Color-coded Duplex sonography of vertebral arteries. 11 cases of blunt cervical spine injury

In 11 patients with locked cervical spine facets after blunt injury, the patency of the vertebral arteries was evaluated by color-coded Duplex sonography (CCDS) up to 11 years after the accident. In 7 patients the dislocations had been reduced, 2 had been treated conservatively, and 9 had been fused. In 9 patients (3 of them with persistent locking) the mean systolic peak flow velocity was 55 cm/sec and the vessel diameter was 0.35 cm. Only 2 patients had an abnormal CCDS. In 1 with persistent locking the ipsilateral vertebral artery was occluded, and in the other flow signals were abnormal and the vessel diameter was smaller than on the contralateral side. The high coincidence of vertebral artery occlusions and locked dislocations, as well as fracture dislocations reported by others, was not confirmed in our series.

Mood effects on attitude judgments: independent effects of mood before and after message elaboration

This study investigated the independent effects of induced mood on the encoding of persuasive messages and on the assessment of attitude judgments. In Experiment 1, positive or negative mood was induced either before the encoding of a counterattitudinal message or before the assessment of attitude judgments. When mood was induced before message presentation, Ss in a bad mood were more persuaded by strong than by weak arguments, whereas Ss in a good mood were equally persuaded by strong and by weak arguments. When Ss encoded the message in a neutral mood, however, the advantage of strong over weak arguments was more pronounced when Ss were in a good rather than in a bad mood at the time of attitude assessment. In Experiment 2, Ss exposed to a counterattitudinal message composed of either strong or weak arguments formed either a global evaluation or a detailed representation of the message. Positive, negative, or neutral mood was then induced. Ss in a good mood were most likely and Ss in a negative mood least likely to base their reported attitudes on global evaluations.

[Locked rotational dislocation of the cervical spine]

There is no generally accepted treatment protocol for dislocations of single articular processes of the cervical spine. However, the data in our own series and a survey of the literature show that in this type of injury the primary diagnosis rate is low (around 50%), that closed reduction maneuvers can be neurologically hazardous, and that operative fusion prevents certain complications. Among the 20 patients treated at the authors' institution the injury was located in the lower cervical spine in all but one patients and it was caused by a high-speed traffic accident in 14 patients. Four patients had no therapy at all; the others were fused by an anterior approach in 8, a dorsal approach in 6, and a combined method in 2 patients. There was one death due to intimal tearing of a vertebral artery. Closed reduction caused a transient neurological lesion in 2 patients. In 6 patients whose dislocation was neither reduced nor fused, 3 developed chronic instability. In our new treatment protocol dislocation of a single articular process is only reduced after a diskectomy to prevent extrusion of the disc. If reduction from the anterior approach fails or if it cannot be achieved due delayed treatment, the entrapped nerve root is decompressed. Fusion of the injured segments is carried out by bone blocks and plates or hooks.

Osteosynthesis of irreducible fractures of the clavicle with 2.7-MM ASIF plates

Thirty-six patients with Allman group-2 fractures of the clavicle were treated by ORIF with 2.7-mm ASIF dynamic compression plates. The indications for surgery were an open fracture in one patient, ipsilateral fractures of the arm or the ribs in five patients, bilateral clavicular fractures in one patient, and an inability to reduce the fracture in all other patients. There were no instances of deep infection. One patient suffered a refracture after plate removal; three patients developed pseudarthrosis because plates that were too short were used. The total failure rate was 12%. It is concluded that the 2.7-mm DCP is the method of choice for internal fixation of midshaft clavicular fractures and that a minimum of three screws should be placed in each fragment.

[The Spiegelberg device for epidural registration of the ICP]

The Spiegelberg device is based on air-filled balloon system and was designed for epidural ICP monitoring. Zero adjustment is done automatically with the device in situ, thus avoiding zero drift. In 14 patients with mostly severe head injury (Glasgow Coma Scale score of 8 or lower in 10 patients) and 19-84 years old monitoring was carried out during treatment in the intensive care unit. ICP values were checked by repeating functional tests of the monitoring system, by serial cranial CT, and by a study of the clinical outcomes. Four patients died. There were no technical problems or infections. Clinically reliable data were obtained in 10 patients. The ICP shown was correlated with all other parameters; it was lower than would be expected in 1, and higher in 3 patients. With six simultaneous measurements with Gaeltec ICT/b, Camino subdural or an intraventricular catheter system the values were found to correlate only in 1 case. Experimental and clinical data suggest that the Spiegelberg-monitored ICP is somewhat higher than the ICP shown by other epidural systems. Clinical trials will be continued.

Mood effects on attitude judgments: Independent effects of mood before and after message elaboration

This study investigated the independent effects of induced mood on the encoding of persuasive messages and on the assessment of attitude judgments. In Experiment 1, positive or negative mood was induced either before the encoding of a counterattitudinal message or before the assessment of attitude judgments. When mood was induced before message presentation, Ss in a bad mood were more persuaded by strong than by weak arguments, whereas Ss in a good mood were equally persuaded by strong and by weak arguments. When Ss encoded the message in a neutral mood, however, the advantage of strong over weak arguments was more pronounced when Ss were in a good rather than in a bad mood at the time of attitude assessment. In Experiment 2, Ss exposed to a counterattitudinal message composed of either strong or weak arguments formed either a global evaluation or a detailed representation of the message. Positive, negative, or neutral mood was then induced. Ss in a good mood were most likely and Ss in a negative mood least likely to base their reported attitudes on global evaluations.

Fresh autogeneic, frozen allogeneic, and decalcified allogeneic bone grafts in dogs

In fully-grown mongrel dogs, diaphyseal ulnar defects 25 mm long were stabilised by screws and plates, and were temporarily filled with silicone rubber blocks. After eight weeks the block was replaced either by fresh autogeneic cancellous bone, allogeneic deep-frozen cancellous bone, allogeneic decalcified bone matrix, or bone matrix gelatin. After 24 weeks the implants were evaluated by radiography, histology, and measurements of new bone volume, using computer-assisted density registration on microradiographs. Only the autogeneic bone grafts led to healing in all instances. Bone regeneration in the other groups was not significantly better than in the sham group in which no graft was employed. Decalcified bone matrix proved ineffective.

Decalcified and undecalcified cancellous bone block implants do not heal diaphyseal defects in dogs

In a previous study it has been shown that granulae of decalcified bone matrix do not induce bony healing of 8-week-old mid-diaphyseal defects in dogs. The aim of this study was to test whether osteoinduction combined with the osteoconductive mechanisms provided by the natural structure of cancellous bone blocks would yield better results. A 30-mm-long diaphyseal defect of the left ulna was created in eight adult mongrel dogs and the bone was stabilized with a plate. A Silastic spacer was inserted in the defect for 8 weeks, followed by implantation of frozen undecalcified or decalcified allogeneic cancellous bone blocks for 16 weeks. Healing was analyzed using morphologic methods. At 16 weeks after implantation all grafts had been resorbed. In the decalcified group one defect healed, while none in the other group did so. The implant material was bioassayed in nude rats for osteoinductivity, which was found to be low in decalcified matrix and not detectable in undecalcified bone.

CONCLUSION

Allogeneic cancellous bone blocks, demineralized or not, have no osteoinductive capacity and no osteoconductive function that promotes healing of mid-diaphyseal bone defects in dogs.

[Bone replacement using demineralized allogeneic bone in animal experiments]

The implantation of bone matrix in muscle bag or trepanation defects of rats with greatest reproducibility will induce osteogenesis and defect healing. The phenomenon of osteo-induction was possible to obtain only in first steps in higher developed mammals. Investigations in nude rats have shown a clear difference in biologic reaction on the matrix of various species. The osteo-regeneration in replacement weak defect of ulnar bone in dogs showed a massive greater reactivity of autogenous spongiosa, whereas bank spongiosa and bone matrix produced not more new bone as the control. An increase of osteoinductive matrix potency is a supposition for practical use in case of severe bone defects.

Dog bone less osteogenetic than rat bone. Bone-matrix transplants in nude rats

Demineralized bone matrix and bone-matrix gelatin prepared from cortical rat bone, and from cortical and cancellous canine bone were implanted into muscle pouches of nude rats for 6 weeks. Evaluation was done by histology, histomorphometry, and determination of alkaline phosphatase. Rat matrix consistently induced new bone and high phosphatase levels. Canine matrix induced but small amounts of bone and lower phosphatase levels, with cortical matrix somewhat more inductive than cancellous matrix; demineralized cancellous bone matrix from the dog was the only material tested not showing any inductivity. Irrespective of bone type or species, gelatin had clearly higher induction capacity than demineralized bone matrix.

[Post-traumatic hemarthrosis of the hip joint. Pathophysiolgic significance and therapeutic consequences]

A correlation between the intra-articular pressure in the hip joint and blood flow in the femoral head has been demonstrated in both experimental and clinical data. A small effusion volume (2.5 cc) is capable of causing pathological pressure values, depending upon the position of the joints, although the highest volume capacity in the hip is well over 10 cc. Relief of post-traumatic tension hemarthrosis seems to be an essential therapeutic step, as it may prevent necrosis of the femoral head.

[Partial resection of the ulna as a diaphyseal bone defect model in the dog]

A 25-mm periosteal cylinder was removed from the middle of the ulna in fully grown mongrel dogs. A silastic block was interposed and the defect was fixed by a plate. Eight weeks later, the block was removed. During the following 24 weeks, spontaneous bone regeneration was evaluated by radiologic and histomorphometric evidence. In a second series, three screws were placed transversely to the longitudinal axis from the ulna into the radius to stabilize the partial resected ulna. The observation period after silastic removal was 16 weeks. Evaluation was based on radiology and on Indian ink stain of the vessels. Plate fixation provides an essentially stable defect model, with partly considerable bone apposition to the proximal area of resection. This is explained by the entry of the only nutrient artery into the proximal diaphyseal third. No instance of spontaneous defect healing following plate fixation was observed. The transverse fixation of the ulna revealed early radiologic signs of instability.

The influence of fibrin sealant on demineralized bone matrix-dependent osteoinduction. A quantitative and qualitative study in rats

Allogeneic demineralized bone matrix (DBM) and bone matrix gelatin (BMG) were implanted with or without fibrin sealant (FS) ectopically (abdominal wall) and orthotopically (7-mm trepanation defect) in 38 male Sprague-Dawley rats. Evaluation was done by descriptive histology, histomorphometry of orthotopic implants, and determination of alkaline phosphatase in ectopic implants. The observation period was 21 days with ectopic implantation and 26 days with orthotopic implantation. In all ectopic specimens, new bone developed without any qualitative difference between specimens with and without FS. The alkaline phosphatase activity did not change significantly upon addition of FS. Morphometry revealed slight differences between the groups with and without FS. The peripheral bone deposits in the BMG + FS group, was significantly larger than in the BMG group. These investigations demonstrated neither a clearly positive nor negative effect of FS on ectopic osteoinduction or BMG-dependent osteoregeneration.

Cognitive and affective bases of opinion survey responses

Two experiments investigated the determinants of agreement with propositions that advocated social privileges for either people in general or specific social groups. Liking for the group to which a group-specific proposition referred had a contrast effect on agreement with a related general proposition that was considered immediately after it, but had a positive influence on agreement with a general proposition that did not occur until several items later. The latter effect was eliminated by instructing Ss to base their judgments on the consequences of the policies described in the propositions. Instructions to base judgments on affective reactions to the propositions produced contrast effects of group-specific propositions on judgments of general ones regardless of whether these items were separated or together in the questionnaire.

[Abduction fractures of the femur neck in adolescents]

Valgus fractures of the femoral neck during growth are a rarity. Four cases are reported, and, in addition, one patient from the literature. Three were treated by bed rest, two by primary screw fixation. Clinical results were good; there was no necrosis. In accordance with the experience with similar fractures in adults primary osteosynthesis is recommended in all cases to prevent secondary displacement. Decompression of the hip joint by aspiration should be done for diagnosis and for decompression of tension haemarthrosis.

Inferior acromioclavicular separation. Report of an unusual case

An inferior acromioclavicular separation occurred in a 33-year-old man. Diagnosis was based on plain roentgenograms and a computed axial tomographic scan. There were no fractures and no vascular or nerve damage. Open reduction was performed 48 hours after injury followed by tension wire fixation of the acromioclavicular joint and repair of torn ligaments. Clinical outcome four months after injury was perfect.

Pressure-volume ratio in human cadaver hip joints

In postmortem examinations 26 hip joints of 23 adult individuals were filled with Ringer's solution in order to furnish data on the relationship between intra-articular pressure, capsular content, and joint position. A tube system was connected to an 18-gauge needle and to a pressure transducer. After instillation of 2.5, 5.0, 7.5, and 10.0 ml of Ringer's solution, intra-articular pressure was recorded in six different joint positions (extension, 45 degrees and 90 degrees flexion, 40 degrees internal and 40 degrees external rotation, and 45 degrees abduction in extension). Intra-articular pressure depends mainly on the position of the joint, with highest values in external and internal rotation and lowest values in 45 degrees flexion. In this last position, the pressure was zero in two of four cases after injection of 10 ml, whereas with external rotation and instillation of 2.5 ml almost 60 kPa was recorded. In extension and after filling with 10 ml the pressure exceeded the level of normal systolic blood pressure in all cases. Under pathologic conditions intra-articular pressure of the hip joint can rise well above arterial pressure and thus eventually compromise vascular supply to the femoral head, even in the presence of only minimal intra-articular effusion.

Irradiation-sterilization of rat bone matrix gelatin

Bone matrix gelatin induces bone formation in muscle, and when implanted orthotopically it improves bone repair. Co-60 sterilization of bone gelatin impairs the protein-bound induction mechanisms. Gelatin samples nonirradiated or irradiated by 25 or 50 kGy were implanted into a pouch in the abdominal wall of Sprague-Dawley rats, as well as into a 7-mm calvarial defect. Evaluation was done by histologic studies, histomorphometry of orthotopic implants, and determination of alkaline phosphatase in ectopic implants. Gelatin irradiated with 50 kGy was absorbed in the muscle bed without evidence of any specific host reaction. Irradiation of 25 kGy led to histologically confirmed ectopic bone formation, but the wet weight of the explants was only half that of the nonirradiated control samples. Alkaline phosphatase activity was equal in both of these groups. With orthotopic implantation, neither a histologic nor a morphometric effect was seen with 25 kGy. Loss of osteoinduction with 25-kGy irradiation is apparently masked by osteoconductive mechanisms with orthotopic implantation.

Experimental osteoinduction in rats: collagen-apatite versus osteogenin-containing gelatine

An experimental study in rats was done to investigate the bone-regenerating properties of collagen apatite (Collapat) and to compare it with osteoinduction dependent on osteogenin-containing gelatine (OCG). The test substances were implanted orthotopically (calvarial defect--7 mm in diameter) and heterotopically (paravertebral muscles, abdominal muscles). The results were evaluated histologically and enzymatically (alkaline phosphatase). Collapat caused neither osteoinduction in the heterotopic site nor healing of the bone defects. Foreign body reaction without new bone formation was encountered. OCG implantation leads to new bone formation in the muscles within 3 weeks, associated with a significant increase in alkaline phosphatase activity, and to extensive new bone formation in the calvarial defect within 4 weeks. The defects did not heal if left empty. The value of clinical application of Collapat appears to be doubtful. Osteoinduction with OCG requires further experimental investigation.