71 research outputs found
Effects of gamma irradiation on the biomechanical properties of peroneus tendons
PURPOSE: This study was designed to investigate the biomechanical properties of nonirradiated (NI) and irradiated (IR) peroneus tendons to determine if they would be suitable allografts, in regards to biomechanical properties, for anterior cruciate ligament reconstruction after a dose of 1.5–2.5 Mrad. METHODS: Seven pairs of peroneus longus (PL) and ten pairs of peroneus brevis (PB) tendons were procured from human cadavers. The diameter of each allograft was measured. The left side of each allograft was IR at 1.5–2.5 Mrad, whereas the right side was kept aseptic and NI. The allografts were thawed, kept wet with saline, and attached in a single-strand fashion to custom freeze grips using liquid nitrogen. A preload of 10 N was then applied and, after it had reached steady state, the allografts were pulled at 4 cm/sec. The parameters recorded were the displacement and force. RESULTS: The elongation at the peak load was 10.3±2.3 mm for the PB NI side and 13.5±3.3 mm for the PB IR side. The elongation at the peak load was 17.4±5.3 mm for the PL NI side and 16.3±2.0 mm for the PL IR side. For PL, the ultimate load was 2,091.6±148.7 N for NI and 2,122.8±380.0 N for IR. The ultimate load for the PB tendons was 1,485.7±209.3 N for NI and 1,318.4±296.9 N for the IR group. The ultimate stress calculations for PL were 90.3±11.3 MPa for NI and 94.8±21.0 MPa for IR. For the PB, the ultimate stress was 82.4±19.0 MPa for NI and 72.5±16.6 MPa for the IR group. The structural stiffness was 216.1±59.0 N/mm for the NI PL and 195.7±51.4 N/mm for the IR side. None of these measures were significantly different between the NI and IR groups. The structural stiffness was 232.1±45.7 N/mm for the NI PB and 161.9±74.0 N/mm for the IR side, and this was the only statistically significant difference found in this study (P=0.034). CONCLUSION: Our statistical comparisons found no significant differences in terms of elongation, ultimate load, or ultimate stress between IR and NI PB and PL tendons. Only the PB structural stiffness was affected by irradiation. Thus, sterilizing allografts at 1.5–2.5 Mrad of gamma irradiation does not cause major alterations in the tendons’ biomechanical properties while still providing a suitable amount of sterilization for anterior cruciate ligament reconstruction
Recommended from our members
450 closed fractures of the distal third of the tibia treated with a functional brace
Four hundred fifty closed fractures of the distal third of the tibial diaphysis, treated with a functional brace, are the subject of this study. Four (0.9%) of the fractures resulted in nonunion. The average healing time was 16.6 +/- 5.6 weeks, with a range from 10-40 weeks. The average final shortening was 5.1 +/- 4.8 mm with a range from 0-25 mm. Four hundred twenty four (94.2%) fractures healed with < 12 mm shortening. Initial shortening at the time of injury essentially was unchanged, from 4.4 +/- 4.5 mm to 4.4 +/- 3.9 mm final shortening. Axially unstable closed tibial fractures do not shorten beyond the initial shortening. Four-hundred five fractures (90.0%) healed with less than 8 degrees angular deformity in either the frontal or sagittal planes, and 302 (67.1%) healed with less than 5 degrees deformity in any plane. Overall, 391 fractures (87%) healed with shortening less than 12 mm and angulation in any plane less than 8 degrees . These degrees of angular deformity and shortening seem to compare favorably with those reported by other investigators using intramedullary nails. It seems that functional bracing is an effective method of treatment of a selected group of tibial fractures
Recommended from our members
Fractures of the Humeral Shaft
The incidence of humeral shaft fractures is relatively low compared to that of other long bone fractures. Generally, they do not represent major problems when treated by closed techniques. Internal fixation is rarely used even by the most aggressive surgeons and it has been long recognized that complications from surgery are likely to occur. With the use of fracture bracing techniques clinical results have been encouraging and the morbidity has been very low. Fracture bracing allows for early range of motion of the joints and muscle activity and therefore reduces or eliminates the sequelae of immobilization and inactivity. Minor angulatory deformities which frequently occur do not constitute a functional deficit. The few degrees of angulation at the fracture site are difficult to recognize and therefore are not cosmetically unsightly. The shortening of the humeral shaft that has been observed in a few instances is also of no clinical significance. Rotational deformities have usually been minimal and represent a loss of external rotation of the shoulder in its last few degrees. These mild deformities are also of no clinical significance
Recommended from our members
Kondylenfrakturen der Tibia
Intrakondyläre Frakturen der proximalen Tibia haben seit Jahren verwirrende Probleme für den orthopädisch tätigen Chirurgen dargestellt. Es bestehen immer noch viele Kontroversen über das Ausmaß der Inkongruenz, die in einem Gelenk vorhanden sein darf, ohne daß es zu einer eventuellen degenerativen Gelenkerkrankung kommt. Ein Umstand, der wohl allgemein anerkannt wird, ist der, daß eine ausgedehnte Immobilisierung des Kniegelenks in Anwesenheit einer intraartikulären Fraktur zerstörerisch wirken kann, und daß bei Inkongruenz ein vollständig bewegliches Gelenk mit weniger Wahrscheinlichkeit eine Degeneration durchmacht
Recommended from our members
Frakturen der Tibia
Tibiafrakturen werden meist als größere Verletzungen angesehen, da verzögerte Knochenbruchheilung und Pseudarthrosen häufig auftreten, Achsenfehlstellungen üblich sind, die Infektionsrate größer als bei den meisten anderen Knochen ist und die Dauer der Arbeitsunfähigkeit und Rehabilitation recht lang ist. Es sollte einleuchtend sein, daß eine einzige Behandlungsmethode nicht auf alle Frakturtypen zu allen Zeiten und unter allen Umständen anwendbar ist. Die Verantwortlichkeit des Operateurs impliziert, daß er ein angemessenes Wissen von den unterschiedlichen Systemen und Techniken zur Verfügung hat und die geeignetste Behandlungsmethode, die unter den gegebenen Umständen erforderlich ist, einleitet. Die offene Reposition und innere Fixierung von Frakturen ist eine erprobte und akzeptable Behandlungsmethode bei vielen Frakturen der langen Knochen und hat zahllosen Patienten im Verlaufe von Jahrzehnten gedient. Man muß jedoch begreifen, daß die innere Fixierung einer Fraktur eine Verletzung des natürlichen biologischen Prozesses der Osteogenese bedeutet und daß sie die normale Heilung stört. Es gibt ansehnliche Belege in der Literatur, daß das Anlegen einer Platte oder das Einführen eines Nagels die Heilung einer Fraktur verzögert. Die Unterbrechung des normalen Heilungsprozesses sowohl durch eine innere bzw. starre Fixierung wie auch durch eine äußere Immobilisierung der Frakturen haben wir in Kap. 2 erörtert
Recommended from our members
Fractures of the Distal Radius
Fractures of the distal radius are the most common fractures in the upper limb of the middleand older-age population. These fractures, commonly classified as Colles’ fractures, have received relatively little attention in orthopaedic circles. Perhaps this is due to the fact that none of the commonly used methods of treatment have been able to completely eliminate the complications of shortening and loss of the radial and volar tilt of the distal radius. Such complications have been accepted as inevitable in certain fractures and their clinical significance have not been considered serious. Patients seem to get accustomed to the deformity and the residual limitation of motion and weakness of grasp. All common methods of treatment seem to require a relatively long period of incapacitation before maximum recovery is achieved. Some have recommended methods of treatment which ensure maintenance of reduction of the fragments either by internal fixation of the fragments or by external fixators with pins above and below the fracture. This latter treatment, although capable of providing maintenance of anatomic reduction, is often associated with complications of varying types, such as loosening of the pins and low grade infections along their tracts. More important perhaps is the fact that the rigid immobilization of the wrist joint in a distracted position leads to the development of stiffness which in the elderly requires a long time before its complete disappearance
Recommended from our members
Frakturen des Femurs
Erfahrungen mit der funktionellen Schienung bestimmter Femurfrakturen waren aufgrund der Tatsache lohnend, daß die Länge, Frakturstellung und Rotation bei den funktionellen Laufübungen während der Frakturheilung adäquat aufrechterhalten blieben. Der Femur war jedoch der Knochen, der am wenigsten gut im Einklang mit der funktionellen Schienung reagierte. Achsenfehlstellungen, gewöhnlich vom Varustyp, wurden häufig angetroffen, und es war oft schwierig für den Patienten, die Funktion in der Schiene nach einer Periode der Ruhe durchzuführen
Recommended from our members
Fractures of the Forearm
We began functional bracing of fractures of the forearm after having gained experience with bracing of tibial and femoral fractures. It was initially suspected that braces similar to prostheses worn by amputees could successfully stabilize the fragments and prevent deformities. However, further experiences have indicated that the soft tissues are primarily responsible for the stability of the osseous structures. The prevention of pronosupination of the forearm is achieved by molding the proximal portion of the brace over the olecranon and condyles of the distal humerus. It was also recognized later that isolated fractures of the ulna do not require the prevention of forearm pronosupination thus leading to the conclusion that such fractures can be successfully stabilized with a “sleeve” that simply compresses the soft tissues of the forearm while permitting motion of all joints of the extremity
- …