Hisashi Kurosawa

Load-bearing mode of the knee joint: physical behavior of the knee joint with or without menisci.

The load-bearing mode of the knee joint and the load-carrying capacity of the menisci were investigated by a load-deflection and load-contact study using stresses of as much as 3 times body weight on 14 freshly amputated knee specimens. A flection angle of 0 degrees was used. The average deflection and the average size of the contact area of the intact knees were 1.04 x 10(-1) cm and 14.1 cm2 respectively when the knees were loaded to 1,500 N. The elastic modulus of the entire joint was 2.7 x 10(2) MPa over the load of 1,500 N. At first, the knee joint was not congruous at a low load under about 500 N; the joint contacts both menisci in conjunction with some part of the exposed cartilage. However, the joint became markedly congruous at higher loads, around 1,000 N. The joint was in contact with the menisci and the exposed cartilage, and as more load was applied, the areas of contact widened to the peripheral areas of both the compartments. After menisci were removed, the deflection increased. The size of the contact areas decreased significantly by a third to a half. Consequently, the average stress increased 2 to 3 times that of the intact knee. The elastic modulus was increased over 2 fold after menisci were removed. The results of the energy study indicate that the menisci gave more elastic stability to the joint. After the menisci were removed, more energy was dissipated during cyclic loading. Thus, the menisci provide surface compliance and serve to transmit stresses across the wider areas to the periphery, and, therefore, help to avoid stress concentration both in the articular cartilage and in the subchondral bone, especially under high loads over 1,000 N.

Roentgenographic and clinical findings of patellofemoral osteoarthrosis. With special reference to its relationship to femorotibial osteoarthrosis and etiologic factors.

In order to determine definitive clinical and roentgenographic findings of patellofemoral osteoarthrosis (PF-OA) and the etiologic factors of this disease as well as its relationship to femorotibial osteoarthrosis (FT-OA), 108 knees having moderate to severe PF-OA with or without FT-OA were investigated. Pain and disabilities of activities of daily living (ADL) due to PF-OA most likely appeared during movements requiring deep flexion of the knee. Roentgenographic findings revealed a great majority of the disease occurred on the lateral side of the PF joint, both in cases of PF-OA alone and in PF-OA combined with FT-OA. There was no relationship between the degree of PF-OA advancement determined by roentgenographic findings and that of ADL disabilities. PF-OA and FT-OA seemed to be caused by different etiologic factors, because the degrees of involvement of the PF and FT joints were not correlated with each other in the cases of PF-OA combined with FT-OA. Since a clear history of dislocation or subluxation of the patella was noted in 18% of PF-OA (this figure increased to 28% if limited to the cases affected with PF-OA alone), and since roentgenographic findings also agreed with this evidence, dislocation or subluxation of the patella seemed to be one of the causes of PF-OA.

Load-bearing pattern of the ankle joint - Contact Area and Pressure Distribution

SummaryThe contact area of eight human talocrural joints was measured. After preparation, the talocrural joint was set into the compression machine. Under loading the casting was made by silicon rubber and the pressure distribution was measured by pressure sensor sheet. The contact area was localized at anterior and lateral parts. Under 1,500 N loading, the contact area was 522 mm2 and the maximum pressure was 9.9 MPa. Slight diastasis caused a decrease of the contact area and an increase of pressure.ZusammenfassungAn acht menschlichen oberen Sprunggelenken wurde der Gelenkkontakt analysiert. Nach der Vorbereitung wurde das obere Sprunggelenk in eine Kompressionsmaschine eingespannt. Unter beibehaltener Belastung wurde eine Gußform aus einer Gießmasse hergestellt and auch die Verteilung des Druckes mit einem drucksensitiven Papier vermessen.Die Gelenkkontaktfläche auf der Talusrolle liegt im ventrolateralen Bereich. Unter 1500 N Kompression ist der Maximumdruck 9.9 MPa and der Flächeninhalt 522 mm2. Eine kleine Diastase des oberen Sprunggelenks bewirkt eine Verringerung der Kontaktfläche und eine Vermehrung des Druckes.

Clinical features of 22 cases with “Inter-Sterno-Costo-Clavicular Ossification”

SummaryWe present 22 cases with inter-sterno-costoclavicular ossification. Clinical and pathological findings show that abnormal ossification observed in this situation is due to non-suppurative chronic inflammation of the soft tissues around the sterno-costo-clavicular region such as the costo-clavicular ligament. We have classified X-ray findings into three stages according to the extent of the ossification; localized, generalized, and hyperostotic, and show that the disease progressed in this sequence. A considerable number of the patients showed abnormal X-ray findings in the spine or the sacro-iliac joint. Frequent association of pustulosis palmaris et plantaris was noted in this disease. Most of the cases were treated effectively with anti-inflammatory drugs, but a few cases required surgical resection of the ossified mass with the clavicle or the first rib in order to relieve the severe pain.ZusammenfassungEs wird über 22 Fälle von “InterSterno-Costo-Clavikulärer Ossifikation” berichtet. Die klinischen und pathologisch-anatomischen Befunde zeigen, daß die abnorme Ossifikation durch tine nichteitrige, chronische Entzündung im Bereiche der Sterno-Costo-Clavikular-Region und des costo-clavikulären Ligamentes hervorgerufen wird. Wir klassifizieren die Röntgenbefunde in 3 Stadien, entsprechend dem Grad der Verknöcherung: lokalisiert, generalisiert und hyperostotisch. In dieser Reihenfolge schreitet auch die Erkrankung fort. Eine betrdchtliche Zahl der Patienten zeigten auch abnorme Röntgenbefunde an der Wirbelsäule oder den Sacroiliacalgelenken. Eine häufige Begleiterscheinung der Erkrankung war auch eine Pustolosis palmaris et plantaris. Die meisten Fälle wurden erfolgreich mit entzündungshemmenden Medikamenten behandelt; bei einigen Patienten wurde eine Besserung der Beschwerden erst nach chirurgischer Entfernung der verknöcherten Masse, einschließlich Clavikula oder 1. Rippe, erzielt.

Insufficiency of the anterior cruciate ligament - Review of our 118 cases

SummaryRecurrent anterior and internal rotatory subluxation of the tibial plateau is a disabling symptom in patients with insufficiency of the anterior cruciate ligament.Since 1970 we have used the N-test, a special jolt test to detect the characteristic instability. One hundred eighteen cases with anterior-internal rotatory instability of the knee seen at the Kanto Rosai Hospital and the University of Tokyo Hospital and diagnosed by arthroscopy and arthrotomy from 1973 to 1978 were reviewed. Most of the patients were athletes or sportsmen and the injuries commonly occurred in deceleration-injury mechanism and 81% of the cases were associated with meniscal tear.Thirty-two cases were reconstructed by iliotibial tract transfer, twenty of whom had been evaluated from 1–5 years after operation. Postoperatively, giving-way incidents disappeared in eleven, markedly decreased in five, and were unchanged in four patients. The anterior and internal rotatory subluxation of the tibial plateau disappeared or decreased in seventeen and was unchanged in two cases.Some type of defective anterior cruciate ligament was recognized in all our 118 cases and the capsular lesions were considered to play only a secondary role in exhibiting the instability.ZusammenfassungDie periodisch rezidivierende Subluxation des Tibiakopfes nach vorne and innen ist ein charakteristisches Syndrom bei Patienten mit einer Insuffizienz des vorderen Kreuzbandes. Um these Instabilitat ermitteln zu können, verwenden wir seit 1970 den sogenannten “N-Test”, eine von uns entwickelte Variante des “Pivot-shift”-Testes.Im Kanto Rosai Hospital und in der Universitätsklinik Tokio konnten von 1973–1978 118 Fälle mit dieser Instabilitat untersucht and durch Arthroskopie und Arthrotomie diagnostisch gesichert werden. Die Mehrzahl der Patienten waren Sportler, bei denen es bei Decelerationsmechanismen zum Unfall kam. In 81% der Fälle lag gleichzeitig ein Meniskusriß vor. Von 32 durch Verlagerung des Tractus iliotibialis behandelten Patienten werden 20 1–5 Jahre post operationem nachuntersucht. In 11 Fällen verschwand das „giving-way”, das unsichere, plötzliche Nachgeben im Knie vollständig; in 5 Fällen nahm es deutlich ab und nur 4mal blieb es unverändert. In 17 Fällen verschwand oder verringerte sich die Rotationssubluxation nach vorne and innen und nur in 2 Fällen trat keine Veränderung ein. Ein Defekt des vorderen Kreuzbandes wurde in all unseren 118 Fällen festgestellt wohingegen Kapselverletzungen beim Zustandekommen der Instabilität als zweitrangig angesehen werden.

Muscle fiber atrophy in the quadriceps in knee-joint disorders

SummaryIn order to determine whether there is a different susceptibility of muscle fiber types in the m. vastus lateralis (VL) in knee-joint disorders, histochemical studies were performed on 112 cases. Anterior cruciate ligament (ACL) injuries affected 51 patients; ACL injuries associated with meniscus (ACL+M) injuries affected 29. Twenty-five patients had sustained meniscus injuries and seven had injuries of the collateral ligaments (CL). Fifty-two were athletic and 60 were not. On each biopsy, fiber-type distribution was obtained and the degree of atrophy of each fiber type was estimated from two parameters, the mean diameter and the percentage of atrophied fibers. The “distribution of type-1 fibers averaged 38.0% ± 12.0%. There were no significant differences among disorders in the distribution of type-1 fibers. Both parameters of fiber atrophy revealed a difference in susceptibility between type-1 and type-2 fibers. Atrophy of type-1 fibers was found only in ACL and ACL+M injuries. Type-2 fibers were atrophied in all four disorders. Atrophy of type-2 fibers could be a nonspecific change due to the inactivity of the VL, but type-1 fiber atrophy may relate specifically to the condition of ACL insufficiency.ZusammenfassungEs wurden an 112 Fällen von Kniegelenkserkrankungen histochemische Muskeluntersuchungen durchgeführt, um festzustellen, ob eine unterschiedliche Anfälligkeit der Muskelfasern des M. vastus lateralis (VL) besteht. Darunter waren 51 Patienten mit Verletzungen des vorderen Kreuzbandes (ACL). Neunundzwanzig Patienten hatten ACL-Verletzungen kombiniert mit Meniscusverlet zung (ACL+ M). Fünfundzwanzig Patienten hatten Meniscusverletzungen und 7 Patienten Verletzungen der Seitenbänder (CL). Zweiundfünfzig Personen waren Sportler, 66 waren Nichtsportler. Bei jeder Biopsie wurde die Verteilung der Fasertypen festgestellt und der Grad der Atrophie jedes Fasertyps anhand von 2 Parametern geschätzt, nämlich dem mittleren Durchmesser und der Prozentzahl der atrophierten Fasern. Das Vorkommen von Typ-1-Fasern zeigte eine große Variationsbreite von 13.5% bis 66.5%, im Durchschnitt 38.0% ± 12.0%. Die beiden Parameter ließen eine verschiedene Anfälligkeit für Atrophie bei Typ-1- und Typ-2-Fasern erkennen. Eine Atrophic der Typ-1-Fasern wurde nur bei Verletzungen der ACL und ACL+ M gefunden. Die Typ-2-Fasern waren bei alien vier Erkrankungen atrophiert. Die Atrophic der Typ-2-Fasern laßt sich als eine unspezifische Veränderung auf Grund der Inaktivität des M. vastus lateralis deuten, während die Typ-1-Faseratrophie eine spezifische Reaktion auf die ACL-Insuffizienz darstellen könnte.

Contact study of the hip joint - Load-deformation pattern, contact area and contact pressure

Summary1. Contact study of the human hip joint was performed in order to understand load-deformation pattern under compressive loading, contact area and contact pressure by our method. 2. Weight-bearing function of the hip joint was confirmed. Deformation of articular cartilage and subchondral bone were made reasonably and joint congruity was considered to be obtained with increasing load. 3. Neither contact area nor distribution of the contact pressure were symmetrical or concentric, and both were dependent on the magnitude of load. 4. The relationship between weight-bearing and early cartilage degeneration was discussed.Zusammenfassung1. Belastungsuntersuchungen des menschlichen Hüftgelenkes wurden durchgeführt, um einen Einblick zu gewinnen in die Belastungsverformung des Gelenkes unter Druckbelastung, sowie um eine Information zu erhalten über die Belastungsflächen und deren Druckbeanspruchung. 2. Die lasttragende Funktion des Hüftgelenkes wurde bestimmt. Die Belastungsdeformation des Gelenkknorpels und des subchondralen Knochens wurde dargestellt und es wurde festgestellt, daß mit zunehmender Belastung eine Verbesserung der Gelenkkongruenz erreicht wird. 3. Weder die Kontaktfläche noch die Druckverteilung waren symmetrisch oder konzentrisch, und beide waren abhängig von der Größe der Belastung. 4. Die Wechselbeziehungen zwischen Belastung und vorzeitiger Knorpeldegeneration werden diskutiert.

The prognosis of meniscectomy in athletes. The simple meniscus lesions without ligamentous instabilities

This study analyzes patient participation in athletic activities after meniscectomy. Seventy simple menis cus lesions in 68 patients without ligamentous insuf ficiency were studied by means of a detailed question naire and clinical and radiological examinations. Fol low-up ranged from 1 to 18.4 years, averaging 4.5 years. These cases are classified into two groups, depending on the intensity of athletic activities. Group 1 consisted of international class athletes and Group 2 consisted of both competitive and rec reational athletes. None of those studied have given up sports following meniscectomy. Results were worse in Group 1 than in Group 2 in both clinical and subjective evaluation. In Group 1 volleyball players presented results worse than those of football (Amer ican style) players and wrestlers. In Group 2 there was no significant difference in results among athletes of various sports. We conclude that the results after meniscectomy are influenced by the quality and fre quency of postoperative athletic activities.

Magnetic resonance imaging and spectroscopy of thigh muscles in cruciate ligament insufficiency

In 21 patients with injury-related, chronic, anterior cruciate ligament insufficiency, 1H-magnetic resonance (MR) imaging and 31P-MR spectroscopy of the quadriceps muscles were performed with a systemic superconductive MR apparatus. The quadriceps of the noninjured side was used as the control. The quadriceps had a reduced cross-sectional area, but the knee flexors were not reduced. T2 values were prolonged in the vastus lateralis, medialis, and intermedius, but those of the rectus femoris were not. Phosphocreatine per inorganic phosphate measured with 31P-MR spectroscopy was decreased in the atrophied muscles, which correlated with the muscular cross-section. There was no difference in the muscular pH as recorded by the chemical-shift measurements of phosphocreatine and inorganic phosphate. Serial measurements of muscle cross-sectional area and high-energy phosphate bonds reflect the recovery of muscles.

Tissue reactions to calcined bone graft

Calcined bone blocks made by heating raw bovine bone at 1200 degrees C were implanted into defects in canine femoral condyles. X-ray diffraction patterns showed that the calcined bone was well-crystallized hydroxyapatite. Rapid, good new bone growth was observed around the calcined bone which was gradually absorbed along its surface and also by the Haversian canals.