, respectively. The differences between the pre and postoperative JOA and VAS scores were significant (P < .05). However, the differences of JOA and VAS scores at postoperative 3 months and final follow-up were not statistically significant.Posterior approach operation is an ideal surgical technique for treatment of TLDH; the operative time, blood loss, hospitalization duration, and symptomatic improvement are favorable.

Use of Ultrasonic Device in Cervical and Thoracic Laminectomy: a Retrospective Comparative Study and Technical Note.

Multilevel severe compressive myelopathy is a challenging disorder for the surgeons, the aim of this study is to assess the efficacy and safety of a newly designed ultrasonic burr as an assistant tool to the ultrasonic scalpel in laminectomy for this disease. This is a retrospective comparative study, the included subjects were patients who received cervical and thoracic laminectomy using ultrasonic device (LUD, n = 9, 10 surgeries) and controls with the high-speed burr (LHB, n = 16). Fifteen patients (60.0%) showed severe cord occupancy and the average number of laminae operated was 3.5. Ultrasonic devices caused less blood loss (P = 0.02) and quicker operative time per level (P < 0.001) than LHB, and was associated with more operated laminae (P = 0.04). Preoperative JOA scores (P = 0.51), improvement rate (P = 0.47), and dural injury (P = 0.51) were not related to LUD. Our experience indicates ultrasonic devices are safe and effective for laminectomy treating multilevel and severe compressive myelopathy, the instrument could be used with ease especially for cases with ossified posterior longitudinal ligament and ossification of the ligamentum flavum, proper utility of the instrument is crucial to prevent complications.

Effect of pathological fracture on limb salvage surgery with preservation of the epiphysis in children with osteosarcoma of the distal femur: Two case reports.

The outcome of limb salvage treatment for femoral osteosarcoma with pathological fractures in children is currently unknown. The aim of the present study was to present two cases of patients who received limb salvage surgery with preservation of the epiphysis at the Department of Orthopedics of The General Hospital of Jinan Military Commanding Region (Shandong, China). Between January, 2007 and January, 2013, two pediatric patients were admitted to our hospital with pathological fractures. One of the patients was a girl, aged 11 years, with confirmed osteosarcoma of the right distal femur; the other patient was a boy, aged 9 years, with osteosarcoma of the left distal femur. After receiving two cycles of neoadjuvant chemotherapy following tumor biopsy, the patients received limb salvage surgery with epiphyseal preservation, with wide resection of the tumor and biological reconstruction by allogeneic bone and fibular autograft, followed by 10 cycles of adjuvant chemotherapy. With a mean follow-up of 64 months, there were no postoperative complications, local recurrence or metastasis. The limb function recovered well, although limb shortening was observed. The female patient underwent a second fixation and limb lengthening after epiphyseal closure. Therefore, with effective neoadjuvant chemotherapy, limb salvage surgery with epiphyseal preservation is not contraindicated for pediatric patients with pathological fractures from femoral osteosarcoma. Biological reconstruction by allogeneic bone and vascularized fibular autograft following wide tumor resection is a viable option for such patients, with a good postoperative functional outcome.

Non-fusion procedure using PEEK rod systems for lumbar degenerative diseases: clinical experience with a 2-year follow-up.

BACKGROUND: Polyetheretherketone (PEEK) rod system is a novel pedicle-based dynamic stabilization system. This study evaluated clinical and radiographic outcomes of non-fusion surgery by PEEK rod systems for treatment of degenerative lumbar diseases with a 2-year follow-up. METHODS: From February 2012 to October 2012, 38 patients who underwent non-fusion surgery using PEEK rod systems were included in the study. Data on Oswestry Disability Index (ODI) score and Japanese Orthopaedics Association (JOA) score were collected and radiographs were obtained to evaluate disc height index (DHI) and range of motion (ROM) at each interval. RESULTS: Both JOA and ODI scores significantly improved postoperatively. DHI showed a slight increase immediately after the surgery but gradually dropped below preoperative levels. Mean ROM values changed from 8.8° preoperatively to 1.8° at the 2-year follow-up point. Screw loosening occurred in one case at the 2-year follow-up. CONCLUSIONS: The preliminary results indicated a significant improvement in clinical outcomes and advantageous implant safety. The non-fusion procedure using PEEK rod systems might be a viable alternative for treatment of lumbar degenerative diseases. The distraction technique needs to be improved for better postoperative DHI.

Sustained release of bioactive protein from a lyophilized tissue-engineered construct promotes the osteogenic potential of mesenchymal stem cells.

Tissue-engineered constructs (TECs) seeded with mesenchymal stem cells (MSCs) represent a therapy for large bone defects. However, massive cell death in TECs in the early postimplantation period prompted us to investigate the osteoinductive mechanism of TECs. Previous studies demonstrated that stem cell extracts retained equivalent levels of bioactive proteins and exhibited an osteoinductive nature similar to that of intact cells. These data led us to hypothesize that despite the massive cell death in TECs, devitalized MSC-derived proteins remain on the scaffolds and are released to improve cell function. Here, TECs were prepared using demineralized bone matrix seeded with human umbilical cord Wharton's jelly-derived MSCs (hWJMSCs), and the cells seeded in TECs were devitalized by lyophilizing the TECs. Scanning electron microscopy, BCA protein assays, quantitative cytokine array analysis and immunofluorescent staining indicated that approximately 3 mg/cm(3) of total protein and 49 types of cytokines derived from hWJMSCs were preserved in the lyophilized TECs (LTECs). The sustainable release of total protein and cytokines from LTECs lasted for more than 2 weeks. The released protein improved the osteogenic behavior of and gene expression in MSCs. Furthermore, the lyophilized hWJMSC-derived proteins had immunoregulatory properties similar to those of live MSCs in mixed lymphocyte reactions. Collectively, we present a novel perspective on the osteoinductive mechanism of TECs and introduce LTECs as new systems for delivering multiple cytokines to enhance MSC behavior.