Cancer risk after metal on metal and polyethylene on metal total hip arthroplasty.

The incidence of cancer after metal on metal total hip arthroplasty (McKee-Farrar) and polyethylene on metal total hip arthroplasty (Brunswik, Lubinus) was compared with that of the general population in Finland. The mean followup time for the patients who had metal on metal total hip arthroplasty was 15.7 (9092 person years) and for the patients who had polyethylene on metal total hip arthroplasty it was 12.5 years (19,846 person years). One hundred thirteen malignant cancers were observed in patients who had metal on metal total hip arthroplasty and 212 were observed in patients who had polyethylene on metal total hip arthroplasty. The standardized incidence ratio for all cancers of the metal on metal arthroplasty group was 0.95 (95% confidence limits 0.79-1.13) and that of the polyethylene on metal arthroplasty group was 0.76 (95% confidence limits 0.68-0.86). The risk of total cancer in the patients who had metal on metal total hip arthroplasty was 1.23-fold compared with that of the patients who had polyethylene on metal total hip arthroplasty. Both groups had significantly less lung cancer than the general population: the leukemia incidence in the patients who had metal on metal total hip arthroplasty was slightly increased (observed to experienced 7/3.03, standardized incidence ratio 0.61; 95% confidence limits 0.17-1.56). The leukemia rate of the patients who had metal on metal total hip arthroplasty was 3.77-fold compared with that of the patients who had polyethylene on metal total hip arthroplasty, but this difference was not statistically significant. No sarcomas were observed at the site of the prosthesis. The incidence of the other forms of cancers did not differ significantly from those in the general population. The observed variation in the incidence of different cancers among patients who had total hip arthroplasty compared with the general population suggests that factors other than total hip arthroplasty play a major role in the origin of cancer.

Ceramic endoprosthesis in total hip arthroplasty.

Aluminia-on-aluminia hip prosthesis with titanium alloy stem was used in 255 cases, for 143 patients with cemented acetabular cup and 112 with an uncemented screw cup. The average age of the patients was 62 years. Of the patients, 35 were treated bilaterally. The indication for surgery was osteoarthritis in 186 cases, fractures and nonunions of the hip joint in 34 cases, and congenital dislocations of the hip joint in 16 cases. Previous surgery of the hip joint was recorded for 43 cases. All procedures were primary arthroplasties. Only personal clinical examinations together with radiographic studies were accepted as clinical data. Three patients failed to show up for routine follow-up evaluation and these were excluded from the series. Revision operation was classified as failure. The indications for revision were aseptic loosening, late infection, and fracture of the acrylic cement resulting in loosening of the acetabular or femoral component. The acetabular component was cemented in 143 patients and the mean follow-up period for these patients was 6.7 years (range, 1-12 years). In this series, a revision operation was undertaken for 16 patients (11%). In 12 cases, broken acrylic cement resulted in acetabular aseptic loosening. In the series of 112 patients with uncemented titanium screw cup, the mean follow-up period was 3.6 years (range, 1-7 years) and a revision operation was undertaken in seven cases (7%). In two, the indication was late infection; in one, technical failure; and in two, progression of Pigmented villonodular synovitis. Acetabular aseptic loosening resulted in revision in only two cases. With cementless acetabular component bone transplantation is indicated.(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome of closed injuries exceeding 20-unit blood transfusion need.

A series of 129 patients with closed injuries receiving more than 20 units (1 unit = 500 ml) of blood within the first 48 h of accident was analysed. The transfusion policy included type-specific crossmatched whole blood stored with citrate phosphate-adenine as the main replacement. One unit of fresh whole blood was transfused for every 5 to 6 units of stored blood. Also platelet concentrates and fresh frozen plasma were in routine use. The patients required 340 surgical procedures, on average 2.6 per patient. Thrombocytopenia with a lowest recorded platelet count of less than 100,000/mm3 occurred in 81 patients (63 per cent) of whom 18 had disseminated intravascular coagulation. This serious complication seemed to be associated with large retroperitoneal blood accumulations, the latter possibly acting as an enhancing factor. The mortality rate in the whole series was slightly lower than recorded previously in the literature. Among patients receiving 21 to 39 blood units the mortality was 25 per cent and among those receiving 40 units or more the mortality was 52 per cent.

Anterolateral decompression for neural involvement in thoracolumbar fractures. A review of 78 cases.

Of a total of 905 patients with fracture or fracture-dislocation of the thoracolumbar spine admitted from 1969 to 1982, a neurological deficit was present in 334 (37%). All unstable injuries were initially treated by reduction and posterior fusion. In 79 of these patients, an anterolateral decompression was undertaken later because of persistent neurological deficit and radiographic demonstration of encroachment on the spinal canal. One patient died of pulmonary embolism; 78 were reviewed after a mean period of four years. Of these 78 patients 18 made a complete neurological recovery while 53 appeared to have benefited from the procedure; 25 remained unchanged. The best results were obtained in burst fractures at thoracolumbar and lumbar levels when a solitary detached fragment of a vertebral body had been displaced into the spinal canal. These results indicate that anterolateral decompression of the spinal canal should be considered, after careful evaluation, for certain injuries of the spine in which there is severe neural involvement.

Unstable fractures of the thoracic and lumbar spine: the audit of an 8-year series with early reduction using Harrington instrumentation.

A series of 112 patients with acute unstable fractures of the thoracic or lumbar spine managed uniformly by early reduction using Harrington's instrumentation was analysed. The level of injury was T6-T11 in 19, T12-L1 in 67 and L2-L5 in 26 patients. On admission, 28 patients had complete paraplegia corresponding to the level of the lesion, 55 had partial lesions and 29 no neural damage. The policy of management comprised reduction by dual distraction rods and simultaneous short posterolateral fusion as an emergency procedure. Anterior decompression of the spinal canal, if required, was performed subsequently. The duration of the postoperative period in bed was 6 weeks. The rods were removed after 9-12 months. The radiographical result and neurological recovery were assessed after an average personal follow-up for 3.1 years. The height of the fractured vertebra was initially well restored, the mean angle of kyphosis being 14 degrees on admission and 5 degrees immediately postoperatively. However, gradually the fractured vertebral body and the intervertebral discs collapsed slightly and at follow-up the mean angle of kyphosis was 12 degrees. On the other hand, the reduction of the initial sagittal displacement of the fractured vertebral body into the spinal canal, could be maintained and a good anatomical end-result was achieved in most cases. The ultimate radiographical results were better after injuries of the thoracic spine and the thoracolumbar junction than after those of the lumbar spine. Improvement of neural function was seen in 28 patients (34 per cent of those with a deficit). Complications of clinical importance occurred in 29 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Posterior spinal fusion using internal fixation with the Daab plate.

The results of posterior spinal fusion, supplemented by internal fixation with the Daab plate in 43 patients, are presented. The Daab plate is a quadruped implant placed longitudinally in the coronal plane and fixed by simply pinching it around the spinous processes. The cause of the instability necessitating fusion was acute trauma in eight patients, late posttraumatic condition in 11, pure degenerative process in seven and spondylolisthesis in nine patients. In addition, there were solitary cases of tuberculous spondylitis, pyogenic spondylitis and metastatic destruction of the vertebral body. The fusion site was cervical in three, thoracic in eight, thoracolumbar in 12 and lumbar or lumbosacral in 20 cases. The mean follow-up time was 19 months. The consolidation of the fused area could, apart from radiographs, ultimately be evaluated at removal of the implant in 39 patients. The fusion was successful in 37 patients. Compared with previous reports, this result must be considered satisfactory when the severity of the cases in this series is noted. Internal fixation in connection with posterior fusion is needed only exceptionally, but in complicated cases the Daab plate seems to afford a simple method of securing the position of the segments for the first postoperative months.

Fat embolism in patients with multiple injuries.

The diagnostic criteria of clinical fat embolism syndrome are most important. Petechial rush, positive chest X-ray films, low arterial oxygen content, and cerebral involvement are major features. Three different grades of fat embolism can be distinguished. The development of the first grade cannot be prevented. By early internal fixation of long-bone fractures in patients with multiple injuries it may be possible in most cases to prevent the development of the third grade, the severe clinical fat embolism syndrome. Thus specific treatment because of fat embolism was indicated in only three cases in this series of 211 patients with broken long bones and multiple injuries.

Treatment of spinal fractures with paraplegia.

Of 206 patients with vertebral fractures in the thoraco-lumbar spine with spinal cord injuries, an antero-lateral decompression with stabilization of the injured segment of the vertebral column was undertaken in 56 cases. In all these cases there was a compression of the spinal cord from the front. 8 patients made a complete recovery, 31 a good recovery, and 6 were improved. In 8 patients no improvement was noted. 2 patients developed pressure sores later and 1 patient died one year after the operation of uraemia. 22 patients out of 55 got a normal function of the bladder and 25 patients out of 54 a normal function of the anal sphincter. 16 patients out of 17 made a complete or good recovery after removal of a displaced rotated vertebral bony fragment from the spinal canal, and 7 patients out of 9 with wedge shaped fractures. In our clinic today, in cases of vertebral fractures with neural involvement, reduction and internal fixation with Harrington rods and fusion of the injured segment is undertaken as soon as possible, also during the night. If narrowing of the neural canal and compression of the spinal cord are verified, a decompression operation with interbody fusion is undertaken during the next days.

Early operative treatment of injuries of te thoracolumbar spine.

Following the assessment of our results, the following treatment policy is suggested for thoracolumbar spinal fractures. Stable fractures without neural involvement are treated conservatively. Stable fractures with neural involvement are rare, and the spinal cord or cauda equina should be decompressed. Unstable fractures are treated operatively with internal fixation and fusion. Unstable fractures with neural involvement are always treated operatively. Stabilization can usually be achieved by Harrington rods and fusion. Restitution of the normal anatomy gives the best chance for functional improvement.

Pelvic fractures.

Stabilization of unstable pelvic fracture is warranted to relieve pain and to reduce bleeding. A trapezoid frame external fixation is suggested for reduction and retention of such fractures. Some controversy exists concerning the sources of bleeding and the measures for control. On the one hand, bleeding arises from fractures of the cancellous bone. On the other hand, blood vessels may be torn by the fracture. Massive bleeding is common which requires a good blood bank service. The complications of pelvic fracture consist bleeding, nervous and urological injuries.

Replacement of the femoral head by ceramic endoprosthesis. An experimental study on rabbits.

In 31 rabbits the femoral head was replaced by a ceramic endoprosthesis. For 11 of the experimental animals the endoprostheses were made by the Arabia China Factory in Helsinki, and for 20 by Staatliche Porzellan Manufaktur in Berlin. The operation was performed under fully sterile conditions and the follow-up time was between 6 and 34 weeks. The hip joint was examined clinically, roentgenologically, macroscopically and histologically. The bending tolerance of the ceramic endoprosthesis was not adequate. Mechanical loosening of the proximal part of the prosthesis occurred in 68 per cent and was combined with fracture of the prosthetic stem. This created a pseudarthrosis-like reaction in the acetabular area and limited the movement of the hip joint. The distal fragment of the stem was always surrounded by a thin layer of dense bone. In the nonfractured cases (32 per cent), however, the reaction was only moderate and the movement of the hip joint was well preserved. The tissue reactions to the ceramic material were slight, but the great number of secondary reactions following stem fractures make the use of the ceramic endoprosthesis questionable in experiments with rabbits.

Treatment of para-articular ossification after total hip replacement by excision and use of free fat transplants.

Six patients with para-articular ossification after total hip replacement were treated by excision and free fat tissue transplantation. The results of treatment were good and at the follow-up examinations, 2 to 8 years after the operation, a good range of movement of the hip joint was noted in all cases. It was apparent that the free fat transplant had prevented the recurrence of the para-articular ossification.

The effect of temporary exercising of a joint during an immobilization period: an experimental study on rabbits.

The right hind limbs of adult rabbits were immobilized for 5 weeks. The rabbits were then allowed to move freely for 8 weeks. The rabbits of the control group were immobilized uninterruptedly. In a second group of rabbits the plaster was removed during the immobilization period 6 days a week for 5 minutes for careful exercise and in a third group of rabbits, for violent exercise. The temporary careful exercise was of no benefit and was sometimes harmful, and the violent exercise was usually injurious for the immobilized knees as regards the stiffening, thickening and the development of radiologically detectable degenerative changes.

Operative control of massive haemorrhage in comminuted pelvic fractures.

In 42 patients, massive haemorrhage following comminuted pelvic fractures was treated by operation through a mid-line, Pfannenstiel, anterior iliac crest-femoral or posterolateral approach, or using these in combination. The superior and inferior gluteal, pudendal and obturator arteries were the usual source of bleeding. Bleeding from the pelvic bone tissue was of minor importance. Temporary compression of the abdominal aorta was sometimes required to help control bleeding before ligation of injured vessels could be accomplished. An average of nine units of blood was given to each patient before operation and 30 units during or after the procedure. Of the 12 deaths, only three were attributable to bleeding from the pelvic fractures, indicating the value of operation in the treatment of massive haemorrhage from such injuries.

External fixation of unstable pelvic fractures.

The Hoffmann external fixator was used to stabilize unstable pelvic fractures in 56 patients with multiple injuries. It was applied under general anaesthesia and the dislocated pelvis reduced and secured with a single tie bar. In 16 cases residual dislocation of less than 1.5 cm was noted after the reduction and the reduced position was maintained in 48 out of 51 cases, a minor redislocation occurred in the remaining 3 patients. Few complications could be attributed to the method, infection was noted in one patient, the iliac crest was fractured in one case and an exostosis of the iliac crest occurred in one youth. Forty-three patients were symptom free with regard to the pelvis at the time of review whereas 5 patients had residual pain and 3 diffuse symptoms. The technique of application is simple but requires two surgeons at the time of reduction and fixation of the pelvis.