Ligament force and joint motion in the intact ankle: a cadaveric study

The aims of this study were to measure the forces in the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) and the motion in the tibiotalar and subtalar joints during simulated weight-bearing in eight cadaver ankle specimens. An MTS test machine was used to apply compressive loads to specimens held in a specially designed testing apparatus in which the ankle position (dorsiflexion-plantarflexion and supination-pronation) could be varied in a controlled manner. The forces in the ATFL and CFL were measured with buckle transducers. Tibiotalar motion and total ankle joint motion were measured with an instrumented spatial linkage. The specimens were positioned sequentially at 10° dorsiflexion, neutral, and 10° and 20° plantarflexion, and this sequence was repeated at 15° supination, neutral pronation/supination, and 15° pronation. Force and motion measurements were recorded in each of these positions with and without a 375 N compressive load simulating weight-bearing. From 10° dorsiflexion to 20° plantarflexion, all motion occurred in the tibiotalar joint. In contrast, the ratio of subtalar motion to tibiotalar motion was 3:1 for supination-pronation and 4:1 for internal-external rotation. Inverse loading patterns were observed for the ATFL and CFL from plantarflexion to dorsiflexion. Compressive loading did not affect CFL tension, but it magnified the pattern of increasing ATFL tension with plantarflexion. The largest increase in ATFL force was observed in supination and plantarflexion with a compressive load (76 ± 23 N), whereas CFL tension mainly increased in supination and dorsiflexion with a compressive load (109 ± 28 N). In conclusion, the results showed that the ATFL acted as a primary restraint in inversion, where injuries typically occur (combined plantarflexion, supination and internal rotation). Also, the subtalar joint was of primary importance for normal supination-pronation and internal-external rotation. Received: 29 April 1997 Accepted: 25 July 1997     

伞降着陆环境下踝关节外侧副韧带及关节囊损伤的生物力学研究

目的 模拟空降兵着陆瞬间踝关节由跖屈位到内翻位的变化,测定外侧副韧带及关节囊等软组织损伤时的负荷,并分析其在受力过程中所表现的特性,为研制新式伞兵护踝及伞靴提供理论依据. 方法 采用人体踝关节标本6具,通过自制夹具固定在MTS-858生物材料试验机上,施加轴向力,轴向压缩范围10 cm,当负荷曲线出现峰值时停止.记录负荷峰值及达到峰值的时间,绘制负荷-时间曲线. 结果 模拟空降兵着陆瞬间踝关节由跖屈位到内翻位试验中,标本踝关节负荷在达到峰值前随时间逐渐增加,达到峰值后迅速下降.负荷峰值约2207.18 N,达到峰值时间约9.76s.当负荷达到峰值时,踝关节外侧副韧带及关节囊主要呈现钝性断裂损伤,断端极不整齐.全部标本经C型臂摄X线片,均无骨性损伤. 结论 模拟空降兵跳伞着陆瞬间踝关节由跖屈状态到内翻状态下,外侧副韧带及关节囊纤维组织在负荷-时间曲线中表现出“等长收缩”及“等张收缩”特性.本试验为改进护踝或伞靴设计,以更好地防止外侧副韧带及相关软组织损伤提供了一定的理论依据.     

A mini-invasive adductor magnus tendon transfer technique for medial patellofemoral ligament reconstruction: a technical note

Patellar dislocations are associated with injuries to the medial patellofemoral ligament (MPFL). Several techniques for MPFL reconstruction have been recently published with some disadvantages involved, including large skin incisions and donor site morbidity. Arthroscopic stabilizing techniques carry the potential of inadequate restoration of MPFL function. We present a minimally invasive technique for MPFL reconstruction using adductor magnus tendon autograft. This technique is easily performed, safe, and provides a stabilizing effect equal to current MPFL reconstructions. Skin incision of only 3–4 cm is located at the level of the proximal half of the patella. After identifying the distal insertion of the adductor magnus tendon, a tendon harvester is introduced to harvest the medial two-thirds of the tendon, while the distal insertion is left intact. The adductor magnus tendon is cut at 12–14 cm from its distal insertion and transferred into the patellar medial margin. Two suture anchors are inserted through the same incision at the superomedial aspect of the patella in the anatomic MPFL origin. The graft is tightened at 30° knee flexion. Aftercare includes 4 weeks of brace treatment with restricted range of motion.     

Gravity-assisted pivot-shift test for anterior cruciate ligament injury: a new procedure to detect anterolateral rotatory instability of the knee joint

The denominated gravity-assisted pivot-shift test was introduced as a new procedure to detect anterolateral rotatory instability of the knee joint. The patient lies in the supine position or slightly rotated onto the affected side. The affected knee flexed approximately 60° and the ipsilateral hip flexed, abducted and externally rotated so that the plane of the knee motion runs parallel to the floor. The examiner instructs the patient to raise the affected leg off the examining table and to extend the affected knee gradually. If the lower leg is internally rotated suddenly, with the knee subluxated at an angle of approximately 20°, followed by the reduction in flexion, this test is regarded as positive. This test was investigated on 51 anterior cruciate ligament (ACL) deficient knees, being positive in 30 knees (Group P) and negative in 21 (Group N) with the positive rate of 59%. There was no significant correlation between the result of this test and the clinical features, but Group N included relatively small number of females and recurrent injuries tended to occur more frequently in Group P. Thirty-six knees received ACL reconstruction subsequently. There was no statistically significant difference between the groups in the side-to-side difference in anterior knee laxity at one year postoperatively. However, three patients with the side-to side difference of more than 3 mm belonged to Group P. Relatively low positive rate in ACL deficient knees suggests that it may not be used as a diagnostic procedure for ACL injury. It is possibly used for the prediction of high risk patients for symptomatic giving-way and/or patients with poor prognosis after ACL reconstruction.     

Arcuate ligament of the wrist: normal MR appearance and its relationship to palmar midcarpal instability: a cadaveric study

Objective To describe the magnetic resonance (MR) imaging and gross anatomic appearance of the scaphocapitate (SC) ligament and triquetrohamocapitate (THC) ligament, which are the radial and ulnar limbs of the composite arcuate ligament, a critical volar midcarpal stabilizing ligament. Design T1 spin-echo and 3D gradient-echo MR imaging in the standard, coronal oblique, and axial oblique planes were performed both before and following midcarpal arthrography in seven cadaveric wrists. The seven specimens were then sectioned in selected planes to optimally visualize the SC and THC ligaments. These specimens were analyzed and correlated with their corresponding MR images. Results The SC and THC ligaments can be visualized in MR images as structures of low signal intensity that form an inverted “V” joining the proximal and distal carpal rows. The entire ligamentous complex is best visualized with coronal and axial oblique MR imaging but can also be seen in standard imaging planes. Conclusion SC and THC ligaments together form the arcuate ligament of the wrist. Their function is crucial to the normal functioning of the wrist. Palmar midcarpal instability (PMCI) is a resulting condition when abnormalities of these ligaments occur. Dedicated MR imaging in the coronal and axial imaging planes can be performed in patients suspected of having PCMI.     

Localization of growth factors in the reconstructed anterior cruciate ligament: immunohistological study in dogs

This study was designed to examine localization of the growth factors in the autogenous patellar tendon graft used to reconstruct the anterior cruciate ligament (ACL) in the canine model. Among the various growth factors, basic fibroblast growth factor, transforming growth factor-β1, and platelet-derived growth factor were selected for analysis as potential factors that regulate graft remodeling processes. In the control patellar tendon and the ACL only basic fibroblast growth factor was positively stained. In the reconstructed graft increased levels of staining for all the three factors were observed in the early postoperative period, reaching the greatest expression 3 weeks after implantation. Thereafter immunoreactivity of these growth factors decreased and returned to the preoperative levels, which were similar to that of the control ACL 12 weeks postoperatively. This rapid reduction in the level of their localization indicates that once the extrinsic cells are infiltrated to the graft and revascularization completed, these growth factors may have less significance for subsequent remodeling. Received: 25 April 1999/Accepted: 25 October 1999     

The effect of graft placement on the clinical outcome of the anterior cruciate ligament reconstruction: a prospective study

The effect of the graft placement on the clinical outcome of patients after anterior cruciate ligament (ACL) reconstruction has been studied sparsely. We conducted a prospective follow-up of 140 patients who underwent an arthroscopic ACL reconstruction with a hamstring graft. One hundred and four of them (74%) could be examined at the 2-year follow-up. Clinical examination included Lysholm, Tegner, and International Knee Documentation Committee rating scores, arthrometric anterior–posterior knee laxity assessment, and muscle strength assessments. The graft placement was measured from lateral radiographs using a system recommended for measuring the attachment positions of the cruciate ligaments as well as a method called ‘the sumscore of the graft placement’, which takes into account both the femoral and the tibial graft placements simultaneously. The sumscore was smaller in knees with normal anterior–posterior knee laxity in the Lachman test (P = 0.002) and normal rotational knee laxity in the pivot shift test (P = 0.01) than in those with abnormal laxity. The tibial graft placement was more anterior when the Lachman test was normal (P = 0.04). The Lysholm score was better when the femoral graft placement was more posterior (r = −0.20, P = 0.04). The optimal femoral graft placement was between 25 and 29% of length of the femoral condyle along the Blumensaat’s line from posterior to anterior. The optimal tibial graft placement was between 32 and 37% of the length of the tibial plateau from the anterior corner, and the optimal sumscore was between 61 and 66. The sumscore and its components (the femoral and tibial graft placements) showed a clear association with the clinical outcome of the patients. The best outcome was achieved when the sumscore was small; that is the graft placement showed posterior enough in the femur, and anterior enough in the tibia.     

The Gore-Tex prosthetic ligament as a salvage procedure in deficient knees

The purpose of this study was to evaluate the results of prosthetic ligament replacement of the anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) with the Gore-Tex polytetrafluorethyene prosthesis (W.L.Gore and Co., Flagstaff, Ariz.) in 52 patients (54 knees). All patients sustained multiple (failed) knee operations or had knees with gross instability. Twenty-eight (29 knees) of the ¶52 patients (54%) in whom the Goretex prosthesis was still in situ were available at a minimum follow-up of 5 years (mean 9 years, range 5–11 years). The mean age at examination was 39 years (range 30–57 years); there were 15 men and 13 women. The results of the procedure were compared with the results of the same patients at a mean follow-up of 3 years. Eighty-one percent of the patients of the whole group complained about pain. This was 78% for the patients with an ACL reconstruction and 75% for the patients with a PCL reconstruction. The Tegner activity score and the Lysholm knee score showed a statistically significant difference over time. The anterior instability pattern improved in only 43% of the knees and the posterior instability in 41% of the knees. The Lachman test showed also a significant difference over time. In all patients X-ray showed an increase in degenerative changes. In conclusion, the PTFE prosthetic ligament in the reconstruction of the ACL and the PCL in the (chronically) unstable knee seems to deteriorate over time.     

Biomechanical evaluation of using one hamstrings tendon for ACL reconstruction: a human cadaveric study

Harvesting both the semitendinosus and gracilis tendons for anterior cruciate ligament (ACL) reconstruction has a negative impact on muscle strength as well as knee function and stability. With a new “All-inside” technique, using only one hamstrings tendon (semitendinosus or gracilis) is possible because of a reduction in length requirements. The research question of this in vitro study was whether the use of only one hamstrings tendon (semitendinosus or gracilis) could restore knee kinematics and in situ force in the ACL to the level of an intact knee. Ten human cadaveric knees were tested in the following conditions: (1) intact, (2) ACL-deficient, and (3) ACL reconstruction with the “All-inside” technique using the (a) single semitendinosus tendon graft, or (b) single gracilis tendon graft. Using a robotic testing system, external loads, i.e. (1) an anterior tibial load of 134-N and (2) combined rotatory loads of 10-Nm valgus and 5-Nm internal tibial torques, were applied. The multiple degrees of freedom knee kinematics and the in situ forces in the ACL and ACL grafts were determined. In response to a 134-N anterior tibial load, the use of either graft could restore anterior tibial translation to within 1.3 mm of the intact knee. The in situ forces in the two grafts were not significantly different from those of the intact ACL. Under the combined rotatory loads, both grafts could restore knee kinematics as well as the in situ force in the grafts to the level of the intact ACL. The “All-inside” technique using either the semitendinosus or gracilis tendon for ACL reconstruction could satisfactorily restore time-zero knee kinematics and the in situ forces in either graft to those for the intact ACL, supporting clinical findings.     

同种异体组织重建关节韧带临床疗效的初步观察

目的评价同种异体组织重建膝关节前交叉韧带(ACL)、后交叉韧带(PCL)、内侧副韧带(MCL)、外侧副韧带(LCL)和肩关节喙锁韧带(CCL)的疗效. 方法回顾调查43例患者,将其分为3组,A组ACL或ACL/MCL损伤34例;B组PCL或PCL/LCL 损伤6例;C组完全肩锁关节损伤3例.分别应用同种异体骨-髌腱-骨(B-PT-B) 、半腱肌腱与股薄肌腱、胫后肌腱、跟腱-骨重建. 结果平均随访19个月, A、B两组术前Lysholm评分63.0±5.6,术后89.0±5.9,手术前后差异有非常显著性意义(P<0.01); 术后国际膝关节文献委员会(IKDC)评分A级3例(8%),B级23例(58%),C级12例(30%),D级2例(5%).KT2000测定A组手术前后胫骨前移分别为(13.10±0.29)mm和(4.70±1.37)mm;B组胫骨后移则分别为(10.53±2.50)mm和(5.74±1.33)mm,手术前后差异有非常显著性意义 ( P<0.01).术后健患侧比较A、B两组健患差异<3 mm 33例(83%);>5 mm 4例(10%);前后抽屉试验36例(90%)由术前3度恢复至术后平均1.3度.合并MCL/LCL损伤患者的侧方应力试验由术前3度恢复至术后平均1.2度,并呈现明显的硬终点;单纯与复合性ACL或PCL损伤,伸屈正常分别占91%和88%.喙锁韧带重建后X线片显示肩锁关节间隙基本正常,肩锁与肩肱关节活动良好. 结论同种异体移植物重建膝关节ACL、PCL、MCL、LCL与肩关节喙锁韧带疗效满意,是自体组织重建的良好替代物.     

Histological and ultrastructural evaluation of Leeds-Keio ligament 20 years after implant: a case report

We were capable of undertaking a histological and ultrastructural evaluation of an intact Leeds-Keio ligament implanted 20 years ago to assess the neoligamentization process inside this artificial ligament. The histological evaluation disclosed a collagen fibrils orientation very close to the structure of a normal anterior cruciate ligament (ACL) where the collagen fibres are multidirectional [Strocchi et al. in J Anat 180(3):515–519, 1992]. On the other hand we found an unimodal distribution of collagen fibrils in the reconstructed ACL. This suggests that even at long-term follow-up stress exerts a variable influence. The multidirectional arrangement of collagen fibres resembles a normal ACL, but the unimodal distribution of fibrils is quite different from those seen in normal tendon and ligaments which tend to have a bimodal peak [Decker et al. in J Submicrosc Cytol Pathol 23:9–21, 1991; Strocchi et al. in J Anat 180(3):515–519, 1992]. Studies based on biopsy suffer from the potential weakness that the specimen may not have been representative of the entire prosthesis. Further long-term studies, possibly with the entire prosthesis and not only a biopsy, would highlight the behaviour and remodelling of this artificial ligament in greater detail and could be important for the development of future generations of artificial ligaments or tissue engineering ACL reconstruction.     

The distal fascicle of the anterior inferior tibiofibular ligament as a cause of tibiotalar impingement syndrome: a current concepts review

Impingement syndromes of the ankle involve either osseous or soft tissue impingement and can be anterior, anterolateral, or posterior. Ankle impingement syndromes are painful conditions caused by the friction of joint tissues, which are both the cause and the effect of altered joint biomechanics. The distal fascicle of the anterior inferior tibiofibular ligament (AITFL) is possible cause of anterior impingement. The objective of this article was to review the literature concerning the anatomy, pathogenesis, symptoms and treatment of the AITFL impingement and finally to formulate treatment recommendations. The AITFL starts from the distal tibia, 5 mm in average above the articular surface, and descends obliquely between the adjacent margins of the tibia and fibula, anterior to the syndesmosis to the anterior aspect of the lateral malleolus. The incidence of the accessory fascicle differs very widely in the several studies. The presence of the distal fascicle of the AITFL and also the contact with the anterolateral talus is probably a normal finding. It may become pathological, due to anatomical variations and/or anterolateral instability of the ankle resulting from an anterior talofibular ligament injury. When observed during an ankle arthroscopy, the surgeon should look for the criteria described to decide whether it is pathological and considering resection of the distal fascicle. The presence of the AITFL and the contact with the talus is a normal finding. An impingement of the AITFL can result from an anatomical variant or anteroposterior instability of the ankle. The diagnosis of ligamentous impingement in the anterior aspect of the ankle should be considered in patients who have chronic ankle pain in the anterolateral aspect of the ankle after an inversion injury and have a stable ankle, normal plain radiographs, and isolated point tenderness on the anterolateral aspect of the talar dome and in the anteroinferior tibiofibular ligament. The impingement syndrome can be treated arthroscopically.     

Biomechanical analysis of knee hyperextension and of the impingement of the anterior cruciate ligament: a cinematographic MRI study with impact on tibial tunnel positioning in anterior cruciate ligament reconstruction

This study analyzed the interaction between the anterior cruciate ligament (ACL) and the intercondylar notch roof (INR) in hyperextension of the knee using magnetic resonance cinematography. Cinematographic image series of 15 knees were investigated. Two independent observers identified the image that displayed the beginning of contact between the ACL and the INR. They determined knee extension on this image and on the image that displayed maximum hyperextension of the knee. Correlations between a variable representing impingement and the inclination angle of the INR, the anterior laxity of the knee, and full hyperextension were examined. Theoretical, impingement-free tibial tunnel positions for the knees were calculated as a percentage of the anteroposterior tibial width. All ACLs of the knees in this study made contact with the INR. The average extension angle at the beginning of impingement was –6.3 ± 3.8°. There were significant correlations between impingement and maximum manual displacement as measured with the arthrometer ¶(r = 0.77; P < 0.001), maximum hyperextension (r = 0.67; P = 0.007), and notch roof angle (r = –0.73; P = 0.002). There were biomechanically acceptable tunnel positions for all knees but one. Hyperextension is physiologically associated with impingement of the ACL. In uninjured knees there was a correlation between ACL impingement and hyperextension, inclination of the INR, and maximum manual displacement of the tibia. Impingement free tibial tunnel positioning is possible in most knees without notchplasty.     

Effect of pretension in reconstructions of the anterior cruciate ligament with a Dacron prosthesis

To study the effect of the pretension level in reconstructions of the anterior cruciate ligament (ACL) we examined 26 patients with isolated ACL insufficiency and intact Dacron ligament prosthesis at 4-year follow-up. The patients were divided into two groups of 13 each, based on pretension level applied at the reconstruction: in group I the ligament was pretensioned to 60 N and in group II to 40 N. The patients were evaluated by the Tegner and Lysholm scores, KT-1000 arthrometer measurements, and isokinetic muscle performance testing and were assessed by the Knee Ligament Standard Evaluation Form of the International Knee Documentation Committee. At followup there were no differences between the two groups in any of the evaluated parameters except for squatting ability. The two groups differed significantly (P<0.01) with regard to the squatting score: 11 patients in group I had decreased squatting ability, and 6 of these were not able to squat beyond 90° of flexion. In contrast, only 4 patients in group II had slightly impaired squatting ability. It is likely that this difference between the two group is related to the magnitude of the pretension applied to the ligament prosthesis, and that the pretension exerts its influence through a change in the knee kinematics introduced at the time of the reconstruction.     

人工韧带联合自体肌腱在前交叉韧带重建失败后翻修手术中应用

目的探讨在前交叉韧带重建失败后,应用LARS新型中空人工韧带联合自体肌腱行翻修手术的可行性及短期临床效果。方法回顾性分析自2015年6月至2016年7月收治的因前交叉韧带重建失败行翻修手术的11例患者的临床资料。11例患者均在关节镜下行翻修手术,采用LARS新型中空人工韧带联合自体肌腱重建前交叉韧带,采用KT-2000检查术前与末次随访时膝关节屈曲30°平均差值,根据国际膝关节评分委员会评分标准(IKDC)、Lysholm及Tegner评分系统对术前及末次随访时患者情况进行评价,探讨其临床疗效。结果本组患者随访6~18个月,平均12个月。末次随访时,膝关节屈曲30°平均差值较术前明显减小[(2.05±0.28)mm比(6.15±0.85)mm],差异有统计学意义(P<0.01)。末次随访时,IKDC、Tegner及Lysholm评分均较翻修前有显著改善,差异有统计学意义(P<0.01)。结论 LARS中空人工韧带联合自体肌腱在前交叉韧带重建失败翻修术中是一种可行的移植物选择,术后临床效果改善明显,值得推广。     

Reconstruction of the posterior cruciate ligament with LAD-augmented semitendinosus and gracilis tendons: a preliminary report

We present our technique for reconstruction of the posterior cruciate ligament (PCL) using the semitendinosus and gracilis tendons with the Kennedy ligament augmentation device (LAD). The safe and excellent exposure of the posterior aspect of the knee allowed us to identify the most isometric position in the intercondylar notch of the femur. In addition to this advantage, firm fixation of the LAD-augmented tendons with staples prevented the tibia from sagging posteriorly during early protected motion of the knee. Evaluation of 12 patients followed for more than 2 years showed 9 (75%) good results. In this small series no correlation was found between clinical results and the number of major structures injured, indicating that postoperative care is as important as isometric placement of the PCL in obtaining satisfactory results.     

Outcomes of medial patellofemoral ligament reconstruction for patellar instability: a systematic review

It has been suggested that in the majority of patellar dislocation cases the medial patellofemoral ligament (MPFL) is disrupted. Accordingly several authors over the past decade have recommended repair or reconstruction of the MPFL to reduce the high incidence of recurrent dislocation. The purpose of this review was to determine whether MPFL reconstruction is a suitable procedure with regards to clinical and radiological outcomes for patients with patellar instability. A literature search using the electronic databases AMED, British Nursing Index, CINAHL, the Cochrane database, EMBASE, ovid Medline, Physiotherapy Evidence Database (PEDro), PsycINFO, Pubmed and Zetoc were performed from their inception to May 2007. All English language, human subject clinical papers reporting outcomes following MPFL reconstruction were included. Eight papers, collectively assessing 186 MPFL reconstructions, were finally included for review. Three reviewers independently assessed the methodological quality of each of the studies using the CASP appraisal tool. When analysed, it would appear that MPFL reconstruction may provide favourable clinical and radiological outcomes for patellar instability patients. However, following a critical appraisal of these papers a number of methodological weaknesses were identified including recruiting small samples, not controlling for confounding variables, and providing limited statistical analysis of results. Future study is recommended to address these methodological flaws, in addition to beginning to assess the effectiveness of this procedure, in different patient groups.