Instability after anterior cruciate ligament rupture

Manual tests and 2 external devices were used together with roentgen stereophotogrammetry (RSA) and an active weight-bearing radiographic method to measure the sagittal laxity in 11 knees with anterior-cruciate-ligament rupture. In 5 knees no ligament surgery had been performed (unstable knees) and in 6 knees a reconstruction had been performed one year before the examination (stable knees). There were positive correlations between all methods, including the manual tests when all knees, both stable and unstable, were analyzed together. However, the mean values of the total displacement differed between the methods, especially when comparing the weight-bearing radiographs with the three other methods. Some knees with substantial displacement during passive loading did not show any displacement when weight bearing; the measurements thus depended on both the ligamentous laxity and the patient's neuromuscular control of the joint. When the stable knees were analyzed separately, higher mean values were recorded with the external devices than with RSA using 180 N load. This could be explained by an error from soft tissue deformation which added to the skeletal displacement when the external devices were used.     

The risk of anterior cruciate ligament rupture with generalised joint laxity

We assessed hyperextension of the knee and joint laxity in 169 consecutive patients who underwent an anterior cruciate ligament reconstruction between 2000 and 2002 and correlated this with a selected number of age- and gender-matched controls. In addition, the mechanism of injury in the majority of patients was documented. Joint laxity was present in 42.6% (72 of 169) of the patients and hyperextension of the knee in 78.7% (133 of 169). All patients with joint laxity had hyperextension of their knee. In the control group only 21.5% (14 of 65) had joint laxity and 37% (24 of 65) had hyperextension of the knee. Statistical analysis showed a significant correlation for these associations. We conclude that anterior cruciate ligament injury is more common in those with joint laxity and particularly so for those with hyperextension of the knee.     

Valgus osteotomy with anterior cruciate ligament laxity.

Some patients with medial joint degeneration post-medial meniscectomy also have a significant anterior cruciate ligament (ACL) instability. Ten patients were treated by a combined high tibial valgus osteotomy with ACL reconstruction. All patients had relief of instability and decreased pain, although only one returned to full activity. The operation is recommended as a salvage procedure for an ACL deficient knee with instability and medial joint degeneration.     

Proprioception and performance after anterior cruciate ligament rupture

The aim of this study was to investigate the characteristics of proprioception in patients with an anaterior-cruciate-ligament (ACL)-injured knee and to determine whether there is a correlation between proprioception and performance. We studied 32 patients with unilateral isolated ACL ruptures. Proprioception of the knee was evaluated by examining the joint position sense. Functional performance was evaluated with the one-leg hop (OLH) and one-leg vertical jump (OLV) tests. The mean error angle of the joint position sense was 3.6±1.5° on the intact side and 5.2±1.9° on the injured side. The joint position sense was thus clearly reduced on the injured side (p<0.05). The distance of jumping in the OLH test and the height of jumping in the OLV test was also clearly reduced on the injured side compared with that on the intact side (p<0.01) both with and without visual control. Moreover, we found a significant correlation between proprioception and performance in the ACL-injured knees, and this correlation was more distinct with visual deprivation. In conclusion, decreased proprioception in patients with ACL deficiency reduced their functional ability.

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Résumé Le but de cette étude était détudier les caractéristiques de proprioception chez les malades avec une lésion du LCA, et déterminer sil y avait une corrélation entre proprioception et performance. Nous avons étudié 32 malades avec une rupture isolée unilatérale du LCA. La proprioception du genou a été évalué en examinant le sens des positions de larticulation. La fonction a été évaluée avec le saut à cloche-pied (OLH) et saut vertical unipodal (OLV). Langle moyen derreur de position était 3,6±1,5° sur le côté intact et 5,2±1,9° sur le côté blessé. Le sens de position était donc notablement réduit du côté blessé (p<0.05). La distance de saut dans lépreuve OLH et la hauteur du saut dans lépreuve OLV ont aussi été réduite du côté blessé comparé avec le côté intact (p<0.01) les deux avec et sans contrôle visuel. De plus, nous avons trouvé une corrélation certaine entre proprioception et performance dans les genoux avec lésion du LCA, et cette corrélation était encore plus nette avec privation visuelle. En conclusion, la diminution de la proprioception chez les malades avec une insuffisance du LCA à réduit leur capacité fonctionnelle.

     

Manual laxity tests for anterior cruciate ligament injuries

The manual laxity examination is the primary means by which clinicians evaluate ACL injuries. This paper reviews the literature and identifies the following ACL laxity tests: anterior drawer test, Lachman test. MacIntosh test, jerk test, flexion rotation drawer test, Slocum test, and the Losee test. Test technique, grading, limitations, and reliability are discussed for each test. General limitations of manual laxity tests are also presented. A review of ACL anatomy and the biomechanics of the pivot shift sign are provided to facilitate an understanding of the underlying principles of ACL laxity tests. J Orthop Sports Phys Ther 1990;11(10):474-481.     

Histological changes in the human anterior cruciate ligament after rupture

BACKGROUND: Four phases in the response to injury of the ruptured human anterior cruciate ligament are observed histologically; these include an inflammatory phase, an epiligamentous repair phase, a proliferative phase, and a remodeling phase. One objective of this study was to describe the histological changes that occur in the ruptured human anterior cruciate ligament during these phases. Myofibroblast-like cells that contain alpha-smooth muscle actin are present in the midsubstance of the intact human anterior cruciate ligament. A second objective of this study was to determine whether an increased number of myofibroblast-like cells is found in the midsubstance of the ruptured human anterior cruciate ligament because it was thought that those cells might be responsible in part for the retraction of the ruptured anterior cruciate ligament. In the early phase of this study, it was found that the number of myofibroblast-like cells in the midsubstance of the ruptured anterior cruciate ligament was actually decreased, and this hypothesis was abandoned. During the epiligamentous repair phase, synovial tissue was formed that covered the ends of the ruptured anterior cruciate ligament. Most of the synovial lining cells were myofibroblast-like cells that contained alpha-smooth muscle actin. The primary objective of this study was to determine the location and the characteristics of the alpha-smooth muscle actin-containing myofibroblast-like cells that appear in the human anterior cruciate ligament following rupture. METHODS: Twenty-three ruptured and ten intact human anterior cruciate ligaments were evaluated for cellularity, nuclear morphology, blood vessel density, and percentage of cells containing a contractile actin isoform, alpha-smooth muscle actin. The histological features of the synovial and epiligamentous tissues were also described. RESULTS: At no time after rupture was there evidence of tissue-bridging between the femoral and tibial remnants of the anterior cruciate ligament. The ruptured ligaments demonstrated a time-dependent histological response, which consisted of inflammatory cell infiltration up to three weeks, gradual epiligamentous repair and resynovialization between three and eight weeks, and neovascularization and an increase in cell number density between eight and twenty weeks. Compared with the intact ligaments, there was a decrease in the percentage of myofibroblast-like cells containing alpha-smooth muscle actin within the remnant of the ligament. However, many of the epiligamentous and synovial cells encapsulating the remnants contained alpha-smooth muscle actin. CONCLUSIONS: After rupture, the human anterior cruciate ligament undergoes four histological phases, consisting of inflammation, epiligamentous regeneration, proliferation, and remodeling. The response to injury is similar to that reported in other dense connective tissues, with three exceptions: formation of an alpha-smooth muscle actin-expressing synovial cell layer on the surface of the ruptured ends, the lack of any tissue bridging the rupture site, and the presence of an epiligamentous reparative phase that lasts eight to twelve weeks. Other characteristics reported in healing dense connective tissue, such as fibroblast proliferation, expression of alpha-smooth muscle actin, and revascularization, also occur in the ruptured human anterior cruciate ligament. CLINICAL RELEVANCE: Unlike extra-articular ligaments that heal after injury, the human intra-articular anterior cruciate ligament forms a layer of synovial tissue over the ruptured surface, which may impede repair of the ligament. Moreover, a large number of cells in this synovial layer and in the epiligamentous tissue express the gene for a contractile actin isoform, alpha-smooth muscle actin, thus differentiating into myofibroblasts. These events may play a role in the retraction and lack of healing of the ruptured anterior cruciate ligament.     

Correlation of estradiol in pregnancy and anterior cruciate ligament laxity

The purpose of this study was to determine whether a correlation existed between estradiol in pregnancy and laxity of the anterior cruciate ligament by measuring anterior tibial translation. All patients underwent measurement of anterior tibial translation using KT-1000 knee arthrometer testing and serum estradiol determination during the third trimester of pregnancy and postpartum. Forty knees were studied. The average serum estradiol levels decreased from 10,755.0 ng/L to 50.3 ng/L. There was an average decrease anterior tibial translation with a manual maximum displacement of 3.0 mm (range, 1 mm-5 mm) from the first to second examinations. Average measurement of anterior tibial translation in pregnant women showed a statistically significant increase in laxity in the third trimester of pregnancy compared with the postpartum laxity. The results of this study show that high serum estradiol levels during the third trimester of pregnancy correlate with increased anterior tibial translation and that this anterior tibial translation decreases with the return of serum estradiol to nonpregnant levels.     

全身多关节韧带松弛对关节镜下前交叉韧带重建疗效的影响

目的 探讨全身多关节韧带松弛对前交叉韧带(ACL)损伤患者关节镜下重建术后临床效果的影响.方法 2005年1月至2007年3月共收治20例全身多关节韧带松驰(第5指掌指关节被动背伸角>90°)ACL损伤患者(为C组),同期根据第5指掌指关节被动背伸角度小于70°、70°～90°分别随机抽取20例采用相同术式的ACL损伤患者(A组和B组)作为对照.所有60例患者均采用天节镜下自体胭绳肌双束4隧道技术重建,移植物采用微型钢板纽扣进行悬吊式固定.术后通过国际膝关节文献委员会(IKDC)评分和膝关节Lysholm评分系统对患者膝关节功能进行主观评估,通过轴移试验和KT-2000检查了解膝关节的稳定性,比较3组患者的疗效.结果 60例患者术后获24～48个月(平均30.4个月)随访,3组患者双侧松弛度差异平均分别为(0.65±0.88)、(1.75±1.12)、(2.45±1.41)mm,差异有统计学意义(P<0.05),其中A组19例(95%)小于3 mm,1例(5%)3～5 mm;B组17例(85%)小于3 mm,3例(15%)3～5 mm;C组11例(55%)小于3 mm,7例(35%)3～5 mm,2例(10%)大于5 mm.轴移试验结果:A组中无阳性病例;B组1例Ⅰ度阳性;C组6例Ⅰ度阳性,2例Ⅱ度阳性.3组患者IKDC评分平均分别为(92.15±3.73)、(90.00±4.87)、(86.00 ±5.03),Lysholm评分平均分别为(94.15±2.30)、(92.80±2.51)、(88.40±4.50)分,3组之间比较差异均有统计学意义(P<0.05).结论 对于存在全身多关节韧带松弛的患者,采用关节镜下自体腘绳肌肌腱重建ACL的临床效果较差.     

The effect of ketorolac on anteroposterior knee laxity after anterior cruciate ligament reconstruction

This study investigated the effect of ketorolac on anteroposterior laxity after anterior cruciate ligament (ACL) reconstruction. A total of 168 ACL reconstructions performed between July 2003 and November 2004 were reviewed. The 6-week KT-1000 manual maximum differences between the ACL-reconstructed knee and nonoperative knee were compared for patients who received ketorolac and those who did not. Mean manual maximum difference in anterior displacement was 0.6 mm in the ketorolac group and -0.6 mm in the non-ketorolac group (P=.03). When bone-patellar tendon grafts were analyzed as a separate group, mean manual maximum difference was 0.5 mm in the ketorolac group and -1.4 mm in the non-ketorolac group (P=.007). When hamstring grafts were analyzed separately, mean manual maximum difference was 0.7 mm in the ketorolac group and 0.4 mm in the non-ketorolac group (P=.59). The use of ketorolac during bone-patellar tendon autograft ACL reconstruction was associated with increased AP laxity at 6 weeks postoperatively. Level of Evidence: Level III, retrospective comparative study.     

Instrumented Lachman tests for the evaluation of anterior laxity after reconstruction of the anterior cruciate ligament

Using a KT-1000 arthrometer, in fifty subjects were measured the anterior ligamentous laxity in a knee in which the anterior cruciate ligament had been reconstructed and in the normal, contralateral knee. We also determined the anterior tibial displacement and anterior compliance, using the Lachman test. The subjects were divided into groups according to the type of autogenous intra-articular substitute (either the central one-third of the patellar tendon or the semitendinosus tendon) that had been used for the anterior cruciate ligament and according to the duration of follow-up (range, twenty-four to 101 months). Lachman tests were performed, applying sixty-eight and ninety newtons of force, and indices for anterior compliance were calculated. Although significantly more anterior laxity was demonstrated with both sixty-eight and ninety newtons of force in the reconstructed knees than in the contralateral, normal knees (p less than 0.001), thirteen subjects, of whom eight lacked full extension of the reconstructed knee, had more anterior laxity in the normal knee. Analyses of variance showed no significant differences in the results of the Lachman tests as related to either the type of reconstruction or the length of postoperative follow-up. The results suggested that the two types of ligamentous substitute that were used in this study were equally efficient in limiting anterior tibial displacement, as demonstrated by the Lachman test. The study also demonstrated that the substitutes did not elongate significantly during the period of the study.     

Partial rupture of the anterior cruciate ligament. Natural course

A prospective study was done of 29 patients with conservatively treated partial ruptures of the anterior cruciate ligament that were stable at the initial examination under anesthesia. The ruptures were reevaluated for stability and knee function from 12 to 60 months after injury. Many had developed signs of instability. The forward drawer sign (Lachman test) and the pivot shift tests were positive. There was also measurable sagittal instability (anterior drawer sign). In every case, knee function was almost completely restored.     

Diagnosis of rupture of the anterior cruciate ligament

Clinical examination has remained the key for diagnosis of meniscal and ligament lesions of the knee. Economical use of imaging techniques is based on adequate clinical examination. Standard radiographic examination is still a simple and valuable method. Magnetic resonance tomography has made great progress during the past few decades. For this reason, this article centers on this imaging modality.     

Magnetic resonance imaging of anterior cruciate ligament rupture

Background  

Magnetic resonance (MR) imaging is a useful diagnostic tool for the assessment of knee joint injury. Anterior cruciate ligament repair is a commonly performed orthopaedic procedure. This paper examines the concordance between MR imaging and arthroscopic findings.     

Instability of knees with ligament lesions. Cadaver studies of the anterior cruciate ligament

We studied the importance of the two parts of the anterior cruciate ligament (ACL), the medial collateral ligament (MCL), and the posterior medial capsule (PMC) to translatory and spontaneous axial rotatory instability in 15 osteoligamentous knee preparations. Instability was recorded continuously from zero to 90 degrees of flexion with application of a constant force to the tibia. Isolated cutting of the ACL caused a moderate anterior translatory movement, which increased if the MCL was also cut. Transection also of the PMC resulted in an even larger range of anterior translatory movement. Combined lesions to the MCL and the PMC and the posterolateral part of the ACL did not cause such instability provided the anteromedial part of the ACL was intact. Application of a valgus moment to specimens with injured ACL and medial structures induced a spontaneous anteromedial subluxation of the tibia in a semiflexed position. When flexion was increased to 70-80 degrees, a sudden reduction was observed.     

Comparison of sagittal obliquity of the reconstructed anterior cruciate ligament with native anterior cruciate ligament using magnetic resonance imaging

Purpose: This study was conducted to compare the obliquity of asymptomatic anterior cruciate ligament (ACL) grafts with normal controls using sagittal magnetic resonance imaging (MRI). Type of Study: Case control study. Methods: Sagittal MRIs from 30 patients with a reconstructed ACL graft and from 30 individuals with an intact ACL were reviewed. Reconstructed patients were operated on with a 2-incision technique using a patellar tendon autograft. These selected patients had a normal or nearly normal IKDC score with a 3 mm or less anterior posterior translation on KT-1000 arthrometer testing compared with the intact knee. MRI showed a continuous and homogeneous graft without evidence of roof impingement. Obliquity of the grafted ACL was determined on each lateral MRI by measuring the intersection of the graft line with the tibial plateau plane. These figures were compared with data similarly obtained from 30 individuals with a stable knee and an intact ACL determined by history and physical examination. Results: Graft obliquity in reconstructed patients averaged 67° with a range between 55° and 81°. In normal controls, intact ACL obliquity averaged 51° with a range between 45° and 55°. The difference between the two groups was statistically significant (P <.0001). Conclusions: MRIs of patients with an appropriate tibial tunnel placement in order to avoid notch impingement showed a continuous and homogeneous graft similar to the native ACL, but with a more vertical graft that does not recreate the normal sagittal obliquity. However, according to arthrometer testing, these more vertical grafts can control anterior posterior knee displacement.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 19, No 3 (March), 2003: pp 257–261     

Preoperative anterior knee laxity did not influence postoperative stability restored by anterior cruciate ligament reconstruction.

Eighty-six chronic anterior cruciate ligament (ACL)-injured patients were quantitatively measured for anterior knee stability preoperatively and at 2 years or later (mean, 30 months) postoperatively to examine the influence of preoperative knee laxity on the postoperative knee stability restored by the ACL reconstruction using multiplied hamstring tendon graft. The patients were divided into 3 groups according to the preoperative injured minus normal anterior laxity difference (AL-D) (group I [n = 27] <5 mm, group II [n = 48] 5 to 9 mm, group III [n = 11] >10 mm). The 3 groups were comparable in gender, age, meniscal status, graft excursion measured during operation, time from injury to operation, and activity level. The postoperative AL-D in group I was 0.8 +/- 1. 7 mm, that in group II was 1.1 +/- 1.6 mm, and in group III was 1.5 +/- 1.4 mm. There were no significant statistical differences among these 3 groups. With our surgical technique including postoperative rehabilitation, patients with severe instability could be treated successfully without needing any additional procedures such as extra-articular augmentation or specially designed postoperative rehabilitation programs.     

Augmentation of acute rupture of the anterior cruciate ligament

Acute repair and augmentation of anterior cruciate ligament rupture is indicated in the active individual who is going to place excessive demands on the knee. Repair of any other ligament injury with the addition of augmentation of the anterior cruciate ligament repair provides a better chance for functional stability and lessens the incidence of secondary meniscal injury.     

Rehabilitation after anterior cruciate ligament reconstruction

The "Frankfurt rehabilitation regimen" following anterior cruciate ligament reconstruction is presented. ACL rehabilitation is discussed in the light of knowledge on knee biomechanics and proprioception as well as clinical results of reconstruction. Special emphasis is given to exercise therapy.     

Active knee motion after cruciate ligament rupture. Stereoradiography

In 10 patients with an old injury of the anterior cruciate ligament, the three-dimensional movements of the knee joint were studied when the patients flexed their knees. Tibial motions were recorded using roentgen stereophotogrammetric analysis. Internal rotation and adduction of the tibia were reduced in the injured knees when compared with the intact knees; during flexion of the knee joint, the tibial intercondylar eminence occupied a more lateral and posterior position on the injured side. Our results may indicate that the knee joint is continuously exposed to abnormal stresses when the anterior cruciate ligament is torn.