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.

[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.

[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.