Personalized precision medicine is the core pursuit of modern clinical medicine. Based on CT, MRI, and other image data, 3D printing technology achieves personalized matching and precise treatment with the affected area through layer-by-layer superposition printing and promotes new cooperation between medicine and industry. This paper expounds on the typical application of 3D printing technology in the field of bone and joint surgery from 3 aspects: bionic printing model, metallic implants, and bioprinting. The remarkable effects of a bone joint bionic model are further clarified in surgical teaching, practice, and visual doctor-patient communication, but the image resolution and printing accuracy need to be further improved. We analyze the safety and effectiveness of metal implants, especially 3D printed porous tantalum, in the treatment of large bone defects, and many attempts of bioprinting bone and cartilage, as well as the challenges of biological ink and cell survival. 3D printing technology has promoted the improvement of the diagnosis and treatment of bone and joint surgery. In the future, researches should further study the effect of tantalum microstructure on biological function, prepare high-quality tantalum implants, and explore the breakthrough direction of bone tissue engineering printing technology.

Objective To establish the preparation technology and production method of 3D printed porous tantalum prosthesis for reconstruction of acetabular bone defect and to evaluate its efficacy in preliminary clinical application. Methods Four patients with Paprosky ⅡB bone defect of the acetabulum who were going to undergo total hip arthroplasty (THA) in our center from June to December 2018 were recruited in this study according to our inclusion and exclusion criteria. Based on the personalized CT data of the patient's complete pelvis, the prosthesis for acetabular bone defect was designed by specialized 3D software and fabricated by powder bed electron beam additive manufacturing. The hip visual analog scale (VAS) score, 36-item short-form (SF-36) score and Harris score for hip joint before and after operation were compared, the postoperative complications were observed, and radiographical examination was completed at the last follow-up. Results All patients obtained good postoperative outcomes after undergoing computer-designed, personalized 3D printed porous tantalum prosthesis assisted THA to repair Paprosky ⅡB acetabular defects. During a follow-up period of 22.5±3.5 months, no surgery-related complications occurred. At the last follow-up, the Harris score was 86.2±0.3, which was significantly higher than that before operation (64.5±12.1), indicating significantly improved hip function; The VAS score was 2.5±0.7, obviously lower than that before operation (7.5±0.7); the SF-36 score was increased from 39.3±6.3 to 81.6±3.8. Compared to preoperative conditions, significant improvement was achieved in quality of life. Radiological examination showed that the implanted hip prosthesis and the 3D printed porous tantalum prosthesis for the bone defect had good stability, no radiolucent line was observed, and the acetabular bone defect was effectively reconstructed. Conclusion Our established preparation technology of personalized 3D printed porous tantalum prosthesis has demonstrated excellent effectiveness for reconstruction of acetabular bone defects in preliminary clinical application.

目的 探讨将3D打印多孔钽作为外科植入材料的生物安全性.方法 按照GB/T 16886《医疗器械生物学评价》标准对3D打印多孔钽进行遗传毒性、溶血、体外细胞毒性、植入后局部反应、皮内反应、皮肤致敏、急性全身毒性、亚慢毒性试验等生物安全性评价.结果 3D打印多孔钽的遗传毒性、溶血、体外细胞毒性、植入后局部反应、皮内反应、皮肤致敏、急性全身毒性和亚慢毒性试验结果均符合GB/T 16886的要求.结论 将3D打印多孔钽作为外科植入材料具有良好的生物相容性.

目的 总结个性化多孔钽假体设计的基本原则,以指导假体模型设计,减少设计风险,满足临床应用要求.方法 从53例三维(3D)打印多孔钽植入假体的设计中,综合考虑假体(尺寸、力学性能)、骨组织(生物力学、力生物学特征)及钽材(密度、价格)的影响,总结多孔钽植入假体设计的基本原则.结果 个性化3D打印多孔钽假体的设计需要满足"四性原则",即假体解剖匹配性原则、假体安全性原则、骨组织受力有效性原则、骨组织安全性原则;并在满足"四性原则"的基础上进一步考虑假体成本最低化原则.按"四性原则"设计的多孔钽植入假体,经临床应用和随访(最长随访时间3年)发现,患者缺损部位功能恢复良好,无1例失败.结论 "四性原则"可保障个性化多钽假体在临床应用上的有效性和安全性,结合成本最低化原则,则可进一步促进个性化多孔钽的临床应用.

[目的]观察减压联合钽棒治疗股骨头坏死的中长期疗效,并探讨影响治疗效果的相关因素.[方法]对2009年1月～2014年1月采用减压联合多孔钽棒置入治疗的股骨头坏死患者18例(19髋)进行回顾性分析.以Harris评分、影像学评估及保髋成功率作为疗效评价指标.并以性别、年龄、ARCO分期、坏死范围等进行分组,行统计学分析.[结果]通过5～ 10年的随访,保髋成功率为73.68％.术前无骨髓水肿、坏死范围小的患者末次随访Harris评分显著高于其对应者(P＜0.05).至末次随访时,5例患者保髋失败,行全髋关节置换术(THA).钽棒置入术时年龄≥40岁的患者保髋失败的比例高于年龄＜40岁的患者,但差异无统计学意义(P＞0.05).ARCO分期越高保髋失败比率越大(P＜0.05).术前有骨髓水肿者保髋失败比率显著大于术前无骨髓水肿者(P＜0.05).坏死范围＞30％者保髋失败比率显著大于坏死范围＜30％者(P＜0.05).[结论]减压联合多孔钽棒置入在治疗早期(ARCO:Ⅱb期以内)股骨头坏死的中长期随访疗效可靠,特别适合年龄小、无骨髓水肿、坏死范围小的患者.

骨关节内(intra-articular,IA)注射给药是一种重要的骨关节炎(osteoarthritis,OA)给药方法.该给药方法可增强药物局部作用、提高药物生物利用度和减少系统给药毒副作用.然而,骨IA注射给药后,药物会被机体快速清除,降低药效.使用药物递释系统进行骨IA注射给药能有效克服上述不足.其中微球、纳米粒、水凝胶、脂质体等药物递释系统在OA治疗方面得到了广泛研究.文章对药物递释系统在骨IA注射给药用于治疗OA的研究进行综述.

Tantalum, known as "pro-biometal", has excellent bio-inertness and bio-compatibility. Pure tantalum has been used in orthopedics for longer than 80 years. But pure tantalum has little in common with bone tissue in the elastic modulus and is not conducive to osseointegration, while, porous tantalum can not only provide mechanical strength but also reduce stress occlusion, facilitate stress conduction, promote bone shaping, and has excellent osteoinduction, which is widely used in orthopedics and has achieved ideal outcomes. However, due to great diversities in human body and randomness of bone defect sites, such as patients with bone tumors and those with bone deformities, standardized porous tantalum is unable to meet the patients' individualized treatment requirements. From the perspective of clinical development, the optional treatment should be individualized, and the best implant should also be individualized. In the future, we need to focus on the following problems, tantalum powder and its price, special equipment and manufacturing process, differences between 3D and traditional manufacure, and multicomponent gradients and others.

背景:钙化软骨层为柔软的透明软骨与坚硬的软骨下骨能够稳定连接提供了重要保障。但目前对钙化软骨层在此中发挥的生物力学作用并不十分清楚。目的:利用有限元分析技术探讨钙化软骨层的生物力学作用。方法:自愿捐赠的人体正常股骨髁标本1个,依据仿生学原理,构建骨软骨复合组织的三维有限元模型。该模型包含透明软骨、钙化软骨层和软骨下骨3层结构。对模型分别施加压缩载荷（0.5-3.0 MPa）与剪切载荷（0.1-0.5 MPa）,分析3层结构的应力分布情况。结果与结论:（1）在压缩与剪切载荷作用下,透明软骨的应力峰值范围分别为0.15-0.86 MPa与0.58-0.74 MPa,钙化软骨层的应力峰值范围分别为0.33-1.91 MPa与1.27-1.62 MPa,软骨下骨的应力峰值范围分别为0.55-3.22 MPa与2.36-2.98 MPa;（2）有限元分析法通过钙化软骨层的应力分布特征揭示了其生物力学作用,即介导负荷以逐级递增方式从透明软骨传至软骨下骨,使负荷在骨软骨复合组织的3层结构中得以顺利传递。

Objective To explore whether the calcified cartilage zone (CCZ) is essential for tissueengineered bone scaffold for repairing osteochondral defect in mini-pigs.Methods The bone scaffold materials were prepared by frozen-drying type Ⅱ collagen cross-linked with trephined on decellularized pig bone with or without natural CCZ.The autologous bone marrow stem cells (BMSCs) of mini-pigs were injected into the cartilage layer of the scaffold to prepare the tissue-engineered implants.Thirty mini-pigs were randomized equally into blank control group,non-CCZ group,and CCZ group,and in each pig,full-thickness osteochondral defects of 8 mm in diameter were created on both knees and repaired using the corresponding implants.At 12 and 24 weeks after the operation,the defects were assessed by general observation,magnetic resonance imaging (MRI),HE staining,safranin 0-fast green staining,type-Ⅰ,type-Ⅱ collagen immunohistochemical staining and O'Driscoll histological scores.Results In each group,obvious improvement in cartilage defect repair was observed at 24 weeks after the operation as compared with that at 12 weeks.In the blank control group,the defect was partly repaired by fibrous tissue,and deep defects remained at 24 weeks;in non-CCZ group,the defect was moderately repaired by the implants with small defects in the cartilage;in CCZ group,the defect was nearly fully repaired by the implant,which was well integrated with the host tissue and clearly showed the three-layered structure.Histological observations showed that the defects was filled with fibrous tissue in the blank control group,by bone and fibrocartilage without an identifiable three-layered structure in non-CCZ group,and with bone and hyaline cartilage without distinct boundaries with the host tissue in CCZ group.The O'Driscoll scores in the blank control,non-CCZ,and CCZ groups were 3.8 ±0.83,10.3 ±0.63,and 15.1 ±0.58 at 12 weeks,and were 5.5 ±0.52,14.2 ±0.68,and 18.8 ±0.87 at 24 weeks,respectively,showing significant differences among the groups at both 12 weeks and 24 weeks after the operation (P ＜ 0.01).Conclusion Compared with the scaffold without CCZ,the scaffold retaining natural CCZ achieves optimal repair of full-thickness osteochondral defects in mini-pigs,suggesting the importance of the CCZ in the design of tissue-engineered cartilage scaffold.

Objective To investigate the feasibility of bone marrow mesenchymal stem cells (BMSCs) combined with type Ⅱ collagen-hyaluronic acid-oxidized chondroitin sulfate (Col Ⅱ-HA-OCS) biomimetic hydrogel to repair articular cartilage defect in porcine and the role of the transplanted cells played in the process of cartilage repair.Methods A articular cartilage defect model which remaining cartilage calcified zone was created in the knee of Bama minipigs,the autologous BMSCs was used as seeds for transplantation and was labeled by the 5,6-carboxyfluorescein diacetate succinimidyl ester (CFDA SE).Animals were randomly divided into three groups:Group A (blank group) was left untreated,group B (cell-free biomimetic hydrogel group) was filled with biomimetic hydrogel and group C (BMSCs combined with biomimetic hydrogel group) was filled with the CFDA SE labeled autologous BMSCs combined with biomimetic hydrogel.One month after the operation,BrdU labeled liquid was injected intravenously into the animals 24 h and 48 h before specimens were taken from the executed animals.Partial cartilage repaired tissue in Group C was taken,cryosectioned and stained with DAPI and BrdU immunofluorescence.Confocal laser scanning microscope was used to observe and count the cells.Specimens of the three groups were analyzed through gross observation and histological staining,and scored according to the international cartilage repair society (ICRS) gross morphological score and ICRS histological score.Results Laser scanning confocal microscopy showed (97.3 ± 2.6) ％ of the cells were derived from the implanted BMSCs in repaired tissue and that the ratio of these cells with proliferative capacity was (76.6 ± 2.5) ％.Gross observation suggested most of the cartilage defect areas in Group C were filled with ivory tissue,but those in Group A and B were still obvious depression.Histological staining showed the cartilage defect areas in Group C were filled with cartilage like tissue,which was well integrated with the surrounding normal cartilage,presented a few cartilage lacunas could be seen,and had contents of Col Ⅱ and glycosaminoglycan similar with the adjacent normal cartilage.There was almost no filler in the defect area in Group A.There was little fibrous tissue in the defect area in Group B.ICRS gross score was (8.3 ± 1.0) points in Group C,higher than that in Group A [(0.5 ± 0.6) points] and Group B [(2.3 ± 0.5) points] (P ＜ 0.05).ICRS histological score was (10.3 ± 2.4) points in Group C,higher than that in Group A [(0.5 ± 0.6) points] and Group B [(4.5 ± 1.0) points] (P ＜ 0.05).Conclusions BMSCs combined with Col Ⅱ-HA-OCS biomimetic hydrogel for repairing porcine articular cartilage defects can achieve satisfactory results.Implanted BMSCs are the main component of the cell composition in the repaired tissue and gradually differentiated into chondrocytes.

Objective To compare the stress distributions on the anterior horn,body part and posterior horn of menisci between the normal and the injured knees with anterior cruciate ligament (ACL) deficiency using the three-dimensional finite element analysis.Methods A three-dimensional finite element model of tibiofemoral joint was created to simulate the motion states of the normal and ACL-deficiency knees at extension,as well as 15° and 30° flexions.Meanwhile,700N axial load and 134N posterior load were applied to the femur.Then,the stress on the anterior horn,body part and posterior horn of medial and lateral menisci were compared between the normal and ACL-deficient knees.Results With ACL deficiency,when stretching the knees straightly,the stress on the anterior horn of medial meniscus increased to 100.7％ of the normal knees,bigger than that of the affected lateral meniscus (30.7％).At 15° and 30° flexions,the stress on the posterior horn of the medial meniscus in ACL-deficiency knees increased by 36.4％ and 59.7％ respectively when compared to normal knees,while the stress on that of the lateral meniscus did not increase significantly.Apart from the stress on the body part of the lateral meniscus increasing by 39.5％ at extension in ACL-deficiency knees,no obvious changes were observed in the stress on the body part of the medial and lateral menisci.Conclusion ACL deficiency has different effect on the stress of different parts of the meniscus.It mainly increases the stress on the anterior horn of the medial meniscus at extension and that of the posterior horn of the medial meniscus at flexion.

目的 探讨发育性髋关节高脱位(Developmental Dysplasia of the Hip,DDH)真臼重建非短缩截骨全髋置换术中避免坐骨神经损伤的有效方法.方法 20髋Crowe IV型DDH者,采用真臼重建非短缩截骨全髋置换,股骨头旋转中心上移42～68mm (48.654±7.28) mm,术中应用Outside-in全关节囊切除,复位时内收20°,屈髋60°,屈膝90°.复位后外展30°,屈髋60°屈,膝90°.麻醉恢复后,根据患者对患肢远端疼痛和麻木的耐受逐渐伸直.应用Harris评分评估髋关节功能.结果 所有病人都获得12～108月随访,最后一次Harris评分(87.3±10.6),术前Harris评分35分(7～58分),术前术后比较有显著性差异.1髋坐骨神经术中损伤,3髋坐骨神经术后损伤,最终神经损伤均完全恢复.结论 Crowe Ⅳ型DDH全髋置换真臼重建非短缩截骨屈髋外展屈膝位能成功减少坐骨神经损伤.

Objective To explore the histological findings of the focal subchondral bone marrow lesions (BMLs) of the knee joint detected by MRI.Methods From September 2013 to February 2015,the knee osteoarthritis patients (aged 40 ～ 70) referred for total knee arthroplasty were examined with sagittal short inversion time inversion-recovery (STIR) and T1-and T2-weighted turbo spin-echo MRI imaging before surgery.MRI detected the subchondral BMLs (hyperintense on STIR images and T2-weighted MR images,and hypointense on T1-weighted MR images) at the non-weight-bearing area in 10 patients (3 males and 7 females).Five specimens were obtained from 5 patients (2 males and 3 females) with the mean age of 61 ± 6.1 (ranged from 53 to 67) in the surgery.All the sections were stained with HE and Safranin O/fast green for observing the pathological features.The percentage of various tissue areas and the trabecular bone volume (BV/TV) were measured by Image Pro Plus 6.0 imaging system.Results Five BMLs included 2 cases involved in the patella,2 in anterior femoral condyle and 1 in posterior femoral condyle.All the acetabular components were well fixed by the radiograph imaging.Ⅰ ～ 1V cartilage lesions were found at the BMLs.Cystic change was found in 1 case of patella and the others were cancellous bone.Histological appearance contained 1 case of bone cyst,and the rest 4 cases were consisted of normal tissues (76.9％) and several abnormalities (23.1％).Trabecular bone volume (BV/TV) of the 4 cases was 26.7％.Compared with the control regions,significant differences were found in the bone marrow necrosis (t =-4.0,P =0.029),trabeculae abnormalities (t =-4.0,P =0.028) and BV/TV (t =6.4,P =0.008).Conclusion Focal subchondral BMLs at the non-weight-bearing area of the knee joint represent a number of noncharacteristic histological abnormalities,and have some common features,especially the cartilage lesions and decrease of trabeculae.

[目的]采用三维有限元,对比分析前交叉韧带(anterior cruciate ligament,ACL)正常时和断裂后膝关节半月板和软骨的应力分布. [方法]构建胫股关节三维有限元模型,把ACL断裂引起的股骨外旋增加量(5.4°)设置为边界条件,以模拟ACL断裂后膝关节在伸直位的运动状态,同时在股骨上施加700 N向下载荷和134N向后载荷,对比分析ACL正常时和断裂后两种情况下半月板和软骨的应力分布.另一方面,在ACL断裂的胫股关节模型中分析两种工况:应用股骨外旋增加量模拟膝关节运动状态、不模拟运动状态,计算出这两种工况下胫股关节间的应力并进行比较.[结果]当ACL断裂后,除了外侧股骨软骨,内外侧间室中半月板和软骨的应力均比正常时有不同程度的增加,内侧胫骨软骨的应力增幅最大(57.6％),内侧间室的平均应力增幅大于外侧间室(34.1％vs 4.7％).在ACL断裂胫股关节模型的两种工况之间,胫股关节间的平均应力差异为20％,外侧间室的平均应力差异大于内侧间室(32.6％ vs7.4％).[结论]ACL断裂使胫股关节间的应力重新分布,主要引起内侧间室的应力明显增加.ACL断裂后膝关节的运动状态本身就可以造成关节间应力改变,所以在有限元分析时模拟膝关节的运动行为是有必要的.

OBJECTIVE:To investigate the effect of chondrocytic biomimetic matrix scaffold materials containing type 2 collagen (Col2) hydrogel, chondroitin sulphate (CS) and (or) hyaluronic acid (HA) on chondrogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) in vitro.METHODS:BMSCs were cultured in different groups as following: control, Col2, Col2-CS, Col2-HA, Col2-CS-HA. On day 7, 14, 21 and 28, cell proliferation and differentiation activities were determined using CCK-8 assay. The mRNA and protein expressions of Col2, sex-determining region Y (SRY)-related high mobility group-box gene 9 (SOX9) and aggrecan were detected using reverse transcription PCR and immunofluorescence technique.RESULTS:CCK-8 assay indicated that chondrocytic biomimetic matrix scaffold materials based on Col2 could be used as good extracellular matrix for BMSCs culture in vitro. CS and HA increased the proliferation and differentiation activities. All the groups induced effectively BMSCs to differentiate into chondrocytes. Compared with the other groups, Col2-CS-HA-coated group up-regulated the mRNA and protein expressions of Col2, SOX9 and aggrecan the most effectively.CONCLUSION:Chondrocytic biomimetic matrix scaffold materials based on Col2 could effectively induce rat BMSCs to differentiate into chondrocyte-like cells in vitro, and supplementation of the hydrogels with both CS and HA had the maximum efficacy.

Objective To explore the feasibility of constructing tissue engineered cartilage by using the cartilage particle as seed ceils and collagen Ⅱ-hyaluronic acid-chondroitin sulfate (COL Ⅱ-HA-CS) bionic matrix sol.Methods Cartilage particles were acquired from 5 months old Guizhou minipig knee joint;particles with different diameters were acquired by sieve filtration.The proliferation and adhesion of chondrocytes were evaluated at day 1,3,and 7.The bionic sol matrix at final concentration of 10 g/L was prepared by dissolving COL Ⅱ-HA-CS (mass ratio:8.0∶1.5∶0.5) in 0.15 mol/L HCl;The quality of prepared gel was examined.The cartilage particles with the diameter of strongest proliferation rate was seeded into COL Ⅱ/HA/CS sol mix at 5 × 107/L the in vitro results were evaluated by Living cell immunofluorescence and histological observation after 1 week.Results Cartilage particles with different sizes all developed visible chondrocytes adherence and proliferation,and particle size less than 120 μm showed strongest chondrocytes proliferation ability,the difference is statistically significant (P ＜ 0.05).Neutralized COL Ⅱ/HA/CS bionic sol matrix showed good flowability at low temperature;and transferred to gel at 37 ℃ for 6 min.After 1 week the cultured cartilage particles/gel complex showed transparent chondroid appearance,smooth surface and certain level of flexibility;Immunofluorescence observation showed good chondrocytes activity;Histological observation demonstrated chondrocytes were evenly distributed with good viability.Conclusion It reached the best proliferation of chondrocytes when particle size was less than 120 μm;Cartilage particles and COL Ⅱ/HA/CS bionic matrix sol are feasible to culture and construct bionic cartilage in vitro.

Objective To evaluate the biosecurity of 1-ethyl-3-3-dimethyl-aminopropyl carbodiimide (EDAC) acrosslinking agendemonstrate whetheEDAare poisonouand provide theoretical basifothe biosecurity foEDAcrosslink collagen.MethodThree New Zealand white rabbitwere injected 1％, 2％ EDA200 μl intradermally to observe the occurrence of swelling and erythemin 2 hours, 4 hours, 24 hours, 48 hourand 1 week, then calculated the primary irritanindex (PII) and evaluated the type of skin response to the EDAC.L929 mouse fibroblascellwere treated with 0.4％, 1.0％, 2.0％, 4.0％ EDAand cultured fo6 hours, 12 hours, 24 hours, then added cell counting kit-8 (CCK-8) and cultured fo4 hourto observe optical density by using microplate readeand calculate the relative growth rate of cells.With EDAcrosslinked type Ⅱ collagen and composited particleof cartilage to repaicartilage defect, and the control groupused type Ⅱ collagen composited particle of cartilage.Taken specimenafteone mouth, general tissue and histological section of cartilage were observed.Result1.0％ and 2.0％ EDAhave moderate toxicity to skin in 4 hours.Differenconcentrationof EDAcan inhibigrowth of L929 cells, and with the increase of concentration of EDAC, inhibition growth of cellwill be stronger.EDAcrosslinking type Ⅱ collagen groupwaseen differendegreeof softening and stripping, While the control group did nosee cartilage damage.Conclusion Skin irritation test, acute systemitoxicity tesand cell toxicity tesdemonstrated EDAitoxion living organ and cell.

目的 在磁共振(magnetic resonance imaging,MRI)上测量膝关节重度骨关节炎(osteoarthritis)伴内翻畸形患者股骨远端不同旋转轴线,评估各参照轴线相对于外科经股骨上髁轴(surgical transepicondylar axis,STEA)的准确性.方法 回顾性分析2013年6月至2014年1月在我中心明确诊断为膝关节重度骨关节炎伴内翻畸形患者(内翻≤15°)86例(86膝)的临床资料,其中男性34例,女性52例;年龄51 ～70(63.7±8.7)岁,由2位医师在MRI横断面图像上定位STEA、临床经股骨上髁轴(clinical transepicondylar axis,CTEA)、后踝轴(posterior condylar line,PCL)外旋3°线(3°extorsion against PCL,3°PCL)、前后轴(anterior posterior line,APL)的垂线,测量各轴线相对于STEA偏差的角度,并用方差分析比较各角度接近STEA的精确性.结果 3°PCL相对于STEA外旋(0.63°±1.82°)、CTEA相对于STEA外旋(3.78°±0.75°),APL垂线相对于STEA外旋(5.38°±3.17°),精确度:A角(3° PCL相对于STEA旋转的角度)＞CSA(CTEA相对于STEA旋转的角度)＞ASA(APL垂线相对于STEA旋转的角度),各角度两两比较差异具有统计学意义(P＜0.01).结论 膝关节重度骨关节炎伴轻度内翻人群中,股骨远端截骨轴线除STEA外,3°PCL准确性最高;术中STEA定位困难时,参照3°PCL进行截骨可获得较好的股骨旋转准确度.

OBJECTIVE To summarize the application status of three-dimensional (3-D) printing technique in joint surgery and look forward to the future research directions. METHODS The recent original articles about the application and research of 3-D printing technique in joint surgery were extensively reviewed and analyzed. RESULTS In clinical applications, 3-D printing technique can provide "tailored" treatment and custom implants for patients, which helps doctors to perform the complex operations easier and more safely; in fundamental research, tissue engineered scaffolds with desirable external shape and internal organization are easily fabricated with 3-D printing technique, which can meet the demand of cell adherence and proliferation. Even more, cells may be deposited with the biomaterials during the printing. CONCLUSION With the development of medical imaging, digital medicine and new materials, 3-D printing technique will have a wider range of applications in joint surgery.

[目的]对比分析外侧半月板撕裂合并外侧间室软骨不同程度损伤的关节镜疗效.[方法]将2010年1月～2012年12月外侧半月板撕裂合并股骨外髁或胫骨外侧平台软骨损伤的75例患者为软骨损伤组.男35例,女40例;年龄13 ～73岁,平均42.3岁.根据软骨损伤Outerbridge分级,将Ⅰ～Ⅱ级为软骨损伤A组34例;Ⅲ级为软骨损伤B组22例;Ⅳ级为软骨损伤C组19例.将2012年1 ～12月的单纯外侧半月板撕裂患者100例为对照组.男50例,女50例,年龄4～64岁,平均41.7岁.所有患者采用关节镜技术治疗.对照组的随访时间为8～ 19个月,平均13.9个月,软骨损伤组为8～43个月,平均21.4个月.临床疗效通过恢复时间、治愈率、Lysholm和膝骨关节炎JOA评分评估.[结果]对照组的平均恢复时间为(3.78±1.99)个月,软骨损伤组为(8.06±4.71)个月(P＜0.05);对照组平均Lysholm评分和治愈率为(97.6≈6.20)分和95％;软骨损伤组为(92.9±12.0)分和76％(P＜0.05).软骨损伤组A、B和C组的JOA评分分别为(96.2±8.53)分、(95.9±6.29)分和(87.6±12.4)分(P＜0.05);Lysholm评分分别为(95.5±8.86)分、(95.0±7.88)分和(84.2±16.7)分(P＜0.05);治愈率为88.2％、81.8％和42.1％ (P＜0.05).[结论]外侧半月板撕裂合并软骨损伤患者比单纯外侧半月板撕裂患者的恢复时间长、临床疗效差,以年龄超过45岁的外侧半月板撕裂合并软骨OuterbridgeⅣ级损伤恢复时间最长,临床疗效最差.