Biomedical subjects

O Böstman

Publications and source records attributed to O Böstman.

At least 19 recordsLinked to original sources

PubMed1992

[Absorbable rods and screws: a new method of fixation for fractures of the olecranon].

Between April 1986 and July 1990 fractures of the olecranon in 41 adult patients were treated by fixation with absorbable rods (20 patients) and screws (21 patients) of self-reinforced polyglycolide (SR-PGA), 3.2 mm in diameter and 20-70 mm in length. Patients were followed up for a mean time of 2 years 7 months (range 1 year to 4 years 6 months). After reduction of the fracture, channels were drilled from the proximal fragment through the cortex of the distal fragment and the fractures were fixed with absorbable rods or screws. By one year from follow-up maintenance of an anatomical reduction of the fracture was seen in 34 patients. Failure of fixation requiring a second operation occurred in 2 cases. In all cases functional recovery was at least satisfactory. Sinus formation as a sign of transient tissue reaction was observed in 3 cases, but did not influence the healing of the fractures or the functional recovery. The results in patients treated with rods or screws was similar. Absorbable screws combined with small rods and absorbable sutures allow treatment of +ore severe fractures of the olecranon than do rods alone.

Adult↗

PubMed1992

Self-reinforced absorbable screws in the fixation of displaced ankle fractures: a prospective clinical study of 152 patients.

The series consisted of 152 patients with ankle fractures treated between May 1987 and August 1989 using absorbable screws of self-reinforced polyglycolide 3.4 mm in inner diameter and 25-70 mm in length. The mean follow-up time was 2 years, 5 months (range, 1 year, 7 months-3 years, 10 months). After open reduction, a channel was drilled through the fracture surfaces and the fragments were fixed with one absorbable screw or screws. A plaster cast was used postoperatively. At 1-year follow-up observation, the radiographical result was anatomical in 93.3% of 104 patients with unimalleolar and bimalleolar ankle fractures (Weber A or B) and in 80.5% of 41 severe ankle fractures. Seven patients were unavailable for follow-up observation. Two reoperations were performed because of primary or secondary failure of fixation. In all unimalleolar and bimalleolar fractures and in 95.1% of severe ankle fractures the functional recovery score was at least satisfactory. Sinus formation as a sign of tissue reaction was observed in 10 patients 2-6 months postoperatively, but this did not influence the healing of the fracture or the functional recovery. This report is the first extensive publication on the clinical use of absorbable screws.

Activities of Daily Living↗

PubMed1992

Mechanical failures of internal fixation in T and Y fractures of the distal humerus.

To evaluate the factors resulting in mechanical failures of internal fixation of distal T-type and Y-type humeral fractures, we reviewed the clinical course and final results in 61 consecutive cases treated with AO-ASIF internal fixation devices. The patients were followed for at least 2 years (range, 2-11 years). Mechanical failure occurred in 18 cases (29.5%). In 12 patients this resulted from an unstable fixation. Severe osteoporosis was present in four patients. In two patients no specific causative factor could be detected. A second osteosynthesis was undertaken in five patients, and four additional patients were later operated on for nonunion. The functional outcome after these mechanical failures was, unexpectedly, poor in only 6 of the 18 patients. In spite of this comforting finding, the conclusion is that to minimize the failure rate in the management of these demanding fractures strict adherence to the correct technical fixation principles is mandatory, and when the bone is very osteoporotic a nonsurgical approach seems advisable.

Adolescent↗

PubMed1992

Absorbable pins of self-reinforced poly-L-lactic acid for fixation of fractures and osteotomies.

We reviewed 27 patients with small-fragment fractures or osteotomies treated by internal fixation with absorbable self-reinforced poly-L-lactide pins. The follow-up time ranged from eight to 37 months. The two most common indications were chevron osteotomy of the first metatarsal bone for hallux valgus and displaced fracture of the radial head. No redisplacements occurred, and there were no signs of inflammatory foreign-body reaction. Biopsy in two patients 20 and 37 months after implantation showed that no polymeric material remained.

Adult↗

PubMed1992

Polymeric debris from absorbable polyglycolide screws and pins. Intraosseous migration studied in rabbits.

The migration of polymeric particles during degradation of absorbable implants made of polyglycolide was investigated in the cancellous bone of distal rabbit femur by using a transverse osteotomy model. The osteotomy was fixed either with a 4.5 x 25 mm screw or with two 1.5 x 30 mm pins. The histologic sections obtained at 3, 6, 12, and 36 weeks were morphometrically analyzed using polarized-light microscopy. The migration of the polymeric debris into the host-tissues showed two different patterns. On the one hand, particles were in all specimens seen lying intracellularly in phagocytic cells in a regular front close to the original tissue-implant boundary. In addition, in several specimens there occurred expansions filled with largely extracellular polymeric particles that bulged into the hematopoietic bone marrow up to 2.8 mm from the original implant cavity. This kind of particle migration over long distances could not be explained by cellular transport, but may have been caused by an increased osmotic pressure that developed within the implant cavity during depolymerization of polyglycolide.

Animals↗

PubMed1992

Talocrural arthrodesis with absorbable screws, 12 cases followed for 1 year.

In 11 patients, 12 arthrodeses of the ankle joint were performed by using absorbable self-reinforced poly-l-lactide (SR-PLLA) or polyglycolide (SR-PGA) screws. 8 patients had posttraumatic arthrosis, 3 rheumatoid arthritis, and 1 rigid flexion contracture of the ankle due to neuropathy. The average follow-up time was 14 (7-22) months. Solid fusion was achieved in 11 of 12 cases in 9(6-16) weeks.

Absorption↗

PubMed1992

Foreign-body reactions to polyglycolide screws. Observations in 24/216 malleolar fracture cases.

Out of 216 patients with displaced malleolar fractures operated on using absorbable polyglycolide screws, 24 developed a transient local nonbacterial inflammatory reaction on an average 3 months after the operation. Upon histopathologic examination, these tissue responses were found to be nonspecific foreign-body reactions. Neither the age of the patient nor the number of screws used in the fixation affected the incidence of the reactions. The first-generation screws that were colored with an aromatic quinone dye showed a higher incidence, 19 reactions among 105 patients, than the new noncolored implants, 5 among 111 patients (P less than 0.01). No deleterious effect of these tissue responses on the union of the fractures could be detected, but the possible long-term consequences of this complication are so far unknown.

Adult↗

PubMed1992

Postoperative complications of distal humeral fractures. 27/96 adults followed up for 6 (2-10) years.

Of 96 adult patients with a distal intercondylar, intraarticular fracture of the humerus treated operatively during a 10-year period, 27 patients suffered a local complication, while the total number of individual complications were 34. There were six postoperative infections, 12 neural injuries, and 16 fixation failures. Because of the complication, a reoperation was performed in 12 of the 27 patients. The final outcome was assessed at a reexamination after a mean follow-up period of 6 (2-10) years. Three patients had a permanent dysfunction of the ulnar nerve. In another 3 patients, failure of the fixation had resulted in an established nonunion of the distal humerus. It appeared that the possibilities of internal fixation in several cases had been overestimated.

Adolescent↗

PubMed1992

[Resorbable rods and screws of polyglycolide in stabilizing malleolar fractures. A clinical study of 600 patients].

Absorbable internal fracture fixation implants have been in large-scale clinical use since 1984. The main advantage of these devices is that no subsequent operation for implant removal is required. In this study the results obtained in a series of 600 patients with displaced malleolar fractures who were operated on over a 6-year period (1985-1990) using rods or screws made of polyglycolide were analysed. Rod fixation was used in 63% and screw fixation in 37% of the patients. Recovery was uneventful in 91.5%. Bacterial wound infection occurred in 1.2% and failure of fixation necessitating reoperation in 0.8% (5 patients). In 4 of these 5 patients a refixation procedure with AO devices was performed. In one elderly patient with failed fixation talocrural arthrodesis had to be done. A sterile inflammatory foreign-body reaction complicated the course in 6.5%. The incidence of these reactions was higher during the early years of the study, when the implants contained an aromatic quinone dye, than later, when stain-free implants were used. The foreign-body reactions were transient and did not significantly influence the ultimate results of treatment. During the 6-year period the use of absorbable implants has made it possible for resources corresponding to several hundred hardware removal procedures to be used for other purposes.

Adolescent↗

PubMed1992

Degradation and tissue replacement of an absorbable polyglycolide screw in the fixation of rabbit femoral osteotomies.

Degradation and tissue replacement of a totally absorbable polyglycolide screw, 4.5 millimeters in diameter and thirty millimeters in length, were studied histologically, morphometrically, and radiographically at sequential stages of resorption at as long as thirty-six weeks after fixation of a transverse distal femoral osteotomy in rabbits. The initial mean shear force to failure was 95.0 newtons for the specimens that had been fixed with the polyglycolide screw compared with 257.0 newtons for the distal part of the contralateral, intact femur. The physical appearance of the screw was unaltered at three weeks. The first histological signs of degradation were seen at six weeks, along the thread ridge. Premature breakage of the screw resulted in gross displacement and non-union of the osteotomy in one animal. The degradation of polyglycolide was accompanied histologically by a typical non-specific foreign-body reaction. This kind of tissue response seemed to be associated with an osteolytic proximal expansion of the implant cavity that was suggestive of increased pressure within the cavity during degradation of the screw. In eight specimens, a wall of new bone formed around this area of osteolysis and demarcated the implant cavity from the surrounding normal cancellous bone. Seventy-four per cent of the periphery and 28 per cent of the central core of the screw had been resorbed at twelve weeks. At thirty-six weeks, no polymeric material could be discerned, and the predominant tissue component within the implant cavity was loose connective tissue. The volume fractions of trabecular bone and hematopoietic bone marrow were significantly lower (p less than 0.01) than those of the intact, control side, but the degree of restoration of tissue varied considerably from animal to animal.

Animals↗

PubMed1992

Biodegradable fixation of distal humeral physeal fractures.

Polyglycolic acid (PGA) has been used worldwide as a biodegradable suture material since 1970. Biodegradable polyglycolide implants were introduced in osteofixation of cancellous bone fractures in 1985. From September 1987 to September 1989, 19 consecutive children with physeal fractures of the distal humerus necessitating open reduction and internal fixation were treated by transphyseal biodegradable fixation using 1.5 x 60-mm2 self-reinforced polyglycolide (SR-PGA) pins. Included were nine displaced fractures of the lateral humeral condyle, five severe avulsions of the medial epicondyle of the humerus, four displaced fractures of the humeral capitellum, and one intraarticular fracture of the medial condyle of the humerus. After accurate reduction, two smooth Kirschner pins 1.5 mm in diameter were introduced across the growth plate for temporary fixation. The metallic pins then were removed one by one and subsequently replaced with the cylindrical SR-PGA pins 1.5 mm in diameter. After operation, a padded plaster splint was worn for four weeks. Neither secondary displacement nor signs of growth disturbance were seen during the 26-month follow-up time (mean, 17.2 months). Not only the reduction of the costs but also the psychological aspects should be considered when dealing with biodegradable fixation of physeal fractures in children. Transphyseal biodegradable fixation has established itself as a procedure of choice for handling simple physeal fractures.

Adolescent↗

PubMed1991

Delayed union of fibular fractures accompanying fractures of the tibial shaft.

Among 440 adult patients with tibial shaft fracture and accompanying fibular fracture there were eight cases with radiographically ununited fibulae 4 months after the injury, each with uneventful tibial union. Fractures with severe soft-tissue injuries were excluded from this study. In 293 patients the treatment method of the tibial fracture was conservative, comprising closed reduction and immobilization by long plaster cast. In 147 patients it was intramedullary Küntscher nailing, and all the eight cases with delayed fibular union occurred among these, the frequency being 5.4%. The typical accompanying fibular fracture to develop delayed union was a comminuted one in the middle or distal third of the bone. At a followup examination 5 to 8 years after the original injury four of the eight fractures were found to have ultimately spontaneously united, while three showed a radiographically indisputable nonunion. One patient had undergone segmental fibular ostectomy because of persistent local pain but in the remaining patients the subjective symptoms were negligible. The occurrence of delayed fibular union in association with rigid intramedullary nailing of concomitant tibial shaft fracture is a phenomenon of which trauma surgeons should be aware even if the natural course of the condition often seems to be benign.

Adolescent↗

PubMed1991

Impact of the use of absorbable fracture fixation implants on consumption of hospital resources and economic costs.

Within a 6-year period (1984-1989) absorbable pins, rods, and screws made of polyglycolide, polylactide, or lactide-glycolide copolymer were used in the internal fixation of 881 fractures, 73.1% of which were displaced malleolar fractures of the ankle. During the last 3 years the patients treated using absorbable fracture fixation constituted 19.6% of all fracture patients managed by internal fixation at the department. The number of hardware removal procedures avoided during the 6-year period as a result of the use of the absorbable implants was estimated at approximately 700. By determining all direct and indirect costs associated with internal fracture fixation and the influence of the percentage of hardware removal, a cost coefficient was calculated for certain fracture types when treated using absorbable versus metallic internal fixation. In bimalleolar fractures, an optimal indication for absorbable fixation, the coefficient was 1.04 (cost of absorbable fixation 4% higher than that of metallic fixation) if the removal percentage with metallic fixation was zero and 0.91 (cost of absorbable fixation 9% lower than that of metallic fixation) if the removal percentage was 100%. The breakeven point was a removal rate of 31%.

Absorption↗

PubMed1991

Chevron osteotomy fixed with absorbable polyglycolide pins.

Seventy-eight chevron osteotomies augmented by internal fixation with self-reinforced polyglycolide pins, 2 mm in diameter, were performed in 60 patients suffering from a painful hallux valgus. The mean metatarsophalangeal angle was 31 degrees, and there was a metatarsus primus varus varying from 10 degrees to 20 degrees. The average follow-up time was 14 (range, 12 to 31) months. No postoperative redisplacement or disturbance of healing of the osteotomy was observed, but recurrence of hallux valgus occurred in 8 feet (10%), each initially with a moderate to severe hallux valgus. Some pain at the first metatarsophalangeal joint during physical activity remained in 12 feet (15%). There was a mean shortening of 2.5 mm of the first metatarsal bone, and the most significant shortening was associated with pain in the forefoot. The metatarsophalangeal joint motion was not decreased. The subjective overall result was excellent or good in 75% of the patients. Because of the biodegradability of the implants used, no secondary procedures to remove the implants were necessary.

Adolescent↗

PubMed1991

Absorbable polyglycolide screws in internal fixation of femoral osteotomies in rabbits.

In 20 rabbits, a transverse distal femoral osteotomy was fixed using a 4.5 by 30-mm absorbable screw made of polyglycolide. No postoperative external support was used. The consolidation of the osteotomy was investigated histologically, morphometrically, and microradiographically in groups of 4 to 6 rabbits that were followed for 3, 6, 12, or 36 weeks. Fourteen osteotomies showed solid bony union; and in 3, several bone trabeculae were seen to bridge a still partially ununited osteotomy. In another 3 rabbits, each with a follow-up time of 12 or 36 weeks, no convincing signs of progressing consolidation could be seen. Only 1 of these rabbits showed displacement of the distal fragment.

Animals↗

PubMed1990

Degradable polyglycolide rods for the internal fixation of displaced bimalleolar fractures.

Cylindrical biodegradable rods of self-reinforced polyglycolide were constructed for internal fixation of fractures in cancellous bone. The self-reinforced texture was achieved by embedding polyglycolide fibres in a polyglycolide matrix. In a prospective clinical study, 62 patients with displaced bimalleolar fractures were managed by open reduction and internal fixation using these rods. The results were assessed between 1.1 and 3.4 years from implantation. One wound infection occurred (1.6%). Five patients (8.1%) developed a sterile accumulation of fluid at the site of operation which required drainage: the final outcome was not affected. Minor displacement of the fracture (1-2 mm) occurred in nine patients (14.5%) but did not need further operation. The functional result was excellent in 39 patients (63%). This was considered acceptable given the severity of the fractures. Consequently, at our hospital, when a displaced malleolar fracture needs internal fixation biodegradable rods are now the treatment of choice. The psychological and financial advantages of avoiding implant removal are considerable.

Adult↗

PubMed1990

Absorbable polyglycolide pins in fixation of displaced fractures of the radial head.

In a prospective study 24 patients with a displaced fracture of the radial head were treated by open reduction and internal fixation using absorbable polyglycolide pins, 2 mm in diameter. All patients admitted with fractures involving a quarter or more of the radial head, whether comminuted or not, were included in the study whenever there was a displacement of 2 mm or more between the fragments. The mean follow-up time was 28 months (range 15-43 months). A postoperative redisplacement of 1-3 mm between the fragments was seen in four patients with severely comminuted fractures. A transient inflammatory reaction around the implants occurred in two cases 8-12 weeks postoperatively. The functional end-result was classified as excellent or good in 22 patients (91%). This study indicated that successful fixation of displaced fractures of the radial head can be accomplished by using absorbable pins.

Adolescent↗

PubMed1990

Blood loss, operating time, and positioning of the patient in lumbar disc surgery.

Many textbooks and papers on lumbar disc surgery still, nearly 40 years after the first description of a variant of the kneeling position, pay no attention to the positioning of the patient. In this study, the association between intraoperative blood loss, operating time, and position of the patient was studied in 436 patients undergoing a standard macrosurgical operation for lumbar disc herniation. Prone position on bolsters was used in 216 cases, 192 of which were primary operations, and a frame-supported kneeling position in 220, 203 of which were primary operations. The mean blood losses in prone versus kneeling positions in the primary operations were 376 ml and 150 ml, respectively (P less than 0.001), and the mean operating times were 74 minutes and 52 minutes, respectively (P less than 0.001). The 99% confidence interval for the difference between the mean operating times was from 15 to 29 minutes. A moderate nonlinear positive correlation was found between intraoperative blood loss and operating time. No intraoperative complications attributable to the position of the patient emerged. On the basis of the findings in this study, the use of kneeling position is strongly advocated.

Adult↗