Limb asymmetry during recovery from anterior cruciate ligament reconstruction

There is limited literature that follows a population of Anterior Cruciate Ligament Reconstruction (ACLR) patients through recovery. Our aim was to examine differences in movement and loading patterns across time and between limbs over four visits during 12 months post‐ACLR. We hypothesized that kinematic and kinetic data during a stop‐jump would have time‐ and limb‐dependent differences through 12 months post‐surgery. Twenty‐three ACLR athletes performed five vertical stop‐jumps at 4, 5, 6, and 12 months post‐op with motion capture and force plate data collection. The peak knee flexion (PKF) was different between the 4 and 12, 5 and 6, and the 5 and 12 month visits with earlier months exhibiting higher PKF. The peak vertical ground reaction force (vGRF) was lower at 4 than at 5 and 6 months. The peak posterior ground reaction force (pGRF) was lower at 4 months than all other visits. Frontal knee and sagittal hip range of motion (ROM) were different between 12 months and each previous visit. Asymmetries were present in peak vGRF, peak knee extension moment and impulse up to 12 months. The loading rate and peak pGRF demonstrated between limb differences up to 6 months; limb stiffness demonstrated differences up to 5 months post‐ACLR. PKF was only asymmetric at the 4 month visit. While some variables improved in the 12 months post‐ACLR, limb asymmetries in peak knee extension moment, peak vGRF and impulse persisted up to 12 months. Additionally, frontal plane knee and sagittal hip ROM had not normalized at 12 months. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1887–1893, 2018.

     

Distribution of nerve endings in the human dorsal radiocarpal ligament

PURPOSE: The purpose of this investigation was to evaluate the nerve-ending apparatus populations within a large number of adult human dorsal radiocarpal (DRC) ligaments to test the hypothesis that the majority of nerve endings could be grouped into established classifications and that the nerve endings could be found in predictable locations within the substance of the ligament. METHODS: The DRC ligaments were harvested from 20 wrists of 10 fresh cadavers with an average age of 75.6 years within 12 to 18 hours of death. Before the tissues were harvested, radiographs were taken to exclude any arthritic conditions of the wrists. Tissues were fixed, sectioned with a cryostat, and serial sections were collected on glass slides. Slides were processed for fluorescence immunohistochemistry using antibody to protein gene product 9.5 and a secondary antibody conjugated to a fluorescent tag (Alexa Fluor 488). The sections were evaluated with an LSM-510 confocal laser microscope and a Kontron KS 400 image analyzer. Labeled nerve endings were counted, mapped, and reconstructed. RESULTS: The average number of nerve endings in each DRC ligament was 10.1+/-4.7. More than 76% of the nerve endings were found in the 2 ends of the ligament with 23.3% in the central third and approximately 80% distributed in the superficial layer. More than 80% of the nerve endings were discovered in the epiligamentous sheath rather than in the perifascicular spaces. CONCLUSIONS: The distribution of the nerve endings follows a consistent pattern. These results will provide a foundation of morphologic information useful in understanding normal and abnormal neural control of wrist joint mechanics.     

Distribution of neurofilament-positive nerve fibres and sensory endings in the human anterior cruciate ligament

The present immunocytochemical study describes the distribution of neurofilament-containing nerve fibres and corpuscular-like endings in the human anterior cruciate ligament. The entire anterior cruciate ligament of a non-injured knee joint from a child was cut into serial 15-m-thick frozen sections, which were processed for immunofluorescence staining with a monoclonal antibody against the 68-kDa neurofilament subunit. Numerous neurofilament-positive fibres were found in bundles. These bundles were mostly located near blood vessels in the subsynovial layer and in interfascicular gaps. Only a few single nerve fibres were found independent of blood vessels in interfascicular gaps and between collagen bundles. Neurofilament-containing nerve fibres were preferentially located near the bony attachments of the anterior cruciate ligament. Two types of corpuscular-like endings were found, i.e. spiral-like (type I) and spray-like (type II) endings. Similary to nerve fibres, both types of corpuscular-like endings were found mainly near the tibial and femoral attachment sites (15 of 17), whereas only two were found in the middle third of the ligament. Most likely, the type I and type II corpuscular-like endings serve a mechanoreceptive function involved in the sensory control of normal movements and in stress protection.     

Lubricin distribution in the torn human anterior cruciate ligament and meniscus

The objective of this study was to: (1) determine the distribution of lubricin in the human torn anterior cruciate ligament (ACL) and meniscus; (2) determine the distribution of lubricin in the human intact ACL and meniscus; (3) and identify potential cellular sources of lubricin in these tissues. Ten torn ACLs and six torn menisci were obtained from surgeries; for comparison, 11 intact ACLs and 13 intact menisci were obtained from total knee replacements. Samples were formalin fixed and processed for immunohistochemical staining with a monoclonal antibody for lubricin. In torn ACLs and menisci, lubricin was generally found as a discrete layer covering the torn surface. No surface lubricin staining was found on the transected edges produced during excision. Lubricin was also found on the native surfaces of intact ACLs and menisci. In all tissues, lubricin was found in the matrix and intracellularly. The surface layer of lubricin coating torn edges of ACLs and menisci may interfere with the integrative healing process needed for repair. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1916–1922, 2011     

Congenital absence of the anterior cruciate ligament associated wih discoid meniscus

Abstract Congenital absence of the anterior cruciate ligament (ACL) is a rare condition that has been reported only occasionally with other anomalies such as congenital dislocation of the knee, congenital short femur and congenital absence of the menisci. The association of abnormalities in the development of the menisci, condyles and tibial epiphysis has been explained by embryological studies, because these structures develop from common mesenchymal tissue. We report the case of a 12-year-old boy with congenital absence of the anterior cruciate ligament; he was previously treated for a valgus knee in another hospital.Radiography and magnetic resonance imaging showed a congenital absence of the ACL and aplasia of the tibial spine. We preferred conservative treatment until the boy reaches the age of growth maturation, and we have delayed ACL reconstruction to after closure of the physis. The question that arises from this case and from the literature is what kind of treatment to do and when.     

A prospective study to assess the outcomes of revision anterior cruciate ligament reconstruction

Purpose

Continuously increasing numbers of primary anterior cruciate ligament (ACL) reconstructions invites a parallel increase in graft failures and need for revision ACL reconstruction surgery. High failure rates has previously stigmatised the revision surgery. We performed this study using multiple outcome measures together with clinical examination to offer a full assessment of the outcomes of this procedure.

Methods

Twenty patients, with mean age of 29.4 years (17–50 years), were included in this study prior to their revision ACL reconstruction surgery. All patients were followed prospectively collecting the Knee injury and Osteoarthritis Outcome (KOOS), International Knee Documentation Committee (IKDC) and Tegner-Lysholm scores pre- and post-operatively together with clinical assessment of the antero-posterior knee laxity.

Results

After a mean follow up interval of 30 months (16–60 months) significant post-operative improvement of IKDC, Tegner-Lysholm scores and knee antero-posterior laxity together with the Symptoms, Activities of Daily Living (ADL) and Quality of Life (QOL) components of the KOOS score was noticed (P < 0.05). However, there was no similar improvement in pain and sports components of the KOOS score (P > 0.05). There was no difference in the outcomes of different graft types.

Conclusion

Good outcomes of revision ACL reconstruction surgery are achievable. The use of different graft types did not affect the outcome of the procedure. Most of the patients opted to less aggressive sports participation after the revision procedure.     

前交叉韧带胫骨棘止点撕脱骨折的现状与思考

随着关节镜的大量应用,人们对前交叉韧带(ACL)胫骨棘止点撕脱骨折治疗有了更新的认识,国内外对该类骨折从损伤机制、治疗方法、术前术后功能评估、预后等多个方面开展了相关研究工作。但目前临床上对于非手术治疗和内固定方法的应用仍存在着很大的盲目性,单纯凭经验的手法整复、不同内固定方式对骨折的治疗及预后的影响等方面仍然存在较多问题。本文对此进展情况进行了综述,并对其中存在的问题加以分析归纳,提出了有关见解。     

Magnesium ring device to restore function of a transected anterior cruciate ligament in the goat stifle joint

A bioresorbable, mono‐crystalline magnesium (Mg) ring device and suture implantation technique were designed to connect the ends of a transected anterior cruciate ligament (ACL) to restabilize the knee and load the ACL to prevent disuse atrophy of its insertion sites and facilitate its healing. To test its application, cadaveric goat stifle joints were evaluated using a robotic/universal force‐moment sensor testing system in three states: Intact, ACL‐deficient, and after Mg ring repair, at 30°, 60°, and 90° of joint flexion. Under a 67‐N anterior tibial load simulating that used in clinical examinations, the corresponding anterior tibial translation (ATT) and in‐situ forces in the ACL and medial meniscus for 0 and 100 N of axial compression were obtained and compared with a control group treated with suture repair. In all cases, Mg ring repair reduced the ATT by over 50% compared to the ACL‐deficient joint, and in‐situ forces in the ACL and medial meniscus were restored to near normal levels, showing significant improvement over suture repair. These findings suggest that Mg ring repair could successfully stabilize the joint and load the ACL immediately after surgery, laying the framework for future in vivo studies to assess its utility for ACL healing. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2001–2008, 2016.     

Biomechanics of the anterior cruciate ligament and implications for surgical reconstruction

Abstract Injury to the anterior cruciate ligament (ACL) is regarded as critical to the physiological kinematics of the femoral-tibial joint, its disruption eventually causing long-term functional impairment. Both the initial trauma and the pathologic motion pattern of the injured knee may result in primary degenerative lesions of the secondary stabilisers of the knee, each of which are associated with the early onset of osteoarthritis. Consequently, there is a wide consensus that young and active patients may profit from reconstructing the ACL. Several factors have been identified as significantly influencing the biomechanical characteristics and the functional outcome of an ACL reconstructed knee joint. These factors are: (1) individual choice of autologous graft material using either patellar tendon-bone grafts or quadrupled hamstring tendon grafts, (2) anatomical bone tunnel placement within the footprints of the native ACL, (3) adequate substitute tension after cyclic graft preconditioning, and (4) graft fixation close to the joint line using biodegradable graft fixation materials that provide an initial fixation strength exceeding those loads commonly expected during rehabilitation. Under observance of these factors, the literature encourages mid-to long-term clinical and functional outcomes after ACL reconstruction.     

前交叉韧带股骨等距重建位置的比较

目的 :比较模拟生理负荷条件下前交叉韧带股骨重建位置的等距特性。方法 :7具新鲜冷冻尸体膝关节标本 ,在前交叉韧带胫骨附着区取 3点以及胫骨附着区取 5点分别钻骨隧道 ,通过钢丝和等距测量器施加初负荷 ,检测膝关节屈曲过程中胫骨和股骨隧道间的距离变化。结果 :膝关节从 0～ 90°屈曲过程中 ,股骨韧带附着区中点、上点和后点与胫骨附着区 5点间呈等距变化 ,但股骨韧带附着区中点、上点与胫骨附着区 5点间距离变化具有组内显著性差异。结论 :股骨韧带附着区后点是理想的等距重建点。     

Roles of the anterior cruciate ligament and the medial collateral ligament in preventing valgus instability

Both the medial collateral ligament (MCL) and the anterior cruciate ligament (ACL) are reported to prevent valgus instability of the knee. In this study, the anatomical mechanisms by which these ligaments prevent valgus instability were experimentally investigated. The valgus rotation angle and the magnitude of the medial joint space opening were measured in six cadaveric knees, using biplanar photography before and after the MCL and/or the ACL were severed. A significant increase in the valgus rotation angle and a large medial joint space opening were observed when the MCL was severed. An increase in the valgus rotation angle was also observed when the ACL was severed, but only a small medial joint space opening was present. The increase in the valgus rotation angle after ACL severance was nearly parallel to the increase in the internal rotation of the tibia. Thus, we concluded that both ligaments function to prevent valgus instability, but that the anatomical reasons for their function are different. The MCL prevents valgus instability by stopping an opening in the medial joint space. The ACL, on the other hand, prevents the internal rotation of the tibia. When the ACL is severed, the internal rotation increases, and causes the valgus rotation angle to also increase, despite the presence of only a small medial joint space opening. Received: May 16, 2000 / Accepted: August 3, 2000     

Strain in the anteromedial bundle of the anterior cruciate ligament under combination loading.

Strain within the anteromedial bundle (AMB) of the anterior cruciate ligament (ACL) was measured in 13 human knee specimens in order to determine the combination of external loads most likely to cause injury. Using a load application system that allowed 5 df with the flexion angle being fixed, pure loads of anterior/posterior force, medial/lateral force, varus/valgus torque, and internal/external axial torque were applied at three flexion angles: 0 degrees, 15 degrees, 30 degrees. Combined loads were applied in pairs at two flexion angles: 0 degrees and 30 degrees. Liquid mercury strain gauges were used to measure strain in the ACL. Anterior tibial force was the primary determinant of strain in the anteromedial bundle. This strain was significantly larger at 30 degrees flexion than at 0 degrees. The strain sensitivity of the AMB to medial force was approximately one-half that to pure anterior force. The effect of anterior and medial forces was additive when applied in combination. Neither pure axial torque nor pure varus/valgus torque was observed to strain significantly the AMB at any of the flexion angles investigated. However, valgus torque in combination with anterior force resulted in a significantly larger strain than pure anterior force. Internal axial torque in combination with anterior force also resulted in a larger strain than pure anterior force.     

A rare case of giant cell tumour arising from anterior cruciate ligament: Its diagnosis and management

Tenosynovial giant cell tumour is a locally aggressive tumour arising from the synovia of the fibrous tissue surrounding the joints, tendon sheaths and tendons. Areas of predilection are the hand, and in the case of synovial joints, the knee joint is particularly affected. We describe a rare case of an intra-articular localized tenosynovial giant cell tumour arising from the anterior cruciate ligament (ACL) in a 27 year male who presented with pain and giving way of his left knee without prior history of any trauma. Tests for internal derangement of knee were negative. MRI reported an ACL tear with a heterogeneous fibrous mass attached to the distal part, most probably an organized haematoma. It was decided to do a diagnostic arthroscopy before proceeding for ACL reconstruction. Arthroscopy revealed a purple coloured mass attached to distal part of ACL. The mass was removed piecemeal using an additional posterolateral portal. ACL was found intact. Histopathology reported it to be tenosynovial giant cell tumour. The patient was asymptomatic at each subsequent follow up. It is a rare diagnosis which presented as an ACL tear; in such suspected cases it is prudent to perform a diagnostic arthroscopy before going for ACL reconstruction.     

Avulsion of both posterior meniscal roots associated with acute rupture of the anterior cruciate ligament

A rare case of acute avulsion of both posterior meniscal roots concomitant with an acute anterior cruciate ligament (ACL) tear in a professional soccer player is described. While avulsion of the lateral meniscal root has been extensively reported in association with ACL injuries, medial root avulsion has never been reported in association with acute ACL. A review of the video documentation of the match accident revealed the exact mechanism of injury was a forceful external rotation of the standing limb.     

Collagen scaffold supplementation does not improve the functional properties of the repaired anterior cruciate ligament

Primary suture anterior cruciate ligament (ACL) repair was abandoned in favor of reconstruction due to a high rate of clinical failures. However, the insertion of a collagen scaffold loaded with platelets into the wound at the time of suture repair (“enhanced primary repair”) has been shown to improve functional healing in animal models. Our objectives were to determine if using a collagen scaffold alone (without platelets) would be sufficient to increase the structural properties of the repaired ACL and decrease postoperative knee laxity compared to suture repair without the scaffold. Eight Yucatan minipigs underwent bilateral ACL transection and suture repair. In one knee, the repair was augmented with a collagen scaffold (SCAFFOLD group) while the other had suture alone (SUTURE group). After 13 weeks of healing, knee joint laxity and the structural properties of the ACL were measured. The addition of the collagen scaffold to suture repair of a transected ACL did not significantly improve the mean anteroposterior knee laxity [SCAFFOLD vs. SUTURE: 6.1 ± 1.4 vs. 4.4 ± 2.0 mm (p = 0.07), 8.1 ± 2.0 vs. 7.6 ± 2.0 mm (p = 0.66), and 6.2 ± 1.2 vs. 6.1 ± 1.8 mm (p = 0.85) at 30°, 60°, and 90° flexion, respectively]. Likewise, there were no significant differences in the structural properties [SCAFFOLD vs. SUTURE: 367 ± 185.9 vs. 322 ± 122.0N (p = 0.66) and 90.7 ± 29.5 vs. 85.0 ± 30.3N/mm (p = 0.74) for the yield load and linear stiffness, respectively]. The use of a collagen scaffold alone to enhance suture repair of the ACL was ineffective in this animal model. Future work will be directed at stimulating biological activity in the scaffold. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:703–709, 2010     

Outcomes of revision anterior cruciate ligament reconstruction secondary to reamer-irrigator-aspirator harvested bone grafting

Introduction

Patients with widened or misplaced tunnels may require bone grafting prior to revision anterior cruciate ligament (ACL) reconstruction. Utilising reamer-irrigator-aspirator (RIA) harvested bone from the femur showed promising filling rates. Nevertheless, the procedure has neither been validated in a larger population nor been assessed with regards to radiological and clinical outcome of the subsequently conducted revision ACL reconstruction. Therefore, the aim of this study was to evaluate tunnel filling rates, positioning of the revision tunnels and outcome parameters of such two-staged revision ACL reconstructions.