Intra-articular ganglion cysts of the knee joint: a report of 85 cases and review of the literature.

Intra-articular ganglia and cysts of the knee joint are rare and mostly incidental findings in MRI and arthroscopy. During a period of 15 years, nearly 8000 knees were arthroscopically examined. In total, 85 intra-articular soft tissue masses were found within the knee cavity. Of these, 76 were incidental and asymptomatic findings in arthroscopy performed for treatment of osteoarthritic symptoms. Several repeated minor knee traumata were reported in this group but no histories of serious traumatic events. Nine ganglion cysts were obviously solely responsible for the intermittent or chronic non-specific knee discomfort, and classified as symptomatic. There were no histories of previous injury to the knees, no clinical signs of instabilities or meniscal and femoropatellar pathologies, and no associated further intra-articular lesions in arthroscopy. Forty-nine cystic masses originated from the ACL, 16 from the PCL, 12 from the anterior (eight medial, four lateral) and three from the posterior horn of the menisci (two medial, one lateral). Three were located in the infrapatellar fat pad, one arose from a medial plica and one from a subchondral bone cyst. All ganglion cysts were successfully resected or excised using arthroscopic technique. A review of the literature is given and compared with the findings and data of this study.

Computer based method for the three-dimensional kinematic analysis of combined posterior cruciate ligament and postero-lateral complex reconstructions on cadaver knees.

The aim of this study is to evaluate the effect of combined posterior cruciate ligament (PCL) and postero-lateral corner (PLC) reconstruction on laxity and three-dimensional kinematics of cadaver knees. We performed anatomical double bundle PCL reconstruction, and functional one bundle 'over-the-bottom' PCL reconstruction combined with one type of PLC reconstruction, running from the postero-lateral tibia to an isometric point near the lateral epicondyle of the femur. Our results showed that combined reconstruction was necessary to restore rotatory laxity. PLC reconstruction, according to the technique described, invariably created a shift towards internal rotation of the kinematic curves, compared to the intact knee.

Comparison of two methods for reconstruction of the posterior cruciate ligament using a computer based method: quantitative evaluation of laxity, three-dimensional kinematics and ligament deformation measurement in cadaver knees.

The aim of this paper is to present a biomechanical comparison of two different methods for reconstruction of the posterior cruciate ligament in cadaver knees. We used an original computer-based method allowing precise calculation of three-dimensional (3D) knee kinematic parameters as well as the estimation of combined graft deformation (elongation-flexion-torsion). After isolated posterior cruciate ligament (PCL) dissection, double bundle and 'over-the-bottom' methods were performed successively on each knee using synthetic polyester ligaments. The effect of pre-tensioning was tested with the 'over-the-bottom' method. antero-posterior (A-P) and rotational laxity as well as 3D kinematics were recorded and analysed. Our computer based method allowed us to show that both reconstruction methods were equivalent in restoring A-P and rotational laxity as well as kinematic curves. Combined deformation of the prostheses was equivalent for both ligaments.

Computer-based method for the 3-D kinematic analysis of posterior cruciate ligament and postero-lateral corner lesions.

Posterior cruciate ligament (PCL) rupture, whether or not combined with postero-lateral corner (PLC) tears, are more often diagnosed today thanks to improved imaging techniques. However, due to the lack of reliable instrumentation to quantitatively evaluate the knee, much is still unknown about the function of these ligamentous structures. The aim of this paper is to present results on the effect of progressive resection of the PCL and PLC on knee laxity and 3-D knee kinematics. The results show that 3-D movement analysis is important and complements laxity measurements by helping to interpret the complex alteration of knee function.

[Functional anatomy of the posterior cruciate ligament]. / Die funktionelle Anatomie des hinteren Kreuzbandes.

The human posterior cruciate ligament (7 unselected specimens) consists of 2 different bundles with a common tibial attachment: 1. a thin, flat and slightly twisted posterior bundle running to the posterior medial condyle taut in extension and lax in flexion of the knee, 2. a thick oval anterior bundle with parallel fibers running to the roof of the notch lax in extension and taut in flexion. This contra-tensile function explains the different posterior instability in extension or flexion of the knee in case of an isolated rupture of only 1 of these bundles.

[Baker's cyst--a pre-arthrotic factor?]. / Die Baker-Zyste--ein präarthrotischer Faktor?

Between July 1989 and 1994 127 Baker-cysts have been operated and histologically examined with synovial biopsies out of the same knee. All Baker-cysts and synovial biopsies - including out of synovial membranes without macroscopically pathological findings and without other pathological intraarticular causal lesions - revealed a chronic synovitis. The Baker-cyst has to be regarded as a primary or secondary causative factor of chronic effusions and involves the development of a chronic synovitis by the disorder of the synovial and hydraulic system of the knee-joint. The exstirpation of the Baker-cyst as a prearthrotic factor is advised therefore.

[Considerations in differential therapy of insufficiency of the anterior cruciate ligament. Principles and clinical consequences]. / Uberlegungen zur differenzierten Therapie bei Insuffizienz des vorderen Kreuzbandes. Grundlagen und klinische Konsequenzen.

Ruptures of the anterior cruciate ligament are among the most frequent injuries of the joints. There is no longer any doubt regarding the necessity for surgical intervention. Several clinical and experimental studies suggest that the instability of the knee joint results in an accelerated degeneration of the menisci and cartilage. There are differences of opinion regarding the type of surgical procedures to stabilize the knee-joint. Although there are many different surgical procedures described in various publications, only one technique emerges as the preferred one. This paper will demonstrate different therapeutic concepts, based on the biomechanical background for the treatment of the anterior knee instability. It will consider the morphology of injuries, the demands of the patient and the full range of rehabilitative possibilities. Described herein are the indications and techniques of augmentation, protection and prosthetic replacement.

[Technical, material and biomechanical requirements for alloplastic replacement of the anterior cruciate ligament surgical technic]. / Materialtechnische und biomechanische Grundlagen beim alloplastischen Ersatz des vorderen Kreuzbandes Operationstechnik.

Chronically instable knee-joints progressively draw to an arthrosis as a result of the irregular kinematic. Different operative techniques to replace the anterior cruciate ligament using exclusively autologous, homologous or heterologous grafts in all cases of chronic instabilities, but the primary sole suture of acute ACL injuries, too, didn't show long-term stable results in many cases. Recurrent ruptures were found first of all at the intraarticular edge of the femoral tunnel caused by permanent abrasions of the replacement. The reason why is the large angle of the ACL and each replacement respectively under motion. The question of what tissue could or should be used for renewed autogenous reconstructions in case of re-instabilities and after using bone-tendon-bone-mid-third patellar-tendon-grafts isn't yet been discussed to the end. Because of the fact that there is no isometric behaviour of the complete ACL but of a few fibres only depending on the position of the knee the complete reconstruction of the ACL is absolutely impossible, but only a partial substitute. The anatomically limited intraarticular joint-space (notch) confines the replacements in their dimension and endangers voluminous reconstructions by an impending impingement especially as a result of the immediately postoperative swelling of the transplants. The use of the mid-third-patellar-tendon-graft destroys a lot of proprioceptors and causes a partly loss of the neuromuscular balance previously impaired by the loss of the ACL including its receptors. In addition to this the still existing proprioceptors of the ligamentous stumps can be definitively destroyed by big tunnels. Each autologous graft passes a long-term transformation and at best achieves to 50% of the maximum stress capacity of an original ACL after two years. Resulting from these reasons synthetic and unlimited-ly available ligaments presented themselves to be used for ACL replacements. The Trevira-ligament of polyethylenetherephthalat (= TRE-VIRA HOCHFEST 730R) seems to be best qualified therefore at the present. It meets the material and technical requirements and makes allowance for all biomechanical knowledge. A modified over-the-top technique by arthroscopy or mini-arthrotomy (minimized operative trauma) enables the preservation of still existing ligamentous tissue on the one hand and guarantees the immediate postoperative functional therapy on the other hand. A recurrent instability independent of cause doesn't bring about a worse starting position for the following renewed stabilization and enables corrective operative techniques including the substitute of a ruptured synthetic ligament if required.

[Alloplastic replacement of the anterior cruciate ligament. Material technical and biomechanical principles, surgical technique]. / Alloplastischer Ersatz des vorderen Kreuzbandes. Materialtechnische und biomechanische Grundlagen, Operationstechnik.

The Trevira-ligament of Polyaethylenter-ephthalat (= Trevira-hochfest 730) seems to be the best qualified replacement of the anterior cruciate ligament at the present. It meets all material and technical requirements and makes allowances for all biomechanical knowledges. The modified over-the-top-technique by arthroscopy or mini-arthrotomy (minimal operative trauma) makes it possible to conserve still existing ligamentous and soft tissue and guarantees the post-operative immediate functional therapy. A potential reinstability--independent of each cause--doesn't imply worse starting conditions and enables corrections including the substitute of a ruptured synthetic ligament.