In six ballet dancers with overuse syndromes of the foot a study on the effect of taping on stabilisation, proprioception and muscular activity was performed. By using synchronous surface electromyography and 3-dimensional motion analysis three standard ballet positions without and with applied tape were performed. Muscular activities of pronator muscles (peroneus longus) and supinator muscles (tibialis posterior) were recorded. EMG measurements showed significant differences between patients with stable or unstable ankles and painful or pain-free feet. Applying tape led to significant changes of muscle activities in height and antagonist reflex patterns. These changes were highest in dancers with unstable ankle joints and metatarsalgia.

The coracoacromial ligament (CAL) plays an important role in the pathoetiology of the subacromial impingement syndrome especially in those patients who do not have bony abnormalities. A total of 40 shoulders were dissected to determine the anatomical and biomechanical properties of the CAL in shoulders with either intact rotator cuffs or rotator cuff disease, taken from cadavers of persons who were of various ages at death. The specimens from cadavers with rotator cuff degeneration had a shorter lateral and medial band of the CAL than those of the specimens taken from shoulders with intact rotator cuffs. The cross-sectional area of the lateral band was also enlarged in older specimens with rotator cuff degeneration. Analysis of the structural properties showed a higher load to failure and a higher stiffness in the younger than in older specimens. In material properties, there was a higher failure stress in specimens with normal rotator cuffs than in the specimens with rotator cuff disease but only in older specimens. The decreased material properties in older specimens with rotator cuff disease may be caused by the previously reported histological differences with tissue disorganization and a lack of parallel bundle orientation associated with rotator cuff disease.

Photodynamic laser therapy has been shown to be a new method for the treatment of synovitis in various animal models. Its principle is the accumulation of a photosensitizing drug in the inflamed synovium which is destroyed by photoactivation of the drug. In the present animal study we demonstrate the effect of a second-generation photosensitizer and suggest a concept for light dosimetry within the joint. We used 38 inbred rabbits for the IgG-induced arthritis model; ¶2 mg/kg of the benzoporphyrin derivative monoacid ring-A (BPD-MA) Verteporfin were administered 3 h before irradiation, which was performed using a 690-nm diode laser coupled to quartz glass fiber with a cylinder diffusor tip at a total light energy of either 180 or 470 J. During irradiation specific fluorescence of BPD-MA was monitored using a spectroscopy unit. The effect of the photodynamic laser therapy was documented grossly and histologically after 1 week. Within the 470 J-group a complete necrosis of the inflamed synovium was observed. The bradytrophic structures of the joint, however, remained unchanged. Throughout the 180 J-group the extent of necrosis was minor. During irradiation the tissue fluorescence of BPD-MA showed a dose-dependent decrease. Using BPD-MA as a photosensitizer a highly selective and minimal invasive synoviorthesis can be performed. At a dose of 2 mg/kg the histological effect depends on the light dose. For optimum efficacy a total energy of 470 J seems favorable. Online fluorescence detection can be used to monitor the effect of light administration. For dosimetry therefore an online tissue fluorescence detection may represent a technical solution.

Die rheumatische Entzündung nimmt ihren Ausgang vom entzündlichen Pannusgewebe, das die betroffenen Gelenke mit ihren Kapseln, Sehnen und Bändern zerstört. Bei der photodynamischen Lasertherapie (PDT) für die chronische Polyarthritis erfolgt in der Synovialis die selektive Anreicherung eines Medikaments (Photosensibilisator), dessen nachfolgende Laseraktivierung einen zytotoxischen Effekt bewirkt. Die Durchführbarkeit einer photodynamischen Therapie wurde am Tiermodell der IgG-induzierten Arthritis des Kaninchens erprobt. Dieses Tiermodell entspricht histologisch den proliferativen Phasen einer Rheumatoiden Arthritis. Als Photosensibilisatoren wurden 3 verschiedene Substanzen getestet (Photosan-3, 5-Aminolävulinsäure und das Benzoporphyrinderivat BPD-MA). Eine spezifische Anreicherung der Photosensibilisatoren in der Deckzellschicht und im lymphoplasmazellulären Infiltrat wurde beobachtet. Nach Laserbestrahlung des Gelenks zeigte sich eine vollständige Zerstörung der Synovialis bis zur darunter liegenden Gelenkkapsel mit 2 der 3 Photosensibilisatoren, Photosan-3 und BPD-MA. Im Gegensatz dazu waren die bradytrophen Strukturen von Knorpel, Meniskus und Ligamenten weder makroskopisch noch mikroskopisch verändert. Die photodynamische Lasertherapie stellt ein neues Verfahren zur Behandlung der Synovitis dar. Ihre Vorteile sind Effektivität und maximale Selektivität bei gleichzeitig minimaler Invasivität. Damit bietet die photodynamische Therapie eine neue Perspektive für die chirurgische Behandlung chronisch-entzündlicher Gelenkerkrankungen.

The results of 320 arthroscopic procedures are reported here, in which laser surgery using the holmium: YAG laser is compared with conventional mechanical methods. The patients were followed-up during a 2-year period and the data analyzed in a prospective study. The following knee injuries were included: meniscal lesion, chondromalacia, combined meniscal/cartilage lesion, rheumatoid synovialitis and patellofemoral pain syndrome. Because strict inclusion criteria were used, the patient collective is homogenous. Gender, age, injured side, intrasurgical diagnosis, and the initial values of the Lysholm score (modified after Klein) are congruous. After 2 years, the results of the laser collective were significantly improved, whereas the results for the conventional collective, especially for chondromalacia and synovialitis, did not show the same improvement. Analysis of the effect of various instruments and the laser system itself show differing results for the various knee disorders. The hemostatic effect of the holmium: YAG laser was excellent during surgery of all knee disorders, including surface treatment. Operating time for laser surgery was not prolonged, in contrast to what is often claimed. This study shows that chondromalacia, combined meniscal-cartilage lesions, and chronic rheumatoid synovialitis are treated more effectively and with better results with the holmium: YAG laser than with conventional arthroscopic methods. Furthermore, laser treatment of lateral retinacular release can be considered to be better than mechanical techniques. No significant advantage can be found for using the laser during meniscectomy. Lasers are useful for treating smaller, hard-to-reach joints and lower the risk of iatrogenic cartilage damage. The holmium: YAG laser is a suitable instrument for arthroscopic surgery.

The introduction of arthroscopic techniques has improved the surgical therapy of rheumatoid arthritis. The additional application of the holmium:yttrium aluminum garnet (Ho:YAG) laser likewise holds great promise by providing complete hemorrhagic control. Unfortunately, a minimally invasive solution for use in smaller joints has not yet emerged. The present study describes the possible treatment of these joints by means of photodynamic laser therapy. Cell culture studies with human synovial fibroblasts obtained from patients with rheumatoid arthritis have demonstrated a cytotoxic effect after administration of Photosan-3 as a photosensitizer and subsequent laser irradiation at 630 nm. for the in vivo studies, IgG-induced arthritis in rabbits, which is histologically consistent with the proliferative phase of rheumatoid arthritis, was used as the animal model. The histologic picture following photodynamic laser therapy with Photosan-3 revealed complete synovial destruction which also extended to the border of the subjacent joint capsule. In contrast, bradytrophic structures, e.g. cartilage. menisci, and ligaments, remained unchanged at both the macroscopic and microscopic levels. Therefore, photodynamic laser therapy can be considered a new method in the surgical treatment of inflammatory disease of the synovial membrane. It has the advantage of being minimally invasive, while offering a high degree of efficacy and selectivity.

For over 10 years fiber-guided laser systems have been used in arthroscopic surgery. The possibility of a mutagenic risk by the use of lasers has not been sufficiently repudiated, especially for the Excimer laser at a wavelength of 308 nm, which is close to the absorption spectrum of DNA. The aim of this study therefore was to approximate the mutagenic risk of UV-laser wavelengths using an in vitro transformation assay. BALB/3T3 fibroblasts were irradiated with Excimer laser wavelengths of 248 nm and 308 nm. The resulting transformation rates were compared to those of untreated cells and to cells that were subjected to an x-ray dose of 1 Gy. Pulse energy, frequency, and irradiation time were varied over a wide range, from sublethal fluences to total cell death. Furthermore, the effect of repeated irradiation (split-dose) was analyzed. The results for the 248 nm irradiation showed a highly significant transformation rate (P < 10(-9)). In contrast, results for the 308 nm irradiation were not at all significant (P < .18). The transformation rate of cells that were treated with x-rays was increased exponentially compared with the controls. Although an increased transformation rate was found after 248 nm irradiation, that of the wavelength 308 nm was not enhanced. The study therefore shows that the use of the Excimer wavelength 308 nm in arthroscopic procedures does not imply a specific mutagenic risk.

The results of experimental and clinical studies using different laser systems in intradiscal blind and endoscopic/foraminoscopic lumbar disc operations are described. We describe the evolution from blind intradiscal techniques starting in 1989 to current endoscopic/foraminoscopic procedures in 1997. Lasers are important and useful tools in these procedures.

The principle of photodynamic laser therapy (PDT) for chronic polyarthritis consists in specifically concentrating a drug (photosensitizer) in the synovium. Subsequent activation of the photosensitizer by means of laser leads to a cytotoxic effect. The practicability of PDT was first shown in cell cultures of human synovial fibroblasts. For further tests an animal model consisting of IgG-induced arthritis in rabbits was used. In this model, concentration of the photosensitizer in the synovial lining cells, in the media of arteries and in the lymphoid infiltrate was seen. After laser irradiation there was total selective demarcation of the synovium. In contrast, bradytrophic tissues such as cartilage, meniscus and ligament structures were changed neither macroscopically nor microscopically. In the animal model PDT combines high selectivity with minimal invasiveness and can be used in small joints. PDT thus offers ideal preconditions for future minimal invasive treatment of chronic inflammatory joint diseases.

We experimentally tested the effect of Laser light at wavelengths of 1064 nm, 1320 nm, 1440 nm and 2100 nm on intervertebral disc tissue. The tested parameters were tissue ablation, determined by weight reduction, and temperature change, measured with thermoelements. We used bovine nucleus pulposus tissue for ablation measurement and human spine segments for temperature measurement. We found that variation of single parameters such as power, frequency and energy per pulse had only a slight effect on ablation. The decisive factor for the mass of tissue ablated seems to be the total applied energy. One indispensable requirement is a suction unit; we procured a manifold increase in ablation rate using suction. In the investigations of tissue temperature, we found no risk to upper or lower plate when the fiber was centered correctly in the disc. Within a distance of 10 mm from the fiber tip, the temperature development was found to be radial, so no more tissue damage is to be expected in front of the tip than to the side of it. Although the various wavelengths tested are absorbed differently in water there were only small differences in temperature. Using a neodymium: YAG laser with a fiber of 400 micron diameter, we sometimes measured high cannula temperatures, showing that case one has to be exercised, especially with high energies. In conclusion, it can be said that both the Holmium:YAG laser and the neodymium:YAG laser are suitable for disc decompression with the parameters used currently in surgery.

The results of 320 patients after holmium:YAG laser treatment in comparison to conventional mechanical methods during a 2-year period were analyzed in a prospective, randomized study. The following knee injuries were included in the study: meniscal lesion, chondromalacia, combined meniscal/cartilage lesion, rheumatoid synovitis and femoropatellar pain syndrome. Because strict inclusion criteria were used, the patient series is homogeneous, not only in terms of sex, age, injured side and intrasurgical diagnosis, but also because the initial values of the Lysholm score modified after Klein are similar. After 2 years, the results of the laser series were significantly improved, whereas the results for the conventional series, especially for chondromalacia and synovitis, did not show the same improvement. Analysis of the effect of various instrumentation and the laser system itself show differing results for the different knee disorders. The hemostatic effect of the holmium-YAG laser was excellent during surgery for all knee disorders, including surface treatment. The operation time for laser surgery was not prolonged, as is often stated. This study shows that chondromalacia, combined meniscal-cartilage lesions and chronic rheumatoid synovitis are treated more effectively and with better results with the holmium-YAG laser than with conventional arthroscopic methods. Furthermore, laser treatment of meniscectomy and lateral retinacular release is also better than mechanical techniques. This study demonstrates the feasibility of the holmium-YAG laser for arthroscopic surgery. A combination of different instruments seems to be most effective.

Chronische Polyarthritis (cP) läßt sich noch immer nicht zufriedenstellend behandeln. Wahrscheinlich durch eine Autoimmunreaktion ist bei cP die Synovialmembran entzündlich verändert, und es kommt in schwereren Fällen zu einer Zerstörung von Knorpel und Knochen des Gelenkes [FEHR]. Medikamentöse Behandlungen, wie z. B. mit Methotrexat, und die Synoviorthese mit Osmiumsäure oder Radionukliden sind mit starken Nebenwirkungen belastet, so daß der mechanischen Entfernung der entzündeten Synovialis (Synovektomie) ein besonderer Stellenwert zukommt [SIEBERT]. Trotz zunehmendem Einsatz arthroskopischer Technik besteht gerade bei den kleinen Gelenken der Hände und Füße noch Bedarf an einem weniger invasiven Verfahren als Alternative zur Synovektomie.

The aim of this study was the dynamic measurement, with magnetic resonance imaging, of temperature in cartilage irradiated by laser. Fresh specimens, each with chondromalacia grade II and III, were irradiated with a Holmium:YAG laser under MRI control. Temperature was measured by means of the proton-shift method, which allows high temporal and spatial resolution. With this method a maximum increase in temperature of 35 degrees was found after irradiation with 1.0 J and 10 Hz for 5 s at a distance of 1 mm. In no case at all was an increase in temperature of more than 10 degrees observed in the cartilage adjacent to the subchondral bone. These results exclude the possibility of significant thermal damage from laser treatment as described.

Since 1987/1988 percutaneous laser disc decompression (PLDD) has been used clinically for treatment of intervertebral disc prolapses. Credible prospective investigations that have been conducted since 1989 with large patient collectives are now available for analysis of their medium-term results and comparison with other minimally invasive procedures. Our follow-up examination of the first 180 patients treated with PLDD from 1989 to 1993 shows a success rate of 72.8%, similar to that with other percutaneous techniques (automated percutaneous lumbar discectomy, percutaneous lumbar discectomy, chemonucleolysis). To guarantee success, the spinal surgeon must have command of the correct technique and also use the appropriate instruments. Good results with the PLDD procedure can be procured when contraindications and indications for patient selection are strictly observed. Overall, our 5 year results seem encouraging.