腕关节极度过伸位时韧带长度变化的活体研究

目的 探讨腕关节在中立位、极度过伸位及过伸桡偏位时腕关节韧带长度的变化情况.方法 对6名志愿者腕关节进行CT扫描,获取腕关节在中立位、极度过伸位及过伸桡偏位时的断层扫描图像,利用Mimics10.0软件进行三维重建,测量并比较此3种位置下的腕关节掌与背侧共9根韧带的长度. 结果 与中立位相比,腕关节极度过伸位时桡舟头、桡舟月、长桡月、尺月、尺头、尺三角及背侧骨间韧带止于舟骨部分明显伸长,差异有统计学意义(P＜0.05)；背侧桡腕、背侧骨间韧带止于小多角骨部分明显缩短,差异有统计学意义(P＜0.05)；而从极度过伸位至极度过伸桡偏位时,桡舟头、尺月、长桡月、背侧骨间韧带止于舟骨和三角骨部分明显缩短,差异有统计学意义(P＜0.05)；尺三角、尺头、桡舟月及背侧桡腕韧带明显伸长,差异有统计学意义(P＜0.05). 结论 腕过伸位时尺头韧带、尺三角韧带、桡舟月韧带、尺月韧带、桡舟头韧带、长桡月韧带、背侧骨间韧带止于舟骨部分张力较大；而背侧桡腕韧带、背侧骨间韧带止于小三角骨部分张力较小,这些变化规律有助于了解腕部韧带损伤的发生及损伤范围.     

腕投掷运动时腕关节韧带长度变化的活体研究

目的 探讨腕关节在投掷运动过程中腕关节韧带长度的变化.方法 对6例志愿者腕关节进行CT扫描,获取腕关节在投掷运动过程中的5个位置,即桡偏20°背伸60°,桡偏10°背伸30°,中立位,尺偏20°掌屈30°,尺偏40°掌屈60°时各腕骨、尺桡骨远段的三维重建图像,在重建图像基础上利用Mimics软件测得在腕关节投掷运动过程中掌、背侧腕关节韧带的长度.结果 腕关节由中立位至桡偏20°背伸60°时桡舟头韧带、长桡月韧带、尺头韧带、尺三角韧带长度显著伸长,分别延长(3.4±0.5)、(2.0±0.2)、(2.6±0.5)、(2.1±0.4)mm,差异均有统计学意义(P<0.05);腕关节由中立位至尺偏400掌屈60°时背侧桡腕韧带、背侧骨间韧带止于小多角骨部分长度显著伸长,分别延长(1.7 ±0.2)、(3.8 ±0.4)mm,差异有统计学意义(P<0.05).尺月韧带、背侧骨问韧带止于舟骨部分在投掷运动过程中其长度均较中立位时旱增长趋势.结论 腕关节在桡背伸至尺掌屈运动过程中,桡舟头韧带、长桡月韧带、尺头韧带、尺三角韧带缩短,提示张力减低,背侧桡腕韧带、背侧骨间韧带止于小多角骨部分伸长,张力增大,尺月韧带、背侧骨间韧带止于舟骨部分于中立位时张力最小,其变化规律有助于指导临床腕关节韧带损伤的修复.     

三角纤维软骨复合体解剖及生物力学研究

目的从解剖完整的腕关节入手,阐明三角纤维软骨复合体各组成部分的解剖特点,评估三角纤维软骨复合体(TFCC)对于维持远侧桡尺关节稳定的重要性。方法对8个新鲜解冻的腕关节和6个经甲醛浸泡的腕关节进行显微解剖。同时对影响远侧桡尺关节稳定性的因素作了初步的评估。前臂中旋位,垂直于尺骨予20N拉力下测量尺骨相对于桡骨的位移,然后先后切断掌背侧桡尺韧带,测量尺骨相对于桡骨的位移变化。结果发现掌背桡尺韧带由三角纤维软骨盘外周增厚而成,止于尺骨茎突基底部,是维持远侧桡尺关节稳定性的主要因素之一,切断掌背侧桡尺韧带会导致远侧桡尺关节明显不稳。结论TFCC由三角纤维软骨盘、掌背侧桡尺韧带、尺骨月骨韧带、尺骨三角骨韧带、尺侧腕伸肌下腱鞘、半月板同源物、尺侧囊组成。掌背桡尺韧带是维持远侧桡尺关节稳定性的主要因素之一,掌背侧桡尺韧带损伤会导致远侧桡尺关节明显不稳。     

舟月骨间韧带在腕尺桡偏时舟月骨三维运动中的作用

目的 观察在腕关节尺桡偏运动时,舟月骨间韧带(scapholunate interosseous ligament,SLIL)及其各亚区分级切断后对舟骨与月骨三维运动的影响,从亚区水平对SLIL在舟月骨三维运动中的作用进行研究.方法 取12例新鲜冰冻成人上肢标本(左、右侧各6例),共分为正常对照组、断SLIL近侧组、断SLIL近+背侧组、断SLIL近+掌侧组、SLIL全断组(每组6例).采用三维激光扫描及图像重建技术,测定在腕关节尺桡偏时舟骨与月骨的三维运动数据,并进行统计学处理.结果 在正常腕关节做尺桡偏运动时,舟、月骨同时也做尺桡偏运动,但还伴有明显的屈伸方向上的运动;与此同时,舟、月骨还做一定的旋前、旋后活动.在切断近+掌和近+背侧亚区组,舟月骨的活动受到影响.全切断SLIL会导致舟骨掌屈度增加,月骨掌屈活动减弱.结论 采用三维激光扫描及图像重建技术可准确测定腕舟月骨的三维活动度,从SLIL亚区水平上进行的研究表明,部分或全部切断SLIL后会对舟月骨的掌屈程度产生明显影响,但SLIL近侧亚区在控制舟、月骨的活动上不起主要作用.     

舟月骨间韧带在腕尺桡偏时舟月骨三维运动中的作用

目的 观察在腕关节尺桡偏运动时,舟月骨间韧带(scapholunate interosseous ligament,SLIL)及其各亚区分级切断后对舟骨与月骨三维运动的影响,从亚区水平对SLIL在舟月骨三维运动中的作用进行研究.方法 取12例新鲜冰冻成人上肢标本(左、右侧各6例),共分为正常对照组、断SLIL近侧组、断SLIL近+背侧组、断SLIL近+掌侧组、SLIL全断组(每组6例).采用三维激光扫描及图像重建技术,测定在腕关节尺桡偏时舟骨与月骨的三维运动数据,并进行统计学处理.结果 在正常腕关节做尺桡偏运动时,舟、月骨同时也做尺桡偏运动,但还伴有明显的屈伸方向上的运动;与此同时,舟、月骨还做一定的旋前、旋后活动.在切断近+掌和近+背侧亚区组,舟月骨的活动受到影响.全切断SLIL会导致舟骨掌屈度增加,月骨掌屈活动减弱.结论 采用三维激光扫描及图像重建技术可准确测定腕舟月骨的三维活动度,从SLIL亚区水平上进行的研究表明,部分或全部切断SLIL后会对舟月骨的掌屈程度产生明显影响,但SLIL近侧亚区在控制舟、月骨的活动上不起主要作用.     

舟月骨间韧带在腕尺桡偏时舟月骨三维运动中的作用

目的 观察在腕关节尺桡偏运动时,舟月骨间韧带(scapholunate interosseous ligament,SLIL)及其各亚区分级切断后对舟骨与月骨三维运动的影响,从亚区水平对SLIL在舟月骨三维运动中的作用进行研究.方法 取12例新鲜冰冻成人上肢标本(左、右侧各6例),共分为正常对照组、断SLIL近侧组、断SLIL近+背侧组、断SLIL近+掌侧组、SLIL全断组(每组6例).采用三维激光扫描及图像重建技术,测定在腕关节尺桡偏时舟骨与月骨的三维运动数据,并进行统计学处理.结果 在正常腕关节做尺桡偏运动时,舟、月骨同时也做尺桡偏运动,但还伴有明显的屈伸方向上的运动;与此同时,舟、月骨还做一定的旋前、旋后活动.在切断近+掌和近+背侧亚区组,舟月骨的活动受到影响.全切断SLIL会导致舟骨掌屈度增加,月骨掌屈活动减弱.结论 采用三维激光扫描及图像重建技术可准确测定腕舟月骨的三维活动度,从SLIL亚区水平上进行的研究表明,部分或全部切断SLIL后会对舟月骨的掌屈程度产生明显影响,但SLIL近侧亚区在控制舟、月骨的活动上不起主要作用.     

舟月骨间韧带在腕尺桡偏时舟月骨三维运动中的作用

目的 观察在腕关节尺桡偏运动时,舟月骨间韧带(scapholunate interosseous ligament,SLIL)及其各亚区分级切断后对舟骨与月骨三维运动的影响,从亚区水平对SLIL在舟月骨三维运动中的作用进行研究.方法 取12例新鲜冰冻成人上肢标本(左、右侧各6例),共分为正常对照组、断SLIL近侧组、断SLIL近+背侧组、断SLIL近+掌侧组、SLIL全断组(每组6例).采用三维激光扫描及图像重建技术,测定在腕关节尺桡偏时舟骨与月骨的三维运动数据,并进行统计学处理.结果 在正常腕关节做尺桡偏运动时,舟、月骨同时也做尺桡偏运动,但还伴有明显的屈伸方向上的运动;与此同时,舟、月骨还做一定的旋前、旋后活动.在切断近+掌和近+背侧亚区组,舟月骨的活动受到影响.全切断SLIL会导致舟骨掌屈度增加,月骨掌屈活动减弱.结论 采用三维激光扫描及图像重建技术可准确测定腕舟月骨的三维活动度,从SLIL亚区水平上进行的研究表明,部分或全部切断SLIL后会对舟月骨的掌屈程度产生明显影响,但SLIL近侧亚区在控制舟、月骨的活动上不起主要作用.     

舟月骨间韧带在腕尺桡偏时舟月骨三维运动中的作用

目的 观察在腕关节尺桡偏运动时,舟月骨间韧带(scapholunate interosseous ligament,SLIL)及其各亚区分级切断后对舟骨与月骨三维运动的影响,从亚区水平对SLIL在舟月骨三维运动中的作用进行研究.方法 取12例新鲜冰冻成人上肢标本(左、右侧各6例),共分为正常对照组、断SLIL近侧组、断SLIL近+背侧组、断SLIL近+掌侧组、SLIL全断组(每组6例).采用三维激光扫描及图像重建技术,测定在腕关节尺桡偏时舟骨与月骨的三维运动数据,并进行统计学处理.结果 在正常腕关节做尺桡偏运动时,舟、月骨同时也做尺桡偏运动,但还伴有明显的屈伸方向上的运动;与此同时,舟、月骨还做一定的旋前、旋后活动.在切断近+掌和近+背侧亚区组,舟月骨的活动受到影响.全切断SLIL会导致舟骨掌屈度增加,月骨掌屈活动减弱.结论 采用三维激光扫描及图像重建技术可准确测定腕舟月骨的三维活动度,从SLIL亚区水平上进行的研究表明,部分或全部切断SLIL后会对舟月骨的掌屈程度产生明显影响,但SLIL近侧亚区在控制舟、月骨的活动上不起主要作用.     

舟月骨间韧带在腕尺桡偏时舟月骨三维运动中的作用

目的 观察在腕关节尺桡偏运动时,舟月骨间韧带(scapholunate interosseous ligament,SLIL)及其各亚区分级切断后对舟骨与月骨三维运动的影响,从亚区水平对SLIL在舟月骨三维运动中的作用进行研究.方法 取12例新鲜冰冻成人上肢标本(左、右侧各6例),共分为正常对照组、断SLIL近侧组、断SLIL近+背侧组、断SLIL近+掌侧组、SLIL全断组(每组6例).采用三维激光扫描及图像重建技术,测定在腕关节尺桡偏时舟骨与月骨的三维运动数据,并进行统计学处理.结果 在正常腕关节做尺桡偏运动时,舟、月骨同时也做尺桡偏运动,但还伴有明显的屈伸方向上的运动;与此同时,舟、月骨还做一定的旋前、旋后活动.在切断近+掌和近+背侧亚区组,舟月骨的活动受到影响.全切断SLIL会导致舟骨掌屈度增加,月骨掌屈活动减弱.结论 采用三维激光扫描及图像重建技术可准确测定腕舟月骨的三维活动度,从SLIL亚区水平上进行的研究表明,部分或全部切断SLIL后会对舟月骨的掌屈程度产生明显影响,但SLIL近侧亚区在控制舟、月骨的活动上不起主要作用.     

舟月骨间韧带在腕尺桡偏时舟月骨三维运动中的作用

目的 观察在腕关节尺桡偏运动时,舟月骨间韧带(scapholunate interosseous ligament,SLIL)及其各亚区分级切断后对舟骨与月骨三维运动的影响,从亚区水平对SLIL在舟月骨三维运动中的作用进行研究.方法 取12例新鲜冰冻成人上肢标本(左、右侧各6例),共分为正常对照组、断SLIL近侧组、断SLIL近+背侧组、断SLIL近+掌侧组、SLIL全断组(每组6例).采用三维激光扫描及图像重建技术,测定在腕关节尺桡偏时舟骨与月骨的三维运动数据,并进行统计学处理.结果 在正常腕关节做尺桡偏运动时,舟、月骨同时也做尺桡偏运动,但还伴有明显的屈伸方向上的运动;与此同时,舟、月骨还做一定的旋前、旋后活动.在切断近+掌和近+背侧亚区组,舟月骨的活动受到影响.全切断SLIL会导致舟骨掌屈度增加,月骨掌屈活动减弱.结论 采用三维激光扫描及图像重建技术可准确测定腕舟月骨的三维活动度,从SLIL亚区水平上进行的研究表明,部分或全部切断SLIL后会对舟月骨的掌屈程度产生明显影响,但SLIL近侧亚区在控制舟、月骨的活动上不起主要作用.     

The anatomy of the ligaments of the wrist and distal radioulnar joints

The ligaments of the wrist are responsible for guiding and constraining the complex motion of the carpal bones relative to the forearm bones, the metacarpals, and contiguous carpal bones. The majority of wrist ligaments are found within the joint capsule as organized thickenings composed of parallel collagen fascicles, small caliber nerves and blood vessels, and lined on their deep surfaces by synoviocytes. The palmar radiocarpal ligament complex is composed of the radioscaphocapitate, long radiolunate, radioscapholunate and short radiolunate ligaments. The ulnocarpal ligaments include the ulnolunate, ulnotriquetral and ulnocapitate ligaments. Dorsally, the radiocarpal joint is spanned by the dorsal radiocarpal ligament. Palmar ligaments connecting the proximal and distal carpal rows include the scaphotrapeziotrapezoid, scaphocapitate, triquetrocapitate and triquetrohamate ligaments. Within each row are interosseous ligaments connecting adjacent carpal bones, each divisible into dorsal and palmar components. There are unique regions within some of the ligaments, such as a zone of fibrocartilage in the proximal regions of the scapholunate and lunotriquetral interosseous ligaments, and strong deep regions connecting the trapezoid, capitate, and hamate. The distal radioulnar joint is connected by the triangular fibrocartilage complex, composed of a fibrocartilaginous disc and the palmar and dorsal radioulnar ligaments. The ulnocarpal ligaments attach to the palmar radioulnar ligament rather than directly to the ulna, allowing increased independence between wrist and forearm motion.     

Micro-CT扫描下舟月骨间韧带的显微解剖学研究

目的研究舟月骨间韧带(SLIL)的形态和血供分布,并从解剖学角度探讨临床上SLIL损伤对其血供的影响及重建的方法。方法2018年10月至2018年12月,选取12例新鲜成人前臂标本,从尺动脉或桡动脉灌注明胶-氧化铅溶液,于Micro-CT下扫描,通过Mimics软件三维重建图像,观察SLIL在中立位的形态和韧带内滋养血管分布,测量韧带掌侧、背侧和近端的宽度、长度、厚度,测量SLIL内滋养血管入口处的解剖参数,并分析其与舟、月骨的血供关系。结果①数字化技术三维重建SLIL的大体形态并测量其解剖参数,近端长度均值最大,掌侧、背侧长度相近;韧带掌侧最宽,厚度最小,而背侧与近端在厚度与宽度上相近。②SLIL的近端无滋养血管分布,掌侧与背侧均有丰富的滋养血管分布,其血供分布差异无统计学意义(P>0.05)。③SLIL的掌侧与背侧内滋养血管从SLIL附着处进入舟、月骨内形成吻合。结论SLIL掌侧较宽且厚度小,从解剖学角度分析其较其它亚区更易损伤;其掌侧与背侧亚区均有丰富的血供且与舟、月骨内相吻合,而近端无血管分布,因此,掌、背侧韧带早期轻度损伤有一定的自我修复能力,而近端损伤则较难修复,韧带掌侧与背侧损伤对舟、月骨血供会产生一定影响。     

Static scapholunate dissociation: a new reconstruction technique using a volar and dorsal approach in a cadaver model

We used 4 fresh-frozen cadaver arms to assess a method of reconstruction we designed for static scapholunate dissociation. The dorsal scapholunate ligament, scapholunate interosseous ligament, radioscapholunate, and radioscaphocapitate ligaments were sectioned. Radiographs were taken before sectioning, after sectioning, and after reconstruction. Passive motion was also measured before sectioning and after the repair. The dorsal scapholunate ligament was repaired directly; the palmar radioscapholunate and radioscaphocapitate ligaments were reconstructed using a free flexor carpi radialis tendon autograft and Mitek mini suture anchors (1.8-mm diameter and 5.4-mm length; Mitek Products, Norwood, MA) for anatomic fixation. An independent board-certified hand surgeon analyzed the radiographs of the wrists taken before and after sectioning and after reconstruction. Assessment of the unsectioned wrists revealed an average scapholunate angle of 45 degrees. After scapholunate dissociation was created the average scapholunate angle was 71 degrees. Repair of the dorsal scapholunate ligament alone did not improve the scapholunate angle. Average scapholunate angle after repair of the dorsal scapholunate ligament and reconstruction of the palmar ligaments was 43 degrees. Average range of motion on flexion, extension, and radial and ulnar deviation before ligament sectioning and after reconstruction was unchanged at 54 degrees, 59 degrees, 19 degrees, and 40 degrees respectively. This technique shows an improvement in scapholunate angle on lateral radiographs, and passive motion remained relatively unchanged.     

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.     

Dorsal wrist ligament insertions stabilize the scapholunate interval: cadaver study

This study examined sequential arthroscopic sectioning of volar, interosseous, and dorsal ligaments about the scapholunate complex in cadaver wrists. We attempted to clarify the contributions of the dorsal ligamentous complex to scapholunate instability and carpal collapse. We found that after sequential sectioning of volar ligaments and the scapholunate interosseous ligament, no scapholunate diastasis or excessive scaphoid flexion occurred. After dividing the dorsal intercarpal ligament, scapholunate instability occurred without carpal collapse. With sectioning of the dorsal radiocarpal ligament from the lunate, a dorsal intercalated scapholunate instability deformity ensued. This information may be of value in comprehending the pathogenesis of scapholunate instability and carpal collapse and in devising the rationales for conservative measures and surgical intervention.     

Radiocarpal articular contact characteristics with scaphoid instability

The relative importance of the three major periscaphoid ligament complexes in maintaining the normal radiocarpal articulation was assessed. Pressure-sensitive film recorded the changes in radioscaphoid and radiolunate articular contact that occurred with sequential ligament sectioning in 12 cadaver wrists. Alterations in the radiocarpal articular contact as a result of ligament disruption are evident in the absence of the recognizable static x-ray changes of carpal instability. The scapholunate interosseous ligament is essential in preventing scapholunate diastasis and dorsoradial subluxation of the proximal scaphoid. Rotatory subluxation of the scaphoid occurs when disruption of the scapholunate interosseous ligament is coupled with disruption of either the palmar intracapsular radiocarpal ligaments or the scaphotrapezial ligament complex. These data help explain the development of degenerative arthritis caused by carpal ligamentous instability.     

Clinical applications of volar portals in wrist arthroscopy

Volar portals for wrist arthroscopy have certain advantages over the standard dorsal portals for visualizing dorsal capsular structures as well as the palmar aspects of the carpal ligaments. The volar radial portal is relatively easy to use and is an ideal portal for evaluation of the dorsal radiocarpal ligament and the palmar aspect of the scapholunate interosseous ligament. The volar midcarpal portal may be considered as an occasional accessory portal for visualizing the palmar aspects of the capitate and hamate in cases of avascular necrosis or osteochondral fractures. The volar ulnar portal is especially useful for the viewing and debridement of palmar tears of the lunotriquetral ligament.     

Occult scapholunate ganglion: a cause of dorsal radial wrist pain

There are multiple causes for chronic dorsal wrist pain over the scapholunate ligament, including occult dorsal carpal ganglion cyst, scaphoid impaction syndrome, dorsal carpal capsulitis, distal posterior interosseous nerve syndrome, and dynamic scapholunate ligament instability. Patients with such pain often have normal x-rays. A retrospective study of 21 patients undergoing surgical exploration for chronic dorsal radial wrist pain who had no palpable cyst and normal x-rays revealed that 18 of the patients had occult scapholunate ganglion cysts or myxomatous degeneration within the scapholunate ligament. All had failed long-term conservative management. Surgery involved an approach through Langer's lines, resection of a large triangular portion of the capsule between the dorsal intercarpal and radiotriquetral ligaments, and tangential debridement of the area of myxoid degeneration proximal to the distal 2 to 3 mm of dorsal scapholunate interosseous ligament. None of the patients had scapholunate instability or scaphoid impacting syndrome. Of the 18 patients with histologically confirmed myxomatous changes in the scapholunate ligament, 16 had an excellent outcome as defined by rigorous criteria; 1 had a good outcome. There was 1 patient with a poor result. A compelling argument is made for surgical exploration of the scapholunate joint in patients with persistent dorsal radial wrist pain and scapholunate point tenderness.     

Volar portals in wrist arthroscopy

Volar portals for wrist arthroscopy have certain advantages over the standard dorsal portals for visualizing dorsal capsular structures as well as the palmar aspects of the carpal ligaments. The volar radial (VR) portal is relatively easy to use and is an ideal portal for evaluation of the dorsal radiocarpal ligament (DRCL) and the palmar aspect of the scapholunate interosseous ligament. The volar midcarpal portal may be considered as an occasional accessory portal for visualizing the palmar aspects of the capitate and hamate in cases of avascular necrosis or osteochondral fractures. The volar ulnar (VU) portal is especially useful for the viewing and debridement of palmar tears of the lunotriquetral ligament. Copyright © 2002 by the American Society for Surgery of the Hand     

The role of the dorsal intercarpal ligament in dynamic and static scapholunate instability

PURPOSE: Scapholunate instability (SLI) is the most common carpal instability. Recent studies have suggested that the dorsal intercarpal (DIC) and the dorsal radiocarpal ligaments play an important role in stabilization of the scaphoid and lunate. Differences between dynamic SLI and static SLI with a dorsal intercalated segment instability (DISI) are clearly described in the clinical literature; however, there has never been a clear explanation of the anatomic differences. This study describes the role of the DIC in the development of dynamic and static SLI with DISI in a cadaver model. METHODS: Five fresh cadavers were studied radiographically and by 3-dimensional digitization. Six increasing stages of instability were developed by sectioning progressively the following structures: the dorsal capsule, the palmar and proximal (membranous) portion of the scapholunate interosseous ligament, the DIC from its insertion on the scaphoid and trapezium, the dorsal scapholunate interosseous ligament from the scaphoid, the DIC ligament from its attachment on the lunate, and the lunotriquetral interosseous ligament. RESULTS: The scaphoid position and the scapholunate gap changed significantly after sectioning the entire scapholunate interosseous ligament and DIC from the scaphoid when a 5-kg load was applied. The lunate position was unchanged in both the loaded and the unloaded conditions. After detaching the DIC from the lunate, both the scaphoid and lunate moved and the scapholunate gap increased significantly in both loaded and unloaded conditions and showed a DISI deformity. CONCLUSIONS: This study describes an anatomic difference between dynamic and static scapholunate instability. Complete disruption of the scapholunate ligament did not result in the development of a static collapse of the lunate. The DIC had an important role in stabilizing the scaphoid and lunate and preventing DISI deformity. This study suggests that in the clinical setting the DIC ligament should be assessed intraoperatively and consideration should be given to repair and/or reconstruction of the DIC ligament attachments to both the scaphoid and the lunate.