[Clinical application of a classification based on crucial curvature of coronal imbalance in degenerative lumbar scoliosis].

Objective: To present efficacy of clinical application of a classification based on crucial curvature of coronal imbalance in degenerative lumbar scoliosis (DLS). Methods: A case series study. Clinical data of 61 cases (8 males, 53 females) who underwent posterior correction surgery for DLS from January 2019 to January 2021 were retrospectively analyzed. The mean age was (71.7±6.2) years (ranged 60-82 years). According to the direction of C7 plumb line (C7PL) deviated from central sacral vertical line (CSVL) and orientation of L4 coronal tilt, the author determined which one was the crucial curve. If C7PL deviated from CSVL in the same direction as concave side of the thoracolumbar curve and L4 coronally tilts opposite direction of C7PL deviates from CSVL, then the crucial curve was thoracolumbar curve (type 1). On the contrary, if C7PL deviated from CSVL in the same direction as concave side of the lumbosacral curve and L4 coronally tilts consist with direction of C7PL deviates from CSVL, then the crucial curve was lumbosacral curve (type 2). According to absolute value of coronal balance distance (|CBD|), each type of patients was divided into two groups, respectively, namely coronal balance (CB) (|CBD|≤3 cm) and coronal imbalance (CIB) (|CBD|>3 cm). Changes of Cobb angles of thoracolumbar curve and lumbosacral curve and CBD were recorded and analyzed. Results: The rate of preoperative CIB was 55.7% (34/61) in all the patients. Of the patients, 23 cases were classified as type 1 and 38 cases as type 2. The rate of preoperative CIB was 34.8% (8/23) in type 1 patients and 68.4% (26/38) in type 2. The rate of postoperative CIB was 27.9% (17/61) in all the patients, with 13.0% (3/23) in type 1 and 36.8% (14/38) in type 2. The |CBD| of CB group in type 1 patients decreased from (2.6±1.4) cm before the operation to (1.5±1.0) cm after (P=0.015); and the correction rate of thoracolumbar curve (68.8%±18.4%) was significantly higher than that of lumbosacral curve (34.5%±23.9%) (P=0.005). The |CBD| of CB group in type 2 patients decreased from (2.6±3.0) cm before the operation to (1.6±1.2) cm after (P=0.027); the correction rate of lumbosacral curve (71.3%±18.6%) was higher than that of thoracolumbar curve (57.3%±21.1%), but the difference was not statistically significant (P=0.546). There was no significant difference in |CBD| of CIB group in type 2 patients before and after the operation (P=0.222); the correction rate of lumbosacral curve (38.3%±14.8%) was significantly lower than that of thoracolumbar curve (53.6%±16.0%) (P=0.001). There was a correlation between the change of CBD (3.8±1.5) cm and the difference in correction rate between thoracolumbar and lumbosacral curve (32.3%±19.6%) in CB group in type 1 patients after surgery (r=0.904, P<0.001). There was a correlation between the change of CBD (1.9±2.2) cm and the difference in correction rate between lumbosacral and thoracolumbar curve (14.0%±26.2%) in CB group in type 2 patients after surgery (r=0.960, P<0.001). Conclusion: Clinical application of a classification based on crucial curvature of coronal imbalance in DLS is satisfactory, and its combination with matching correction can effectively prevent the occurrence of coronal imbalance after spinal correction surgery.

[Effectiveness and cost analysis of two chemical molluscicides in hilly schistosomiasis-endemic regions].

OBJECTIVE: To investigate the effectiveness and cost of 50% and 80% wettable powder of niclosamide ethanolamine salt (NESWP) and 26% metaldehyde and niclosamide suspension concentrate (MNSC) in hilly schistosomiasis-endemic regions, so as to provide insights into the selection of chemical molluscicides in hilly regions. METHODS: In September 2020, a wasteland in Guanshanqiao Village, Yanrui Township, Yushan County of Jiangxi Province was selected as the experimental region, which was sectioned into five blocks and defined as four experimental groups (A1, A2, B, C) and a blank control group (D). 80% NESWP were given at doses of 1 g/m2 and 1.5 g/m2 in groups A1 and A2 using the spraying method, 50% NESWP was given at a dose of 2 g/m2 in Group B using the spraying method, and 26% MNSC was at a dose of 4 g/m2 in Group C using the spraying method, while no chemical treatment was given in Group D. Snail survey was performed using a systematic sampling method before chemical treatment and 1, 3, 7 d and 15 d post-treatment to examine the molluscicidal effect, and all molluscicidal costs were estimated to calculate the cost of chemical treatment per 1 m2 and the cost of the reduction in the mean density of living snails per 1%. RESULTS: The highest mortality of snails was 78.95% and the lowest density of living snails was 0.2388 snails/0.1 m2 in the experimental groups within 7 d of chemical treatment, and the highest mortality of snails was 94.74% and the lowest density of living snails was 0.058 0 snails/0.1 m2 7 d post-treatment. There were no significant differences in the snail mortality among the A1, A2, B and C groups 1 (χ2 = 2.250, P > 0.05), 3 (χ2 = 1.779, P > 0.05) or 15 d post-treatment (χ2 = 2.286, P > 0.05), while a significant difference was detected in the snail mortality among the four groups 7 d post-treatment (χ2 = 7.990, P = 0.046). In addition, there were no significant differences in the snail mortality between A1 and A2 groups 1 (χ2 = 0.724, P > 0.05), 3 (χ2 = 0.584, P > 0.05), 7 (χ2 = 0.400, P > 0.05) or 15 d post-treatment (χ2 = 0.251, P > 0.05). The costs of chemical treatment per 1 m2 were 0.58, 0.60, 0.64 Yuan and 0.73 Yuan in groups A1, A2, B and C, and the costs of the mean density of living snail per 1% reduction were 19.29, 20.44, 21.68 Yuan and 23.53 Yuan in groups A1, A2, B and C, respectively. CONCLUSIONS: 80% NESWP shows a high molluscicidal efficacy and low cost in hilly schistosomiasis-endemic regions.

[Impact of "Elaphurus davidianus return home project" on the transmission of schistosomiasis in Poyang Lake areas].

OBJECTIVE: To investigate the prevalence of Schistosoma japonicum infections in Elaphurus davidianus released to Poyang Lake areas and evaluate the impact of the project of "E. davidianus released to wild environments for natural reproduction and growth" "(E. davidianus return home project") on the transmission of schistosomiasis in Poyang Lake areas. METHODS: During the period from April 2018 to December 2019, the population distribution, inhabiting activity and natural reproduction of E. davidianus released to Poyang Lake areas were investigated by means of GPS and artificial observations. The S. japonicum infection was identified in animal feces in E. davidianus inhabitats using a hatching test, and snail distribution was surveyed in E. davidianus inhabiting grass islands using a systematic sampling method. RESULTS: A total of 51 E. davidianus were released to the Poyang Lake areas in 2018, which subsequently produced 5 E. davidianus habitats in Yinlong Lake, Longkou, Nanchi Lake, Lianzi Lake and Zhu Lake. E. davidianus was found to predominantly inhibit in grass islands, farmlands and forest lands in hilly regions around the Poyang Lake areas. The natural reproduction rate of E. davidianus was 25% in the habitats in 2019, and the mean density of snails was 0.009 to 0.039 snails/0.1 m2 in E. davidianus inhabitats; however, no S. japonicum infection was identified in snails. In addition, the mean densities of wild E. davidianus and bovine feces were 4.6 samples/hm2 and 2.1 samples/hm2, Conclusions The E. davidianus released to Poyang Lake areas may get infections with S. japonicum, and cause schistosomiasis transmission through fecal contamination in grass islands. The impact on and the prevalence of S. japonicum infection was 4.35% and 13.16% (P = 0.236), respectively; however, the intensities of S. japonicum infections were "+++" and "+", respectively. CONCLUSIONS: The E. davidianus released to Poyang Lake areas may get infections with S. japonicum, and cause schistosomiasis transmission through fecal contamination in grass islands. The impact on local schistosomiasis transmission and the response strategy requires to be investigated following the release of E. davidianus to lake regions, to ensure the achievement of the goal of schistosomiasis elimination and the successful implementation of the "E. davidianus return home project" in Poyang Lake areas.

[Survey of Schistosoma japonicum infections in wild animals in hilly transmission-controlled areas of Jiangxi Province].

OBJECTIVE: To understand the situation of Schistosoma japonicum infections in wild animals in transmission-controlled schistosomiasis-endemic areas in Jiangxi Province, so as to provide scientific evidence for implementing precision control interventions and achieving the goal of transmission interruption and elimination of schistosomiasis. METHODS: Five endemic villages from Ruichang City and Pengze County that were heavily endemic for schistosomiasis in Jiangxi Province, were selected as the study villages. Wild animals like wild mice were captured, and the livers of wild animals were purchased from the snail habitats in the study villages for detection of S. japonicum infections. In the study villages, S. japonicum human infections were screened using indirect hemagglutination assay (IHA) followed by parasitological examinations with miracidial hatching test and Kato-Katz method, and the S. japonicum infection in livestock was tested using a miracidial hatching test with a plastic tube. In addition, snail survey was conducted in the study villages by means of systematic sampling combined with environmental sampling, and the S. japonicum infection in snails was detected using a loop-mediated isothermal amplification (LAMP) assay. RESULTS: A total of 240 liver specimens were sampled or purchased from 5 species of wild animals in the study villages, including wild mice, weasels, pigs, deer and rabbits. A total of 172 wild mice were captured, with a 2.91% rate of S. japonicum infection, and there was no S. japonicum infection detected in other wild animals. The prevalence of Capillaria hepatica infection was 12.21%, 1.96% and 12.50% in wild mice, deer and pigs, respectively. In addition, there was no S. japonicum infection found in either humans or livestock in the study villages, and the mean snail density varied from 0.13 to 0.80 snails/0.1 m2 in the study villages. LAMP assay detected S. japonicum infection in 2 tubes in a study village. CONCLUSIONS: The role of wild animals in schistosomiasis transmission and their potential risks can not be neglected in hilly schistosomiasis-endemic areas of Jiangsu Province after transmission control. Intensified surveillance and targeted control measures should be implemented to consolidate schistosomiasis control achievements.

Evaluation of the predictors of postoperative aggravation of shoulder imbalance in severe and rigid thoracic or thoracolumbar scoliosis.

OBJECTIVE: To study the predictors of postoperative aggravation of shoulder imbalance in severe and rigid thoracic or thoracolumbar scoliosis. METHODS: In this study, 49 patients with severe and rigid thoracic or thoracolumbar scoliosis were analyzed retrospectively. The patients underwent whole-spine anteroposterior and lateral radiography preoperatively and postoperatively. On the radiographs, we measured parameters, including T1 tilt, radiographic shoulder height (RSH), proximal curve, middle curve, distal curve, apical vertebral translation (AVT) of the middle curve, thoracic trunk shift (TTS), coronal balance, and sagittal balance. We regarded RSH and T1 tilt as postoperative shoulder balance parameters and divided the patients into improved and aggravated groups of shoulder imbalance. Univariate analysis, receiver operating characteristic (ROC) curve, and multivariate logistic regression analyses were used in the statistical analyses. RESULTS: The RSH was -17.01 ± 21.85 mm before surgery and 4.76 ± 18.11 mm at follow-up. The T1 tilt angle was -10.20° ± 19.53° before surgery and -2.72° ± 13.48° at follow-up. The results of the univariate analysis suggest that preoperative RSH and proximal to middle curve change ratio were significantly higher in the patients in the improved RSH group (p < 0.01). In addition, preoperative RSH, preoperative T1 tilt, and apical vertebral translation of the middle curve were significantly higher, and preoperative proximal curve, postoperative proximal curve, and preoperative distal curve were significantly lower in the patients with improved T1 tilt group (p < 0.01). In a binary logistic regression analysis, preoperative RSH [B = -0.120, odds ratio (OR) = 0.887, p = 0.006] was found to be an independent predictor of postoperative aggravation of RSH. Similarly, preoperative T1 tilt (B = -0.488, OR = 0.614, p = 0.001) was found to be an independent predictor of postoperative aggravation of T1 tilt. Moreover, the relationship between changes in RSH and T1 tilt was either concordant or discordant. CONCLUSION: Several radiographic parameters were found to affect postoperative aggravation of RSH and T1 tilt. In particular, preoperative RSH and T1 tilt were found to be independent predictive factors of postoperative aggravation of RSH and T1 tilt, respectively.

Key pathway to prevent the collapse of femoral head in osteonecrosis.

OBJECTIVE: Osteonecrosis of the femoral head (ONFH) is a multifactorial disease, with unclear pathogenesis. The collapse of the femoral head is an important turning point in ONFH, especially for young patients. Many methods have been proposed, but the best treatment lacks consensus among orthopedic surgeons. Thus, understanding the collapse mechanism of the femoral head in ONFH is the key to a successful outcome of joint preservation. This review aims to provide an update of the collapse mechanism of the femoral head in ONFH and to focus on the most appropriate therapeutic strategies to adopt in clinical practice. MATERIALS AND METHODS: We reviewed the international literature to identify studies focusing on ONFH and therapeutic options. PubMed, Medline and Cochrane Library databases were searched for English language papers. RESULTS: An imbalance between bone resorption and bone formation as well as stress distribution on insufficient trabecular bone may be the most important collapse mechanism in ONFH. CONCLUSIONS: Treatment to avoid femoral head collapse should focus on local effective mechanical support with modification of bone remodeling in the femoral head.

Broadband nonlinear optical response in multi-layer black phosphorus: an emerging infrared and mid-infrared optical material.

Black phosphorous (BP), the most thermodynamically stable allotrope of phosphorus, is a high-mobility layered semiconductor with direct band-gap determined by the number of layers from 0.3 eV (bulk) to 2.0 eV (single layer). Therefore, BP is considered as a natural candidate for broadband optical applications, particularly in the infrared (IR) and mid-IR part of the spectrum. The strong light-matter interaction, narrow direct band-gap, and wide range of tunable optical response make BP as a promising nonlinear optical material, particularly with great potentials for infrared and mid-infrared opto-electronics. Herein, we experimentally verified its broadband and enhanced saturable absorption of multi-layer BP (with a thickness of ~10 nm) by wide-band Z-scan measurement technique, and anticipated that multi-layer BPs could be developed as another new type of two-dimensional saturable absorber with operation bandwidth ranging from the visible (400 nm) towards mid-IR (at least 1930 nm). Our results might suggest that ultra-thin multi-layer BP films could be potentially developed as broadband ultra-fast photonics devices, such as passive Q-switcher, mode-locker, optical switcher etc.

Using the modified Delphi method to establish a new Chinese clinical consensus of the treatments for cervical radiculopathy.

PURPOSE: Although cervical radiculopathy is very common, there is no standard treatment for this condition, with little high-level evidence available to guide the treatment choice. Thus, this study aimed to review the current data on the management of cervical radiculopathy; and, further, to establish a new Chinese clinical consensus of the treatments for cervical radiculopathy using the Delphi method. METHODS: First, a systematic review of the previously established treatment guidelines and of articles related to cervical radiculopathy was conducted to establish a protocol for the clinical consensus of the treatment for cervical radiculopathy. Second, from February 2012 to June 2014, we performed a modified Delphi survey in which the current professional opinions from 30 experienced experts, representing almost all of the Chinese provinces, were gathered. Three rounds were performed, and consensus was defined as ≥70% agreement. RESULTS: Consensus of the treatments for cervical radiculopathy was reached on seven aspects, including the proportion of patients requiring only non-surgical therapies; the effectiveness of neck immobilization, physiotherapy, pharmacologic treatment; surgical indications; contraindications; surgery. CONCLUSIONS: The modified Delphi study conducted herein reached a consensus concerning several treatment issues for cervical radiculopathy. In the absence of high-level evidence, at present, these expert opinion findings will help guide health care providers to define the appropriate treatment in their regions. Items with no consensus provide excellent areas for future research.

Bone-cartilage interface crosstalk in osteoarthritis: potential pathways and future therapeutic strategies.

Currently, osteoarthritis (OA) is considered a disease of the entire joint, which is not simply a process of wear and tear but rather abnormal remodelling and joint failure of an organ. The bone-cartilage interface is therefore a functioning synergistic unit, with a close physical association between subchondral bone and cartilage suggesting the existence of biochemical and molecular crosstalk across the OA interface. The crosstalk at the bone-cartilage interface may be elevated in OA in vivo and in vitro. Increased vascularisation and formation of microcracks associated with abnormal bone remodelling in joints during OA facilitate molecular transport from cartilage to bone and vice versa. Recent reports suggest that several critical signalling pathways and biological factors are key regulators and activate cellular and molecular processes in crosstalk among joint compartments. Therapeutic interventions including angiogenesis inhibitors, agonists/antagonists of molecules and drugs targeting bone remodelling are potential candidates for this interaction. This review summarised the premise for the presence of crosstalk in bone-cartilage interface as well as the current knowledge of the major signalling pathways and molecular interactions that regulate OA progression. A better understanding of crosstalk in bone-cartilage interface may lead to development of more effective strategies for treating OA patients.

Molybdenum disulfide (MoS2) as a broadband saturable absorber for ultra-fast photonics.

The nonlinear optical property of few-layered MoS2 nanoplatelets synthesized by the hydrothermal exfoliation method was investigated from the visible to the near-infrared band using lasers. Both open-aperture Z-scan and balanced-detector measurement techniques were used to demonstrate the broadband saturable absorption property of few-layered MoS2. To explore its potential applications in ultrafast photonics, we fabricated a passive mode locker for ytterbium-doped fibre laser by depositing few-layered MoS2 onto the end facet of optical fiber by means of an optical trapping approach. Our laser experiment shows that few-layer MoS2-based mode locker allows for the generation of stable mode-locked laser pulse, centered at 1054.3 nm, with a 3-dB spectral bandwidth of 2.7 nm and a pulse duration of 800 ps. Our finding suggests that few-layered MoS2 nanoplatelets can be useful nonlinear optical material for laser photonics devices, such as passive laser mode locker, Q-switcher, optical limiter, optical switcher and so on.

Strontium-containing hydroxyapatite bioactive bone cement in revision hip arthroplasty.

Clinical outcome of cemented implants to revision total hip replacement (THR) is not as satisfactory as primary THR, due to the loss of bone stock and normal trabecular pattern. This study evaluated a bioactive bone cement, strontium-containing hydroxyapatite (Sr-HA) bone cement, in a goat revision hip hemi-arthroplasty model, and compared outcomes with polymethylmethacrylate (PMMA) bone cement. Nine months after operation, significantly higher bonding strength was found in the Sr-HA group (3.36+/-1.84 MPa) than in the PMMA bone cement group (1.23+/-0.73 MPa). After detached from the femoral component, the surface of PMMA bone cement mantle was shown relatively smooth, whereas the surface of the Sr-HA bioactive bone cement mantle was uneven, by SEM observation. EDX analysis detected little calcium and no phosphorus on the surface of PMMA bone cement mantle, while high content of calcium (14.03%) and phosphorus (10.37%) was found on the surface of the Sr-HA bone cement mantle. Even higher content of calcium (17.37%) and phosphorus (10.84%) were detected in the concave area. Intimate contact between Sr-HA bioactive bone cement and bone was demonstrated by histological and SEM observation. New bone bonded to the surface of Sr-HA cement and grew along its surface. However, fibrous tissue was observed between PMMA bone cement and bone. The results showed good bioactivity of Sr-HA bioactive bone cement in this revision hip replacement model using goats. This in vivo study also suggested that Sr-HA bioactive bone cement was superior to PMMA bone cement in terms of bone-bonding strength. Use of bioactive bone cement may be a possible solution overcoming problems associated with the use of PMMA bone cement in revision hip replacement.

Strain and mechanical behavior measurements of soft tissues with digital speckle method.

Soft tissues of the body are composite, typically being made up of collagen and elastin fibers with high water contents. The strain measurement in soft tissues has proven to be a difficult task. The digital speckle method, combined with the image processing technique, has many advantages such as full field, noncontact, and real time. We focus on the use of an improved digital speckle correlation method (DSCM) and time-sequence electric speckle pattern interferometry (TSESPI) to noninvasively obtain continual strain measurements on cartilage and vessel tissues. Monoaxial tensile experiments are well designed and performed under constant temperature and the necessary humidity with smart sensors. Mechanical behaviors such as the tensile modulus and Poisson ratio of specimens are extracted based on the deformation information. A comparison of the advantages and the disadvantages of these techniques as well as some problems concerning strain measurements in soft tissues are also discussed.

[Anterior lumbar interbody fusion of canine with allograft cortical ring plus autogenous cancellus].

OBJECTIVE: To prove the biological characteristics of spinal intervertebral fusion with allograft cortical ring plus autogenous cancellus from iliac bone (called as composite ring). METHODS: Eight hybrid dogs were adopted in the study. The composite ring and autogenous tri-cortical blocks were implanted into the intervertebral space of dogs respectively. The intervertebral discs were removed before implantation. The fusion segments were evaluated by x-ray, histological examinations at 1, 2, 4 and 6 months after operation to compare the healing status of two implants. RESULTS: The X-ray film and histological examination showed the lumbar interbody was fused after 4 months of operation in composite ring group, while the autogenous iliac bone blocks fused with peripheral bone tissue after 6 months of operation. Composite ring healed more quickly and completely, showed different osteogenesis behavior compared with that of massive allografts. CONCLUSION: Composite ring can promote the fusion of intervertebral body and can be used as a potential material for spinal surgery.

Relative bioavailability of salmon calcitonin given intramuscularly.

BACKGROUND: Salmon calcitonin, a polypeptide hormone, is used in the treatment of osteoporosis, hypercalcemia and Paget's disease. The purpose of this study was to evaluate the pharmacokinetics and relative bioavailability of two salmon calcitonin products, Miacalcic (Novartis Pharmaceuticals, Basle, Switzerland) and Calcinin (Purzer Pharmaceuticals, Taipei, Taiwan). METHODS: This was a randomized, single-dose, crossover study conducted under fasting conditions with a washout period of 1 week between doses. Ten healthy male subjects were enrolled in this study. Each subject received a 100 IU dose (20 micrograms; 50 IU/ampule x 2) of salmon calcitonin intramuscularly (i.m.) followed by collection of blood samples at specified time intervals. Serum salmon calcitonin concentrations were measured using a validated radioimmunoassay method with a detection limit of 15.0 pg/ml. Values for the area under the serum concentration from time zero to last time and infinity curve (AUC0-t and AUC0-infinity), peak concentration (Cmax), time to peak concentration, terminal first order rate constant, terminal half-life, mean residence time, total clearance divided by absolute bioavailability, onset time, maximal effect and duration were compared for each product. RESULTS: The 90% confidence intervals for AUC0-t, AUC0-infinity and Cmax after logarithmic transformation were 93.2% to 113.1%, 97.2% to 114.9% and 84.9% to 108.0%, respectively. CONCLUSIONS: Based on the two one-sided tests procedure, we conclude that Miacalcic and Calcinin are bioequivalent.

[Experimental study and clinical application on osteogenesis of percutaneous autogenous bone marrow grafting in bone defects].

OBJECTIVE: To observe the osteogenesis of percutaneous autogenous bone marrow grafting in cicatricial bone defect, to seek a good method for treating fracture nonunion. METHODS: Eighteen rabbits were adopted in this study. 1 cm bone defect model was made in each side of radius, 6 weeks later, 2 ml autogenous bone marrow was injected in the right radial bone defect as experimental group, 2 ml autogenous peripheral blood in the left side as control group. X-ray features, histologic changes, Ca and P content in the site of bone defect were studied in various times. Also 15 patients were treated clinically for the nonunion fracture, the average time from nonunion to bone marrow grafting was 13 months. RESULTS: In experimental group, the increasing new bone tissue were observed in X-ray and histologic examination. While in control group, no osteogenesis was observed. Ca and P content of experimental group was higher than that of control group. For the 15 patients, 13 cases healed in 5-9 months, 2 cases failed. CONCLUSION: Percutaneous autogenous bone marrow grafting is capable of osteogenesis in the cicatricial bone defects. It can be used in nonunion cases which are not fit for operation of bone grafting because of poor condition of the skin.

Selective reinnervation of regenerating mixed nerve fibres across a silicone tube gap. Further experimental evidence of neurotropism.

This study investigated specific regeneration of a mixed motor and sensory nerve by the method of spinal dorsal root ganglions resection. A 10 mm segment of tibial nerve was resected and the nerve ends inserted in a silicone tube. Fourteen weeks later, dorsal root ganglia from L6 to S1 were resected on the experiment side. Twenty weeks later, the regenerating motor nerve fibres of mixed nerves selectively grew into motor branches. The rate of misdirected growth in mixed nerves was less than 6%. These results suggest that regenerating motor and sensory axons of mixed nerves are able to select their distal target organs accurately. Better results may be obtained using the entubulation repair method.

[The study of repairing ability of freeze-dried bone allograft].

There were many methods to preserve allogeneic bone allograft, however, a lot of studies have shown that the freeze-dried bone allograft banking is the best one. But it is not clear what temperature to lyophilize the allograft is better. In this experiment, we used method, in which the temperature of lyophilization was raising naturally and regularly, to lyophilize the allograft. The repairing ability of the freeze-dried allograft was studied in rabbits and comparison was made with that of autograft and fresh allograft. The results indicated that the repairing ability of bone defects was not significantly different between autograft and freeze-dried allograft. There was no significant difference between autograft and fresh allograft 3 weeks after transplantation, but significant difference was noted 8 weeks after grafting. It is suggested that this might be associated with the latent period before immunological rejection and the method itself, in which the temperature of lyophilization raising naturally is beneficial.

In vitro and in vivo effects of PGE2 on cementless fixation of implant.

The effects of prostaglandin E2(PGE2) in vivo and in vitro on cementless fixation of porous coated implant were studied. The results revealed that high levels of PGE2 in the local tissue benefit bone ingrowth in the early stage of implantation. Co-Cr-Mo alloy itself hampers the growth of osteoblasts and decreases the local secretion of PGE2. In the early stage of arthroplasty, the use of PGE2 inhibitors should be forbidden, and proper loading stimulation is preferable. High level PGE2 of local tissue in the later stage indicates bone resorption.

Axonal projections and functional recovery following fascicular repair of the rat sciatic nerve with Y-tunnelled silicone chambers.

The projection of regenerating axons and the specificity of motor reinnervation were studied after repair of the transected rat sciatic nerve with Y-tunnelled silicone chambers. This geometry was used experimentally to face either the proximal tibial or peroneal fascicle with two distal fascicular options usually the distal peroneal and tibial fascicle. A 4 mm gap separated the proximal and distal fascicles. Four weeks after the repair, preferential motor reinnervation could be demonstrated and there were always more axons projecting towards the distal homonymous fascicle. In contrast, if the distal stumps were disconnected from the target no fascicle specific projection of axons was observed. This was true even if segments from the median and ulnar nerve were used to replace either the distal tibial or peroneal segments. It appeared as though the size and not the type of fascicle determined the number of attracted axons. The results suggest that there is no fascicle specific guidance of regenerating nerve fibers.