Gebhard Suger

Basal ganglia participation in language pathology

Abstract Language disturbances were studied in 40 patients with well-demarcated vascular lesions of the speech-dominant hemisphere. Computerized cranial tomography was used for localization of the lesion. Special emphasis was given to the analysis of automatized speech and repetitive verbal phenomena. Subcortical infarctions with basal ganglia involvement led to transient aphasia although long-lasting abnormalities of language could be detected in these patients. Aphasia was more severe if a cortical lesion was combined with a basal ganglia lesion. Automatisms and recurring utterances occurred only with combined cortical and basal ganglia lesions. A lesion of Wernickes area alone, without involvement of prerolandic structures or subcortical nuclei, was sufficient to produce long-lasting aphasia, whereas lesions of Brocas area alone produced only transient language disturbances. The results are compatible with a recent theory of multiple cerebral representation of function.

In vivo effect of shock-waves on the healing of fractured bone

In a controlled animal experiment we attempted to clarify the question of whether there is a stimulating effect of extracorporeal shock-waves on the repair process of fractured long bones. As a fracture model we used an osteotomy in the diaphysis of the ovine tibia and an external fixation device. Shock-wave treatment at two levels of intensity and with four different numbers of applied shocks was performed with an electromagnetic acoustic source. Healing of the osteotomized bone was evaluated by biomechanical and radiological investigations on the whole bone as well as on bone sections from areas of the fracture gap and the periosteal fracture callus. We found a non-significant tendency to deterioration of the fracture healing with increasing shock-wave intensities. The study of treatment parameters led neither to significantly different biomechanical outcomes nor to altered radiological results in comparison to the untreated control group. RELEVANCE:--While we cannot comment upon the effectiveness of extracorporeal shock-waves in the delayed treatment of fractures or pseudarthrosis, our results suggest that shock-waves have no beneficial effect in acute fracture repair.

The influence of stiffness of the fixator on maturation of callus after segmental transport

The treatment of large bony defects by callus distraction is well accepted, but the duration of treatment is long and the rate of complications increases accordingly. We have examined the effect of the stiffness of the axial fixator on reducing the time for maturation of callus. We created a mid-diaphyseal defect of 15 mm in the metatarsal bone in sheep and stabilised it with a ring fixator. After four days a bony segment was transported for 16 days at 1 mm per day. After 64 days the animals were divided into four groups, three with axial interfragmentary movement (IFM) of 0.5, 1.2 and 3.0 mm, respectively, and a control group. The 3.0 mm IFM group had the smallest bone density (p = 0.001) and area of callus and the largest IFM after 12 weeks; it also had typical clinical signs of hypertrophic nonunion. The most rapid stiffening of the callus was in the 0.5 mm group which had the smallest IFM (p = 0.04) after 12 weeks and radiological signs of bridging of the defect. These results indicate that suitable dynamic axial stimulation can enhance maturation of distraction callus when the initial amplitude is small, but that a large IFM can lead to delayed union.

Influence of preoperative mechanical bone quality and bone mineral density on aseptic loosening of total hip arthroplasty after seven years

OBJECTIVE To test mechanical bone quality and bone mineral density of the femoral head at the day of implantation as indicators for femoral prosthesis loosening. METHODS Mechanical bone quality of a femoral head slice was assessed by destructive compression testing combined with bone mineral density measurements using peripheral quantitative computed tomography. Fourteen patients with walking pains were attainable for a radiographical follow-up mean 7.1 years after implantation. RESULTS Radiolucent lines along the stem were evident in 11 of 14 femurs, most of them seen in Gruen zones 7, 6, 1, 3, 14, and showed strong correlations to preoperative bone strength (r=-0.80; P<0.001) and axial stiffness (r=-0.75; P=0.002), yet not to bone mineral density (r=-0.67; P=0.009). Slight varus deviations <3 degrees were noted in six femurs. Preoperative strength was reduced in this femurs to 54% (P=0.006), and stiffness to 61% (P=0.038), while bone mineral density did not differ significantly. CONCLUSIONS Femoral prosthesis loosening after seven years can be predicted by mechanical bone quality of the femoral head at the time of implantation. Bone mineral density measurements may also indicate future stem loosening but have to interpreted carefully, keeping in mind a poorer predictive value. RELEVANCE Indications and choice of type of hip arthroplasty should be balanced in osteoporotic bones in particular. While preoperative bone mineral density measurement allows the prediction of mechanical bone quality, its relevance in predicting failure in arthroplasty treatment remains unclear.

Die Korrektur posttraumatischer diaphysärer Fehlstellungen an der unteren Extremität

Summary. Post-traumatic deformities do occur as a result of disturbed fracture healing with loss of bone stock, necrosis of fragments or the development of pseudarthrosis resulting in malunion or progressive malalignment. In the majority of the cases these disturbances can be related to technical problems of primary fracture treatment like insufficient reduction or implant failure. On the other hand, complex deformities with involvement of the adjacent joints may also be a result of injuries of the growth plate in childhood. In some cases primary correction is impossible because of critical conditions of the bone and the soft tissue envelope in the center of deformation. If a secondary correction is indicated, knowledge of all reconstructive techniques is essential to choose the appropriate method and carry out successful and exact correction of malalignment of the affected limb after detailed planning.Zusammenfassung. Fehlstellungen nach Extremitätentraumen können als Folge von Frakturheilungsstörungen auftreten, welche zu Knochensinterungen und Pseudarthrosen mit zunehmender Achsabweichung und Verkürzung führen. Daneben führen Verletzungen im Kindesalter unter Beteiligung der Wachstumsfugen zu komplexen Fehlern, die nicht zuletzt auch das angrenzende Gelenk in seiner Kontur mit betreffen können. Nicht selten liegen die Ursachen auch in technischen Fehlern der Frakturerstversorgung, insbesondere Instabilität der Osteosynthese oder ungenügende Reposition, die je nach angewandtem Stabilisationsverfahren zu typischen Fehlstellungen führen. Bei komplizierten Frakturheilungsverläufen mit kritischer lokaler Weichteil- und Knochensituation kann – trotz rechtzeitigen Erkennens einer sich abzeichnenden Fehlstellung – deren frühzeitige Korrektur sich aus eben den lokalen Gründen verbieten. Auch bei der Spätkorrektur solcher Fehlstellungen mit initial lokaler Knochen- und Weichteilproblematik müssen alle Verfahren der Rekonstruktion beherrscht werden, um – nach exakter planerischer Analyse – unter Berücksichtigung der Komplexität und der lokalen Situation die Auswahl des jeweils optimalen Korrekturverfahrens zu treffen

Korrekturen bei Asymmetrien der unteren Extremität

ZusammenfassungDie operative Korrektur bei Asymmetrien der unteren Extremitäten ist sehr komplex. Trotz modernster diagnostischer Technik sind die sorgfältige Anamneseerhebung und die körperliche Untersuchung des Patienten nach wie vor der erste Schritt zur Festlegung der weiteren Diagnostik. Die Kenntnis der methodenabhängigen Normwerte, ihrer physiologischen Schwankungen und der intraindividuellen Differenzen sind Grundvoraussetzung. Bei der posttraumatischen Deformität kann man sich an der gesunden Gegenseite orientieren. Ab der 3fachen intraindividuellen Standardabweichung besteht in der Regel die Indikation zur Operation. Die Indikationsstellung darf sich aber nicht nur auf einzelne Messwerte stützen, die Beschwerden und Bedürfnisse des Patienten sowie die Kompensationsmöglichkeiten müssen ebenfalls berücksichtigt werden. Aus der Vielzahl der möglichen Operationstechniken muss die für den Patienten geeignetste gewählt werden. Vor allem bei kniegelenksnahen Umstellungsosteotomien zur Behandlung der medialen Gonarthrose sollte der Patient realistisch über die Erfolgsaussichten und endoprothetische Alternativen aufgeklärt werden. Bei Kindern zwischen 10 und 14 Jahren ist heute die perkutane Epiphysiodese eine zuverlässige minimal invasive Methode zur Korrektur von Längen- und Achsdeformitäten im Bereich der unteren Extremität.AbstractThe surgical correction of malalignments of the lower extremities is a very demanding procedure. It requires extensive knowledge of: (1) fundamental lower extremity biomechanics, (2) various diagnostic modalities, and (3) methodology for multidimensional preoperative planning. Despite advanced techniques in diagnostics and surgery, the history of the patient and a physical examination are still the first steps in the diagnostic chain. The knowledge of the method-dependent normal values, their physiological range and intra-individual differences are a prerequisite. In posttraumatic deformities, the healthy leg is a good reference for the patients geometric orientation. As a rule, values differing by three times the standard deviation or more are good indications for an operation. These are 15 and 12 mm for the upper and lower leg, 18 and 15 mm for the whole leg and only 3°mm for the mechanical leg axis measured using computer tomograpy and long standing x-rays, respectively. The indication for surgical correction is not only based on geometric data. The patients functional needs, symptoms, complaints and compensation possibilities must also be taken into account. The lower extremities have to be assessed in a psychosocial context. Among the huge number of possible surgical techniques, the procedure best suited for the patient has to be selected. This requires extensive knowledge and advanced technical skills from the treating orthopaedic surgeon. In supracondylar or high tibial osteotomies for the treatment of medial arthritis of the knee joint, the patient should be informed of the long term prognosis and endoprosthetic alternatives. Today, percutaneous epiphysiodesis is a very reliable and minimally invasive surgical technique for correcting the length and axis of the lower extremity in children between 10 and 14 years. With well planned epiphysiodesis procedures, it is often possible to avoid complex osteotomies in younger patients.

Osteotomies in malalignments of the lower extremities

ZusammenfassungDie operative Korrektur bei Asymmetrien der unteren Extremitäten ist sehr komplex. Trotz modernster diagnostischer Technik sind die sorgfältige Anamneseerhebung und die körperliche Untersuchung des Patienten nach wie vor der erste Schritt zur Festlegung der weiteren Diagnostik. Die Kenntnis der methodenabhängigen Normwerte, ihrer physiologischen Schwankungen und der intraindividuellen Differenzen sind Grundvoraussetzung. Bei der posttraumatischen Deformität kann man sich an der gesunden Gegenseite orientieren. Ab der 3fachen intraindividuellen Standardabweichung besteht in der Regel die Indikation zur Operation. Die Indikationsstellung darf sich aber nicht nur auf einzelne Messwerte stützen, die Beschwerden und Bedürfnisse des Patienten sowie die Kompensationsmöglichkeiten müssen ebenfalls berücksichtigt werden. Aus der Vielzahl der möglichen Operationstechniken muss die für den Patienten geeignetste gewählt werden. Vor allem bei kniegelenksnahen Umstellungsosteotomien zur Behandlung der medialen Gonarthrose sollte der Patient realistisch über die Erfolgsaussichten und endoprothetische Alternativen aufgeklärt werden. Bei Kindern zwischen 10 und 14 Jahren ist heute die perkutane Epiphysiodese eine zuverlässige minimal invasive Methode zur Korrektur von Längen- und Achsdeformitäten im Bereich der unteren Extremität.AbstractThe surgical correction of malalignments of the lower extremities is a very demanding procedure. It requires extensive knowledge of: (1) fundamental lower extremity biomechanics, (2) various diagnostic modalities, and (3) methodology for multidimensional preoperative planning. Despite advanced techniques in diagnostics and surgery, the history of the patient and a physical examination are still the first steps in the diagnostic chain. The knowledge of the method-dependent normal values, their physiological range and intra-individual differences are a prerequisite. In posttraumatic deformities, the healthy leg is a good reference for the patients geometric orientation. As a rule, values differing by three times the standard deviation or more are good indications for an operation. These are 15 and 12 mm for the upper and lower leg, 18 and 15 mm for the whole leg and only 3°mm for the mechanical leg axis measured using computer tomograpy and long standing x-rays, respectively. The indication for surgical correction is not only based on geometric data. The patients functional needs, symptoms, complaints and compensation possibilities must also be taken into account. The lower extremities have to be assessed in a psychosocial context. Among the huge number of possible surgical techniques, the procedure best suited for the patient has to be selected. This requires extensive knowledge and advanced technical skills from the treating orthopaedic surgeon. In supracondylar or high tibial osteotomies for the treatment of medial arthritis of the knee joint, the patient should be informed of the long term prognosis and endoprosthetic alternatives. Today, percutaneous epiphysiodesis is a very reliable and minimally invasive surgical technique for correcting the length and axis of the lower extremity in children between 10 and 14 years. With well planned epiphysiodesis procedures, it is often possible to avoid complex osteotomies in younger patients.

Rekonstruktion vs. Amputation: Entscheidungsfindung bei der chronischen Osteitis

ZusammenfassungDie Entscheidung für oder gegen den Erhalt einer chronisch infizierten Extremität ist schwierig und hängt von unterschiedlichsten Faktoren ab.Neben der lokalen Knochenund Weichteilsituation sind das Alter des Patienten, spezifische Begleiterkrankungen sowie seine psychosoziale Struktur ausschlaggebend für die Entscheidungsfindung.Da sich die Möglichkeiten der Knochen- und Weichteilrekonstruktion insbesondere durch die Einführung der Kallusdistraktion entscheiden verbessert haben,hat die Komplexität des lokalen Infektproblems an Wertigkeit gegenüber vaskulären oder kardiozirkulatorischen Begleiterkrankungen sowie Stoffwechselerkrankungen in der Entscheidungsfindung verloren. Bisher etablierte Klassifikationen der Osteitis zur Beurteilung eines zu erwartenden Behandlungsaufwands und Therapieerfolgs haben deshalb nur noch bedingt Gültigkeit.Entscheidend ist im Vorfeld der Behandlung eine detaillierte Information und Aufklärung des Patienten über notwendigen Behandlungsschritte, etwaige Komplikationen sowie das zu erwartende funktionelle Ergebnis der rekonstruktiven Maßnahme.Dieses ist kritisch abzuwägen gegenüber den Vor- und Nachteilen eines ablativen Vorgehens mit nachfolgender prothetischer Versorgung.AbstractThe decision on reconstruction or amputation of a chronically infected limb is difficult and depends on various factors.Apart from the local bone and soft tissue conditions, the age of the patient, specific associated diseases, and psychosocial environment are also of great importance in making an appropriate decision on treatment.The introduction of callus distraction has considerably improved bone and soft tissue reconstruction, thus relegating the complexity of local infections to minor importance compared to the impact of associated cardiovascular and metabolic diseases.The previously established classifications of posttraumatic osteomyelitis for judging the expected therapeutic necessities and outcome now have only limited value. It is therefore appropriate to provide detailed information and explanations to the patient before any therapeutic procedure concerning the duration of treatment, possible complications as well as the expected functional outcome of the reconstructive procedures. It is important to weigh the outcome of a time-consuming reconstructive procedure against the advantages and disadvantages of an amputation and its subsequent prosthetic management.