Antibacterial sequential growth factor delivery from alginate/gelatin methacryloyl microspheres for bone regeneration.

Autologous or allogeneic bone tissue grafts remain the mainstay of treatment for clinical bone defects. However, the risk of infection and donor scarcity in bone grafting pose challenges to the process. Therefore, the development of excellent biomaterial grafts is of great clinical importance for the repair of bone defects. In this study, we used gas-assisted microfluidics to construct double-cross-linked hydrogel microspheres with good biological function based on the ionic cross-linking of Cu2+ with alginate and photo-cross-linking of gelatin methacryloylamide (GelMA) by loading vascular endothelial growth factor (VEGF) and His-tagged bone morphogenetic protein-2 (BMP2) (AGMP@VEGF&BMP2). The Cu2+ component in the microspheres showed good antibacterial and drug-release behavior, whereas VEGF and BMP2 effectively promoted angiogenesis and bone tissue repair. In in vitro and in vivo experiments, the dual cross-linked hydrogel microspheres showed good biological function and biocompatibility. These results demonstrate that AGMP@VEGF&BMP2 microspheres could be used as a bone defect graft substitute to promote effective healing of bone defects and may be applied to other tissue engineering studies.

Advances in natural and synthetic macromolecules with stem cells and extracellular vesicles for orthopedic disease treatment.

Serious orthopedic disorders resulting from myriad diseases and impairments continue to pose a considerable challenge to contemporary clinical care. Owing to its limited regenerative capacity, achieving complete bone tissue regeneration and complete functional restoration has proven challenging with existing treatments. By virtue of cellular regenerative and paracrine pathways, stem cells are extensively utilized in the restoration and regeneration of bone tissue; however, low survival and retention after transplantation severely limit their therapeutic effect. Meanwhile, biomolecule materials provide a delivery platform that improves stem cell survival, increases retention, and enhances therapeutic efficacy. In this review, we present the basic concepts of stem cells and extracellular vesicles from different sources, emphasizing the importance of using appropriate expansion methods and modification strategies. We then review different types of biomolecule materials, focusing on their design strategies. Moreover, we summarize several forms of biomaterial preparation and application strategies as well as current research on biomacromolecule materials loaded with stem cells and extracellular vesicles. Finally, we present the challenges currently impeding their clinical application for the treatment of orthopedic diseases. The article aims to provide researchers with new insights for subsequent investigations.

Antibacterial microneedle patch releases oxygen to enhance diabetic wound healing.

Cell growth and metabolism require an adequate supply of oxygen. However, obtaining sufficient oxygen from the blood circulating around diabetic wounds is challenging. Nevertheless, achieving a continuous and stable oxygen supply is required for these wounds to heal. Hence, in this study, we report a novel antibacterial oxygen-producing silk fibroin methacryloyl hydrogel microneedle (MN) patch comprising tips encapsulated with calcium peroxide and catalase and a base coated with antibacterial Ag nanoparticles (AgNPs). The tip of the MN patch continuously releases oxygen and inhibits the production of reactive oxygen species. This accelerates diabetic wound healing by promoting cellular accretion and migration, macrophage M2 polarization, and angiogenesis. The AgNPs at the base of the MN patch effectively combat microbial infection, further facilitating wound repair. These findings suggest that using this multifunctional oxygen-producing MN patch may be a promising strategy for diabetic wound healing in clinical settings.

Construction of intelligent drug delivery system based on polysaccharide-derived polymer micelles: A review.

Micelles are nanostructures developed via the spontaneous assembly of amphiphilic polymers in aqueous systems, which possess the advantages of high drug stability or active-ingredient solubilization, targeted transport, controlled release, high bioactivity, and stability. Polysaccharides have excellent water solubility, biocompatibility, and degradability, and can be modified to achieve a hydrophobic core to encapsulate hydrophobic drugs, improve drug biocompatibility, and achieve regulated delivery of the loaded drug. Micelles drug delivery systems based on polysaccharides and their derivatives show great potential in the biomedical field. This review discusses the principles of self-assembly of amphiphilic polymers and the formation of micelles; the preparation of amphiphilic polysaccharides is described in detail, and an overview of common polysaccharides and their modifications is provided. We focus on the review of strategies for encapsulating drugs in polysaccharide-derived polymer micelles (PDPMs) and building intelligent drug delivery systems. This review provides new research directions that will help promote future research and development of PDPMs in the field of drug carriers.

3D printed scaffolds based on hyaluronic acid bioinks for tissue engineering: a review.

Hyaluronic acid (HA) is widely distributed in human connective tissue, and its unique biological and physicochemical properties and ability to facilitate biological structure repair make it a promising candidate for three-dimensional (3D) bioprinting in the field of tissue regeneration and biomedical engineering. Moreover, HA is an ideal raw material for bioinks in tissue engineering because of its histocompatibility, non-immunogenicity, biodegradability, anti-inflammatory properties, anti-angiogenic properties, and modifiability. Tissue engineering is a multidisciplinary field focusing on in vitro reconstructions of mammalian tissues, such as cartilage tissue engineering, neural tissue engineering, skin tissue engineering, and other areas that require further clinical applications. In this review, we first describe the modification methods, cross-linking methods, and bioprinting strategies for HA and its derivatives as bioinks and then critically discuss the strengths, shortcomings, and feasibility of each method. Subsequently, we reviewed the practical clinical applications and outcomes of HA bioink in 3D bioprinting. Finally, we describe the challenges and opportunities in the development of HA bioink to provide further research references and insights.

Hydrogel-based treatments for spinal cord injuries.

Spinal cord injury (SCI) is characterized by damage resulting in dysfunction of the spinal cord. Hydrogels are common biomaterials that play an important role in the treatment of SCI. Hydrogels are biocompatible, and some have electrical conductivity that are compatible with spinal cord tissues. Hydrogels have a high drug-carrying capacity, allowing them to be used for SCI treatment through the loading of various types of active substances, drugs, or cells. We first discuss the basic anatomy and physiology of the human spinal cord and briefly discuss SCI and its treatment. Then, we describe different treatment strategies for SCI. We further discuss the crosslinking methods and classification of hydrogels and detail hydrogel biomaterials prepared using different processing methods for the treatment of SCI. Finally, we analyze the future applications and limitations of hydrogels for SCI. The development of biomaterials opens up new possibilities and options for the treatment of SCI. Thus, our findings will inspire scholars in related fields and promote the development of hydrogel therapy for SCI.

Zn2+ incorporated composite polysaccharide microspheres for sustained growth factor release and wound healing.

The development of new wound dressings has always been an issue of great clinical importance and research promise. In this study, we designed a novel double cross-linked polysaccharide hydrogel microspheres based on alginate (ALG) and hyaluronic acid methacrylate (HAMA) from gas-assisted microfluidics for wound healing. The microspheres from gas-assisted microfluidics showed an uniform size and good microsphere morphology. Moreover, this composite polysaccharide hydrogel microspheres were constructed by harnessing the fact that zinc ions (Zn2+) can cross-link with ALG as well as histidine-tagged vascular endothelial growth (His-VEGF) to achieve long-term His-VEGF release, thus promoting angiogenesis and wound healing. Meanwhile, Zn2+, as an important trace element, can exert antibacterial and anti-inflammatory effects, reshaping the trauma microenvironment. In addition, photo cross-linked HAMA was introduced into the microspheres to further improve its mechanical properties and drug release ability. In summary, this novel Zn2+ composite polysaccharide hydrogel microspheres loaded with His-VEGF based on a dual cross-linked strategy exhibited synergistic antimicrobial and angiogenic effects in promoting wound healing.

Sitagliptin attenuates neuronal apoptosis via inhibiting the endoplasmic reticulum stress after acute spinal cord injury.

Regulation of endoplasmic reticulum stress (ER) stress-induced apoptosis and nerve regeneration is a hopeful way for acute spinal cord injury (SCI). Sitagliptin (Sita) is one of dipeptidyl peptidase-4 (DPP-4) inhibitor, which is beneficial neurons damaged diseases. However, its protective mechanisms of avoiding nerve injury remain unclear. In this study, we further investigated the mechanism of the anti-apoptotic and neuroprotective effects of Sita in promoting locomotor recovery from SCI. In vivo results showed that Sita treatment reduced neural apoptosis caused by SCI. Moreover, Sita effectively attenuated the ER tress and associated apoptosis in rats with SCI. A striking feature was the occurrence of nerve fiber regeneration at the lesion site, which eventually led to significant locomotion recovery. In vitro results showed that the PC12 cell injury model induced by Thapsigargin (TG) also showed similar neuroprotective effects. Overall, sitagliptin showed potent neuroprotective effects by targeting the ER stress-induced apoptosis both in vivo and vitro, thus facilitating the regeneration of the injured spinal cord.

Percutaneous mesh-container-plasty for osteoporotic thoracolumbar burst fractures: A prospective, nonrandomized comparative study.

OBJECTIVE: This study aimed to compare the clinical and radiological results of percutaneous mesh-container-plasty (PMCP) versus percutaneous kyphoplasty (PKP) in the treatment of osteoporotic thoracolumbar burst fractures. METHODS: A prospective study of 122 patients with osteoporotic thoracolumbar burst fractures was conducted. The patients were nonrandomly assigned to receive PKP (62; 16 men, 46 women) and PMCP (60; 14 men, 46 women). The epidemiological data, surgical outcomes, and clinical and radiological features were compared between the 2 groups. Cement leakage, height restoration, deformity correction, canal compromise, and cement distribution were calculated from the radiographs. Visual pain analog scale (VAS), the Oswestry disability index (ODI), and short-form 36 health survey domains role physical (SF-36 rp) and bodily pain (SF-36 bp) were calculated before surgery and immediately and 2 years after surgery. RESULTS: Although VAS, ODI, SF-36 bp, and SF-36 rp scores improved from 7 (6-9), 71.28±16.38, 22 (0-32), and 25 (0-50) preoperatively to 2 (1-3), 20.02±8.97, 84 (84-84), and 75 (75-100) immediately postoperatively in the PMCP group (p<0.05) and from 7 (6-8), 71.40±13.52, 22 (10.5-31.75), and 25 (0-50) preoperatively to 2 (1-3), 21.78±11.21, 84 (84-84), and 75 (75-100) immediately postoperatively in the PKP group (p<0.05), there was no difference between the 2 groups. The mean cost in the PKP group was less than that in the PMCP group ($5109±231 vs. $6699±201, p<0.05). Anterior, middle, and posterior vertebral body height ratios in the PMCP group were greater than those in the PKP group postoperatively (88.44%±3.76% vs. 81.10%±11.78%, 86.15%±3.50% vs. 82.30%±11.02%, and 93.91%±3.01% vs. 91.43%±6.71%, respectively, p<0.05). The Cobb angle in the PMCP group was lower than that in the PKP group postoperatively (6.67°±4.39° vs. 8.99°±4.06°, p<0.05). Cement distribution in the PMCP group was higher than that in the PKP group (30.48%±5.62% vs. 27.18%±4.87%, p<0.05). Cement leakage was observed to be lesser in the PMCP group (2/60) than in the PKP group (10 vs. 62, p<0.05). CONCLUSION: Both PKP and PMCP treatments seem to have significant ability in pain relief and functional recovery. Despite its higher cost, PMCP treatment may have a better inhibition ability of cement leakage, cement distribution, height restoration, and improvement in segmental kyphosis than PKP treatment for osteoporotic thoracolumbar burst fractures. LEVEL OF EVIDENCE: Level II, Therapeutic Study.

Effects of oxygen generating scaffolds on cell survival and functional recovery following acute spinal cord injury in rats.

Persistent local oxygen delivery is crucial to create a microenvironment for cell survival and nerve regeneration in acute spinal cord injury (SCI). This study aimed to fabricate calcium peroxide-based microspheres incorporated into a 3-D construct scaffold as a novel oxygen release therapy for SCI. The scaffolds were able to generate oxygen over the course of 21 days when incubated under hypoxic conditions. In vitro, GFP-labeled bone marrow-derived mesenchymal stem cells (MSCs) were planted into the scaffolds. We observed that scaffolds could enhance MSC survival under hypoxic conditions for more than 21 days. Oxygen generating scaffolds were transplanted into spinal cord injury sites of rats in vivo. Twelve weeks following transplantation, cavity areas in the injury/graft site were significantly reduced due to tissue regeneration. Additionally, the oxygen generating scaffolds improved revascularization as observed through vWF immunostaining. A striking feature was the occurrence of nerve fiber regeneration in the lesion sites, which eventually led to significant locomotion recovery. The present results indicate that the oxygen generating scaffolds have the property of sustained local oxygen release, thus facilitating regeneration in injured spinal cords.

Clinical characteristics and treatment of fracture-dislocation of thoracic spine with or without minimal spinal cord injury.

BACKGROUND: It is important to evaluate clinical efficacy and safety of posterior internal fixation using pedicle screw system. OBJECTIVES: To investigate clinical characteristics of patients diagnosed with fracture-dislocation of the thoracic spine with or without minimal spinal cord. METHODS: Twenty-eight patients with fracture-dislocation of thoracic spine with or without minimal spinal cord injury were retrospectively analyzed. All patients received posterior reduction and internal fixation using pedicle screw system. RESULTS: The mean follow-up duration was 11.4 months. Among 28 patients, 24 cases were complicated with bilateral pedicle or laminal fracture. Preoperatively, the percentage of vertebral displacement was (32.1 ± 20.6)%, significantly declined to (7.5 ± 6.0)% (t= 4.575, P= 0.001) and maintained at (7.9 ± 6.3)% at the final follow-up. Preoperative local kyphosis angle was measured as (16.2 ± 11.3)∘, restored to (15.4 ± 5.9)∘ postoperatively and (15.8 ± 5.4)∘ during the final follow-up. No statistical significance was observed at three time points (all P> 0.05). The remaining 25 patients were evaluated with normal and complete neurological function. No severe complications were observed intra- and postoperatively. CONCLUSIONS: Posterior internal fixation using pedicle screw is an efficacious and safe therapy which achieves proper reduction and preserves spinal cord function.

Clinical Efficacy of Percutaneous Kyphoplasty at the Hyperextension Position for the Treatment of Osteoporotic Kümmell Disease.

SUMMARY OF BACKGROUND DATA: Percutaneous kyphoplasty might be effective for osteoporotic Kümmell disease. OBJECTIVE: To investigate the clinical efficacy of percutaneous kyphoplasty in hyperextension for osteoporotic Kümmell disease. STUDY DESIGN: Retrospective study. METHODS: A retrospective analysis was carried out on data from downstream balloon kyphoplasty treatments in hyperextension for 18 patients with osteoporotic Kümmell disease. All cases were single-segment disease affecting T5 (1 case), T7 (1 case), T8 (2 cases), T11 (6 cases), T12 (4 cases), L1 (2 cases), L2 (1 case), or L4 (1 case). Dual-energy x-ray absorptiometry bone mineral density values ranged from -2.8 to -5.8 SD. The sagittal Cobb angle of the involved segment was measured before and after the operation and the final follow-up also included a visual analog pain score (VAS) and the Oswestry Disability Index (ODI) after comprehensive efficacy assessment. RESULTS: All patients were followed up for 12-36 months, with an average of 15.8 months. Patients showed lower back pain relief and improvement in daily life activities. The kyphosis Cobb angle improved from 32.60±3.82 degrees before surgery to 7.60±1.68 degrees after surgery, and VAS and ODI scores significantly improved from 8.7±0.96 points and 88.6±3.76% to 2.6±0.32 points and 28.6±2.67%, respectively. The last follow-up for the kyphosis Cobb angle yielded a value of 9.60±2.06 degrees, and VAS and ODI averaged 2.2±0.26 points and 26.4±2.46%, respectively. Compared with 2 days postoperatively, the differences were not statistically significant. Intervertebral cement leakage occurred in 1 case, but no symptom was observed and no treatment was performed. CONCLUSION: Percutaneous balloon kyphoplasty in the hyperextension position is an effective method for osteoporosis in Kümmell disease.

[Mid-term effect of unilateral pedicle screw fixation and transforaminal lumbar interbody fusion in the treatment of lumbar degenerative diseases].

OBJECTIVE: To investigate the feasibility and the mid-term effects of unilateral pedicle screw fixation and transforaminal lumbar interbody fusion in treating lumbar degenerative diseases. METHODS: From August 2005 to May 2010, 56 patients with lumbar degenerative diseases underwent lumbar posterolateral fusion,their clinical data were retrospective analyzed. The patients were divided into two groups (unilateral group and bilateral group) according to fixation methods,27 patients in unilateral group who were underwent unilateral pedicle screw fixation, including 18 males and 9 females with a mean age of (57.5 ± 7.1) years old (ranged from 41 to 66 years); and 29 patients in bilateral group who were treated with bilateral pedicle screw fixation (on the basis of the above, with contralateral vertebral pedicle screw fixation), including 19 males and 10 females with a mean age of (54.6 ± 5.1) years old (ranged from 43 to 68 years). The clinical data such as operation time, blood loss volume, hospitalization time and cost were compared between two groups. JOA score system was used to evaluate the neurological function. And fusion status and cage-related complication were also analyzed. RESULTS: All patients were followed up from 36 to 60 months with an average of 45.8 months. No iatrogenic nerve, blood vessels or organs injury were found during operation. Operation time, blood loss volume, hospitalization time and cost in unilateral group were better than that of bilateral group (P < 0.05). There was no significant difference in JOA score between two groups (P > 0.05). Two patients in unilateral group developed with cage related complications, 1 case was cage displacement and 1 case was cage subsidence, while 2 patients in bilateral group developed with complications of no-fusion, and there was no significant differences between two groups (P = 0.58). CONCLUSION: Unilateral pedicle screw fixation is a satisfactory method and can obtain good effects in treating lumbar degenerative diseases in mid-term, however, the indications should be well considered.

Biomechanical study of the funnel technique applied in thoracic pedicle screw replacement.

BACKGROUND: Funnel technique is a method used for the insertion of screw into thoracic pedicle. AIM: To evaluate the biomechanical characteristics of thoracic pedicle screw placement using the Funnel technique, trying to provide biomechanical basis for clinical application of this technology. METHODS: 14 functional spinal units (T6 to T10) were selected from thoracic spine specimens of 14 fresh adult cadavers, and randomly divided into two groups, including Funnel technique group (n = 7) and Magerl technique group (n = 7). The displacement-stiffness and pull-out strength in all kinds of position were tested and compared. RESULTS: Two fixed groups were significantly higher than that of the intact state (P < 0.05) in the spinal central axial direction, compression, anterior flexion, posterior bending, lateral bending, axial torsion, but there were no significant differences between two fixed groups (P > 0.05). The mean pull-out strength in Funnel technique group (789.09 ± 27.33) was lower than that in Magerl technique group (P < 0.05). CONCLUSIONS: The Funnel technique for the insertion point of posterior bone is a safe and accurate technique for pedicle screw placement. It exhibited no effects on the stiffness of spinal column, but decreased the pull-out strength of pedicle screw. Therefore, the funnel technique in the thoracic spine affords an alternative for the standard screw placement.

The treatment of osteoporotic thoracolumbar severe burst fractures with short pedicle screw fixation and vertebroplasty.

BACKGROUND: To investigate the clinical and radiological results of short pedicle screw fixation and vertebroplasty in osteoporotic thoracolumbar severe burst fractures. METHODS: From September 2006 to August 2010, 19 consecutive patients sustained osteoporotic thoracolumbar severe burst fractures with or without neurologic deficit and were included in this prospective study. All patients underwent short pedicle screw fixation and vertebroplasty. Segmental kyphosis, AVBHr and PVBHr, and Canal compromise were calculated on radiographs pre-operatively, post-operative and at final follow up. VAS, ODI and SF-36 were calculated pre-operatively and at final follow up. RESULTS: Mean operative time was 70.8 min (range 60~100 min) and mean blood loss was 92 ml (range 60~160 ml). The mean duration of their hospital stay was 4.5 days (range 3-7 days). The operative incisions were healing well. Average follow up time was 40.1 months (range 24~72 months). The AVBHr was corrected from preoperative (48.1 ± 6.8) % to postoperative (94.1 ± 1.7) % (P < 0.001). The PVBHr was corrected from preoperative (62.7 ± 4.8) % to postoperative (92.8 ± 1.8) % (P < 0.001). Canal compromise was corrected from preoperative (37.3 ± 5.8) % to postoperative (5.9 ± 2.3) % (P < 0.001). The segmental kyphosis was corrected from preoperative (20.6 ± 5.3) degree to postoperative (2.0 ± 3.2) degree (P < 0.001). VAS scores were reduced from preoperative 7.21 ± 0.86 to 2.21 ± 0.98 at final follow up (P < 0.001). SF-36 Bodily pain was reduced from preoperative 75.31 ± 13.85 to 13.74 ± 13.24 at final follow up (P < 0.001), and SF-36 Role Physical was reduced from preoperative 59.21 ± 26.63 to 19.74 ± 22.94 at final follow up (P < 0.001). The ODI scores were reduced from preoperative 81.68 ± 4.44 to 15.37 ± 5.54 at final follow up (P < 0.001). All 4 patients with partial neurological deficit initially had improvement. Cement leakage was observed in 3 cases (two anterior to vertebral body and one into the disc without sequela). There were no instances of instrumentation failure and no patient had persistent postoperative back pain. CONCLUSIONS: Vertebroplasty and short pedicle screw fixation has the advantages of both radiographic and functional results for treating osteoporotic thoracolumbar severe burst fractures using a purely posterior approach.

[Pedicle screw at the fracture level and vertebroplasty via paraspinal approach for the treatment of old thoracolumbar fractures].

OBJECTIVE: To investigate the feasibility and safety of the treatment for thoracolumbar fractures with pedicle screw at the fracture level and vertebroplasty via paraspinal approach. METHODS: From August 2007 to August 2010, 22 old patients with thoracolumbar fractures were treated with pedicle screw at the fracture level and vertebroplasty via paraspinal approach. There were 14 males and 8 females, ranging in age from 60 to 71 years (mean, 64.6 years). The time from injury to surgery varied from 1 to 4 d (mean,2.7 d). All the patients suffered from single thoracolumbar fractures and located at T11 in 2 cases, at T12 in 5 cases, at L1 in 11 cases and at L2 in 4 cases. According to the Denis fracture classification, there were 6 compression fractures and 16 burst fractures. The mean preoperative load-sharing classification of spine fractures was 5.4 score. The mean preoperative thoracolumbar injury classification and scoring was 5.2. Based on the ASIA neurologic grading system, preoperative neurological function was grade B in 2 cases,grade C in 3 cases, grade D in 7 cases and grade E in 10 cases. The neurological function, vertebral central and anterior height, kyphotic angle of the vertebral fractures by radiographs and visual analog scale were calculated pre-operatively, post-operatively and at the last follow-up. RESULTS: Median operating time was 60.8 min (ranged from 50 to 95 min) and median blood loss was 84 ml (ranged from 50 to 130 ml). The operative incisions were healed well. The duration of follow-up averaged 21.6 months (ranged from 12 to 48 months). The anterior vertebral body height was corrected from preoperative (52.3 +/- 10.3) % to postoperative (6.1 +/- 4.2) % and (6.8 +/- 5.4) % at the last follow-up. The central vertebral body height was corrected from preoperative (38.9 +/- 11.2) % to postoperative (8.3 +/- 4.7) % and (9.4 +/- 4.5)% at the last follow-up. The Cobbs angle of the injured vertebral segment was corrected from preoperative (19.5 +/- 9.5) degrees to postoperative (4.3 +/- 4.1) degrees and (6.2 +/- 4.7) degrees at the last follow-up. The VAS scores reduced from preoperative 8.56 +/- 0.88 to post-operative 3.48 +/- 0.91 and 3.20 +/- 0.92 at the last follow-up. The postoperative neurologic function of all 22 patients improved 1 to 2 degrees except 10 patients of grade E. There were no instances of instrumentation failure and no patient had persistent postoperative back pain. CONCLUSION: The pedicle screw at the fracture level and vertebroplasty via paraspinal approach has the advantages of less invasive and blood loss, and could prevent the development of kyphosis and offers improvement of the spinal cord function. Furthermore, it could decrease the risks of postoperative back pain and the failure of instrumentation.

[Case-control study on the relationship between pain and knee function after the internal fixation of femoral fractures].

OBJECTIVE: To investigate the relationship between pain and knee function after the internal fixation of femoral fractures. METHODS: The clinical data of 73 patients after internal fixation on femoral fractures from June 2006 to December 2009 were retrospectively analyzed. All the patients were divided into two groups according to the degree of postoperative pain: low score group and high score group. Among the 39 patients in low score group (VAS 1 to 5 point), 25 patients were male and 14 patients were female, with a mean age of (37.5 +/- 5.3) years (ranged from 27 to 63 years ). Among 34 patients in high score group (VAS 6 to 10 point), 22 patients were male and 12 patients were female, with a mean age of (36.3 +/- 9.6) years (ranged from 29 to 62 years). The intra-articular pressure of knee and hospital for special surgery knee rating scale (HSS) were recorded and analyzed. RESULTS: All the patients were followed up for an average duration of 24.1 months. The intra-articular pressure of knee was rising for two groups, there were significant difference for the high score group compared with the low score group at 3 days after operation (t=15.67, P=0.000) and the end time of follow up (t=5.63, P=0.000). As to knee joint function, in low score group, 21 patients got an excellent result, 4 good, 7 poor and 2 bad; in high score group, 31 patients got an excellent result, 6 good, 2 poor and no bad. The knee function of low score group was better than that of high score group. CONCLUSION: The intra-articular pressure of knee is an important factor of the knee functional recovery, and its external symptoms of pain can be seen as an important index to forecast the prognosins of knee function in early time.

[Therapeutic effects of suture anchors for the reconstruction of distal tendo achillis rupture].

OBJECTIVE: To investigate the techniques and therapeutic effects of suture anchors for the reconstruction of distal tendo achillis rupture. METHODS: The clinical data of 16 patients of distal tendo achillis rupture repaired with suture anchors from June 2005 to August 2008 were retrospectively analyzed. Among them, there were 13 males and 3 females with a mean age of 33.5 years (ranged from 17 to 46 years). The postoperative rehabilitation was conducted for every patient. The operation time, position of suture anchor and complications of the surgery were analyzed. The healing of stendo achillis and functional recovery were assessed by Arner-Lindholm standard. RESULTS: All the patients were followed up for an average of 13.2 months. There were no complications of foreign-body reaction or re-rupture. The average operation time was 35.5 minute. There was no intraoperative injuries of blood vessels, nerves or tendons. A total of 19 suture anchors were used, and only 1 anchor was displaced. The functional recovery of tendo achillis was rated as excellent in 13 cases,good in 2 cases, bad in 1 case. All patients were satisfied with the effects on their current work and life. And no displacement of anchors was found in radiographic films. CONCLUSION: Repairing of the distal tendo achillis rupture with suture anchors can make operation simple and quick, rigid fixation, less complications, and provide good therapeutic effects.

[Clinical application of "funnel technique" in planting thoracic pedicle screws].

OBJECTIVE: To evaluate the safety and accuracy of "funnel technique" in planting thoracic pedicle screws. METHODS: From August 2005 to March 2008, a total of 39 patients with at least one thoracic pedicle screw in T1-T10 using "funnel technique" were retrospectively reviewed. Among the patients, 27 patients were male and 14 patients were female, with a mean age of 38.5 years (ranged from 17 to 56 years). One patient was lost follow-up, and other 1 patient was dead before follow-up. The accuracy of screw placement and the complications related to thoracic pedicle screws were analyzed by postoperative CT-scans. RESULTS: All the patients were followed up ranging from 18 to 30 months, averaged 23.2 months. There were no vascular or viscera complications as well as iatrogenic neurologic injuries. The total number of screws was 208. There was no statistical difference between the percentage of fully contained screws at T1-T4 versus T5-T8 (P = 0.80),T5-T8 versus T9-T10 (P = 0.07), T1-T4 versus T9-T10 (P = 0.06). Twenty-seven screws (13.0%) were misplaced, 14 screws (6.7%) violated lateral cortex of pedicle, 7 screws (3.4%) medially, 5 screws (2.4%) superiorly, 1 screw (0.5%) violated lateral cortex of vertebral body. No violations occurred superiorly or anteriorly. Only 4 screws (1.9%) was a critical perforation. CONCLUSION: The "funnel technique" is a simple, safe, accurate and cost-effective technique for pedicle screw placement. It provides even an entry-level surgeon with a safe way to identify and place thoracic pedicle screws.