人类髌股关节三维运动规律的研究

本实验通过精密机械式三维位移测量方法，采用１０条新鲜离体人膝关节标本定标加载，分析研究了屈膝过程中的髌股关切运动学及Ｑ角变化对髌股关节运动的影响。结果发现，人类髌股关切具有复杂而有规律性的三维运动特点，对传统认为“髌骨具二维运动”的观点提出了修正。同时发现，Ｑ角异常增大或减小，虽然对髌股运动趋势无显著影响，但可影响髌股运动幅度从而影响髌股稳定性。髌骨的许多特征运动均发生在屈膝３０°之前，髌骨此时也最不稳定，容易受到伤害提示临床手术治疗、护具设计及运动员选材时应予重视。     

Q角对髌股关节接触力学的影响

本研究应用染色法和压敏片法,对8例新鲜尸体膝关节在不同Q角和屈膝角度时的髌股接触部位、面积和应力分布进行测试。结果表明:在生理Q角状态下,随着屈膝角度的增大,髌股接触从髌后关节面下极逐渐向上极移行,接触面积也逐渐增大,接触应力呈渐进缓慢增加:并在屈膝80°—90°时出现腱股接触现象,这种现象对保护关节软骨,避免局部软骨压力过高有重要意义。Q角改变后,接触区向内或向外侧偏移,接触面积无明显改变,但接触应力变化显著。作者认为异常的Q角是导致髌股疾病的一个潜在因素,无论是手术矫治还是运动员选材时都应予以重视。     

股四头肌腱与髌韧带张力关系的生物力学研究

本实验使用扣带式传感器对7例尸体膝关节在生理Q角、Q角增大10°、Q角减小10°和胫骨结节抬高术四种状态下,从90°到0°的伸膝过程中7个屈膝角度时的髌韧带张力和股四头肌腱张力进行测试。不同于传统的观点,我们的实验结果表明:髌骨不是只改变股四头肌腱和髌韧带张力方向的简化滑轮结构。Fp/Fq随膝关节屈曲角度的变化而明显改变,这种比率关系是由髌股关节接触区部位的移行决定的。髌骨不仅按照一定的比率传递股四头肌力,而且还起着增大髌韧带张力伸膝力臂的作用。本文还就Q角改变和胫骨结节抬高术对伸膝装置力学机制的影响进行了探讨。     

主胰管胰头段水平角及开角方向与急性胰腺炎相关性的MRI研究

【摘要】目的：探讨主胰管胰头段水平角及开角方向与急性胰腺炎的相关性。方法：回顾性连续搜集临床及上腹部MRI检查诊断为急性胰腺炎的213例患者的临床资料,按纳入和排除标准入选60例（其中男38例,女22例,平均年龄45岁）为观察组,同期收集43例正常胰腺（男22例,女21例,平均年龄53岁）为对照组。两组均行MRCP,数据上传至工作站行图像处理,在主胰管显示清晰完整的层面上连续三次测量主胰管胰头段及主胰管头尾两端连线与水平线的夹角,记录平均数值及主胰管胰头段水平角方向并行统计学分析。结果：急性胰腺炎组,主胰管胰头段及主胰管头尾两端连线与水平线的夹角分别为25.64°±20.32°和28.07°±11.11°,而正常胰腺组为30.56°±18.56°和28.65°±10.49°（t=1.254/0.253,P=0.213/0.801 ）。60例急性胰腺炎组中,主胰管胰头段开角向上36例,主胰管胰头段与水平线的夹角为32.19°±23.19°, 向下24例,其夹角为16.08°±8.80°;43例正常胰腺组,开角方向上37例,主胰管胰头段与水平线的夹角为32.77°±18.91°, 向下6例,其夹角为16.94°±7.66°。急性胰腺炎组与正常胰腺组,向上或向下开角方向,主胰管胰头段与水平线的夹角差异均无统计学意义（t=0.117/0.219,P=0.907/0.828）,而主胰管胰头段与水平线的开角方向差异具有统计学意义（χ2=8.232,P=0.004）。全部病例中向上开角的角度（32.48°±20.98°）与向下开角的角度（16.26°±8.46°）间差异有统计学意义（t=4.901,P=0.000）。结论：急性胰腺炎与主胰管胰头段水平角大小无关,但与水平角的开角方向密切有关,临床急性胰腺炎多以开角向下方向为主。     

不同体位着陆冲击时人体的动态响应

目的探讨不同体位着陆冲击时人体动态响应的变化。方法 5名健康男青年 ,承受峰值 1 0G ,作用时间为 50ms的半正弦脉冲的着陆冲击 ,冲击方向与人体纵轴的夹角 (体位角 )从 30°～ 70°间隔 1 0°增加 ,分别在人体头、肩、胸、髂部安装二维加速度计记录人体的动态响应。结果在本实验条件下 ,人体头Z向 (头盆向 )响应在 50°角时达最小 ,其值为 1 0 .36± 2 .44G ;在 70°角时响应达最大 ,其值为 1 8.0 7± 3.2 9G。胸Z向响应在 70°时达最小 ,其值为 1 0 .39± 3.97G ;在 60°时达最大 ,其值为 1 5.42± 3.61G。头X向 (胸背向 )响应在 30°时达最小 ,其值为 7.58± 1 .1 8G ;在 70°时响应达最大 ,其值为 1 8.89± 1 .85G。胸X向响应在 30°达最小 ,其值为 7.2 1± 1 .99G ;在 70°角时响应达最大 ,其值为 1 7.67± 2 .1 6G。结论在本实验条件下 ,人体对抗着陆冲击的最佳体位角为 50°。     

髌股关节CT测量参数的比较

目的探讨7个反映髌股关节排列关系参数的叠加法测量和单层法测量可信度.方法 15名前膝疼痛患者的30个膝关节,在屈膝0°和30°股肌松弛状态下,分别用CT图像叠加法和单层法测量髌股关节紊乱的7个参数,测量采用盲法重复,并应用组内相关系数(ICC)评价测量可重复性. 结果在屈膝0°和30°叠加测量法和单层测量法的外侧髌骨角(LPA)、髌骨倾斜角(PTA),以及叠加法的适合角(CA)、股骨滑车角(FTA)具有高可信度(ICC>0.9),单层法的CA在屈膝30°下可信度高(ICC>0.9).结论 CT图像叠加法测量LPA、PTA、CA、FTA有好的可重复性.     

视神经孔摄影的新方法

视神经孔摄影的新方法程云桥视神经孔的摄影体位称瑞氏位，是根据视神经管管轴与头颅矢状面呈３５°～４０°角、与水平面呈１０°～１５°角这一解剖特点设计的，而常规体位是将眼眶的外１／３对台面中线，头颅正中矢状面与台面呈５３°角，听鼻线垂直台面，中心射线垂直...     

标准型主动脉弓分支开口位置的MSCT测量

目的:测量标准型主动脉弓分支的最佳显示角度,旨在为临床工作提供帮助。方法:按照入组标准搜集211例标准型主动脉弓患者的颈部MSCT血管成像资料,将显示两血管最小间距的层面确定为各个分支的最佳观测平面,测量其与矢状面的夹角。结果:头臂干动脉和左颈总动脉最佳观测平面与矢状面之间的夹角最大值为120.7°,最小值为14.6°,平均71.47°±2.16°,无年龄及性别差异;显示左颈总动脉和左锁骨下动脉间距的平面与矢状面之间的夹角最大值为96.6°,最小值为3.6°,平均30.82°±1.62°,无年龄及性别差异。结论:MSCT对主动脉弓的解剖观察可为显示主动脉分支开口提供最佳观测位置。     

髌骨倾斜导致髌股关节接触压力与面积改变

我们采用压敏片测量技术对髌骨倾斜状态下髌股关节的生物力学变化特点进行了研究。７例新鲜人尸体标本采用手术方法将髌外侧支持带紧缩造成髌骨外侧倾斜状态，超低压型压敏片置于髌股关节之间，等长加载２００Ｎ，分别在正常状态及髌骨倾斜状态下于屈膝３０°、６０°、９０°、１２０°时测量髌股关节接触压力与面积。结果表明：髌骨倾斜后使髌股关节原正常的“哑铃型”接触压迹转变为“彗星尾状”，外侧面孤立接触，内侧面接触区减少或失接触，接触压力改变表现为髌内侧软骨面接触压力减少或消失，外侧面接触压力集中且明显增高上述改变均以屈膝３０°时最明显。实验结果提示：各种纠正髌骨倾斜状态及治疗髌骨软骨软化症的手术方法，必须以恢复髌骨内外侧关节面压力平衡为标准，特别是屈膝３０°时病理力学的改善最为重要     

前交叉韧带股骨止点临床解剖学研究

目的:通过尸体标本研究前交叉韧带(ACL)股骨止点,进一步明确其解剖学特点,为双束重建ACL准确定位股骨止点提供临床解剖学数据。方法:对30例福尔马林处理的成人膝关节标本进行解剖研究。在屈膝60°时根据ACL纤维张力情况区分前内束和后外束,观察两束在膝关节屈伸过程中的张力变化特性,然后从股骨止点切断韧带,测量止点的相关数据。结果:在屈膝60°位ACL中松弛的纤维束最多。ACL在屈膝过程中沿矢状面发生旋转,其轴心大约位于股骨止点的近前角,接近over-the-top位置,该区域的纤维束在屈膝过程中始终处于紧张状态,具有良好的等长性。ACL股骨止点的长径与短径分别为19.32±2.42mm与10.52±2.24mm,前内束和后外束股骨止点的面积分别为69.37±20.2mm2和86.60±30.22mm2,前内束股骨止点的面积略小于后外束;两束中心点连线的距离为9.42±1.51mm,连线与股骨纵轴的夹角为26.90±8.56°;后外束中心点到over-the-top点连线的距离为11.8±1.60mm,连线与股骨纵轴的夹角为26.26±7.78°;后外束中心到股骨外髁软骨缘的最小距离为6.16±1.00mm;前内束股骨止点中心点位于10∶10±7′(右膝)或1∶49±5′(左膝);over-the-top点位于10∶45±8′(右膝)或1∶08±9′(左膝)。结论:前交叉韧带可被分为功能不同的前内束和后外束,前内束在膝关节的运动中始终保持紧张,具有较好的等长性,前内束止点前上部接近over-the-top区纤维是其旋转轴心,与前内束中心点的纤维相比等长性更好,是手术重建时的关键点。后外束只有在接近伸直和屈曲较大角度时紧张。后外束的定位缺乏解剖标记,本研究通过测量其中心点与前内束中心点、over-the-top点距离及到股骨外髁软骨缘最短距离确定后外束中心点位置,为双束重建ACL提供准确的骨道定位依据。     

Posterior-anterior weight-bearing radiograph in 15° knee flexion in medial osteoarthritis

OBJECTIVE: To evaluate the degree of knee flexion at which: (1) degenerative joint space narrowing is best seen, (2) the tibial plateau is best visualized and (3) the tibiofemoral angle is most correct, in order to assess the degree of flexion in the anteroposterior radiographic view that is most useful for assessing medial compartment osteoarthritis (OA) of the knee. DESIGN AND PATIENTS: We compared the conventional extended view of the knee and views at 15 degrees, 30 degrees, and 45 degrees of flexion with respect to joint space narrowing, alignment of the medial tibial plateau (MTP), and tibiofemoral angles in 113 knees of 95 patients with medial osteoarthritis of the knee (22 men, 73 women; mean age 67 years). RESULTS: At the midpoint and the narrowest point of the medial compartment, joint space narrowing values at 15 degrees, 30 degrees, and 45 degrees of flexion of the knee were smaller than that of the conventional extended view. Superimposition of the margins of the tibial plateau was satisfactory in 12% of patients in the conventional extended view, in 36% at 15 degrees of flexion, in 20% at 30 degrees of flexion, and in 19% at 45 degrees of flexion of the knee. When the knee was at 15 degrees of flexion there was a smaller difference in the tibiofemoral angle, in comparison with the knee extended, than was the case at 30 degrees and 45 degrees of flexion in patients with medial OA. CONCLUSION: A posteroanterior view with 15 degrees of flexion of the knee was able to detect joint space narrowing accurately, to achieve good alignment of the MTP in the medial compartment, and to reduce the difference in tibiofemoral angle compared with a view of the knee in conventional extension, and may be an alternative view in cases of medial OA of the knee.     

Effects of initial graft tension on the tibiofemoral compressive forces and joint position after anterior cruciate ligament reconstruction

BACKGROUND: The initial tension applied to an anterior cruciate ligament graft at the time of fixation modulates knee motion and the tibiofemoral compressive loads. PURPOSE: To establish the relationships between initial graft tension, tibiofemoral compressive force, and the neutral tibiofemoral position in the cadaveric knee. STUDY DESIGN: Controlled laboratory study. METHODS: The tibiofemoral compressive forces and joint positions were determined in the anterior cruciate ligament-intact knee at 0 degrees , 20 degrees , and 90 degrees of knee flexion. The anterior cruciate ligament was excised and reconstructed with a patellar tendon graft using graft tensions of 1, 15, 30, 60, and 90 N applied at 0 degrees , 20 degrees , and 90 degrees of knee flexion. The compressive forces and neutral positions were compared between initial tension conditions and the anterior cruciate ligament-intact knee. RESULTS: Increasing initial graft tension increased the tibiofemoral compressive forces. The forces in the medial compartment were 1.8 times those in the lateral compartment. The compressive forces were dependent on the knee angle at which the tension was applied. The greatest compressive forces occurred when the graft was tensioned with the knee in extension. An increase in initial graft tension caused the tibia to rotate externally compared with the anterior cruciate ligament-intact knee (1.5 degrees and 7.7 degrees of external rotation when tensioned to 90 N at 0 degrees and 90 degrees of knee flexion, respectively). Increases in initial graft tension also caused a significant posterior translation of the tibia relative to the femur (0.9 and 5.3 mm of posterior translation when tensioned to 90 N at 0 degrees and 90 degrees of knee flexion, respectively). CONCLUSION: Different initial graft tension protocols produced predictable changes in the tibiofemoral compressive forces and joint positions. CLINICAL RELEVANCE: The tibiofemoral compressive force and neutral joint position were best replicated with a low graft tension (1-15 N) when using a patellar tendon graft.     

Codominance of the individual posterior cruciate ligament bundles. An analysis of bundle lengths and orientation

BACKGROUND: It is unclear how each bundle of the posterior cruciate ligament contributes to posterior knee stability. HYPOTHESIS: Changes in bundle orientation and length occur such that neither bundle dominates in restraining posterior tibial motion throughout knee flexion and extension. STUDY DESIGN: Controlled laboratory study. METHODS: Six fresh-frozen cadaveric knees were studied in a joint-testing rig with individual quadriceps and hamstring muscle loading. Kinematic data for the tibia and femur were obtained at knee flexion angles from 0 degrees to 120 degrees. The joint was then disarticulated, and the insertions of the two bundles on the tibia and femur were digitized. RESULTS: Length of the anterolateral bundle increased with increasing knee flexion angle from 10 degrees to 120 degrees. Length of the posteromedial bundle decreased with increasing knee flexion angle from 0 degrees to 45 degrees and increased slightly from 60 degrees to 120 degrees. Length of the anteromedial bundle was significantly less than that of the posteromedial at 0 degrees, 10 degrees, and 20 degrees of knee flexion. The anterolateral bundle was significantly more horizontal at flexion angles of 0 degrees, 10 degrees, 20 degrees, 30 degrees, and 45 degrees (P < 0.05). The posteromedial bundle was more horizontal at 120 degrees. CONCLUSIONS: Changes in orientation take place such that neither bundle dominates in restraining posterior tibial motion throughout knee flexion and extension. CLINICAL RELEVANCE: Double-bundle reconstructions achieve more physiologic knee function.     

Effect of patellar tendon shortening on tracking of the patella

BACKGROUND: Although 10% postoperative patellar tendon shortening after bone-patellar tendon-bone autograft reconstruction of the anterior cruciate ligament has been reported, there are no published studies assessing the effect of shortening on patellofemoral joint biomechanics under physiological loading conditions. PURPOSE: To investigate the influence of patellar tendon shortening on patellofemoral joint biomechanics. STUDY DESIGN: Controlled laboratory study. METHODS: The authors evaluated the patellofemoral contact area, the location of contact, and the patellofemoral joint reaction force and contact stresses in 7 cadaveric knees before and after 10% patellar tendon shortening. Shortening was achieved using a specially designed device. Experimental conditions simulating those occurring during level walking were employed: physiological quadriceps loads and corresponding angles of tibial rotation were applied at 15 degrees , 30 degrees , and 60 degrees flexion of the knee. Patellofemoral joint contact areas were measured before and after shortening using the silicone oil-carbon black powder suspension squeeze technique. RESULTS: After patellar tendon shortening, patellofemoral joint contact areas were displaced proximally on the patellar surface and distally on the femoral surface. Although the contact area increased by 18% at 15 degrees of knee flexion (P = .04), no significant change occurred at 30 degrees or 60 degrees of knee flexion (P > .05). Patellofemoral contact stress remained unchanged after patellar tendon shortening (P > .05) at each flexion angle. CONCLUSION: Our results suggest that a 10% shortening of the patellar tendon does not alter patellar contact stresses during locomotion. It is not clear whether apparent changes in contact location in all positions and contact area at 15 degrees would have clinical consequences.     

Orthopaedic management of knee joint impairment in cerebral palsy: A systematic review and meta-analysis

BackgroundThe optimal management of impaired knee joint function in patients with cerebral palsy (CP) remains a significant and ongoing challenge in paediatric orthopaedic surgery.Research questionWhat are the clinical and functional outcomes after operative and non-operative orthopaedic interventions for knee joint impairment in patients with CP?MethodsThis systematic review and meta-analysis of orthopaedic interventions for the management of knee joint impairment in paediatric CP patients evaluated study-level data in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. We performed searches of the following electronic databases from their dates of inception to November 2019: Medline (Ovid), Embase (Ovid) and Pubmed. We extracted mean differences in pre-operative and post-operative measurements for the following outcomes: minimum knee flexion in stance; knee flexion at initial contact; maximum knee flexion in swing; range of motion; popliteal angle; fixed flexion deformity angle; and mean pelvic tilt.ResultsSixty-nine retrospective cohort studies, prospective cohort studies and RCTs comprising 2991 patients were included with 4578 knees analysed. Included studies were of sufficient quality as assessed by the MOOSE checklist. Operative interventions showed significant improvement in knee flexion at initial contact, knee flexion in stance, range of motion, popliteal angle and fixed flexion deformity which were comparable when subgrouped according to operative technique. In contrast, non-operative techniques and botulinum toxin injection did not confer significant improvements. Operative interventions for knee joint impairment led to increased mean pelvic tilt and reduced maximum knee flexion in swing.SignificanceThis review provides strong evidence that operative interventions for the management of knee joint impairment in cerebral palsy patients improve knee kinematics and clinical examination findings.     

The effects of joint angle and reliability on knee proprioception

PURPOSE: The purpose of this study was to examine the reliability and effects of knee angle on the detection and subsequent response to passive knee movement. METHODS: Twenty college-aged male and 20 female volunteers were evaluated for proprioception by a newly developed perturbation test. Subjects were in a prone position on an isokinetic chair with their right lower leg attached to a freely moving resistance adapter. The knee was placed in a starting position of 15, 30, or 60 degrees of flexion. While relaxed, the knee was dropped into extension, and the subjects were instructed to "catch their leg" when movement was perceived. Five trials were completed at each angle, in a random order. An electrogoniometer was secured to the lateral portion of the knee in order to measure angular displacement after perturbation in two specific phases: detection (displacement from leg release to movement cessation) and response (displacement from movement cessation to peak knee flexion). A three-factor ANOVA (two repeated factors (knee angle and proprioception phase) and one between factor (gender)) was performed on the average and standard deviation of the five trials for significant main effects and interactions. RESULTS: The results demonstrated a significant phase by angle interaction, and no gender effect. It was shown that at a more extended knee joint position (15 degrees), significantly less knee movement occurred before perception, followed by a greater response, than in a more flexed position (30 and 60 degrees). CONCLUSION: The major findings of this study suggest that the detection of passive knee movement, and the subsequent voluntary response, may be dependent on joint angle. Considerations of the present method for proprioception assessment are warranted to enhance test-retest reliability.