Nina Lindfors

Bioactive glass S53P4 as bone graft substitute in treatment of osteomyelitis

Bioactive glass (BAG)-S53P4 is an osteoconductive bone substitute with proven antibacterial and bone bonding properties. In a multicentre study 11 patients with verified chronic osteomyelitis in the lower extremity and the spine were treated with BAG-S53P4 as a bone substitute. The cavitary bone defect and the surrounding of a spinal implant were filled with BAG-S53P4. The most common pathogen causing the infection was Staphylococcus aureus. The mean follow-up was 24 months (range 10-38). BAG-S53P4 was well tolerated. Nine patients healed without complications. One patient who achieved good bone formation sustained a superficial wound infection due to vascular problems in the muscle flap, and one patient had an infection due to a deep haematoma. This study shows that BAG-S53P4 is a good and well-tolerated bone substitute, and can be used in treatment of osteomyelitis with good primary results.

A prospective randomized 14‐year follow‐up study of bioactive glass and autogenous bone as bone graft substitutes in benign bone tumors

A prospective randomized long-term follow-up study of bioactive glass (BG)-S53P4 and autogenous bone (AB) used as bone graft substitutes in benign bone tumor surgery during 1993-1997 was conducted. Twenty-one patients (11 in the BG group, 10 in the AB group) participated in a 14-year follow-up. X-rays and MRI scans were obtained, and in the BG group, CT scans were also performed. In the BG group, the filled cavity had a dense appearance on X-ray. MRI showed a mainly or partly fatty bone marrow, and in the large bone tumor group, remnants of glass granules were also observed. Increased cortical thickness was seen in nonossifying fibromas and enchondromas. BG-S53P4 is a safe and well-tolerated bone substitute with good long-term results. BG-S53P4 does not disturb the growth of bone in children.

Pre- and post-operative diffusion tensor imaging of the median nerve in carpal tunnel syndrome

ObjectivesTo use pre- and post-operative diffusion tensor imaging (DTI) to monitor median nerve integrity in patients suffering from carpal tunnel syndrome (CTS).MethodsDiffusivity and anisotropy images along the median nerve were compared among 12 patients, 12 age-matched and 12 young control subjects and correlated with electrophysiological neurography results. Slice-wise DTI parameter values were calculated to focus on local changes.ResultsResults of pre-operative patients and age-matched control subjects differed only in the distal nerve. Moreover, pre-operative patients differed significantly from young controls and post-operative patients. The main abnormalities were increased diffusivity and decreased anisotropy in the carpal tunnel and distal median nerve. Post-operative clinical improvement was reflected in diffusivity, but not in anisotropy. Slice-wise analysis showed high pre-operative diffusivity at the distal nerve. All groups had relatively large inter-subject variation in both diffusivity and anisotropy.ConclusionsDTI can provide information complementary to clinical examination, electrophysiological recordings and anatomical MRI of diseases and injuries of peripheral nerves. However, similar age-related changes in diffusivity and anisotropy may weaken DTI specificity. Slice-wise analysis is necessary for detection of local changes in nerve integrity.Key Points• Diffusion tensor magnetic resonance imaging provides information complementary to conventional diagnostic methods.• Age caused similar changes to diffusivity and anisotropy as carpal tunnel syndrome.• Post-operative clinical improvement was reflected in diffusivity, but not in anisotropy.• Inter-subject variation in diffusivity and anisotropy was considerable.

Bioactive glass and autogenous bone as bone graft substitutes in benign bone tumors

In a prospective randomized study, 25 patients with benign bone tumors were surgically treated with either bioactive glass S53P4 (BG) or autogenous bone (AB) as bone graft material. X-rays were taken preoperatively and postoperatively at 2 weeks and at 3, 8, 12, 18, 24, and 36 months. In addition, for most of the patients, CT scans were performed at the same time-points. No infections or material-related adverse reactions occurred in any patient. The filled cavity was replaced faster by new bone in the AB group than in the BG group (p = 0.0001). However, at 36 months, no statistical difference in cavity volume between the two groups was observed on X-rays (p = 0.7881) or on CT scans (p = 0.9117). In the BG group at 3 years, the filled cavity appeared, however, dense on X-rays, and glass granules on CT scans were observed. During the follow-up period, the cortical thickness seemed to increase more in the BG group than in the AB group (p < 0.0001).

Increase in VEGF secretion from human fibroblast cells by bioactive glass S53P4 to stimulate angiogenesis in bone

Bioactive glasses (BAGs) are being investigated for the repair and reconstruction of bone defects, as they exhibit osteoconductive and osteostimulatory potential. However, successful bone regeneration requires also the neovascularization of the construct which is, among other factors, guided by vascular endothelial growth factor (VEGF). In this study, BAG S53P4 (53% SiO2 , 23% Na2 O, 20% CaO, 4% P2 O5 ) is investigated in relation to VEGF-release and response of fibroblast cells. Human CD-18CO fibroblasts were cultivated in contact with different granules of different sizes (0.5-0.8 mm, 1.0-2.0 mm, and 2.0-3.15 mm) and at different concentrations (0-1 wt/vol % of BAG) for 72 h. The analysis of morphology revealed no toxic effect for all granule sizes and concentrations. Compared with the reference, lactate dehydrogenase-activity of CCD-18CO cells increased in contact with BAG samples. The VEGF release from CCD-18CO fibroblasts cultured on different granule sizes and at different concentrations after 72 h of incubation was quantified. It was found that particles of 0.5-0.8 mm and 1.0-2.0 mm in size enhanced VEGF release, whereas BAG particle sizes of 2.0-3.15 mm led to inhibition of VEGF release. The results are relevant to understand the influence of the particle size and concentration of BAG S53P4 on VEGF expression and neovascularization.

Instrumented spondylodesis in degenerative spondylolisthesis with bioactive glass and autologous bone: a prospective 11-year follow-up.

A prospective long-term follow-up study of bioactive glass (BAG)-S53P4 and autogenous bone (AB) used as bone graft substitutes for posterolateral spondylodesis in treatment of degenerative spondylolisthesis during 1996 to 1998 was conducted. The surgical procedure was a standardized instrumented posterolateral fusion that used USS/VAS. BAG was implanted on the left side of the fusion bed and AB on the right side. The operative outcome was evaluated on x-rays and computed tomography scans, and a clinical examination was also performed. Seventeen patients (12 women, 5 men) participated in the 11-year follow-up. The mean Oswestry Disability Index score at the follow-up was 21 (range 0 to 52), compared with 49 (range 32 to 64) at the preoperative time. A solid bony fusion was seen on computed tomography scans on the AB side in all patients and on the BAG side in 12 patients. The fusion rate of all fusion sites (n=41) for BAG as a bone substitute was 88% at the L4/5 level and 88% at the L5/S1 level. The use of BAG as a bone graft extender can be considered as a good alternative in spinal surgery in the future.

Posterolateral Spondylodesis Using Bioactive Glass S53P4 and Autogenous Bone in Instrumented Unstable Lumbar Spine Burst Fractures; a Prospective 10-Year Follow-Up Study

Background and Aims A prospective long-term follow-up study of bioactive glass (BAG)-S53P4 and autogenous bone (AB) used as bone graft substitutes for posterolateral spondylodesis in treatment of unstable lumbar spine burst fractures during 1996–1998 was conducted. Material and Methods The lumbar fractures were fixed using posterior USS instrumentation. BAG was implanted on the left side of the fusion-bed and AB on the right side. The operative outcome was evaluated on X-rays and CT scans, and a clinical examination was also performed. Results The Oswestry score was excellent, and the mean pain score 1. The mean compression rate of the injured vertebral body was 25%. A solid bony fusion was seen on CT scans on the AB side in all patients and on the BAG side in five patients, and a partial fusion in five patients, resulting in a total fusion-rate of 71% of all fused segments in the BAG group. Conclusions Our long-term results show that BAG-S54P4 bone graft material is safe to be used as a bone graft extender in spine surgery.

Incidence, epidemiology, and operative outcome of replantation or revascularisation of injury to the upper extremity.

Abstract We retrospectively studied the epidemiology of adult patients admitted for possible replantation or revascularisation of an injured upper extremity during the period June 2003 to May 2008. A total of 121 patients were admitted (71 graded severe), mean 24 (14 graded severe), being admitted each year. The annual rate of amputation injuries in the referral area of 1.5 million was 1.5/100 000 and for severe amputation injuries 0.9/100 000. Most injuries occurred in patients aged 41–50. Fifty-eight patients had the accident during working hours (36 severe), and 62 during leisure time (34 severe). The survival rate for subtotal amputations was 77% and for total amputations 55%. Of 15 further vascularisation procedures, two succeeded at the metacarpal level. Most of the accidents occurred during wood-processing with circular saws or powered wood splitters. More efforts should focus on preventing such injuries.

Antibacterial Bioactive Glass, S53P4, for Chronic Bone Infections – A Multinational Study

Osteomyelitis is an infectious process in bone that occasionally leads to bone destruction. Traditionally, the surgical treatment procedure is performed in combination with systemic and local antibiotics as a two-stage procedure that uses autograft or allograft bone for filling of the cavitary defect. Bioactive glass (BAG-S53P4) is a bone substitute with proven antibacterial and bone bonding properties.One hundred and sixteen patients who had verified chronic osteomyelitis was treated using BAG-S53P4 as part of the treatment. Most of the patients had previously undergone numerous procedures, sometimes for decades. A register of patient data obtained from 11 centers from Finland, Italy, the Netherlands, Germany, Azerbaijan and Poland was set-up and continuously maintained at Helsinki University Central Hospital.The location of the osteomyelitis was mainly in the tibia followed by the femur and then the calcaneus. The median age of the patients was 48 years (15-87). The patients were either treated according to a one-stage procedure without local antibiotics (85 %) or by a two-stage procedure using antibiotic beads in the first procedure (15 %). The minimum follow-up was 1 year (12-95 months, median 31).The cure rate was 104/116, the total success rate 90 % and most of the patients showed a rapid recovery.The study shows that (BAG-S53P4) can be used in a one-stage procedure in treatment of osteomyelitis with excellent results.

Reconstruction of Vertebral Bone Defects using an Expandable Replacement Device and Bioactive Glass S53P4 in the Treatment of Vertebral Osteomyelitis: Three Patients and Three Pathogens

Background and Aims: Bioactive glass S53P4 is an antibacterial bone substitute with bone-bonding and osteostimulative properties. The bone substitute has been successfully used clinically in spine; trauma; orthopedic; ear, nose, and throat; and cranio-maxillofacial surgeries. Bioactive glass S53P4 significantly reduces the amount of bacteria in vitro and possesses the capacity to kill both planktonic bacteria and bacteria in biofilm. Three patients with severe spondylodiscitis caused by Mycobacterium tuberculosis, Candida tropicalis, or Staphylococcus aureus were operatively treated due to failed conservative treatment. The vertebral defects were reconstructed using bioactive glass S53P4 and an expandable replacement device. Material and Methods: Decompression and a posterolateral spondylodesis, using transpedicular fixation, were performed posteriorly in combination with an anterior decompression and reconstruction using an expandable vertebral body replacement device. For patients 1 and 2, the expander was covered with bioactive glass S53P4 only, and for patient 3, the glass was mixed with autograft bone. Results: The patients healed well with complete neurological recovery. Fusion was observed for all patients. The total follow-up was 4 years for patient 1, 1 year and 8 months for patient 2, and 2 years and 2 months for patient 3. No relapses or complications were observed. Conclusion: The antibacterial properties of bioactive glass S53P4 also make it a suitable bone substitute in the treatment of severe spondylodiscitis.