Martin Röpke

Patellar Tendon Versus Hamstring Tendon Autografts for Reconstructing the Anterior Cruciate Ligament A Meta-Analysis Based on Individual Patient Data

Background The best means of ensuring knee stability after anterior cruciate ligament (ACL) reconstruction remains a core debate in sports medicine. Hypothesis There is no difference between ACL reconstruction with patellar tendon or hamstring tendon autografts with regard to postoperative knee laxity and instability. Study Design Meta-analysis of individual patient data. Methods Pooled analysis of individual patient data from 6 published randomized clinical trials included 423 patients with symptomatic unilateral anterior cruciate ligament injury randomly assigned to reconstruction with patellar tendon or hamstring tendon autograft. Knee instability, defined as a positive pivot-shift test result, was the primary outcome, and knee laxity, defined as a positive Lachman test result, was the secondary outcome. Odds ratios were computed before and after adjustment for potential confounders and trial effect. Regression analyses were performed to look for effects of covariates on outcomes, and mixed-effects models were used to account for a trial effect. Sensitivity analyses were conducted to explore the effects of missing data and excluding each trial. Results Anterior cruciate ligament reconstruction with patellar tendon autograft was significantly associated with a decreased risk of a positive pivot-shift test result (adjusted odds ratio, 0.46; 95% confidence interval, 0.24–0.86; P = .016). The risk of having a positive Lachman test result was not significantly different between the 2 groups. The estimated treatment effect was not substantially changed by differences in handling missing data or exclusion of any of the trials. A positive pivot-shift test result was more common in female (P = .003) and younger patients (P = .017). Conclusion Postoperative knee instability was less common after ACL reconstruction with patellar tendon autograft than with hamstring tendon autograft.

Surgical Treatment of Isolated Patellofemoral Osteoarthritis

Isolated patellofemoral osteoarthritis in the healthy middle-aged population is a challenging problem. Fifty-one knees in 50 patients with isolated patellofemoral osteoarthritis were treated by partial lateral facetectomy, lateral release, and medialization of the tibial tubercle. The minimum followup was 7 months (mean, 20.2 months; range, 7–32 months). Preoperative radiographs showed Ahlbäck Grades III and IV lateral patellofemoral joint space narrowing. The mean age of the patients was 60.1 years (range, 46–81 years). The subjective outcome was based on the WOMAC and the McCarroll score. Posteroanterior flexion weightbearing views, lateral views, and 45° axial views were taken. According to the WOMAC score, the scores improved considerably by 2.34 points with respect to pain and by 1.63 points with respect to function. The Insall-Salvati index decreased considerably but still remained in the physiologic range. The majority of these patients experienced improvement in their patellofemoral symptoms. However, the clinical outcome was not better in comparison to other surgical procedures. After the short followup, we would not recommend combined lateral facetectomy, lateral release, and medialization of the tibial tubercle until longer results are available.Level of Evidence: Level IV Therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Structural Properties of Sutures Used in Anchoring Multistranded Hamstrings in Anterior Cruciate Ligament Reconstruction: A Biomechanical Study

Sutures are frequently used in anchoring hamstring or quadriceps tendon grafts in cruciate ligament reconstruction. Trumpet like widening of the femoral bone canal was found in patients having had anterior cruciate ligament reconstruction with hamstring autograft. We investigated 5-mm Polylene tape (Genzyme, Boston, MA) and Mersilene tape (Ethicon, Somerville, NJ) as well as No. 6 Ethibond sutures (Ethicon) for ultimate load, stiffness, and elongation under tension of 50 N, 150 N, 250 N, and ultimate load. The Mersilene and Polylene tapes were tested in single loops and Ethibond in double loops having a length of 30 mm. The length is similar to that used intraoperatively for the graft fixation. The suture materials were loaded using a material testing machine at a strain rate of 60 mm/min. The ultimate loads of the loops with knots were 474 N +/-24.7 N for Polylene, 437 N +/-38.2 N for Mersilene, and 338 N +/-16.8 N for Ethibond, and was statistically significant (analysis of variance [ANOVA], P<.05). The elongation under a tension load of 50 N was similar for Ethibond (1.2+/-0.216 mm) and Polylene (1.3+/-0.32 mm). Mersilene (1.7+/-0.34 mm) showed an increased elongation (ANOVA, P=.03). The stiffness for Ethibond was 37.1+/-2.7 N/mm, for Mersilene 38.4+/-3.8 N/mm, and for Polylene was 47+/-3.1 N/mm. The Polylene tape appears to be the most suitable material in terms of strength and stiffness. Nevertheless, the stiffness of all the tested materials is greatly inferior to the stiffness of the commonly used grafts. We believe that a stiffer graft construct might reduce motion during the early period of ingrowing.

Differential expression of VEGF‐A and angiopoietins in cartilage tumors and regulation by interleukin‐1β

Vascular endothelial growth factor (VEGF)‐A and angiopoietin (Ang)‐1 and Ang‐2 are key factors in angiogenic signaling. In this study the expression of these factors was identified in cartilage tumors. As interleukin (IL)‐1β has been found to be an indispensable factor in angiogenic signaling, we further analyzed the effect of IL‐1β on the expression of VEGF‐A, Ang‐1, and Ang‐2 using a previously established cell culture model.

Heterogeneity of angiogenesis and blood vessel maturation in cartilage tumors

Cartilage tumors have a special angiogenic phenotype, with blood vessels arranged predominantly in pericartilage fibrous septa and relatively low microvessel density (MVD), except in dedifferentiated chondrosarcomas. To further elucidate angiogenesis in cartilage tumors, we used double-labeling immunohistochemistry to determine microvessel pericyte coverage index (MPI) and proliferating capillary index (PCI), referring to blood vessel maturation and angiogenic activity in enchondromas, conventional chondrosarcomas, and dedifferentiated chondrosarcomas. Altogether, we found high MPIs (>70%) especially in dedifferentiated chondrosarcomas but without a correlation to the grade of malignancy. PCI was significantly higher in conventional chondrosarcomas grades II and III than in enchondromas, chondrosarcomas grade I, and dedifferentiated chondrosarcomas. Thus, PCI positively correlated with the previously reported differential expression of vascular endothelial growth factor (VEGF)-A in cartilage tumors. Altogether, cartilage tumors exhibit a heterogeneous but predominantly mature angiogenic phenotype with differential proliferative activity.

Semitendinosussehne vs. Ligamentum patellae Klinische Ergebnisse einer prospektiven randomisierten Studie nach vorderer Kreuzbandplastik

ZusammenfassungDas Ziel der vorliegenden prospektiven randomisierten Studie ist die klinische Evaluation der 2-Jahres-Ergebnisse nach arthroskopischer Ersatzplastik des vorderen Kreuzbands unter Verwendung des mittleren Patellarsehnendrittels oder der Semitendinosussehne. Methodik. 20 Patienten wurden in arthroskopischer transtibialer Technik mit einem mittleren Patellarsehnentransplantat (BTB-Gruppe) mit 20 Patienten mit gedoppelter Semitendinosussehne (SET-Gruppe) postoperativ untersucht. Die klinische Evaluation erfolgte präoperativ und zum Zeitpunkt der Nachuntersuchung mittels IKDC, Tegner-Aktivitätslevel sowie dem retropatellare Schmerzscore nach McCarroll. Zur Bestimmung der a.-p.-Translation im Seitenvergleich diente der KT-1000. Ergebnisse. Bezüglich des Gesamtergebnisses im IKDC erreichten in der SET-Gruppe 80% und in der BTB-Gruppe 50% der Patienten gute oder sehr gute Ergebnisse. Die Differenz der a.-p.-Translation im Seitenvergleich betrug in der BTB-Gruppe 1,6 mm (−2–4 mm) und in der SET-Gruppe 2,7 mm (0–7mm) (p<0,05). Die retropatellaren Beschwerden waren im Mc Carrol-Score in der BTB-Gruppe (17,4 Punkte) ausgeprägter als in der SET-Gruppe (19,5 Punkte) (p<0,05). Hinsichtlich der Rückkehr zum früheren Aktivitätsniveau (Tegner-Score SET und BTB 6,9) erreichte die SET-Grupp 2 Jahre postoperativ 6,7 und die BTB-Gruppe 5,6 Punkte. Schlussfolgerung. Da die Kreuzbandplastik mittels gedoppelter Semitendinosussehne trotz geringerer Stabilität ein besseres Gesamtergebnis nach dem IKDC-Score zeigte, ist das Verfahren als Alternative anzusehen. Zur Verbesserung der Stabilität ist die Verwendung von 3- oder 4-fach-Transplantaten mit einer stabileren Fixation anzuraten.AbstractThe aim of our prospective randomised study was to evaluate the clinical results after arthroscopical reconstruction of the ACL using the midthird patellar ligament or semitendinosus tendon. Methods. Forty patients were followed up two years postoperatively. Twenty of them received either a patellar ligament graft (BTB-group) or doubled semiteninosus tendon (SET-group). The clinical evaluation included the preoperative and two years postoperative assessment, based on the IKDC-Score, Tegener-Score and Mc-Carroll-Score. The a.p.-translation was evaluated using the KT-1000. Results. Sixteen (80%) patients of the SET-group and 10 (50%) patients of the BTB-group showed good and excellent results in the over all assessment with the IKDC-Score. The mean side to side KT-1000 difference yielded 1.6 mm (−2–4 mm) in the BTB-group and 2.7 mm (0–7 mm) in the SET-group (p<0.05). The retropatellar pain syndrome based on the Mc-Carroll-Score showed 17.4 points in the BTB-group in comparison to 19.5 points in the SET-group (p<0.05). The level of activity using the Tegner-score showed preoperatively for both the SET- and BTB –group 6.9 points and postoperatively for the SET-group 6.7 points and for the BTB-group 5.6 points. Conclusions. Despite the inferior a.p.-stability for the patients who received doubled semitendinosus tendon grafts they presented clinically superior results compared to the BTB-group. Therefore this technique seems to be the alternative method. In order to improve the stability we recommend the usage of three or four stranded grafts and an improved fixation technique.

Bilateraler Funktionsverlust der Quadrizepsmuskulatur nach einseitiger Kreuzbandruptur mit Begleitverletzung durch zentrales Aktivierungsdefizit

ZusammenfassungZiel der Studie war es zu untersuchen, in welchem Ausmaß ein Defizit der willkürlichen Aktivierbarkeit des M. quadriceps bei schweren Knieverletzungen vorliegt und welchen Einfluss ein Aktivierungsdefizit auf die Muskelfunktion hat. Untersucht wurden 33 männliche Patienten nach Rupturen des vorderen Kreuzbandes (VKB) mit Begleitverletzungen der Kniegelenke im Vergleich zu 22 Patienten mit einer isolierten VKB-Ruptur und einem altersangepassten gesunden Kontrollkollektiv. Mit einer sensitiven Twitch-Interpolationsmethode wurde die isometrische Maximalkraft des M. quadriceps und die Fähigkeit der Probanden, die Quadrizepsmuskulatur willentlich zu aktivieren, bestimmt.Die Patienten mit VKB-Ruptur und Begleitverletzungen hatten eine signifikant schlechtere Aktivierbarkeit der Quadrizepsmuskulatur sowohl auf der verletzten (78,8±2,09%, mean±SEM) als auch gleichermaßen auf der gesunden Seite (78,9±1,91%) im Vergleich zu dem Kontrollkollektiv und zu der Gruppe mit isolierter VKB-Ruptur. Der gemessene Kraftverlust beruhte auf der gesunden Seite alleine auf das beschriebene Aktivierungsdefizit, der Kraftverlust der verletzten Seite dagegen auf das Aktivierungsdefizit und Muskelatrophie. Aktivierungsdefizite sind vermutlich eine Erklärung dafür, dass sich bei einigen Patienten trotz intensiver Therapie eine Muskelatrophie nicht verhindern lässt. Aufgrund bilateraler Aktivierungsdefizite muss die Validität von Muskelfunktionstest, die die gesunde Seite als Referenz nutzen, angezweifelt werden.AbstractThe aim of the study was to investigate the ability to activate the quadriceps femoris muscle voluntarily in patients after severe knee injuries and its influence on muscle function. 33 male patients after ACL-rupture with concomitant injuries were investigated with a twitch-interpolation-method to determine the maximal voluntary contraction force (MVC) and the ability to activate the quadriceps muscle voluntarily. The results were compared to a previously investigated group of patients after isolated ACL-rupture and to an aged-matched control group.The patients with extensive knee injuries presented a significant higher deficit of voluntary quadriceps muscle activation on the injured (78.8±2.09%, mean±SEM) and equally on the uninjured side (78.9±1.91%) compared to the patients after isolated ACL-rupture and to controls. A minor MVC-deficit of the patients quadriceps muscle of the uninjured side could be explained by the voluntary activation deficit alone, the major MVC deficit of the injured side by muscle atrophy and a voluntary activation deficit. The activation deficit is probably the underlying reason for persisting muscle wasting and weakness despite intensive physiotherapy especially in patients with concomitant injuries in addition to an ACL-rupture.

Establishment and characterization of the permanent human cell line C3842 derived from a secondary chondrosarcoma in Ollier’s disease

The permanent human cell line C3842 was established from a secondary chondrosarcoma in a typical case of Ollier’s disease. In the present study, we analyzed the morphological, cytogenetic and molecular biological characteristics of the cultured cells in comparison with the original tumor and investigated the invasion properties of the tumor model using functional imaging of proteolysis, matrigel assay and chick chorioallantoic membrane assay. C3842 cells exhibit the typical features of malignant cartilage tumor cells in vitro, including the expression of collagen types II, IX, XI and aggrecan. The proteolytic ability of C3842 cells is attributed to the expression of several proteases, such as cathepsin B, urokinase plasminogen activator and matrix-metalloproteinase-2, which enable the cells to degrade collagen type I and to permeate matrigel matrix. In accordance with the biological features in vivo, C3842 cells are not able to invade through the epithelium of the chick chorioallantoic membrane. In conclusion, the cell line C3842 provides the first model of a secondary chondrosarcoma in Ollier’s disease in vitro, which is characterized by distinct features of such malignant cartilage tumors.

Clinical outcome of arthroscopic repair of the posterior cruciate ligament

SummaryTwenty-one patients were evaluated with an average follow up of 30 month after arthroscopical reconstruction of the posterior cruciate ligament using the IKDC-Evaluation Document, Lysholm-Score, KT 1000 and X-ray. Complex ligament injuries and chronic instability of the knee were the indications for operative treatment. Semitendinosus – or patella ligament autografts were used. The Lysholm-Score significantly improved preoperatively to postoperatively (p < 0.01). The IKDC revealed 11 patients for group B, 7 patients for group C and 3 patients for group D. The KT1000 measurement showed a postoperative drawer of 3.6 mm compared with the nonoperated side. Thirteen of the 21 patients showed a posterior drawer of less than 3 mm. The lateral posterior stress view of the X-ray revealed a 4.1 mm ( ± 2.9 mm) side to side difference postoperatively in comparison to 9.5 mm ( ± 3.5 mm) preoperatively. Three patients possessed radiological signs of osteoarthritis grad I by Ahlbäck. Our results recommend in patients with complex PCL-injuries as well as in cases of chronic posterior instability a complex reconstruction of the ligaments.Zusammenfassung21 Patienten wurden 30 Monate nach arthroskopischer hinterer Kreuzbandplastik mittels IKDC-Bogen, Lysholm-Score, KT-1000 und radiologisch evaluiert. Die Operationsindikation bildeten komplexe Kniegelenkverletzungen sowie chronische Instabilität bei verlängerter posteriorer Translation. Autologe Semitendinosus- oder Lig.-patellae-Transplantate wurden von der ipsilateralen Seite verwendet. Eine signifikante Verbesserung konnte im Lysholm-Score erzielt werden (p < 0,01). Im IKDC-Bogen erreichten 11 Patienten die Gruppe B, 7 Patienten die Gruppe C und 3 Patienten die Gruppe D. Die postoperative Stabilität mittels KT-1000 ergab eine mittlere verlängerte posteriore Translation von 3,6 mm gegenüber der gesunden Seite, wobei 13 von 21 Patienten weniger als 3 mm zeigten. Bei der radiologischen Untersuchung in hinterer Schublade bestand eine Seitendifferenz von 4,1 mm (2,9 mm) im Vergleich zu präoperativ von 9,5 mm ( ± 3,5 mm); 3 Patienten wiesen eine beginnende Grad-I-Arthrose nach Ahlbäck auf. Die Ergebnisse bestätigten, daß sowohl komplexe Verletzungen als auch chronische posteriore Instabilitäten gute klinische und radiologische Ergebnisse nach operativer Rekonstruktion zeigen.

Down-regulation of ephrin-A5, a gene product of normal cartilage, in chondrosarcoma

As ephrins have been associated with tumorigenesis and tumor progression, we investigated ephrin-A5 (EFNA5) expression in specimens of normal cartilage and chondrosarcomas of different grade by conventional and quantitative reverse transcription polymerase chain reaction (RT-PCR), Western blot, and immunohistochemistry. We detected a significant EFNA5 down-regulation in chondrosarcomas compared with normal cartilage using quantitative RT-PCR (P < .05). The results were confirmed by Western blot and immunohistochemistry. We did not detect any causative genetic or epigenetic alterations in EFNA5 promoter methylation, loss of heterozygosity, or mutation analyses. Apart from slight differences in EFNA5 transcript amounts, we detected no significant influence of hypoxia on EFNA5 expression in C3842 and SW1353 chondrosarcoma cells. As EFNA5 down-regulation is a consistent finding in chondrosarcomas, we presume that it represents another essential alteration in tumorigenesis and tumor progression associated with cell adhesion, in addition to a multitude of other partially unknown biologic functions mediated by bidirectional ephrin/Eph receptor signaling and cross talk.