J. Bruns

Ätiologie und Pathogenese der Osteochondrosis dissecans tali

ZusammenfassungDie Osteochondrosis dissecans tali stellt eine Sonderform der osteochondralen Läsionen des Talus (OLT) dar und sollte nosologisch von diesen unterschieden werden. Ein Trauma mit nachfolgend radiologisch gesicherter osteochondraler Defektzone wird als traumatische OLT der Osteochondrosis dissecans tali im engeren Sinne gegenübergestellt.Die Läsion stellt eine Erkrankung des subchondralen Knochens dar und kann nahezu alle Gelenke des menschlichen Körpers betreffen. Die OD des Talus ist nach Kniegelenk und Ellenbogen die dritthäufigste Lokalisation mit einem Anteil von 4% aller Fälle von OD. Bevorzugt tritt die Osteochondrosis dissecans tali im 2. Lebensjahrzehnt auf, wenngleich ein Auftreten in jeder Altersstufe prinzipiell möglich ist.Die unterschiedlichen ätiologischen Faktoren der Osteochondrosis dissecans (mechanich, vaskulär, endogen, genetisch, bakteriell-infektiös) sind auch für die Osteochondrosis dissecans tali diskutiert worden. Insgesamt wird das Trauma als wichtigster ätiopathogenetischer Mechanismus favorisiert. Unterschiedliche Arbeiten zeigen eine Koinzidenz mit Distorsions- und Supinationstraumata in der Anamnese. Die bevorzugte Lokalisation der Osteochondrosis dissecans tali im Bereich der medialen und seltener der lateralen Talusrolle deckt sich mit experimentellen Untersuchungen, die eine erhöhte mechanische Belastung der Areale bei Varus-/Valgushaltung bzw. Pro-/Supinationsstellung zeigen konnten.Das Supinationstrauma wird in der Modellvorstellung sowohl für die häufigere mediale tassenförmige Läsion (cup-shape) als auch für die laterale waffelförmige Läsion (waver-shape) verantwortlich gemacht. In Anbetracht der komplexen Biomechanik des oberen (OSG) und unteren Sprunggelenks (USG) stellen solche Vorstellungen eine unzulässige Vereinfachung dar, die in Zukunft weitergehender Abklärung bedarf.Die pathogenetischen Stadien unterscheiden sich bei der Osteochondrosis dissecans tali nicht von denen anderer Lokalisationen. Ist ein imaginärer Schwellenwert erreicht, kommt es im Initialstadium (Stadium I) zu einer subchondralen Osteonekrose, die bei ausbleibender Regeneration über eine subchondrale Sklerosierung (Stadium II) zu einer Demarkation (Stadium III) und schließlich zur Dissekation (Stadium IV) führen kann.Die klinische Symptomatik ist unspezifisch. Periartikuläre Schwellungen, Gelenkergüsse, Bewegungseinschränkungen und seltener Gelenkblockaden werden beklagt. Differentialdiagnostisch ist die Abgrenzung zwischen OLT und Osteochondrosis dissecans tali meist schwierig. Hingegen kann die Osteochondrosis dissecans tali von anderen Erkrankungen des Sprunggelenks (Talusnekrosen, Subchondrale Ganglien) gut unterschieden werden.AbstractOsteochondritis dissecans of the talus is a particular form of osteochondral lesions of the talus. A trauma with subsequent osteochondral defect detected immediately by radiology has to be differentiated from osteochondritis dissecans of the talus.Osteochondritis dissecans (o.d.) is primarily a disease of the subchondral bone and can affect almost every joint in the human organism. After the knee and elbow, the talus is the third most common site of the disease accounting for 4% of all cases. It mostly arises in the 2nd decade but can occur at almost any age.Different etiological factors of osteochondritis dissecans (vascular, traumatic, infectious, endogenous, genetic) are discussed in general and in particular for the talus. In the literature, the etiopathogenetic mechanism of trauma is favored. Several studies show an anamnestic coincidence of distorsion and/or supination trauma prior to the onset of o.d. at the talus.The most common localization of the o.d. lesion is the middle and posterior third of the medial and less frequently anterior and middle third of the lateral talus. Biomechanical experiments demonstrated that these areas are those with the highest load under varus/valgus and pronation/supination stress.Trauma is held responsible for both the more frequent medial, cup-shaped lesion and the less frequent lateral, wafer-shaped lesion. Taking into consideration the complex motion patterns of the ankle joint, these conceptions should be abandoned and the exact pathomorphogenetic mechanism assessed more closely in future. Other possible etiological factors such as genetic, metabolic or infectious causes are discussed but are not yet substantiated by scientific and experimental evidence.The different stages of o. d. do not differ from the stages in other joints and from aseptic osteonecrosis. Theoretically, it seems that o.d. is initiated when an imaginary threshold value is reached so that a subchondral osteonecrosis occurs (stage I). Repetitive mechanical forces possibly interfere with the regeneration process of the lesions, resulting in the development of a subchondral sclerosis (stage II). Further disturbance of the regenerative process may lead to a demarcation of the osteochondral area (stage III) and eventually dissecation (stage IV) of the fragment with loose bodies in the joint.Clinical symptoms are nonspecific. Periarticular swelling, hydrarthrosis, reduced range of motion and sometimes joint locking are the most common clinical signs. Differentiation of o.d. from posttraumatic osteochondral lesions of the talus is sometimes difficult or even impossible. In contrast, other entities of the tibiotalar joint (such as talar necrosis or subchondral ganglion) can be easily distinguished.

A ganglion of the anterior horn of the medial meniscus invading the infrapatellar fat pad. Case report.

A case of ganglion of the medial meniscus that had invaded the infrapatellar fat pad is presented. Review of the literature embraces theories of pathogenesis, the effect on the surrounding tissue, the radiological techniques and the therapy.

Perfusion culture system: Synovial fibroblasts modulate articular chondrocyte matrix synthesis in vitro

OBJECTIVE To investigate the interactions of chondrocyte metabolism by synovial cells and synovial supernatants in a new perfusion co-culture system. METHODS Chondrocytes and synovial fibroblasts were obtained from knee joints of slaughtered adult cattle. For experimental studies chondrocytes and synovial fibroblasts were placed together into a perfusion chamber (co-culture) or were placed into two different perfusion culture containers, which were connected by a silicone tube (culturing of chondrocytes with synovial supernatants). A control setup was used without synovial cells. Chondrocyte proliferation was shown by measurement of DNA content. The proteoglycan synthesis was quantified using (35)SO(4)(2-)-labelling and the dimethylmethylene blue assay. (3)H-proline incorporation was used to estimate the protein biosynthesis. Type II collagen synthesis was measured by ELISA, furthermore extracellular matrix deposition was monitored immunohistochemically (collagen types I/II). Regarding to the role of reactive oxygen species LDH release before and after stimulation with hydrogen peroxide was measured. RESULTS The proliferation of chondrocytes shows an increase in monoculture as well as in co-culture or in culture with synovial supernatants more than fivefold within 12 days. (3)H-proline incorporation as a marker for chondrocytes biosynthetic activity decreases in co-culture system and in culture with synovial supernatants. A similar effect is seen measuring total proteoglycan content as well as the (35)SO(4)(2-) incorporation in chondrocytes. Co-culturing and culturing with synovial supernatants lead to a significant decrease of proteoglycan release and content. Quantification of collagen type II by ELISA shows significant lower amounts of native collagen type II in the extracellular matrix of co-cultured chondrocytes as well as in culture with synovial supernatants. The membrane damage of chondrocytes by hydrogen peroxide is reduced when chondrocytes are co-cultured with synovial fibroblasts. CONCLUSION The co-culture perfusion system is a new tool to investigate interactions of different cell types with less artificial interferences. Our results suggest that synovial supernatants and synovial fibroblasts modulate the biosynthetic activity and the matrix deposition of chondrocytes as well as the susceptibility to radical attack of reactive oxygen species.

Synovial hemangioma--a rare benign synovial tumor. Report of four cases.

We report our clinical experiences in the diagnosis and treatment of four patients with synovial hemangiomata. Synovial hemangiomata are rare causes of recurrent, nonspecific joint complaints and occur most often at the knee joint. Nontraumatic joint swelling combined with recurrent, possibly hemorrhagic joint effusions must be considered signs of a synovial hemangioma. Although no preoperative diagnostic tool enables confirmation of the diagnosis, and MRI seems to be the diagnostic procedure of first choice, it is most important fact for the clinician to be aware of the existence of this disease. Early surgical treatment with the excstence of this disease. Early surgical treatment with excision of the tumor within wide margins of noninvolved normal synovial tissue as partial or total synovectomy is the therapy of choice and avoids degenerative changes as demonstrated with the four cases reported here.ZusammenfassungAnhand von 4 Kasuistiken wird über mögliche Symptome, Befunde und präoperativ durchgeführte diagnostische Verfahren beichtet, die mit der Erkennung und Therapie des seltenen, gutartigen synovialen Hämangioms verbunden sein können. Danach gibt es keine präoperative Maßnahme, die in jedem Fall die sichere Diagnosestellung ermöglicht. Daraus ist zu folgern, daß bei mehrdeutigen klinischen und bildgebenden Befunden frühzeitig an das Vorliegen eines synovialen Hämangioms gedacht werden muß. Als Therapie der Wahl ist die möglichst frühzeitige und vollständige Tumorresektion, verbunden (je nach Befund) mit einer partiellen oder totalen Synovektomie, zu empfehlen. Langfristiges Abwarten oder Verzicht auf eine Tumorentfernung haben sekundärarthrotische Veränderungen zur Folge.

Pyridinoline cross-links as markers for primary and secondary bone tumors

Background: Determination of hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) in urine is a promising method to determine bone resorption. This method is independent of gender, diet and kidney function (creatinine clearance >25 mL/min). Methods: The diagnostic efficacy of HP and LP was assessed in the urine of adult patients suffering from primary malignant bone tumors (n=24), bone metastases (n=38) and soft tissue sarcoma with additional osseous involvement (n=13). The values were compared with those obtained from 543 healthy controls (aged 15 to 65 years). Results: Results clearly exhibited a highly significant increase in HP values (57.75 nmol/mmol creatinine) in adult tumor patients (aged 15 to 65 years) in all three subgroups in comparison with the control group values (22.23 nmol/mmol creatinine) (p=0.001). Although the LP fraction is more specific for bone than HP, the values of LP from all subgroups of the adult tumor patients were less distinctly but still significantly increased (p=0.008). Regarding the HP:LP ratio, tumor patients exhibited a markedly increased average molar HP:LP ratio (12.0:1) in comparison to controls (6.6:1). Conclusion: Determination of HP and LP in urine appears to offer clinical utility for the detection of primary and secondary bone neoplasms. Prospective, longitudinal studies will be necessary to evaluate whether the HP:LP ratio is indicative of a relapse of the tumor and consecutively may be adopted in the follow‐up of patients with neoplasms.

Etiological aspects in osteochondritis dissecans patellae

Abstract In a retrospective study probable etiological factors of rare cases of osteochondritis dissecans of the patella were analyzed. Anamnestic data and data obtained from standardized roentgenography in the anterior-posterior, axial, and lateral views of the patella were evaluated. Anamnestic data provided no evidence of the etiology in addition to the fact that several patients mentioned a single or multiple trauma. In contrast to this, evaluation of the roentgenograms showed that most of the patients with osteochondritis patellae exhibited a flat articular surface of the patella (types I and V in Hertel’s classification) and a distinct accumulation of the patellae with greater lateral than medial facet (types II and III in Wiberg’s classification). Furthermore, the axial shape of the patellar groove exhibited a distinct accumulation of type III trochleae, representing a hypoplasia of the medial and hyperplasia of the lateral part of the trochlea. Evaluation of the lateromedial patellar alignment revealed in a distinct accumulation of grade II dislocation medially and laterally. Although the data were obtained from a rather small number of patients, in our opinion these results support the theory of biomechanical induction of osteochondritis dissecans patellae. Further dynamic analyses are needed to clarify biodynamic effects on the patella and the patellofemoral joint.

COST ANALYSIS OF THREE DIFFERENT SURGICAL PROCEDURES FOR TREATMENT OF A PELVIC TUMOUR

Introduction: Malignant pelvic tumours are rare, but adequate treatment is difficult because of anatomical and functional reasons. Different surgical procedures are recommended. Besides aspects influencing the quality of life due to the different surgical techniques, costs of these surgical procedures and the perioperative time interval, depending on the chosen surgical procedure, must also be considered. Methods: Costs of three kinds of surgical treatment – internal hemipelvectomy vs external hemipelvectomy and application of an orthotic device vs ilio-femoral pseudoarthrosis – were compared, including costs of the immediate period of rehabilitation. Costs of the preoperative diagnostic procedure were excluded because they were assumed to be equal. For all calculations, treatment of a periacetabular pelvic tumour type II-b was assumed, according to the Enneking classification, with the need for a pelvic resection with wide margins including removal of the hip joint. This analysis was performed based on the average costs per hour of physicians, nurses and physiotherapists, including a basic daily rate for additional costs, such as housekeeping and administrative costs of the hospital. In all cases, the costs of the operative procedure and the perioperative period up to 3 months were calculated, including the costs for the endoprosthetic device after internal hemipelvectomy and those for the orthotic devices after necessary external hemipelvectomy. Results: For a postoperative period of 3 months, the cost for treatment with resection of the tumour and performing an ilio-femoral pseudoarthrosis is nearly DM 56,741.54; treatment with an internal hemipelvectomy including the endoprosthetic pelvic replacement costs DM 81,439.34; and treatment with external hemipelvectomy and application of an orthotic device with a pelvic cage costs DM 69,138.46. In this analysis, social costs due to the different rates of disability for years or costs of a new prosthetic device after years and aspects related to resulting quality of life were excluded. In contrast, costs of three different actual cases can differ significantly from the estimated costs. The most important influencing items are surgical implants, blood units and similar products, and surgical treatment of postoperative complications. Conclusions: Regarding all these aspects, limb salvage seems to be advantageous over amputation. Whether an ileo-femoral pseudoarthrosis or endoprosthetic pelvic replacement should be performed is a decision that should be made by the physicians, based on the underlying diagnosis and the correlated expected survival. Furthermore, additional factors probably reducing the rate of postoperative complications, such as infections or necrosis following radiotherapy and being summarised under the term “quality of life”, should also be regarded.

Bilateral osteochondritis dissecans of the medial trochlea femoris: an unusual case of patellofemoral pain

We report a case of bilateral osteochondritis dissecans of the medial trochlea femoris. Arthroscopic removement of loose bodies in the symptomatic left knee led to an excellent result; the untreated right knee showed effusion and locking one year later. This condition should be considered in the diagnosis of patellofemoral pain.

Autologous meniscus replacement with rib perichondrium. Experimental results

ZusammenfassungIn einer tierexperimentellen Untersuchung wurde die Fähigkeit untersucht, ob autogenes Rippenperichondrium in der Lage ist, einen Ersatzmeniskus zu bilden. An 18 Schafen wurde eine mediale Meniskektomie durchgeführt, bei 12 Tieren wurde dieser Meniskus durch einen angepaßten autogenen Rippenperichondriumstreifen ersetzt, die übrigen 6 Tiere dienten als Kontrollen ohne Implantation eines Meniskusersatzes. Eine postoperative Gewichtsentlastung wurde durch Achillessehnentenotomie und partielle -tenektomie erzwungen. Die Auswertung erfolgte makro- und mikroskopisch, polarisationsoptisch, rasterelektronenmikroskopisch sowie biomechanisch mit Testung der Reißfestigkeit und des Dehnungsmoduls. Bei den Kontrolltieren zeigt sich lediglich die bekannte Bildung eines kleinen Ersatzmeniskus, der in Form und Größe nur eine kleine Randleiste an der Gelenkkapsel bildet und aufgrund seiner schlechten Gewebequalität biomechanisch nicht prüfbar war. Aus implantierten Perichondriumstreifen bildete sich ein Meniskusersatz, der in der Form der originärer Menisken entsprach und in der Größe mindestens 80 % der explantierter Orginalmenisken entsprach. Mikroanatomisch entwickelte sich im zeitlichen Verlauf eine Faserorientierung, die der origniärer Menisken entsprach. Hinsichtlich der Knorpelprotektion zeigte sich nur in einem Fall eine oberflächliche Läsion in der Verumgruppe. Dagegen boten die Kontrolltiere in allen Fällen eine vom zeitlichen Verlauf abhängige Knorpelarrosion. Histologisch zeigten jedoch alle Perichondriummenisken eine zentrale Verkalkung. Biomechanisch waren die Werte der Ersatzmenisken hinsichtlich der Reißfestigkeit und des Dehnungsmoduls deutlich schlechter als die der originären Menisken.SummaryThe purpose of our study was to examine the potential of autologous perichondrial tissue to form meniscal replacements. Eighteen mature sheep were used. In 12 animals a complete meniscal resection was performed; replacement was formed using strips of autologous perichondrial tissue explanted from the lower rib; six animals with a complete meniscal resection but without any replacement served as controls. In all animals restriction from weight-bearing was achieved by means of transsection and partial achilles-tendon resection. Six animals each, 4 of group T and 2 of group C, were sacrificed after 3, 6, and 12 months. Perichondrial grafts and the underlying articular cartilage were removed and investigated by gross macroscopic examination, by means of light and scanning electron microscopy, polarized light examination, and biomechanical tests evaluating the failure stress and tensile modulus. In all transplanted animals a new perichondrial meniscus developed. After 3 months the transplants resembled in size and thickness normal menisci, while in the control animals only small rims of spontaneously grown tissue were detectable. Microscopically, the perichondrial menisci exhibited similarity to normal collagen fiber orientation and cellular characteristics, but, in their central region, areas of calcification disturbed the regular tissue differentiation. In contrast, spontaneously grown tissue in control animals lacked normal fiber orientation and cellularity. Scanning electron-microscopy of perichondrial menisci revealed surface characteristics similar to normal sheep menisci without fissures and lacerations, while the control specimens exhibited such defects. The femoral and tibial cartilage being in contact with the new menisci showed normal surface characteristics apart from one animal with slight surface irregularities. Control animals showed surficial lesions after 3 months, and the extent increased from 6 to 12 months postoperatively. Exemplary microangiographies of the newly grown tissue exhibited a less intense vascularisation after three months when compared to normal menisci with an improving tendency after 6 and 12 months. Biomechanically, values of the failure stress as well as of the tensile modulus of perichondrial menisci were significantly lower than those of normal contralateral menisci. But, spontaneously regenerated tissue in meniscectomized animals exhibited even smaller values also with significant differences towards original menisci. There were no significant differences in values of newly grown perichondrial menisci and spontaneously grown tissue.

In-vitro-Anzüchtung humaner autogener osteoblastärer Zellen auf natürlichem Knochenmineral

ZusammenfassungDie Behandlung knöcherner Defekte erfolgt mit unterschiedlichen Methoden. Der „Goldstandard“ bei der Auffüllung von Knochendefekten ist die autogene Spongiosaplastik. Die Gewinnung erfolgt durch einen Zweiteingriff, der mit Komplikationen für den Patienten behaftet ist. Seit langem wird nach Alternativen zur Knochendefektbehandlung gesucht. Neben allogenen Knochen haben die verschiedenen Calciumphosphatkeramiken, wie Hydroxylapatit und Tricalciumphosphate eine breite Anwendung erfahren. Das Problem dieser Biomaterialien ist die unzureichende knöcherne Integration und lange Einheilungsphase. Das Ziel im Rahmen des „Tissue Engineering“ ist ein Biomaterial herzustellen, das dem natürlichem Knochen am nächsten kommt. In unserer Studie haben wir das natürliche Knochenmineral Bio-Oss®/Orthos® als Matrix für humane osteoblastäre Zellen verwendet. In vitro konnten wir zeigen, dass ein Anwachsen humaner osteoblastärer Zellen auf dem natürlichen Knochenmineral möglich ist. Auch nach einem Zeitraum von bis zu 3 Monaten zeigten die Zellen noch osteoblastären Charakter und Proliferation. Die histologische Auswertung ergab eine konfluente Zellanheftung und Einwachsen der humanen osteoblastären Zellen in das dreidimensionale interkonnektierende Porensystem. Die Ergebnisse zeigen, dass die standardisierte Anzüchtung humaner osteoblastärer Zellen möglich ist. Durch die Kombination humaner osteoblastärer Zellen mit einer geeigneten Matrix kann die Herstelllung eines autogenen Biokomposits in vitro eine neue Behandlungsmöglichkeit von Knochendefekten darstellen.SummaryDifferent methods are available for the treatment of osseous defects. In recent years the use of autologous bone was established as the golden standard. However, significant disadvantages are limited availability of the bone graft and its harvest implies additional morbidity for the patient. Alternatives to the use of autologous bone, as allogeneic bone from bone banks or biomaterials like hydroxyapatite are therefore of special interest. However, the currently available methods have severe disadvantages; allogenic bone carries a high risk of transmitting infectious diseases, most biomaterials show an unsatisfying osseous integration as well as prolonged healing with disability for the patient. Therefore, the aim has to be the development of a biomaterial that is as close as possible to human bone. In this in vitro study the natural bone mineral Bio-Oss®/Orthos® was used as a matrix for human osteoblast – like cells isolated from bone marrow of healthy patients. Even after three months the cell showed typical osteblast-like behaviour. Histologic evaluation demonstrated the ability of Bio-Oss®/Orthos® to guide cell growth within its matrix structure and therefore mimics in vivo situation of the healthy bone. The results show that culturing human osteoblast-like cells under standardised conditions is possible and that the combination of human osteoblast-like cell with an appropriate matrix may have the potential for a new treatment option of osseous defects.