Fixation technique influences osteogenesis of comminuted fractures.

Comminuted fractures most often are associated with compromised soft tissue conditions and diminished vascularization leading to a reduced osteogenesis. In contrast to stable fixation by compression plating with lag screws, the less stable but also less invasive techniques of external fixation, unreamed nailing, or bridging plates have become increasingly popular. The aim of this study was to compare the bone healing and osteogenesis of these fixation techniques. A triple wedge osteotomy of the sheep tibia was used as a bone healing model. Internal compression plate fixation of all fragments with lag screws was used in one group. In the other three groups, only the main proximal and distal fragments were fixed by external fixation, unreamed interlocking nail, or bridging plate. The sheep with compression plate fixation and lag screws showed the worst results after 12 weeks. The periosteal and endosteal osteogenesis and the apparent density of the newly formed bone in the fracture gaps were significantly lower than those seen in the sheep in the other three technique groups. The best results were found for the bridging plate and external fixator. From these results, it can be concluded that compression plate fixation should be avoided for treatment of comminuted fractures.

[Reconstruction of extensive post-traumatic femoral defects by autogenous rib transplants]. / Die Rekonstruktion langstreckiger posttraumatischer Femurdefekte durch autogene Rippentransplantate.

Extended deficiency pseudarthroses of the femur (7-18 cm) in nine patients were treated by autogenous rib transplantation. For early active pain-free mobilization we used the technique of bridging plate osteosynthesis for stable internal fixation. Within an average of 5 (range 4-7) months osseous restitution was obvious radiologically. In all nine patients the full weight-bearing capacity of the extremity was restored. There were no soft tissue problems and no bone transplant losses. All patients appreciated the uncomplicated postoperative phase after internal fixation with bridging plate osteosynthesis.

[The fibula-pro-tibia operation--indications, results]. / Die Fibula-pro-Tibia-Operation--Indikation, Ergebnisse.

We report on 21 cases with combined soft tissue and far reaching bone defects of the lower leg. The bone defects were bridged by the fibula-pro-tibia-operation. In eleven patients the restoration of the full weightbearing leg was achieved. Five patients have to use a supporting walking splint at the end of the medical treatment. In four cases we found fistulas without secretion. Five amputations of the lower leg were unavoidable.

[Indications for a bridging plate osteosynthesis of compound femoral shaft fractures]. / Indikation zur überbrückenden Plattenosteosynthese komplexer Femurschaftfrakturen.

We performed the clinical and radiological follow-up of 29 comminuted fractures of the femoral shaft treated by bridging plate osteosynthesis. Complete bone healing in 6 open fractures took place within 33 weeks, in 15 closed fractures within 22 weeks. We had to meet 5 postoperative complications: 2 cases of osteomyelitis following open fractures, 1 early wound infection and 2 haematomas. Primary cancellous bone grafting we found unnecessary in all of the 29 fractures. We recommend the technique of bridging plate osteosynthesis for the stabilization of comminuted fractures of the femur especially under the clinical circumstances as follows: 1. Polytrauma, 2. Metaphyseal or condylar fracture, 3. Open fracture, 4. Redisplacement, 5. Fracture in children.

[Dorsal plate osteosynthesis of the tibial shaft. Results of a collective study of the German section of the International AO (Study Group for Osteosynthesis Problems)]. / Die dorsale Plattenosteosynthese am Tibiaschaft. Ergebnisse einer Sammelstudie der Deutschen Sektion der AO-International.

This collective study was conducted by the German section of AO International to work out the indications for fixation of the tibial shaft by means of dorsal plating. Primary dorsal plating was done in 70 cases. Most of the patients had second- or third-degree open fractures with severe ventral soft tissue injuries or closed fractures that could not be reduced and fixed conservatively. In 72 patients, secondary dorsal plate fixation was performed. The main reason for the dorsally positioned plate was persistent instability or axial malalignment after previous external or internal fixation, but failed conservative treatment constituted a further reason. Most of these patients had such severe damage following fractures that dorsal plating was the last chance of avoiding amputation. The high rate of complications (12 infections and 7 non-unions and breakages of implants after primary dorsal plating; 20 infections and 11 non-unions and breakages of implants after secondary dorsal plating) has to be considered in the light of the extraordinary indications for the dorsal plating of the tibial shaft in especially severe fractures or disastrous sequelae. In cases with extremely severe conditions before fixation, dorsal plating of the tibial shaft for secondary operative treatment yields adequate results.

[The significance of postoperative stability for osseous repair of a multiple fragment fracture. Animal experiment studies]. / Die Bedeutung der postoperativen Stabilität für die ossäre Reparation einer Mehrfragmentfraktur. Tierexperimentelle Untersuchungen.

The significance of postoperative mechanical stability for bony repair of a comminuted fracture was investigated in an animal experimental study comparing four commonly applied operative methods of stabilizing fractures: (1) flate osteosynthesis combined with lag screw fixation after reduction of the fragments; (2) bridging plate osteosynthesis; (3) external fixation; (4) static interlocking intramedullary nailing. As the fracture model, a triple-wedge osteotomy of the right sheep tibia was used. The results of in vitro testing of stiffness (N/mm) of each of the four osteosyntheses was as follows: anatomical plate: 746 N/mm; bridging plate 434 N/mm; external fixation 625 N/mm; nailing 416 N/mm. Eight weeks after the operation, the tibiae were explanted and the contralateral tibiae of six sheep were taken as a control group. The three-point bending test revealed no significant difference in bending deviation: anatomical plate 47.58 +/- 22.57 microns; bridging plate 33.93 +/- 7.67 microns; external fixation 33.83 +/- 8.02 microns; nailing 33.0 +/- 17.23 microns. However, it was noted that there was a slightly higher tendency towards stiffness of the bones after bridging plate osteosynthesis, external fixation and interlocking intramedullary nailing and that the amount of stiffness resembled that in non-operated control animals (25.56 +/- 6.66 microns). On the other hand, anatomical plate osteosynthesis showed less stiffness. To assess the tensile strength at the osteotomy area, bone samples were prepared and tested for failure on a material testing machine. The tensile strength of the bone samples showed a distinct difference in all experimental groups according to their anatomical location.(ABSTRACT TRUNCATED AT 250 WORDS)

Significance of postoperative stability for bony reparation of comminuted fractures. An experimental study.

The significance of postoperative mechanical stability to bone repair of comminuted fractures was investigated in an animal experimental study comparing four commonly employed operative methods of fracture stabilization: 1. Plate osteosynthesis combined with lag screw fixation; 2. Bridging plate osteosynthesis; 3. External fixation; 4. Static interlocking intramedullary nailing. As fracture model, a triple wedge osteotomy of the right sheep tibia was used. In regard to biomechanical strength, the method which gave best postoperative stability, plate osteosynthesis in combination with interfragmentary lag screws, did not result in the best bone repair. In this experimental setup, stabilization by bridging methods, inducing bone healing by secondary intention, gave better bone regeneration in the experimental fractures.

[Significance of primary diagnosis of carpal instability]. / Die Bedeutung der primären Diagnostik carpaler Instabilitäten.

In general the dislocation of the carpal bones with subsequent carpal instability is rare. The diagnosis depends on a correct interpretation of the X-ray. In a follow-up study 25 patients with closed carpal instabilities were examined. In 14 the carpal instability had been established in the primary diagnosis and treated adequately. The functional results were good. 11 patients, in whom the dislocation of the carpal bones had been overlooked, did not receive primary therapy and had unsatisfactory function of the hand.

[Reconstruction of large femoral defects in exchange operations following artificial hip replacement]. / Die Uberbrückung langstreckiger Femurdefekte bei Austauschoperationen nach künstlichem Hüftgelenkersatz.

Loosening of the implant is one of the most serious complication in case of total hip replacement. It is caused by the growth of a secondary cancellous channel and in destroyed bone cement. From 1981 to 1986 we operated 63 patients to exchange a loosened hip prosthesis. With 15 patients we have seen a severe damage of the femur shaft. Big parts of the bone tube were missed. To insert the new stem we had to reconstruct the proximal femur and the calcar region by autogenous cortico-cancellous bone grafts in seven cases. In three cases a large defect of the lateral femur cortex was reconstructed by extended cancellous bone graft. In five cases we found a cominuted fracture of the femur shaft. The osteosynthesis was performed by plating. The screws were inserted through the bone into the stem. They find a very strong grip in the polyacetal material. 14 of 15 patients operated in this manner could achieve a walking ability. Most of them improved one step higher in the evaluation scheme according to Merle d'Aubigne. One patient suffering from a septic loosening showed a severe exacerbation with septicemia and ended in a disarticulation of the hip joint. The so called isoelastic prosthesis gives a chance to reconstruct the femur tube. It allows unhindered calcification of bone graft and acts as a forming model for new bone. With this we are able to restore the movement of hip joint as well as weight bearing and working ability of the limb. Additional osteosynthesis is possible to perform.(ABSTRACT TRUNCATED AT 250 WORDS)

[Significance of primary diagnosis in dislocations of the carpal bones]. / Die Bedeutung der primären Diagnose von Handwurzelknochenverrenkungen.

In order to diagnose dislocation of carpal bones it is important to interpret the X-ray film correctly. In most cases of primary dislocations, closed anatomical reduction can be achieved. The resulting stability after primary reduction must be checked in moving the wrist under X-ray intensifier control. If there is reluxation or any persisting instability, operative treatment is indicated. By clinical examples it is shown that very good functional results are obtained after primary diagnosis and correct treatment. Regarding overlooked dislocation of carpal bones, therapeutic management is difficult and the clinical result is often unsatisfactory.

Severely comminuted femoral shaft fractures: treatment by bridging-plate osteosynthesis.

We report on 71 severely comminuted femoral shaft fractures that were operated on between 1980 and 1984 at the Berufsgenossenschaftliche Unfallklinik Duisburg-Buchholz. The method of operative stabilization was plate osteosynthesis in two variations: In one group 39 fractures (ten open) were stabilized by plate osteosynthesis after anatomical reduction of the fractured area. The other group comprised 32 fractures (six open) fixed with a bridging-plate osteosynthesis, without preparation of the fracture zone. The rate of postoperative complications was strikingly diminished after bridging-plate osteosynthesis. Fracture healing occurred within 23 (16-32) weeks after bridging-plate osteosynthesis and within 36 (32-40) weeks after anatomical reduction. No special instrumentation or equipment is necessary to perform a bridging-plate osteosynthesis. The patient rests in a supine position. There is no need for intraoperative image-intensifier control. For operative treatment of severely comminuted femoral fractures we consider the technique of bridging-plate osteosynthesis advantageous, especially in multiply injured patients.

The importance of trochanteric lag screws to achieve primary stability in cementless fixation of the RM hip prosthesis.

To allow the bony incorporation of a cementless prosthesis it is important to achieve stability at the time of operation. To neutralize tension and torsional stresses the RM-shaft prosthesis is fixed with two lag screws in the trochanteric part of the femur. By measuring the applied torque intraoperatively we could demonstrate that the threads of the screws found a better grip when inserted from the bone to the prosthesis. Thus, the stronger fixation of the screws enhanced the primary stability of the cementless prosthesis.

[Surgical hip joint replacement with a cement-free fixation technic--indications, technic and results]. / Operativer Hüftgelenkersatz mit zementfreier Verankerungstechnik--Indikation, Technik, Ergebnisse.

There is reason to doubt the reliability of bone cement in joint replacements. In this paper we report about our indication for the cementless RM-Prosthesis and the follow-up examination of a group of 98 patients four and five years after total hip implantation. The rate of cup-loosening is lower than 1%, in five cases we had to observe stem-loosening. The artificial cup consists of high density polyethylene and has to be inserted with preload. The stem consists of polyacetal with a central metal reinforcement. A snap-fit 32 mm steel-head articulates with the acetabulum. From our experiments we know the importance of neutralisation of sharing and tension forces at the area of the greater trochanter.

[Expert evaluation of meniscus damage]. / Die Begutachtung des Meniskusschadens.

There are four main reasons for mistakes in giving expert opinions about injuries of the meniscus. The report about the accident isn't sufficiently detailed. The expert questions the injured person himself. The mechanics of the knee are unknown. The juridical and medical problems of degeneration and previous damage are unknown. The points are discussed to get a higher standard of expert opinions.

[Dislocations of the carpal bones. Diagnosis and therapy]. / Luxationen der Handwurzelknochen. Diagnostik und Therapie.

Dislocations of the carpal bones are rare. Because of the difficult radiological anatomy of the carpus, the diagnosis of such injuries is often missed. The treatment of a primary diagnosed luxation is easy, and an anatomical position of the carpal bones can be achieved by closed reduction. The functional result is good. In contrast the treatment of delayed diagnosed dislocations is very problematic, and the outcome of the mainly operative therapy is unsatisfactory on the whole. The radiological findings on dislocations of the carpal bones are discussed in principle. The indication of non-operative and operative treatment is outlined.