Biomedical subjects

O Böstman

Publications and source records attributed to O Böstman.

At least 19 recordsLinked to original sources

PubMed2000

Bioabsorbable fixation in orthopaedic surgery and traumatology.

Bioabsorbable internal fixation devices were introduced clinically in the treatment of fractures and osteotomies of the extremities at the Department of Orthopaedics and Traumatology, Helsinki University, in 1984. Since November 5, 1984, a total of 3200 patients were managed using bone or ligament fixation devices made of self-reinforced (matrix and fibres of the same polymer) bioabsorbable alpha-hydroxy polyesters. The devices used included cylindrical rods, screws, tacks, plugs, arrows, and wires. The most common indication for the use of bioabsorbable implants was the displaced malleolar fracture of the ankle. Transphyseal fixation with small-diameter, mainly polyglycolide pins was used in children. The postoperative clinical course was uneventful in more than 90% of the patients. The complications included bacterial wound infection in 4% and failure of fixation in 4%. In one-fifth of the latter cases, however, re-operation was not necessary. The occurrence of non-infectious foreign-body reactions two to three months postoperatively has been observed in 2% of the patients operated in the last few years with polyglycolide implants but none of the patients managed with polylactide implants. This inflammatory tissue response often required aspiration with a needle but did not influence the functional or radiologic result of the treatment. Owing to the biodegradability of these internal fixation devices, implant removal procedures were avoided. This results in financial benefits and psychological advantages. Bioabsorbable implants can also be used in open fractures and infection operations.

Absorbable Implants↗

PubMed2000

Clinical biocompatibility of biodegradable orthopaedic implants for internal fixation: a review.

When the polymeric material reaches the final stages of its degradation process, biodegradable orthopaedic fixation devices elicit a local foreign-body reaction. In most cases, the symptoms of this tissue response are subclinical and pass unnoticed, but in some patients a clinically manifest inflammatory foreign-body reaction ensues. Mild clinical reactions consist of a painful erythematous papule, those of medium severity show a sinus discharging polymeric debris for up to 6 months, and in the patients affected by a severe reaction, extensive osteolytic lesions may develop at the implant tracks. The histopathologic picture is that of a non-specific foreign-body reaction. For implants made of polyglycolide, the average incidence of the manifest reactions is 5%. When slow-degrading polymers are used, the incidence is lower. The tissue responses to polyglycolide manifest themselves 11 weeks after surgery, on an average, whereas foreign-body reactions to devices made of poly-L-lactide can emerge as late as 4 or 5 yr after the original fracture fixation operation. A poorly vascularized bone section, use of a quinone dye as an additive in the polymer, and an implant geometry with large surface area each seems to be associated with an increased risk of the occurrence of a foreign-body reaction. Yet in majority of the patients affected, no known individual marker of high risk is present. Some recent laboratory experiments indicate that it may be possible to diminish the risk of an adverse tissue response by incorporating alkaline salts or antibodies to inflammatory mediators in the implants. The results of in vitro and animal experiments, however, cannot always be directly extrapolated to humans. Only large-scale long-term clinical research will ultimately show which physico-chemical characteristics of a biodegradable orthopaedic implant provide the optimal clinical biocompatibility.

Absorbable Implants↗

PubMed1999

Failure of reduction with an external fixator in the management of injuries of the pelvic ring. Long-term evaluation of 110 patients.

We reviewed 110 patients with an unstable fracture of the pelvic ring who had been treated with a trapezoidal external fixator after a mean follow-up of 4.1 years. There were eight open-book (type B1, B3-1) injuries, 62 lateral compression (type B2, B3-2) and 40 rotationally and vertically unstable (type C1-C3) injuries. The rate of complications was high with loss of reduction in 57%, malunion in 58%, nonunion in 5%, infection at the pin site in 24%, loosening of the pins in 2%, injury to the lateral femoral cutaneous nerve in 2%, and pressure sores in 3%. The external fixator failed to give and maintain a proper reduction in six of the eight open-book injuries, in 20 of the 62 lateral compression injuries, and in 38 of the 40 type-C injuries. Poor functional results were usually associated with failure of reduction and an unsatisfactory radiological appearance. In type-C injuries more than 10 mm of residual vertical displacement of the injury to the posterior pelvic ring was significantly related to poor outcome. In 14 patients in this unsatisfactory group poor functional results were also affected by associated nerve injuries. In lateral compression injuries the degree of displacement of fractures of the pubic rami caused by internal rotation of the hemipelvis was an important prognostic factor. External fixation may be useful in the acute phase of resuscitation but it is of limited value in the definitive treatment of an unstable type-C injury and in type-B open-book injuries. It is usually unnecessary in minimally displaced lateral compression injuries.

Activities of Daily Living↗

PubMed1998

Redisplacement after ankle osteosynthesis with absorbable implants.

A total of 1202 fractures of the ankle were treated with absorbable implants made of polyglycolide/polylactide copolymer or self-reinforced polyglycolide and/or self-reinforced polylactide between November 5, 1984, and January 12, 1994. A redisplacement after fixation was diagnosed in 30 patients (2.5%). The redisplacement occurred in 8 of 934 (0.9%) simple ankle fractures and in 22 of 268 (8.2%) severer ankle fractures. A breakage or loosening of the absorbable implant was verified at reoperation in 8 cases and was suspected in another 9. A technical failure was the main reason in 13 cases. A reoperation was performed for 25 patients. The absorbable implants seem to provide a secure fixation in the majority of ankle fractures, but the use of these implants showed unsatisfactory results in unstable and comminuted fractures.

Absorption↗

PubMed1998

Absorbable polyglycolide and polylactide devices for fracture fixation.

The use of absorbable internal fracture fixation devices instead of conventional metallic ones abolishes the need for subsequent implant removal procedures. Absorbable fracture fixation devices have been increasingly used during the past decade. Approximately 150,000 patients in many countries have already been treated with such implants. The vast majority of the clinically used biodegradable devices are made of polyglycolide (PGA) or polylactide (PLA). The polylactide osteosynthesis devices in clinical use today usually consist of polylevolactide (PLLA). During the past decade, the assortment of implants for fracture fixation purposes has become broader and now includes many different kind of devices.

Journal Article↗

PubMed1997

Totally absorbable fixation in the treatment of fractures of the distal femoral epiphyses. A prospective clinical study.

Nine adolescent patients with a femoral fracture involving the physeal plate were treated by using self-reinforced absorbable polyglycolide (SR-PGA) and poly-L-lactide (SR-PLLA) screws with a follow-up for an average of 2 years and 2 months. During the follow-up all but one of the femurs became skeletally mature. In two of nine patients a clinically significant growth disturbance occurred. The average length difference of the femurs was -5 mm (ranging from +8 mm(-)-41 mm). One valgus deformity was noted. In four patients a lengthening and in four patients a shortening of the operated femur were registered at the end of follow-up. Open reduction and fixation with absorbable screws seem to be suitable for the fixation of distal femoral fractures in adolescents.

Adolescent↗

PubMed1997

In vivo monitoring of the degradation process of bioresorbable polymeric implants using magnetic resonance imaging.

The degradation of a bioresorbable poly(L-lactide) osteosynthesis plug after fixation of a transferred coracoid bone block using the Bristow-Latarjet procedure was examined by means of magnetic resonance (MR) imaging. There were 15 patients with a mean follow-up time of 38 months (range 34-42 months). The gross geometry of the biomaterial plug remained unaltered on the MR images. The bone marrow signal reached the implant surfaces in all cases, and no signs of liquid phase around the implant could be discerned. The implants themselves were visible as homogeneous low signal intensity (SI) black linear structures when compared to the surrounding bone, which had a much higher SI. The mean implant SI was 18.2 (s.d. +/- 6.6), that of the scapular bone 48.9 (s.d. +/- 14.3) and that of the background 4.3 (s.d. +/- 1.5). The SI of a newly manufactured intact implant was 5.7. Serial plain radiographs showed no decreased bone density or focal osteolytic lesions around the poly(L-lactide) expansion plug. The implant channel was discernible on most of the radiographs and a sclerotic rim was detected to outline the implant profile in some of the projections of plain radiographs at each follow-up examination. Computer tomography scans on five patients 3 years postoperatively also revealed a discernible implant channel outlined with a sclerotic rim. The radiographic appearance of the radiolucent implant channel did not change over the follow-up period. Summarizing the present findings, MR imaging seems to be able to visualize poly(L-lactide) implants within the bone. Actually, at present it is the only method available to study the degradation process of implants made of this polymer in humans. No signs of degradation of or of an osteolytic foreign-body reaction to poly(L-lactide) at the host tissue-implant interface could be observed within the follow-up times of this study.

Absorption↗

PubMed1997

Specific features associated with femoral shaft fractures caused by low-energy trauma.

OBJECTIVE: To scrutinize the fracture patterns of femoral shaft fractures caused by low-energy injury mechanism and to delineate the problems associated with the treatment of these fractures. MATERIALS AND METHODS: Of a total of 192 consecutive skeletally mature patients with 201 acute fresh femoral shaft fractures admitted during a 10-year period (1985-1994), 50 patients had a fracture caused by low-energy trauma. The fractures were classified in terms of their configuration, site, degree of comminution, and soft-tissue injury. The previous fractures, chronic illnesses, and continuous medications of the patients as well as the injury mechanisms and concomitant injuries were registered. All general and local complications and their consequences were recorded. Forty patients could be followed until the bony union of the fracture was achieved, the mean follow-up time being 14 months. RESULTS: The incidence of these injuries was 2.5 per 100,000 person-years. There were 32 women and 18 men. The mean age of the patients was 65 years (range, 17-92 years). Thirteen patients were younger than 60 years of age. Thirty-two (64%) had at least one local or general factor weakening the mechanical strength of the bone that predisposed them to a fracture. Thirty-two patients sustained a fracture of the left femur (p < 0.05). All fractures were closed. None of the patients had significant concomitant injuries. In 33 cases, the site of the fracture was in the middle third of the femur. The fracture configuration was spiral in 29, transverse in 10, oblique-transverse in 7, and oblique in 4 cases. Postoperative complications, including delayed union, nonunion, and malunion, occurred with 29 patients. Eighteen reoperations among 12 patients were performed because of these complications. CONCLUSIONS: Femoral shaft fractures caused by low-energy violence occur mainly in patients suffering from a chronic disease or a condition causing osteopenia of the femur. The most common fracture pattern was a spiral one in the middle third of the femoral shaft. Despite the low-energy violence, the treatment of these fractures is not devoid of complications. The treatment of these seemingly simple fractures requires careful planning and meticulous operative technique.

Adolescent↗

PubMed1997

Complications of plate fixation in fresh displaced midclavicular fractures.

BACKGROUND: The role of plate fixation in the management of fresh displaced midclavicular fractures is unsettled. The objective of this study was to evaluate the drawbacks and pitfalls of this treatment method. METHODS: We analyzed the complications encountered in 103 consecutive adult patients with severely displaced fresh fractures of the middle third of the clavicle who were treated by open reduction and internal fixation using AO/ASIF plates. These 103 patients accounted for 9.5% of the 1,081 patients with fresh midclavicular fractures seen between 1989 and 1995. The mean age of the 103 patients was 33.4 years (range, 19-62 years). RESULTS: Seventy-nine patients had an uneventful recovery, whereas 24 (23%) suffered one or several complications. The major complications included deep infection, plate breakage, nonunion, and refracture after plate removal. The most common of the minor complications was plate loosening resulting in malunion. The infection rate was 7.8%. A total of 14 reoperations were performed because of the complications. Permanent nonunion ensued in two patients. A severely comminuted fracture (relative risk of failure, 5.15) as well as a state of alcohol intoxication on admission (relative risk of failure, 3.12) were identified as markers of increased complication risk. CONCLUSIONS: Patient noncompliance with the postoperative regimen could be suspected to have been a major cause of the failures. The high complication rate supports a reserved attitude toward plate fixation of fresh midclavicular fractures. The method should be reserved for patients who have trustworthy personal motives for quick pain relief and functional recovery.

Adult↗

PubMed1997

Complications of transpedicular lumbosacral fixation for non-traumatic disorders.

We analysed the complications encountered in 102 consecutive patients who had posterolateral lumbosacral fusion performed with transpedicular screw and rod fixation for non-traumatic disorders after a minimum of two years. Of these, 40 had spondylolysis and spondylolisthesis, 42 a degenerative disorder, 14 instability after previous laminectomy and decompression, and six pain after nonunion of previous attempts at spinal fusion without internal fixation. There were 75 multilevel and 27 single-level fusions. There were 76 individual complications in 48 patients, and none in the other 54. The complications seen were screw misplacement, coupling failure of the device, wound infection, nonunion, permanent neural injury, and loosening, bending and breakage of screws. Screw breakage or loosening was more common in patients with multilevel fusions (p < 0.001). Screws of 5 mm diameter should not be used for sacral fixation. Forty-six patients had at least one further operation for one or several complications, including 20 fusion procedures for nonunion. The high incidence of complications is a disadvantage of this technically-demanding method.

Adolescent↗

PubMed1996

Absorbable devices in the fixation of fractures.

Totally absorbable internal fracture fixation devices were introduced clinically in the treatment of fractures and osteotomies of the extremities at our department in 1984. A total of 2,500 patients were managed using bone or ligament fixation devices made of self-reinforced (matrix and fibers of same polymer) absorbable alpha-hydroxy polyesters between November 5, 1984, and January 12, 1994. The devices used included cylindrical rods or pins, screws, tacks, plugs, and wires. The most common indication for the use of absorbable implants was displaced malleolar fracture of the ankle. Transphyseal fixation with small-diameter polyglycolide pins was used in children. The postoperative clinical course was uneventful in over 90% of the patients. The complications included bacterial wound infection in 3.6% and failure of fixation in 3.7%. In one-fifth of these cases, however, reoperation was not necessary. The occurrence of noninfectious foreign-body reactions 2 to 3 months postoperatively has been observed in 2.3% of the patients operated in the last years with polyglcolide implants but in none of the patients with polylactide implants. This inflammatory tissue response often required aspiration with a needle or small incision but did not influence the ultimate functional or radiologic result of treatment. Owing to the biodegradability of these internal fixation devices, over 1,000 implant removal procedures were avoided during the 9-year period under review, allowing medical personnel at these facilities to focus on other procedures. Avoidance of removal procedures results in financial benefits and psychological advantages. The benefits of absorbable implants for war surgery are the same as for civilian life. Absorbable implants can also be used in open fractures and infection operations.

Absorption↗

PubMed1996

A retrospective analysis of 36 civilian gunshot fractures.

A critical retrospective analysis was conducted of 36 gunshot fractures admitted from 1985 to 1989 in Finland by using the statistics of the Central Medical Board. The information was analyzed for demographic details and from consumption of hospital resources point of view, with special attention to gunshot injuries to long bones. The fractures were classified by using the grading system of Gustilo et al. into three categories: type A (60%), type B (12.3%), and type C (27.7%). Debridement of wounds was done successfully in two-thirds of the wounds, but was insufficient in nine cases. Fasciotomy was insufficient in seven cases. The fractures were immobilized by external fixation (Hoffmann) in two-thirds of the patients. Primary internal fixation was used in three femoral and one tibial fracture with severe complications. The tibia and femur were the most frequent sites involved, thus accounting for 13 infections. The infection rate, including two septicemias and four cases of osteomyelitis, could have been lower if war surgical principles were accepted or known in the management. The same could be considered in avoiding four compartment syndromes and six ununited fractures.

Adult↗

PubMed1996

Routine implant removal after fracture surgery: a potentially reducible consumer of hospital resources in trauma units.

OBJECTIVE: Assess the workload caused by elective routine removals of internal fracture fixation devices in a large university orthopedic and trauma unit when no premeditated departmental removal policy existed. MATERIALS AND METHODS: Data on all operations performed during a 7-year period were retrieved. Routine removals of internal fracture fixation implants were analyzed for demographic data and clinical details. Patients requiring additional procedures to manage the fracture besides simple hardware removal were excluded. Nationwide data were included for comparison. RESULTS: A total of 5,095 routine implant removal operations were performed after uneventful fracture union. The mean age of the patients was 42 years. The five most common fracture types were fractures of the ankle, the proximal femur, the tibial shaft, the femoral shaft, and the thoracolumbar spine. In 63% of the procedures, a medium-size or large implant was removed. The mean operation time was 37 minutes. The removals accounted for 29% of all elective operations and for 15% of all operations at the department. The corresponding nationwide figure was 6.3% of all orthopedic operations, the number of implant removals in the whole country being 90 operations per 100,000 person-years. CONCLUSIONS: Without a strict departmental removal policy, a remarkable portion of the resources allocated for elective orthopedic operations was spent on routine hardware removal procedures. A more rational and selective attitude toward implant removals is desirable. Further research on the disadvantages of retained hardware and the complications of implant removals is required.

Adult↗

PubMed1996

Metallic or absorbable implants for ankle fractures: a comparative study of infections in 3,111 cases.

Absorbable fracture fixation has been in clinical use since 1984. Our study compares the infection rates and some infection parameters between metallic (2073 patients) and absorbable fracture fixation devices (1012 patients) in displaced ankle fractures. The infection rate associated with metallic fixation was 4.1%, compared with 3.2% absorbable fixation (p 0.3). The patients who had a wound infection were older when metallic fixation was used (p 0.01). They also had a bi- or trimalleolar fracture more often than did patients treated with absorbable fracture fixation, but this difference did not have a significant effect on the wound infection rate (p 0.2). The infections were mostly caused by microorganisms of the Staphylococcus species. Deep infections were equally common with both fixation methods (0.4%), but there was some variation in the bacterial spectrum.

Adolescent↗

PubMed1996

Posterolateral lumbosacral fusion with transpedicular fixation: 63 consecutive cases followed for 4 (2-6) years.

We analyzed the clinical, vocational and radiologic outcomes of 63 consecutive posterolateral lumbosacral fusions performed with transpedicular fixation. The indication for surgery was long-standing intractable lumbar and/or radiating pain with spondylolysis-olisthesis in 31 cases, degenerative disc disease and/or facet joint arthrosis in 23 cases and pain after laminectomy/decompression in 9 cases. Radiographic union was finally achieved in 30 out of the 63 cases. Fixation device-related complications, such as screw misplacement, breakage, bending and loosening, occurred in 33 cases. 15 patients underwent refusion. 43 patients obtained good pain relief. There was no correlation between bony healing and a good clinical outcome. 28/49 preoperatively employed patients returned to work. There was no correlation between relief of pain and return to work. 20 patients retired on a full disability pension. The clinical results were best in the spondylolysis-olisthesis group. Only 2/15 patients with markedly reduced spondylolisthesis maintained the reduction. In 3 patients, progressive disc degeneration above the level of fusion was observed. We conclude that posterolateral lumbosacral fusion with transpedicular fixation provides a satisfactory clinical outcome in patients with spondylolysis-olisthesis, but the high incidence of complications related to the fixation device in the other indications studied is a serious drawback of the method.

Adolescent↗

PubMed1996

Return to work after posterolateral fusion with transpedicular instrumentation for spondylarthrosis of the lumbosacral spine.

We reviewed 41 working-age adults with lumbosacral spondylarthrosis treated by posterolateral spinal fusion using transpedicular instrumentation. The fusion indication was a long-standing, intractable low-back and/or radiating pain, resistant to conservative treatment, without any radiological evidence or disc herniation or spinal stenosis. All patients were evaluated for their post-treatment employment status. The patients were followed up until they had either returned to work or received a permanent disability pension. Only 15 patients out of 41 returned to work after an average postoperative sick leave of seven months. A proper selection of patients is mandatory when this kind of resource-consuming spinal surgery is practised.

Adult↗

PubMed1996

A prospective controlled trial of the fracture of the humeral medial epicondyle--how to treat?

Twenty-one patients, 11 male and nine female, with fracture of medial humeral epicondyle were treated. The mean age of the patients was 21 (range 8-52) years. The average initial displacement was 13 (range 3-24) mm, and four out of 21 patients had a dislocation of the elbow joint. Two patients were first treated conservatively, but later on operation for removal of the non-united fragment and reattachment of the ligaments and muscles was necessary. One patient was treated by primary excision of the fragment. Eighteen patients were treated by open reduction and internal fixation using self-reinforced polyglyclycolide (SR-PGA) screws in five patients, poly-l-lactide (SR-PLLA) screw in one, small (SR-PGA) rods in seven and Kirschner-wires in five patients. Solid union took place in 14 out of 18 patients and a good stability of the elbow joint was achieved. Fifteen patients scored an excellent result according to the scale of Broberg and Morrey. Although this series was not randomly allocated in respect of the method of treatment, it shows that medial epicondylar fractures can be fixed with absorbable implants without any need for removal procedure.

Adolescent↗

PubMed1996

Biodegradable self-reinforced polyglycolide screws and rods in the fixation of displaced malleolar fractures in the elderly. A comparison with metallic implants.

Biodegradable self-reinforced polyglycolide screws and rods 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, a total of 37 patients at least 65 years of age with displaced malleolar fractures were managed by open reduction and internal fixation using either biodegradable screws and rods or metallic implants in a randomly allocated series. The results were assessed approximately one year after the fracture. One wound infection occurred after metallic fixation. Reoperation because of displacement of the fracture was needed in one patient after biodegradable fixation. The functional results were satisfactory in most patients. There were no major difference in the end results between both operative methods used.

Activities of Daily Living↗