The attachments of the anteromedial and posterolateral fibre bundles of the anterior cruciate ligament

The aim of this study was to describe the anatomical locations of the femoral attachments of the anteromedial (AM) and posterolateral (PL) bundles of the anterior cruciate ligament (ACL). Twenty-two human cadaver knees with intact ACLs were used. The femoral attachments of the two bundles were identified, marked and photographed. They were measured and described in terms of the o’clock positions parallel to the femoral long axis and parallel to the roof of the intercondylar notch. The centres of the bundles were also measured in a high–low and a superficial-deep manner referencing from the centre of the posterior femoral condyle, and with respect to their positions within a measurement grid defined in this study. The bulk of the AM bundle was attached between the 9.30 and 11.30 o’clock positions and the PL bundle between the 8.30 and 10 o’clock positions. The AM and PL bundles were consistently found in specific zones of the measurement grid. Using the posterior condyle reference method, the centre of the AM bundle was at 68 ± 7% (range 57–78) in a shallow–deep direction and 55 ± 5% (44–62) in a high–low direction. The PL bundle was found at 56 ± 8% (40–73) in a shallow–deep direction, and 62 ± 7.0% (40–70) in a high–low direction. The attachment was oriented at 37° to the femoral long axis. The results from this study could be used to guide ACL reconstruction techniques.     

膝关节前交叉韧带前内侧束和后外侧束的MR成像研究

目的 提高对膝关节前交叉韧带前内侧束和后外侧束的影像认识,并探讨其3.0T MR的理想常规成像显示平面.方法 回顾性分析149例正常膝关节的3.0TMR图像,采用x2分割法分析前交叉韧带、前内侧束和后外侧束双束结构及双束上、中、下各段在MR矢状面、冠状面、横断面各成像平面显示率的差异.结果 前交叉韧带前内侧束和后外侧束双束结构显示率,横断面(115/149,77.2％)与冠状面(103/149,69.1％)比较,×2=2.4606,P＞0.0125;横断面、冠状面分别与矢状面(21/149,14.1％)比较,x2值分别为119.5138、92.8695,P值均＜0.0125.前内侧束和后外侧束双束上段显示率,横断面( 104/149,69.8％)与冠状面(7/149,4.7％)、矢状面(0/149,0)及冠状面与矢状面分别比较,x2值分别为135.0813、159.7526、7.1684,P值均＜0.0125.前内侧束和后外侧束双束中段显示率,横断面(108/149,72.5％)与冠状面(94/149,63.1％)比较,x2=3.0120,P＞0.0125;横断面、冠状面分别与矢状面( 10/149,6.7％)比较,x2值分别为134.7454、104.2173,P值均＜0.0125.前内侧束和后外侧束双束下段显示率,横断面(103/149,69.1％)与冠状面(110/149,73.8％)比较,x2=0.8065,P＞0.0125;横断面、冠状面分别与矢状面(18/149,12.1％)比较,x2值分别为100.5300、115.9132,P值均＜0.0125.前交叉韧带双束各段在MRI各序列上均呈低信号,形态、走行正常.结论 3.0TMR常规扫描平面能够在一定程度上显示前交叉韧带的双束结构,横断面和冠状面是较为理想的显像平面.     

Lateral radiographic study of the tibial sagital insertions of the anteromedial and posterolateral bundles of human anterior cruciate ligament

Recently, the femoral attachments of anteromedial and posterolateral bundles of anterior cruciate ligament (ACL) have been extensively discussed, however, few publications have mentioned radiographic measurements of the tibial insertions of two bundles. The aim of this study is to determine the radiographic measurements of the tibial sagital insertions for anteromedial (AM) and posterolateral (PL) bundles of ACL. Thirty-one cadaveric proximal tibias were used. After identification of the AM and PL bundles insertion sites on the tibia, the insertion center and the other anatomic landmarks were marked with a lead pin, and lateral radiographs were taken. Sagital percentage is a percentage of the location of the insertion point calculated from the anterior margin of the tibia in the anteroposterior direction. Anterior edge of ACL averaged 25.0%, center of AM averaged 34.6%, center of PL averaged 38.4%, posterior edge of ACL averaged 50.2%. This study defines the radiographic location of the tibial insertions of the anteromedial and posterolateral bundles of ACL. This contributes to more precise evaluation of anatomical double bundle ACL reconstruction surgery postoperatively.     

The role of the anteromedial and posterolateral bundles of the anterior cruciate ligament in anterior tibial translation and internal rotation

BACKGROUND: A rupture of the entire fibers of the anterior cruciate ligament leads to knee instability due to increased anterior tibial translation and increased internal tibial rotation. The influence of isolated deficiency of the anteromedial or posterolateral bundle of the anterior cruciate ligament on the resulting knee kinematics have not yet been reported. HYPOTHESIS: Transection of the anteromedial bundle will lead to increased anterior tibial translation at 90 degrees. Transection of the posterolateral bundle will show an increased anterior tibial translation as well as a combined rotatory instability at 30 degrees. STUDY DESIGN: Controlled laboratory study. METHODS: Kinematics of the intact knee were determined in response to a 134-N anterior tibial load and a combined rotatory load of 10 N.m valgus and 4 N.m internal tibial rotation using a robotic/universal force moment sensor testing system. Subsequently, the fibers of the anteromedial and posterolateral bundle were resected in an alternating order and the new translation in response to the same external loading conditions measured. Statistical analysis was performed using a 2-way ANOVA test. RESULTS: Transection of the anteromedial bundle increased anterior tibial translation at 60 degrees and 90 degrees of knee flexion significantly. Isolated transsection of the posterolateral bundle increased anterior tibial translation in response to 134-N anterior load at 30 degrees of knee flexion significantly and resulted in a significant increase in combined rotation at 0 degrees and 30 degrees in response to a combined rotatory load compared with the intact knee and isolated resection of the anteromedial bundle. CONCLUSION: The anteromedial and posterolateral bundles stabilize the knee joint in response to anterior tibial loads and combined rotatory loads in a synergistic way. CLINICAL RELEVANCE: The results of the current study suggest that, from a biomechanical point of view, it may be beneficial to reconstruct both bundles of the anterior cruciate ligament to better restore normal anterior tibial translation and combined rotation.     

Long-term results of the Leeds-Keio anterior cruciate ligament reconstruction

This paper discusses the long-term results of the anterior cruciate ligament (ACL) reconstruction with the Leeds-Keio (LK) prosthetic ligament. For this type of reconstruction we used arthrotomy and an arthroscopy-assisted technique. The fixation was obtained with two bone plugs, and the distal portion was also attached with a staple. A postoperative protocol was used with a progressive range of motion and weight bearing after 50 days. We performed 50 LK operations in professional and amateur athletes aged 17–39 years with an isolated anterior instability. We reviewed at follow-up (5–7 years) 37 patients; 8 were lost, and 5 had a subsequent failure. At the Lysholm score the patients were classified: 19 excellent, 13 good, 3 fair, and 2 poor. At the IKDC grading the patients were classified as follows: 2 class A, 22 B, 8 C, and 5 D. The Lachman test was 1+ in 15 patients, 2+ in 7, 3+ in 2, and negative in 13: pivot shift was 1+ in 9, 2+ in 7, 3+ in 2, and negative in 25. Results of the KT 1000 test at 30 Ib side to side was <3 mm in 23 patients, 3–5 mm in 6, 6–10 mm in 6, and >10 mm in 2. In view of the results observed and the progressive deterioration over the years, this procedure should no longer be performed as an ACL substitute.     

Mucoid degeneration of the anterior cruciate ligament

Mucoid degeneration of the anterior cruciate ligament (ACL) is a rare cause of knee pain. We report a case of a patient with mucoid degeneration of the ACL, presenting with posterior knee pain and no history of a major knee trauma. On clinical examination, the active range of motion showed a flexion deficit. The posterior knee pain was induced by passive hyperflexion of the knee. There was no evidence of ligamentary instability. MRI showed a diffuse thickening of the ACL with a nodular mass on the femoral insertion occupying the intercondylar notch, with increased signal intensity on both T1- and T2-weighted images. Arthroscopic evaluation showed a diffuse hypertrophy of the ACL, throughout the entire length of the posterolateral bundle (PLB). A yellowish homogenous mass on the femoral insertion of the ACL impinged on the posterior cruciate ligament (PCL) in flexion and occupied the entire intercondylar notch. We performed an arthroscopic debridement of the hypertrophied tissues as precisely as possible. This resulted in a nearly complete removal of the PLB and immediate relief of symptoms. Examination of knee stability after debridement showed a stable ACL. Arthroscopic debridement of the mucoid degeneration of the ACL proved to be a safe and effective method, without causing ligamentary instability in daily activities.     

MRI analysis of the attachment of the anteromedial and posterolateral bundles of anterior cruciate ligament using coronal oblique images

Purpose

The purpose of this study was to evaluate the course of the anteromedial bundle (AMB) and the posterolateral bundle (PLB) of the anterior cruciate ligament (ACL) with magnetic resonance imaging (MRI) in order to clarify the relationship between the bundles and surrounding anatomic landmarks.

Methods

Eighty-eight knees with intact ACLs were included in this study. MRI coronal oblique images were obtained with the knee in extension and used to assess the following characteristics of the AMB and PLB: (1) course of the ligament, (2) location of the tibial attachment, and (3) femoral attachment and geometry of the lateral femoral condyle inner wall.

Results

In terms of the tibial attachment, the AMB was confluent with the apex of the medial intercondylar ridge (MIR) in all cases. Sixty-five PLBs (74%) inserted into the region between the apex and the slope of the MIR. The resident’s ridge was detected in 91% of the knees in the AMB image, whereas the ridge was clearly visualized in only 17% of the knees in the PLB image. A bony eminence was observed at the inner articular margin of the lateral femoral condyle in the PLB image.

Conclusion

In terms of the tibial attachment, the AMB was confluent with the apex of the medial intercondylar ridge in all cases. Most of the PLBs attached to the region between the apex and the slope of the MIR. Because the bone tunnel location influences clearance between the grafts and the surrounding tissues, these results should be considered during anatomic double-bundle ACL reconstruction.

Level of evidence

Study of nonconsecutive patients without a universally applied gold standard, Level III.

     

A long-term study of anterior cruciate ligament allograft reconstruction

We retrospectively reviewed the long-term clinical outcome of unilateral arthroscopic anterior cruciate ligament (ACL) allograft reconstruction. From October 1995 to December 1997, 64 arthroscopic ACL reconstructions were performed. Multiligamentous knee injuries and ACL injuries in polytrauma patients were excluded and out of the remaining 60 patients 55 were available for follow-up. Three patients had suffered a rerupture caused by major trauma. One patient had a rerupture without significant trauma and one failure was caused by deep infection. These five patients were revised. Fifty patients (36 males, 14 females) were included in the final follow-up. At the time of evaluation, the mean duration of follow-up was 10 years and 6 months. All patients were examined by an independent examiner. Seven patients had an extension lag (<5°) and all patients had a knee flexion of at least 120°, with a mean flexion of 135 ± 5° compared to 135 ± 8°. At the time of follow-up, the median IKDC score was 97 (74–100). The Lysholm scoring scale had a median value of 95 (76–100). The median sports level on the Tegner scale was 6 (4–9). The one-leg-hop test showed a mean value of 95 ± 5%. One patient did not perform the one-leg-hop test because of recent surgery to the Achilles tendon. In conclusion, the tibialis anterior or tibialis posterior tendon allograft ACL reconstruction produced good clinical results in the majority of patients at long-term follow-up.     

Infrapatellar heterotopic ossification after anterior cruciate ligament reconstruction

Reconstruction of the anterior cruciate ligament (ACL) is currently a common procedure. We report a case of ACL reconstruction using an autologous patellar tendon graft, where great infrapatellar heterotopic ossification occurred post-operatively. We found no similar cases in the literature. We discuss about the probable origin.     

Proprioceptive comparison of allograft and autograft anterior cruciate ligament reconstructions

The aim of this study is to search if there is any proprioceptive difference between auto and allograft anterior cruciate ligament (ACL) reconstructions, and also to determine if there is any relationship between instrumented anterior knee laxity and proprioception after an ACL reconstruction. The following four groups were constituted for this purpose: group I, control group; group II, autograft reconstructions; group III, allograft reconstructions and group IV, people with injured ACLs. Each group consisted of 20 patients/volunteers. Two subgroups were constituted according to the findings of KT-1000 laxity testing in group II and III; patients/volunteers found to have a laxity of 3 mm or less were enroled in the normal subgroup and those with a laxity of more than 3 mm were enroled in the lax subgroup. Two proprioceptive tests were used: threshold to detect passive motion (TDPM) and joint position sense (JPS) by using Cybex Norm dynamometer. Patients underwent ten tests and the discrepancy in degrees was averaged for ten trials. Comparisons were made to evaluate the proprioceptive differences between groups/subgroups; ANOVA and t test was used for comparisons where appropriate, and the significance was set at P < 0.05. There was a significant difference in degrees between patients with injured ACLs and the other three groups in TDPM evaluations (injured: 1.93° vs. control: 1.03°, autograft: 1.01°, allograft: 0.96°; P < 0.001). Auto and allograft reconstructions were not different from each other and controls. Allo and autograft ACL reconstructions are not different from each other according to proprioceptive measurements. Also, proprioception is not correlated to postoperative anterior knee laxity; many variables involve joint proprioception and mostly the anterior knee laxity may not be the sole determining element, and a lax ACL still may fulfill some of its afferent arc functions as long as it bridges the femur and tibia.     

前交叉韧带中前内束与后外束功能上的差异研究

目的研究前交叉韧带(ACL)中前内束(AMB)与后外束(PLB)在维持膝关节稳定性方面所起的不同作用。方法对12具新鲜冰冻尸体的膝关节标本在分别屈曲0°、15°、30°、60°及90°下对胫骨施加100N的前负荷及在0°、15°、30°下5Nm的胫骨内旋负荷,使两束韧带拉伸并带动电阻应变片形变引起阻值改变,从而引起输出电压值的变化。结果在对胫骨施加100N前负荷的条件下,AMB在屈膝60°和90°时的原位拉力显著>屈膝0°和15°时(P<0.05);而PLB在屈膝0°和15°时的原位拉力显著>屈膝30°、60°和90°时(P<0.05);在屈膝0°和15°时PLB的原位拉力显著>AMB(P<0.05);而在屈膝30°、60°和90°时AMB的原位拉力显著>PLB(P<0.05)。在对胫骨施加5Nm内旋负荷时,在屈膝15°和30°时AMB的原位拉力显著>PLB(P<0.05);在膝关节完全伸直位时二者无统计学差异(P>0.05)。结论虽然在ACL的双束中AMB起主要作用,但PLB的辅助作用仍不可忽视,其体现在膝关节接近伸直位维持前向和内旋稳定性方面。     

A deficient anterior cruciate ligament does not lead to quadriceps avoidance gait

Without an intact anterior cruciate ligament (ACL) to resist anterior tibial translation, it is commonly believed that ACL-deficient patients employ alterations in walking. Although there is no consensus in the literature about the specific kinematic and kinetic adaptations in these patients with ACL tears, the gait adaptation of quadriceps avoidance is perhaps the one most popularized. The purpose of our study was to determine whether quadriceps avoidance is common in patients with ACL-deficiency. We used a video-based motion analysis system and surface electromyography (EMG) to study 18 patients with ACL-deficiency. All patients demonstrated an internal knee extension moment during early mid-stance (similar to normal subjects). Quadriceps EMG activity was noted throughout most of stance. No patients demonstrated an internal knee flexion moment, a decreased internal knee extension moment or a decreased duration of quadriceps EMG activity during stance. The findings of this study would suggest that quadriceps avoidance as a gait adaptation in ACL-deficient patients may be less common than previously reported.     

Kinetic changes associated with extended knee landings following anterior cruciate ligament reconstruction in females

ObjectivesTo determine the relationship between knee flexion excursion symmetry and lower extremity kinematics, kinetics, and muscle, joint, and ligament forces in females 1–3 years after ACL reconstruction.DesignCross-sectional.SettingLaboratory.ParticipantsTwenty-one, college-aged females.Main outcome measuresLower extremity kinetics and kinematics, including estimated muscle, tibiofemoral, and ligament forces were assessed using 3D motion analysis and a musculoskeletal modeling approach. Participants demonstrating greater than 10% asymmetry in knee flexion excursion were classified as landing with an “extended knee”. Group and between-limb differences were compared.ResultsTen participants were classified as landing with an “extended knee” on the involved limb, while eleven exhibited a symmetric landing pattern. Participants landing with an “extended knee” demonstrated reduced knee extension moment and quadriceps force in the involved limb (p < 0.05).ConclusionsThese findings indicate that an “extended knee” landing pattern was associated with reduced knee extension moment and quadriceps muscle force in females 1–3 years after ACL reconstruction. This may represent an altered strategy that clinicians may choose to identify and address during rehabilitation.     

Mucoid degeneration of the anterior cruciate ligament with erosion of the lateral femoral condyle

We report a case of a mucoid degeneration of the anterior cruciate ligament (ACL) that produced osseous erosion of the medial aspect of the lateral femoral condyle. The MRI findings and differential diagnosis are discussed.     

Feasibility,correlates, and validity of the one-leg sit-to-stand test in individuals following anterior cruciate ligament reconstruction

ObjectiveRegular quadriceps strength assessment is important following anterior cruciate ligament reconstruction (ACLR). The one-leg sit-to-stand (OLSTS) test potentially overcomes the barrier of accessibility to specialised testing equipment. However, feasibility and validity testing of OLSTS is lacking in the ACLR population. This study aims to examine the feasibility, correlates, and predictive validity of OLSTS with self-reported running and jumping difficulty in individuals post-ACLR.DesignRetrospective longitudinal study.Methods20 patients with primary unilateral ACLR were tested at 6-months and 1-year post-ACLR. Feasibility was assessed by the number of patients who had safely performed OLSTS at both timepoints. Cross-sectional gender-adjusted Spearman correlations of OLSTS with quadriceps strength, physical impairments, and psychological variables were measured at 6-months. Predictive validity was assessed via ordinal regression, quantifying the associations of OLSTS with self-reported running and jumping difficulty across time-points.ResultsAll patients understood the instructions to and were able to self-administer the OLSTS test safely. OLSTS is a valid measure of quadriceps strength (gender-adjusted Spearman's ρ = 0.53, P = 0.02). Knee pain (ρ = 0.44, P = 0.046) and readiness to return-to-sport (ρ = 0.55, P = 0.02) were additional correlates. Greater OLSTS performance was associated with greater odds of better self-reported running and jumping function (interquartile-range ORs, 12.0 [95% CI: 3.6–45] and 18.5 [95% CI: 5–67], respectively).ConclusionOLSTS is a feasible and valid test of quadriceps strength, demonstrating predictive validity with self-reported running and jumping post-ACLR. OLSTS potentially allows independent tracking of ACLR rehabilitation progress at home – an increasingly urgent necessity in the face of a global pandemic.     

Analysis of the graft bending angle at the femoral tunnel aperture in anatomic double bundle anterior cruciate ligament reconstruction: a comparison of the transtibial and the far anteromedial portal technique

The aim of this study is to investigate and compare the three dimensional bending angle of the graft at the femoral tunnel aperture in the transtibial and the far anteromedial portal technique. Seven fresh-frozen human cadaveric knees were used. Six degrees-of-freedom of knee kinematics and knee position data were measured using an electromagnetic device and the three dimensional bending angles of the each graft at the femoral tunnel aperture were calculated by computer simulation. Additionally, in order to assess the stress on the graft, the length change between the femoral and tibial attachment sites of the AM and PL bundle were calculated. The maximum length of each bundle was detected at full extension of the knee. The relative change of the length of the PL bundle in the range of 70°–0° of knee flexion was significantly larger than that of the AM bundle. (P < 0.05) Maximum graft bending angles in both techniques were obtained at full extension where the graft was fully stretched. The AM and PL graft bending angles in the transtibial technique were significantly larger than in the far anteromedial portal technique at low flexion angle (AM: 0°–10°, PL: 0°–50°) (P < 0.01). This suggests use of the far anteromedial portal technique might result in lower stress on the graft at the femoral tunnel aperture and therefore might reduce graft damage.