健康成人舟月关节间隙形态MRI的研究

目的 研究成人舟月关节间隙形态在MRI上的表现。方法 63例健康成人，均为右利手，其中男38例，女25例；右手41侧，左手22侧。年龄从19—62岁不等，平均31．08岁。采用GE1．5TSigna Horizon MR扫描仪，行冠状面PDW、T2＊W扫描和横断面PDW扫描，记录不同序列上舟月关节间隙的形态。结果 健康成人舟月关节间隙的形态，不论在冠状面还是在横断面上，均以平行型多见，其次为Y型，X型最少见。结论 健康成人舟月关节间隙的形态在MRI能够清晰显示，为临床提供参考。     

四级分析法评估成人颈椎关节突退变

目的探讨一种新的成人下颈椎关节突关节退变的评级方法,为临床观测提供量化的评级标准。方法选用20例在读学生为正常组和40例颈椎病患者为病理组,分别行螺旋CT扫描并重建,测量下颈椎关节突关节横断面长度、宽度及关节间隙大小,计算出正常值范围;制定下颈椎关节突关节退变的评级标准。数据用SPSS 13.0统计软件包进行统计学分析,计算正常组、病理组各数据的均数及标准差;同一关节突关节左右数据间比较行配对t检验,正常组和病理组同一节段的各数据比较用独立样本t检验。结果 （1）正常组下颈椎关节突关节各测量数据左右差异均无统计学意义,取双侧均值。C3-4、C4-5、C5-6、C6-7关节突关节横断面长度分别为：（10.84±0.94）mm、（11.57±0.85）mm、（11.83±0.96）mm、（12.57±0.88）mm;关节突关节横断面宽度分别为：（10.44±0.99）mm、（10.56±0.91）mm、（10.50±1.06）mm、（9.49±0.68）mm;关节间隙中部（J2）最大,分别为：（1.49±0.12）mm、（1.44±0.10）mm、（1.43±0.09）mm、（1.45±0.11）mm;关节间隙两侧（J1、J3）略窄且基本对称。（2）病理组下颈椎关节突关节各测量数据左右差异均无统计学意义,取双侧均值。C3-4、C4-5、C5-6、C6-7关节突关节横断面长度分别为：（10.83±0.83）mm、（11.44±0.85）mm、（12.26±0.70）mm、（12.67±0.74）mm;关节突关节横断面宽度分别为：（10.55±0.98）mm、（10.98±1.06）mm、（10.96±0.85）mm、（9.75±0.81）mm;关节间隙中部（J2病）最大,分别为：（1.34±0.17）mm、（1.30±0.27）mm、（1.34±0.17）mm、（1.25±0.12）mm;关节间隙两侧（J1病、J3病）略窄且基本对称。（3）正常组和病理组间比较：C5-6关节面长度间差别有统计学意义;C4-5、C5-6关节面宽度间差别有统计学意义;C3-4、C4-5、C5-6、C6-7关节间隙大小间差别均有统计学意义;病理组关节突关节退变的特征表现为：关节突肥大、骨赘形成、关节面不规则、关节间隙狭窄、软骨下骨坏死、软骨下骨囊性变。结论自行设计的一种新的下颈椎关节突关节退变的评级标准,分为0-Ⅲ级,该评级标准是一个简单实用的影像学评估方法。     

骶髂关节经皮拉力螺钉固定钉道参数的解剖学测量

目的 为经S_1椎弓根水平骶髂关节拉力螺钉固定术提供应用解剖学依据.方法 2008年6月至2009年7月收集50个成人骨盆的螺旋CT扫描数据,重建骨盆三维模型,模拟经皮托力螺钉固定.测量S_1椎弓根的宽和高、骶髂关节拉力螺钉的进针点和进针方向、进针点至S_1椎体对侧前皮质和髂后上棘的距离.结果 S_1椎弓根的宽和高分别为(20.43±1.63)mm和(20.26±0.99)mm;2枚螺钉的进针点均在髂前上棘和髂后上棘的连线上方,至髂后上棘的距离分别为(49.87±6.80)mm和(51.11±7.15)mm.螺钉平行进入S_1椎弓根,与髂骨翼后外侧面垂直,与冠状面和欠状面的夹角分别为18.35°±5.20°和77.62°±3.98°.进针点到S1椎体对侧前皮质的距离分别为(76.08±4.32)mm和(77.62±3.98)mm.骶髂关节拉力螺钉的长度、S_1椎弓根的高度和宽度、进针点到髂后上棘的距离、进针点与冠状面的夹角在男女之间差异有统计学意义(P<0.05).结论 正常成人在S_1椎弓根水平均町置入2枚直径为6.5 mm的拉力螺钉,钉道参数的解剖学测量为骶髂关节拉力螺钉固定手术导航模板的设计提供了理论基础.     

跟距关节内跟骨骨折移位变化的CT测量

目的 :测量跟距关节内跟骨骨折移位的具体数据 ,分析其移位规律。方法 :对 6 6例跟骨骨折患者双侧跟骨同时行冠状面CT扫描 ,以健侧跟骨CT冠状面上能完整显示后距下关节面、载距突和跟骨体的一幅扫描面图像为基准 ,分别对健侧和患侧跟骨进行测量 ,包括冠状面上跟骨最远端的宽度、跟骨中部的宽度、跟骨长度及Perie角 ,并进行统计学分析。结果 :患侧前跟部宽度较健侧增宽 9 6 6mm(P <0 0 1) ;冠状面中央部跟骨平均增宽 8 81mm (P <0 0 1)。Perie角患侧 32 15° ,健侧 17 4 0°,两者相差 14 75°(P <0 0 1)。跟骨的长度患侧为 5 5 6 7mm ,健侧为 6 0 5 9mm ,差异无显著意义 (P >0 0 5 )。结论 :跟距关节内跟骨骨折以最远端横向移位最大 ,故此在治疗上应高度注意这种病理变化 ,彻底矫正其横向移位。     

下胫腓联合损伤的X线诊断研究

目的 通过对正常国人下胫腓联合及踝关节内侧间隙的数字化X线图像测量,探讨性别、年龄、身高、体质量对它们的影响,明确数字化X线检查在下胫腓联合损伤诊断中的意义. 方法选取492例正常踝关节,应用直接数字X线摄影术拍摄标准踝关节正、侧位片及踝穴位片,图像数据传送至影像工作站,在灰度显示器上对图像进行"软阅读",并利用PACS系统自带软件对下胫腓联合间隙、下胫腓联合重叠影、踝关节内侧间隙、腓骨宽度及腓前距进行模拟测量,对所得数据进行统计学处理,说明其与性别、年龄、身高及体质世的关系.结果正常成人下胫腓联合间隙参考值范围为(3.98±0.78)mm、 踝穴位为(3.67±0.68)mm, 下胫腓联合重叠影参考值范围为(7.06±1.98)mm、 踝穴位为(2.34±0.84)mm,踝关节内侧间隙参考值范围为(4.04±0.50)mm,腓骨宽度的参考值范围为(14.39±1.86)mm,腓前距参考值范围为(4.99±4.04)mm.下胫腓联合间隙、下胫腓联合重叠影、腓前距及内踝间隙与性别、年龄、身高、体质量间的决定系数及P值分别为R2a=0.229,P<0.01;R2a=0.066, P<0.01; R2a=0.032, P<0.01; R2a=0.059,P<0.01. 结论下胫腓联合间隙与身高、体质量、性别、年龄存在强相关性,不适合作为下胫腓联合损伤的评估指标;下胫腓重叠影、内踝间隙、腓前距与身高、体质量、性别、年龄存在弱相关性,可作为评估下胫腓联合早期损伤的重要指标.     

基于CT评估锁骨骨折后胸锁关节形态学改变的研究

目的 基于CT评估锁骨骨折后胸锁关节（SCJ）形态学改变，确定同侧锁骨骨折对SCJ的影响。方法 回顾性分析2019年1月至2023年1月就诊于本院的96例锁骨骨折患者的CT数据。评估双侧SCJ关节间隙宽度（JSW）的解剖学一致性；双侧锁骨内侧（PC）的位置；以及骨骺、关节炎、钙化和关节内气体的未融合。结果 SCJ JSW在冠状面（骨折侧8.70 mm±2.61 mm与非骨折侧7.63 mm±2.58 mm;P=0.001）和轴面（骨折侧9.40 mm±2.76 mm与非骨折侧9.02±2.99;P=0.044）差异具有统计学意义。锁骨内侧的位置在冠状面上差异有统计学意义（骨折侧14.31 mm±3.66 mm，非骨折侧13.49±3.34 mm;P=0.011），这表明位置的上移。结论 急性锁骨骨折可能与同侧SCJ间隙宽度增大和锁骨近端上移有关。这两种形态学改变可能提示SCJ的伴随损伤，并可能增加SCJ不稳定的风险。     

蹲甲皮瓣移植再造拇指术后再造拇指指甲的远期随访

目的 探讨游离甲皮瓣移植再造拇指术后再造拇指指甲的远期改变.方法 对行 甲皮瓣移植再造拇指的患者进行随访,观察再造拇指指甲外观,测量其宽度及长度,并与健侧拇指及供趾健侧趾进行对比,并进行统计学分析.结果 19例患者获得随访,随访时间7～182个月,平均40个月.所有患者行拇指再造时均未作甲床修整.随访发现再造拇指指甲虽然均无畸形,外观佳,但指甲长度和宽度均有缩小,曲度增大.健侧趾甲床宽度为[(19.3±2.4)mm,x±s,下同],再造拇指甲床宽度缩小为(17.1±2.3)mm,两者差异有高度统计学意义(t=5.95,P＜0.01);再造拇指的甲床宽度接近健侧拇指甲床宽度(17.1±1.7)mm,两者差异无统计学意义(t=0.00,P＞0.05),但由于再造拇指甲床曲度明显增大,因而显得比健侧拇指甲床更小.再造拇指的甲床长度缩减更加明显,其测量值为(12.2±2.2)mm,与健侧趾甲床长度(14.7±2.4)mm和健侧拇指甲床长度(15.4±3.2)mm相比,差异均有高度统计学意义(t分别=5.72和4.27,P均＜0.01).采用原套脱伤拇指指骨或髂骨植骨作为骨性支撑的两组再造拇指的甲床大小差异无统计学意义.结论 游离甲皮瓣移植再造拇指术后再造拇指的甲床长度和宽度均会发生明显的萎缩,且由于指甲曲度增大,显得比健侧拇指指甲还小,因此术中无需对供趾甲床进行修剪.     

Galveston固定髂骨钉置入路径的研究

目的 通过成人尸体髂骨形态解剖学及影像学相关数据的测量与分析,探讨Galveston 固定中最理想的髂骨钉置入路径.方法 保存完好的5具10侧新鲜尸体半骨盆,性别不限.于髂骨Chiotic线上方15 mm处每5 mm平行于该线截骨,直至髋臼上缘.分别测量截骨面髂骨钉置入有效路径长度、峡部位置及内径宽度.50例成人患者(性别不限)行骨盆CT三维重建.分别测量Click点至髂前下棘下缘(A)、髂后上棘至髂前下棘下缘(B)、髂后上棘至髋臼上壁(C)三条路径的有效路径长度,以及峡部内径宽度及峡部与进钉点的距离.结果 与尸体髂骨测量结论一致,影像学测量结果示路径A拥有最长的有效路径长度,男性平均(137±8)mm,女性(130±11)mm.经由路径A、B可支持两枚髂骨钉的置入,两路径均允许置入男性长度100 mm,直径8 mm,女性长度80 mm,直径6～7 mm髂骨钉.结论 相对于传统髂骨钉置入路径,Click点至髂前下棘下缘允许更长髂骨钉的置入而穿破髋臼的风险更小,为Galveston固定中髂骨钉置入最理想路径.     

经骶髂关节置入S1椎弓根螺钉的数字解剖学研究

目的 利用数字技术对骨盆后环结构进行解剖学测量,为经骶髂关节置入S1椎弓根螺钉固定提供临床解剖学依据. 方法 收集2008年1月至2011年12月期间共68例成人骨盆(136个半骨盆)的16排螺旋CT扫描数据,利用Mimics 10.01软件重建骨盆三维模型,模拟骶髂螺钉内固定.利用软件自带测量工具测量S1椎弓根宽度、高度、进钉点的位置、进钉方向,以及螺钉的长度和直径,并比较男女性、左右侧及 ＜50岁年龄组与≥50岁年龄组间上述指标的差异. 结果 S1椎弓根宽度、高度平均分别为(21.17±2.69)、(23.65 ±2.70) mm.螺钉进钉点、位于髂后上棘和髂前上棘连线前3/4或后1/4点的上方平均(10.90±5.14) mm处,螺钉在冠状面的夹角平均为32.74°±6.34°,螺钉在矢状面的夹角平均为57.08°±6.11°,螺钉长度平均为(75.92±6.82) mm.左、右侧上述测量指标比较差异均无统计学意义(P＞0.05).男、女性之间螺钉在冠状面、矢状面的夹角比较差异无统计学意义(P＞0.05),其余指标比较差异均有统计学意义(P＜0.05);＜50岁年龄组和≥50岁年龄组螺钉进钉点位置及螺钉长度比较差异有统计学意义(P＜0.05),其余指标比较差异均无统计学意义(P＞0.05).结论 本研究测得的S1椎弓根螺钉进钉点位置、螺钉长度及方向等可作为临床于术的参考依据.男女性之间、不同年龄组间上述指标存在一定差异,临床工作中需实行个体化置钉方案.     

基于CT三维成像的经皮前路寰枢椎关节螺钉内固定相关解剖学研究

目的测量经皮前路寰枢椎关节螺钉内固定(percutaneous anterior transarticular screw fixation,PATSF)相关参数,为提高PATSF的安全性提供参考依据。方法对50例成人志愿者进行寰枢椎螺旋CT扫描三维重建,获取经寰椎上关节面内侧缘横断面、枢椎椎动脉沟冠状面和寰枢椎正中矢状面,观察寰枢椎骨性结构、椎动脉沟的走行,通过测量和计算得出PATSF植钉位置、植钉角度、植钉长度及容许寰椎侧块分离情况的相关参数并进行分析。结果 PATSF植钉位置为枢椎椎体前下缘中点旁开4.0 mm较适宜,植钉最大外偏角度为(29.89±1.41)°,最小外偏角度为(4.37±0.87)°,最大后倾角度为(32.41±1.66)°,优化外偏角度为(17.13±0.88)°,优化后倾角度为(17.62±1.03)°,优化植钉长度为(41.57±0.79)mm。寰枢椎侧方关节面横径为(16.71±1.61)mm,容许寰椎侧块分离移位最大距离为(6.96±1.09)mm,占寰枢椎侧方关节面横径百分比为41.80%±5.69%。结论 PATSF优化植钉法安全可靠;寰椎侧块分离移位程度在一定范围内,仍允许关节螺钉植入。     

Traction radiography for the diagnosis of scapholunate ligament tears

The diagnosis of scapholunate ligament injury by traction radiography was investigated within a consecutive study. The right wrists of 25 healthy volunteers and 22 wrists with arthroscopically proven complete scapholunate ligament tears were examined. Traction radiography was performed under fluoroscopy with a force of 5 kg applied to the thumb. In the normal wrists, this led to selective widening of the scapholunate joint space whereas the lunotriquetral distance remained unchanged. In 25 healthy right wrists, the median scapholunate distance measured 2.1 (range 1.3-2.6) mm on resting radiographs and 2.2 (range 1.7-3.5) mm on the stress radiographs. For the 22 wrists with complete scapholunate ligament tears, the median scapholunate distance was increased from 2.0 (range 1.0-3.0) mm to 3.8 (range 3.0-5.5) mm by traction (median difference of 1.8 (range 1.0-3.0) mm). In conclusion, a scapholunate distance of 3.0 mm or more in unloaded wrists or widening of the scapholunate interval by 1.0 mm or more under thumb traction should both be considered as pathological findings. We recommend traction radiography as a simple and valuable diagnostic procedure for suspected scapholunate ligament injury.     

Radiologic measurement of the scapholunate joint: implications of biologic variation in scapholunate joint morphology

To determine the optimal location for measurement of the scapholunate (SL) joint intercortical width, normal biologic variation in SL joint morphology was evaluated in 40 normal, skeletally mature wrists (16 volunteers, 24 cadavers) using thin-section 1.5T magnetic resonance imaging performed in the axial and coronal planes. The integrity of the SL ligaments was confirmed by magnetic resonance imaging and verified with anatomic dissection of the cadaver wrists. Patterns of SL articular morphology were qualitatively determined using similarity grouping. Scapholunate interval measurements were made at 3 locations each on the mid-SL joint image from both the axial and coronal planes: the articular margins (dorsal-palmar and proximal-distal) and midjoint. Three patterns of midjoint space cortical conformation were observed: parallel congruent (78%), inverted Y (15%), and point-like (8%). The most consistent and narrowest distance between the scaphoid and lunate was found at midjoint: coronal 1.45 mm (44% coefficient of variation) and axial 1.00 mm (22% coefficient of variation). This study demonstrated that measurement of the apparent SL joint interval in an inappropriate site, as with extended or flexed clenched fist views, may provide inaccurate SL joint interval distance assessments. Regardless of SL joint configuration, the midportion of the SL joint shows only moderate biologic variation and the least absolute measurement variance in width and should be the most precise part of the joint to measure. On magnetic resonance imaging, the normal SL joint interval measures less than 2 mm.     

高分辨MRI对CAS斑块成分显示的病理对照研究

目的:通过影像和病理对照研究,分析和评价高分辨MRI对颈动脉粥样硬化斑块不同成分的显示效果,为颈动脉内膜切除术术前判断斑块的稳定性提供参考。方法:26例进行颈动脉内膜切除术的颈动脉粥样硬化性狭窄患者术前进行颈部高分辨MRI检查,取得4种不同序列的图像(T1WI、T2WI、PDWI和3D TOF);对手术取得的斑块标本进行病理学检查,并与最接近层面的MRI影像对比,分析斑块内不同成分的MRI影像特点。结果:手术取得28块斑块,分为238段,主要分布于颈总动脉和颈内动脉,病理上以复杂斑块为特征的IV-V型58段(24．37％)和VI型79段(33．19％)为主;在高分辨MRI影像上,斑块内纤维帽主要表现为TOF序列的带状低信号,钙化组织和纤维化组织分别表现为在所有序列影像上的不规则低信号和不特定信号,脂质池和坏死核在T1WI、PDWI和3D TOF序列上呈等至稍高信号,近期出血表现为T1WI、T2WI和PDWI序列的明显高信号。结论:高分辨MRI可以清楚显示动脉粥样硬化斑块,进行动脉管腔狭窄程度的测定,通过多序列影像联合分析还可以分辨斑块内部成分,有助于术前对斑块稳定性的判断。     

Application of MRI in indirect temporomandibular joint injury without condylar fracture

Objective： To discuss the application of MRI in indirect temporomandibular joint injury without condylar fracture. Methods： MRI examination on temporomandibular joint was conducted in 28 patients with indirect injury to temporomandibular joint without condylar fracture. The scanning sequence included TIWI, PDWI on oblique sagittal section at both open and closed mouth positions, and T1WI, T2WI on oblique coronal section. The MRI appearance was analyzed by 2 senior radiologists. Results： Among the 56 temporomandibular joints of28 patients, 35 joints exhibited pathological changes on MRI, in which there were 9 bone injuries, 21 articular disc dislocation, 24 intracapsular hematocele and hydrops. Conclusions： MRI can clearly reveal bone injury, articular disc dislocation as well as articular capsule abnormality in the indirect injury of temporomandibular joint without condylar fracture. It is highly advocated in clinical use.     

膝关节韧带损伤的MRI诊断价值

目的:探讨膝关节韧带损伤的MRI特点与诊断价值。方法:收集2008年6月至2010年2月经MRI检查的74例膝关节损伤患者,男47例,女27例;年龄12～76岁,平均37.3岁;病程2h～10d。临床表现为膝关节肿胀、疼痛,关节不稳、伸屈活动障碍,外翻试验、抽屉试验阳性,膝内侧明显压痛。对其MRI表现进行回顾性分析。结果:74例韧带损伤,其中前交叉韧带19例,后交叉韧带18例,外侧副韧带13例,内侧副韧带24例。韧带完全断裂12例,其中8例交叉韧带MR表现为韧带的连续性中断、断端回缩,局部或弥漫性肿胀,PDWI上呈中等信号,T2WI和脂肪抑制序列呈高信号;4例侧副韧带MR表现为韧带连续性中断或韧带肿胀增粗,PDWI上呈中等信号,T2WI和脂肪抑制序列呈高信号。部分纵形撕裂62例,MR表现为韧带连续性完整,韧带增粗,PDWI上呈中等信号,T2WI和脂肪抑制序列呈高信号。经手术、关节镜检查确诊44例,与MRI诊断相符41例。结论:MRI能诊断膝关节韧带损伤,是一种理想的诊断膝关节外伤的检查方法,宜作为常规检查。     

Comparison of scapholunate distance measurements on plain radiography and computed tomography for the diagnosis of scapholunate instability associated with distal radius fracture

Purpose

To investigate radiographic criteria for scapholunate instability (SLI) in the setting of distal radius fracture (DRF) confirmed by arthroscopy.

Methods

Eighty-eight wrists with DRF treated by open reduction and internal fixation and assessed for SLI arthroscopically were evaluated. The scapholunate distance (SLD) was measured by preoperative posteroanterior wrist radiography and computed tomography (CT). SLD on radiographs was measured as the distance between the scaphoid cortex and the lunate cortex at the center of the scapholunate joint. SLDs were measured at the volar end (A1), center (A2), and dorsal end (A3) of the scapholunate joint on the central CT axial slice; and at the proximal end (C1), center (C2), and distal end (C3) of the scapholunate joint on the central CT coronal slice. Wrists were divided into three groups by arthroscopic assessments: stable (normal, Geissler grade 1 or 2), G3 (Geissler grade 3), and G4 (Geissler grade 4). SLD measurements on radiographs and CTs (A1–C3) were compared among the three groups. Receiver-operating characteristic (ROC) curve analyses were performed to evaluate the abilities of SLD measurements on radiographs and CTs to identify SLI in wrists with DRF. Interobserver and intraobserver reliabilities of SLD measurements on radiographs and CTs were analyzed by intraclass correlation coefficients (ICCs).

Results

SLDs of C3 differed significantly among the G3 and G4 groups, and among the stable and G4 groups. The area under the curve on ROC curve analysis was 0.855 for the SLD of C3, which was larger than that for SLD on radiographs. For C3, the intraobserver ICC was 0.832 and interobserver ICC was 0.73.

Conclusions

SLD at the distal end of the scapholunate joint on the central coronal CT slice was the most appropriate measurement for discrimination of Geissler grade 4 SLI in wrists with DRF.

Level of evidence

Level 2     

关节软骨病损的磁共振成像及其与组织学的对照研究

[目的]探讨MRI对关节软骨各期病变的敏感成像序列并评价MRI对早期软骨病变的诊断价值。[方法]通过1例新鲜截肢人和4例正常猪膝关节的T2W1、PDWI、GE、STIR、3D FS-FSPGR等序列的成像研究，选定最佳的序列用于6例猪骨性关节炎（Osteoarthritis，OA）模型膝关节扫描，以MRI图像为标准切取标本染色，图像与染色图片对照以评价MR对关节软骨的诊断价值。[结果]5种序列的组织分辨力、病变检出率以3D FS-FSPGR序列最高分别达67．9％和93．7％；蛋白多糖（proteoglycan，PG）和胶原纤维（collagen fibers，CF）主要分布在关节软骨的深层组织。以MRI图像为标准切取的各级软骨标本之间染色浓度，PG呈递减关系，CF呈递增关系。[结论]在5种序列中，3D FS-FSPGR是理想的关节软骨成像序列；MR不仅对中晚期软骨病变有良好显示，对早期软骨病变也能作出正确诊断。     

Radioscapholunate ligament: a gross anatomic and histologic study of fetal and adult wrists

The radioscapholunate ligament was studied using fifty-four dissected adult cadaver wrists. Four of these wrists had arterial perfusions with colored latex and serial sections were made of twenty-one wrists from fetuses ranging in size from 23 to 230 millimeters crown-rump length. The radioscapholunate ligament was consistently identified between the long and short radiolunate ligaments, emerging through the palmar capsule of the radiocarpal joint. It was found to be a neurovascular structure surrounded by synovial tissue with vascular origins from the anterior interosseous and radial arteries and a neural origin from the anterior interosseous nerve. On entering the radiocarpal joint it attaches proximally to the interfacet prominence on the articular surface of the radius and distally to form the proximal membrane of the scapholunate interosseous ligament system. We found no anatomic evidence that this structure should be considered a ligament in a traditional mechanical sense. However, this structure may be clinically important as the vascular supply of the scapholunate interosseous ligament, as well as a sensory pathway from the scapholunate articulation.     

Severity of scapholunate instability is related to joint anatomy and congruency

PURPOSE: To determine whether the bony architecture of the distal radius and proximal scaphoid have a role in stabilizing the scaphoid, and to determine whether a relationship between the bony geometry measurements and the amount of wrist constraint could be determined. METHODS: Eight cadaver wrists were tested in a wrist joint motion simulator. The level of scapholunate instability after sectioning the scapholunate interosseous, radioscaphocapitate, and the scaphotrapezium ligaments was determined and related to radiographic measurements of volar tilt, lateral tilt (ulnar tilt of the radioscaphoid fossa), the depth of the radioscaphoid fossa, and 6 radii of curvature measurements of the proximal scaphoid and distal radius. The force to dorsally dislocate the scaphoid out of the radioscaphoid fossa was computed. RESULTS: The radioscaphoid fossa and scaphoid curvatures were larger in those wrists that did not show gross instability after ligamentous sectioning in the wrist simulator. Similarly, those wrists with a deeper radioscaphoid fossa and greater volar tilt were also more stable. The force required to dislocate these wrists was greater than in those wrists that showed gross carpal instability. CONCLUSIONS: This study suggests that the bony anatomy of the radius and scaphoid have a role in stabilizing the carpus after ligament injury. The effect of ligament sectioning on producing carpal instability may be moderated by the bone geometry of the radiocarpal joint. This may explain why some people may have a tear of the scapholunate interosseous ligament but not present with clinical symptoms.