The extensor sling procedure for the unstable carpo-metacarpal joint of the thumb

Surgical Principles The sling is made by routing part of the extensor carpi radialis longus, from its insertion, through the interspace between the second and third metacarpals, encircling the base of the first metacarpal and then suturing the tendon on itself at its point of entry between the second and third metacarpal. The entire procedure is carried out from the dorsal surface of the hand and deep to the adductor pollicis. Stability of the first carpo-metacarpal joint is restored without interfering with the excursion of the first metacarpal. During pinching great lateral forces act on the first carpo-metacarpal joint and tend to dislocate it laterally. This tendency is normally kept in check by the first intermetacarpal ligament [7]. As with all joints, instability in the carpo-metacarpal joint will promote the early onset of secondary degenerative changes. Increased stability would prevent the changes, or at least delay them, until the usual age of occurrence in the general population. However, no procedure carried out at the stage where significant cartilaginous degeneration is already present, will be able to control the process of arthritis. For the first metacarpal to move laterally the intermetacarpal ligament has to stretch [1]. Re-inforcing the ligament must, therefore, control this tendency. The extensor sling procedure provides a new ligament which lies in the coronal plane of the hand between the first and second metacarpal and prevents lateral subluxation. At the same time it does not interfere with circumduction of the first metacarpal provided that the ligament is sited at the base of the metacarpal.     

Arthroscopic removal of intra-articular osteoid osteoma in the knee: case report and review of the literature

Osteoid osteoma is a relatively common benign bone tumor first described by Jaffe [1]. It most frequently arises in the long bones and exhibits a characteristic X-ray appearance, that is, a small radiolucent zone surrounded by reactive circumferential sclerosis (nidus) [2, 3]. Nocturnal pain, which can be alleviated by aspirin, is one of the characteristic clinical manifestations of this bone tumor [4]. Although it is relatively rare, osteoid osteoma can also arise in the intra-articular regions, and we found 14 such cases arising in the knee joint in the literature [5–18]. Patients with intra-articular osteoid osteoma often present with joint pain, intracapsular effusion, restricted motion, and muscle atrophy in the affected limb, which can be mistaken for more common entities, such as traumatic or degenerative pathologies of the joint. Furthermore, X-ray examination often fails to show the characteristic nidus that is typically seen in extra-articular osteoid osteoma and therefore can result in a delayed diagnosis. We herein present a case of intra-articular osteoid osteoma arising in the knee joint, which was successfully treated by arthroscopy, and review the reported cases of intra-articular osteoid osteoma arising in the knee.     

Ligament tension pattern in the flexed knee in combined passive anterior translation and axial rotation.

Twenty-two fresh-frozen specimens were used to measure tensions generated in selected bands of the major ligaments of the flexed knee (40-90 degrees) when an axially prerotated tibia is subjected to passive anterior shear and when an anteriorly pretranslated tibia is subjected to passive axial torque. The tensions were measured using the buckle transducer attached to the anteromedial band of the anterior cruciate ligament [ACL (am)], the posterior fibers of the posterior cruciate ligament [PCL (pf)], the long fibers of the medial collateral ligament [MCL (lf)], and in the total lateral collateral ligament [LCL]. The knee specimens were subjected to the combined motions in a 6-df passive loading apparatus. The results indicated that the joint resistance to anterior translation increased markedly with internal prerotation and only marginally with external prerotation. This increase in joint resistance, however, was associated with a decrease in ACL function. It has been inferred that the posterior structures, capsular and meniscal, contribute significantly to joint resistance when the tibia is prerotated in either sense. For internal prerotation, the interference between the medial femoral condyle and the central tibial eminence was found to be an additional mechanism of resistance to anterior translation. Also, it has been found that although the ACL (am) tension increased with internal rotation in the normal case, it decreased with internal rotation in the presence of an anterior pretranslation. It is concluded that ACL response to combined joint motion cannot be ascertained by a simple summation of its responses to individual motions.     

Severe septic arthritis of the shoulder with an axillary nerve lesion in a 4-year-old child

Septic arthritis in children frequently affects the joints of the lower extremity, namely the hip and the knee [1–3]. Infection in the glenohumeral joint is rare [4–7], representing 4% of all joint infections [4, 5]. Arthralgia, joint swelling, fever and pseudoparalysis are the most commonly observed symptoms [1, 4, 5, 8]. Diagnosis and thus appropriate management are often delayed [4] and therefore early disease recognition and treatment play a significant role in minimising the risk of developing complications such as joint surface destruction, growth arrest, adjacent osteomyelitis, and loss of joint movement [1, 4–6]. Brachial plexopathy, is infrequently reported [13], and a lesion to the axillary nerve specifically has not yet been reported in literature to our knowledge. Treatment aims include adequate washout and debridement of the joint with the objective of relieving pain and restoring function [5]. This can be achieved either via arthrotomy or arthroscopically [2, 5]. However there is currently no clear consensus with regard to which management option leads to improved outcome [3, 8], because of the lack of studies describing the results of surgical intervention [9]. The case of a 4-year-old boy with a delayed diagnosis of septic arthritis of the right shoulder with massive abscess formation and an axillary nerve lesion is presented.     

双源CT能谱纯化单能量技术在评估喙锁韧带中的价值

目的探讨双源CT能谱纯化单能量技术对喙锁韧带结构显示的可行性及对韧带显示最佳的能量级。 方法回顾性分析40例双能量CT扫描的单侧肩关节患者影像学资料，采用双源CT"单能+"软件分别获得喙锁韧带40 keV、60 keV、70 keV、80 keV、100 keV 5组单能量图像，并与线性融合（M=0.5）图像对比，分析比较不同能级单能量图像间的CT值及信噪比（signal-to-noise ratio，SNR）、最佳单能量图像与线性融合（M=0.5）图像间的SNR以及总体主观图像质量评分。 结果（1）斜方韧带及锥状韧带在40 keV总体主观图像质量评分均高于其他5组（P均<0.05）。2位观察者间主观图像质量评分一致性较好[Kappa（斜方）：0.822~0.978；Kappa（锥状）：0.905~0.971]。（2）5组单能量图像间的斜方韧带CT值及锥状韧带CT值差异均有统计学意义（P均<0.001），且40 keV>60 keV>70 keV>80 keV>100 keV 。（3）40 keV斜方韧带及锥状韧带图像的SNR均高于其他4组，差异有统计学意义（P均<0.05）；70 keV与80 keV斜方韧带及锥状韧带间SNR值比较差异无统计学意义（P>0.05），余各组间的SNR差异均有统计学意义（P<0.05），且40 keV>60 keV>70 keV>100 keV；与线性融合（M=0.5）图像相比，40 keV新单能量图像斜方韧带及锥状韧带SNR值均较高（P<0.05）。 结论双能量CT的单能纯化技术可清晰显示喙锁韧带形态及走行，且在40 keV时对斜方韧带及锥状韧带的显示最佳。     

Bilateral tenosynovial giant cell tumor of the knee accompanied by chronic ACL tear

Tenosynovial giant cell tumors, also known as giant cell tumors of the tendon sheath (GCTTS), are a benign soft tissue tumor arising from the synovial tissue of the joint, tendon sheath, or mucosal bursa, or fibrous tissue adjacent to the tendon. Whereas GCTTS can arise in any synovial sheath, they are predominantly found in hand tendon sheaths and rarely in larger joints such as the knee or ankle [1,2]. The rare occurrence in larger joints, combined with a lack of characteristic symptoms, means GCTTS in the knee usually goes unsuspected in clinical diagnosis. Bilateral development of GCTTS is very rare [3]. To our knowledge, this is the first report to describe a case of bilateral intraarticular GCTTS arising from the anterior cruciate ligament (ACL) in both knee joints. The lesions were encountered during reconstruction of the ruptured ACLs.     

兔肘关节尺侧副韧带急性损伤手术与非手术治疗后负载和强度的比较

目的 比较兔急性肘关节尺侧副韧带损伤后手术修复与非手术治疗的差异.方法 新西兰兔81只按随机数学表法分为三组(n=27),正常对照组(A组):暴露右尺侧副韧带后,但不切断;韧带缝合组(B组):切断右尺侧副韧带后随即缝合韧带;韧带不缝合组(C组):切断右尺侧副韧带后不缝合.分别于术后3、6、12周三个阶段取材,进行生物力学检测.结果 术后12周B组断裂时的最大载荷[(68.23±5.64)N]与C组[(42.45±3.66)N]比较,差异有统计学意义(P<0.05);B组与A组[(72.86±2.99)N]比较,差异无统计学意义(P>0.05).B组应力强度[(3.84±0.47)N/mm2]与C组[(2.84±0.17)N/mm2]比较,差异有统计学意义(P<0.05);B组与A组[(4.09±0.15)N/mm2]比较,差异尤统计学意义(P>0.05).结论 肘关节尺侧副韧带急性损伤后手术治疗明显优于非手术治疗.     

The accuracy of MRI in the detection of Lumbar Disc Containment

Data from 565 knee arthroscopies performed by two experienced knee surgeons between 2002 and 2005 for degenerative joint disorders, ligament injuries, loose body removals, lateral release of the patellar retinaculum, plica division, and adhesiolysis was prospectively collected. A subset of 109 patients from the above group who sequentially had clinical examination, MRI and arthroscopy for suspected meniscal and ligament injuries were considered for the present study and the data was reviewed. Patients with previous menisectomies, knee ligament repairs or reconstructions and knee arthroscopies were excluded from the study. Patients were categorised into three groups on objective clinical assessment: Those who were positive for either meniscal or cruciate ligament injury [group 1]; both meniscal and cruciate ligament injury [group 2] and those with highly suggestive symptoms and with negative clinical signs [group 3]. MRI was requested for confirmation of diagnosis and for additional information in all these patients. Two experienced radiologists reported MRI films. Clinical and MRI findings were compared with Arthroscopy as the gold standard. A thorough clinical examination performed by a skilled examiner more accurately correlated at Arthroscopy. MRI added no information in group 1 patients, valuable information in group 2 and was equivocal in group 3 patients. A negative MRI did not prevent an arthroscopy. In this study, specificity, positive and negative predictive values were more favourable for clinical examination though MRI was more sensitive for meniscal injuries. The use of MRI as a supplemental tool in the management of meniscal and ligament injuries should be highly individualised by an experienced surgeon.     

腕关节的三维可视化研究

[目的]建立腕关节三维数字化可视模型。[方法]获取腕关节0．2mm厚的薄层冠状断层标本，在计算机上对腕骨及主要韧带的断层图像轮廓进行数据分割、对位重建和三维显示。[结果]重建了腕关节桡、尺骨，远近两列（共8块）腕骨，掌骨（5块）及桡尺韧带、腕关节盘（三角纤维软骨）、关节盘同系物、桡月韧带、桡三角韧带、舟头韧带、桡舟头韧带、舟月韧带、月三角韧带、尺三角韧带、尺月韧带、三角头韧带、钩头韧带共28个结构的三维图像。在模型上可对上述结构进行单个结构的显示，也可以进行多个结构的分色显示、透明显示，同时也可以任意放大缩小和任意角度旋转观察。并且，所有结构在任意方向上的径线和角度均可适时测量。[结论]该腕关节三维可视化模型较清晰地反映了腕部骨及韧带的解剖关系，可从多个外科手术角度进行观察，可为腕关节外科手术提供重要的参考资料。     

改良Weaver法治疗陈旧性重度肩锁关节脱位

目的 观察改良Weaver法治疗陈旧性重度肩锁关节脱位的临床疗效。方法 用1枚克氏针由肩峰通过肩锁关节穿入锁骨外端固定肩锁关节，喙肩韧带的肩峰端切断，旋转移位重建喙锁韧带。结果 23例术后随访1－5年，按优，良，差标准评定疗效，优19例（82．6％），良3例（13．0％），差1例（4．3％），优良率95．6％，结论 该方法操作简单，创伤小，远期疗效好，可满意恢复肩关节功能。     

喙锁韧带重建的解剖放射学研究

目的测量不同透视体位下喙锁韧带骨道走行的放射学参数，为临床喙锁韧带重建提供解剖学依据。 方法取22具防腐处理的成人肩关节标本，解剖测量喙锁韧带两部分（斜方韧带，锥状韧带）的走行方向、止点宽度及透视体位下成角。 结果斜方韧带锁骨侧足印宽度（26.2±1.2） mm，喙突侧（22.7±1.6）mm。锥状韧带锁骨侧足印宽度（24.6±1.4）mm，喙突侧（19.2±1.6）mm。影像学测量韧带的插入角度：肩胛骨正位与锥状韧带与锁骨长轴成角（81±4）°，斜方韧带成角（67±7）°。侧位成角：斜方韧带（83±3）°，锥状韧带（70±6）°。与外科标志的毗邻关系：斜方韧带与锥状韧带足印区长轴中心点在锁骨间距（21.9±4.8）mm，在喙突侧间距（15.7±1.6）mm。 结论锥状韧带及斜方韧带止点足印宽度较为恒定，斜方韧带插入角度有变异度较大，锥状韧带较为恒定。两韧带在锁骨及喙突上间距较小。在进行肩锁关节解剖重建时，可参照其解剖学特点。     

Computer-assisted assessment of lateral column movement following plantar fascial release: a cadaveric study.

In patients who fail conservative treatment, releasing the plantar fascia relieves heel pain but destabilizes the lateral column of the foot. After surgery, pain can present in the area of the sinus tarsi, extensor digitorum brevis muscle, between the fourth and fifth metatarsals, and at the calcaneocuboid joint. The precise mechanism and involved structures for this painful compensation remains unclear. The authors hypothesized that the lateral plantar fascial band, bifurcate and cervical ligaments, lateral talocalcaneal ligament, and interosseous talocalcaneal ligament become excessively strained after this surgery. Using eight cadaver lower extremity limbs amputated 7 cm above the ankle joint, structural changes in the foot in response to staged release of the plantar fascia were measured. All ligament, tendon, and osseous structures were exposed along the plantar, medial, and lateral aspects of the foot and ankle. Using a servohydraulic system, compressive loads in increasing increments (50 lbs) were applied along the tibial axis. Tissue and bony structure displacement in the foot was measured using images electronically captured from two fixed cameras and a digital camera following each load change. All measurements were made in pixels and converted to millimeters in a spreadsheet program. Except for plantar fascial measurements, data were expressed as percentage of initial baseline. As expected, increasing compressive loads changed all measurements [repeated measures ANOVA, p<.04]. When releasing the plantar fascia, the inferior sinus tarsi space widened (intact, 85.4+/-10.8%; 1/4 release, 87.7+/-13.0; 1/2 release, 88.3+/-9.2; 3/4 release, 91.2+/-8.8; p<.04). Lateral length increased and medial height decreased, while medial length and lateral height were unchanged as the fascia was sequentially released. Significant movement of the inferior sinus tarsi strained the bifurcate and cervical ligaments, the lateral talocalcaneal ligament, and interosseous talocaneal ligament, which may account for pain following surgery. The initial 1/4 cut of the plantar fascia exerted the greatest mechanical alteration of the foot, suggesting that a partial release may relieve heel pain while optimizing the patient's chances of maintaining structural integrity with 75% of the plantar fascia intact.     

Joint debridement for osteoarthritis of the elbow through a bilateral approach

Surgical Principles There are various surgical procedures for osteoarthritis of the elbow joint, such as, resection arthroplasty, total elbow replacement and joint debridement [2]. The indication for each procedure depends on the activities of the patient as well as the stage of the disease. Resection arthroplasty is indicated for severe osteoarthritis. It provides good mobility and relief of pain but joint instability resulting from this procedure is a definite disadvantage, especially for the manual laborer. Total elbow replacement is also indicated for severe osteoarthritis or rheumatoid arthritis. It provides relatively good stability of the elbow joint, but there is a possibility of loosening of the implants [1, 3]. Total elbow replacement is therefore also contraindicated for a manual laborer. The principle of the joint debridement is to remove the osteophytes, which restrict elbow motion, and to release the contracted capsule in order to improve joint motion and to decrease pain. This procedure is indicated for moderate to severe osteoarthritis. The best indication for this procedure is osteoarthritis of the elbow in active patients or manual laborers. There have been some reports about the joint debridement procedure in which different approaches were used [4, 5]. Ogino developed a joint debridement procedure through a bilateral approach. A salient feature of this procedure is the preservation of the lateral and medial collateral ligaments. First published in: Operat. Orthop. Traumatol. 3 (1991), 270–278 (German Edition).     

Traumatic dislocations and instability of the trapeziometacarpal joint of the thumb

The surgeon treating traumatic injuries to the TMC joint should be aware of the fundamental misconceptions and pervasive axiomatic myths perpetuated in the medical literature: namely that the volar beak ligament is the prime stabilizer, that the dorsal ligament complex plays no significant role in TMC joint function, and that the APL is a deforming force in Bennett fractures. On the contrary, stability of the TMC joint in power pinch and power grasp depends on the TMC joint's two prime stabilizers, the volar beak of the thumb metacarpal and the dorsal radial ligament complex; and the APL is not a deforming force in a Bennett fracture. Screw-home-torque occurs in the final phase of opposition; the acute Bennett fracture can be treated closed and percutaneously fixed if the screw-home-torque technique is used to anatomically reduce the fracture. After soft tissue interposition, if a semi-acute Bennett fracture is diagnosed late, it should be treated open with a volar approach, the screw-home-torque reduction technique, and screw or pin fixation. Rolando multipart fractures of the thumb metacarpal into the TMC joint are best treated closed, with traction in opposition with pin fixation; pure dislocations of the TMC joint that tear the dorsal ligament complex and Bennett fractures with an associated dorsal ligament complex tear (as diagnosed by the screw-home-torque technique) require open reduction and dorsal ligament complex repair. The current literature is so replete with myths and folklore regarding the anatomy that a conscientious surgeon treating a traumatic dislocation or in-stability of the TMC joint should return to the cadaver room and carefully review and understand TMC joint anatomy.     

Stener-like lesions of collateral ligament ruptures of the metacarpophalangeal joint of the finger

Background  The Stener lesion of the ulnar collateral ligament of the metacarpophalangeal (MP) joint of the thumb is characterized by an interposition of the adductor aponeurosis between a distally avulsed ligament and its insertion into the base of the proximal phalanx. Stener-like lesions of the MP joint of the finger have been previously reported in only a few cases. Methods  The authors experienced 38 cases of collateral ligament injuries of the MP joint of the finger. The two most frequently affected sites were the radial side of the little finger (21 cases) and the radial side of the ring finger (8 cases). We have previously reported some of these cases (22 cases), as well as clinical features and arthrographic findings. One Stener-like lesion in a collateral ligament injury of the MP joint of the ring finger was also reported earlier (Ishizuki, 1988). Additionally, Stener-like lesions were found postoperatively in six of eight cases surgically treated for collateral ligament injuries of the MP joint of the finger (little finger involvement in 5 cases and long finger involvement in 1 case). Results  We experienced six cases of a Stener-like lesion of the MP joint of the finger. In five of these cases the distally avulsed collateral ligament was trapped by the opened window of the injured sagittal band. In the other case the ligament was avulsed at a proximal site, and the ruptured end was trapped by the sagittal band. All of the little fingers involving Stener-like lesions were abducted and unable to adduct. Therefore, an abducted little finger is an important sign of this lesion and is considered to warrant surgical treatment. Arthrograms provided information useful for identifying the lesions. In the radial three fingers, palpation of the tumor at the level of the collateral ligament may also be an important examining tool for identifying a displaced ruptured collateral ligament of the MP joint of the finger. Conclusion  We experienced six cases of Stener-like lesions of the MP joint of the finger. In all cases, the avulsed collateral ligament was trapped by the ruptured sagittal band. Surgical treatment was thought to be indicated in these cases. Therefore, it is important to avoid overlooking Stener-like lesions of the MP joint of the finger.     

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。     

单根肌腱多韧带重建治疗急性第一腕掌关节脱位

目的：探讨桡侧腕长伸肌腱重建第一腕掌关节周围4束韧带治疗急性第一腕掌关节脱位的临床疗效。方法：自2008年12月至2012年10月,对4例急性第一腕掌关节脱位的患者切开复位后采用单根桡侧腕长伸肌重建关节周围4组韧带,即背侧韧带,掌侧韧带,桡背侧韧带,第一、二掌骨间韧带;其中男3例,女1例;平均年龄38．7岁（22~63岁）。术后根据X线片、JAMAR握力测试、拇指关节活动范围（rangeofmotion,ROM）、活动时疼痛视觉模拟评分（visualanaloguescale,VAS）等指标评价手术效果。结果：所有患者获随访,时间6~40个月,平均19个月。术后伤口均I级愈合。术后1、3、6个月x线片未见第一腕掌关节脱位复发,关节间隙无明显狭窄退变。JAMAR握力测试患侧恢复至健侧的60％N90％。ROM测定3例屈伸、收展活动恢复正常,1例内收受限。拇指活动时疼痛VAS评分0-1分。结论：对于急性第一腕掌关节脱位,桡侧腕长伸肌腱重建关节周围韧带可恢复关节稳定性,改善功能。     

Injuries to the Ulnar Collateral Ligament of the Thumb Metacarpophalangeal Joint

Injuries to the ulnar collateral ligament of the metacarpophalangeal (MCP) joint of the thumb are relatively common. When an incomplete rupture is present, valgus stress testing with the MCP joint positioned in extension reveals minimal or no instability (less than 30 degrees of laxity or less than 15 degrees more laxity than in the noninjured thumb). When a complete rupture is present, valgus stress testing with the MCP joint positioned in extension reveals marked laxity (more than 30 degrees or more than 15 degrees more laxity than in the noninjured thumb). In this instance, displacement of the ligament proximal and superficial to the adductor aponeurosis, which is often termed a Stener lesion, is likely. Partial ligament injuries in which the ligament is not displaced may be treated nonoperatively. When a Stener lesion is present, however, primary ligament healing cannot occur without operative management. Whether treatment should be operative or nonperative can generally be decided on the basis of the findings from the history, the radiographs, and the physical examination, which should include valgus stress testing.     

Complex instability of the anterior knee

Complex knee instability involves the anterior cruciate ligament (ACL) and one or more major stabilizers of the knee [medial collateral ligament (MCL), lateral collateral ligament (LCL), posterior cruciate ligament (PCL)]. The medial side has a high healing potential and does not need operative treatment in most cases if ACL reconstruction is performed. Reconstruction of the medial ligament complex is indicated in gross instability of the medial meniscus fixation, dislocation of the MCL into the joint, and large dislocated bony avulsions. Injuries on the lateral side do not heal spontaneously and require acute operative treatment (first 2 weeks). Frank knee dislocations and gross multiligament injuries should be reduced acutely, and the integrity of the vascular structures must be examined closely. In a European multicenter study, operative treatment with reconstruction of both cruciate ligaments and functional rehabilitation gave better results than conservative treatment with immobilization of the joint.     

The trapezio-metacarpal joint: the strain of the ligaments as a function of the thumb position. Study on an enlarged model

INTRODUCTION: The aim of this paper was to develop an enlarged anatomical model of the trapezio-metacarpal joint in order to measure the strains on the ligaments when this joint was passively moved in several directions under constant loading. MATERIAL AND METHOD: A model of the two first rays of the hand was made in polystyrene, at a X3 enlargement, and the ligaments substituted by rubber bands with well characterized mechanical properties so as to reproduce the actual ratio of stiffness (approximately = 10) of the different tissues (bones and ligaments) found in real life. The first metacarpal was moved in 6 directions as described by Ebskov (1970) and Pieron (1973, 1980) using a small spring exerting a constant force (1.5 N) tilted at 30 degrees with respect to the transverse plane. The strain was measured between two white marks for each model ligament and each direction respectively, and the percentage of lengthening was calculated. A statistical study was performed using the non-parametrical Test of Wilcoxon in order to compare the ligament strains obtained in the different directions of loading. RESULTS: The largest strains were observed in the intermetacarpal ligament and in the anterior oblique ligament reaching 26 to 39% in direction J (posteromedial) and in direction L (posterolateral). Deformations of the two parts of the dorsoradial ligament and of the posterior oblique ligament were equal or inferior to 12% and were observed in the other 4 directions: D, F, K, I (Anterolateral, maximal anteposition, anteromedial, medial) and their combinations. CONCLUSION:. These data may be useful for helping the understanding of the biomechanics of the basal joint of the thumb. Nevertheless, we are dealing here with a simplified model, which must be considered with caution if the results are to be applied to the living joint.