Eirik Solheim | University of Bergen (original) (raw)

Papers by Eirik Solheim

Annals of Plastic Surgery, 1994

Journal of Craniofacial Surgery, 1995

Journal of Neurosurgery, 1992

z A study was performed to evaluate regeneration of defects in rat calvaria either unfilled or fi... more z A study was performed to evaluate regeneration of defects in rat calvaria either unfilled or filled with a bioerodible polyorthoester only, demineralized bone only, or a composite of both. At 4 weeks, histological and radiographic studies showed that defects filled with a composite ofbioerodible polyorthoester and demiieralized bone or demineralized bone alone were bridged by bone. Unfilled defects or deiects filled with polyorthoester only_did not heal. The polyorthoester caused slight inflammation that subsided by 3 weeks, and-oniy traces of the liller could be detected at 4 weeks. The polyorthoester provided local hemostasis when used either alone or in composites with demineralized bone. The composite implant was moldable, easily contoured, and technically easier to use than demineralized bone alone.

Journal of Craniofacial Surgery, 1998

Annals of Plastic Surgery, 1994

Journal of Biomedical Materials Research, 1992

Local hemostatics for osseous tissue should preferably be absorbable and biocompatible and should... more Local hemostatics for osseous tissue should preferably be absorbable and biocompatible and should not inhibit osteogenesis. The tissue response and effect on demineralized boneinduced heterotopic osteogenesis in the abdominal muscle of 120 male Wistar rats by different local hemostatics were evaluated by light microscopy and 85Sr uptake analyses. Nonabsorbable bone wax of 88% beeswax and absorbable bovine fibrin–collagen paste both significantly inhibited o st eoinduction, whereas a bioerodible polyorthoester drug delivery system with or without 4% gentamicin did not. Bone wax was not absorbed and induced a chronic foreign body reaction. Fibrin–collagen paste induced less inflammation with numerous monocytes and macrophages with engulfed material. Bioerodible polyorthoester caused a very moderate tissue reaction and was mostly resorbed at week 4.

Journal of Craniofacial Surgery, 1995

Journal of Biomedical Materials Research, 1995

Inhibition of orthotopic reossification after surgical removal of bone is sometimes indicated and... more Inhibition of orthotopic reossification after surgical removal of bone is sometimes indicated and may be accomplished by implantation of interpositional materials or by systemic administration of indomethacin. However, implantation of nonresorbable foreign material may induce a chronic inflammation and predispose to infections; and systemic administration of indomethancin may induce systemic adverse effects. We studied the effect of local delivery of indomethacin by a bioerodible polyorthoester on the reossification of segmental defects of the radius in rats. We divided 45 Wistar rats into three groups, A–C. A 3.5 mm-long middiaphyseal osteoperiosteal resection of the right radius was made in each rat. The defect was filled with 15 mg of polyorthoester with 5% indomethacin in group A and 15 mg of polyorthoester without drug in group B. No material was implanted in the defects in the group C rats. The rats were killed 50 days postoperatively. The mean area of the residual defects were greater in the defects with the polyorthoester with 5% indomethacin compared with defects with polyorthoester without drug or without implant as judged by computer-assisted area measurements on radiographs. By light microscopy, no inflammation was seen and only traces of the polyorthoester could be dected in the defects filled with the polyorthoester with or without indomethacin. The results of this study suggest that the polyorthoester may be used as a bioerodible system for local delivery of indomethacin to inhibit reossification of skeletal defects without tissue reaction, unabsorbed carrier, or systemic effects. © 1995 John Wiley & Sons, Inc.

Journal of Biomedical Materials Research, 2000

Implantation of demineralized bone induces new bone formation by the action of contained growth f... more Implantation of demineralized bone induces new bone formation by the action of contained growth factors, of which bone morphogenetic proteins are of prime importance. A biodegradable polymer may be used as a carrier for demineralized bone particles or recombinant bone growth factors to prevent displacement of the implant, preserve its volume and shape, and assure sustained release of the incorporated active components. A polymer for this use should be biocompatible and completely absorbed without interfering with the osteogenesis. We investigated the host-tissue response and effect on demineralized boneinduced bone formation by two biodegradable polymers, a poly(ortho ester) and an amorphous low-molecular poly(DL-lactic acid). Both polymers had a plastic consistency, could easily be molded, and adhered well to the demineralized bone particles. Demineralized bone particles were implanted alone and in combination with each of the polymers in the abdominal muscles of 45 male Wistar rats. Four weeks after the operation the implants were recovered and subjected to 85 Sr uptake analysis to quantify bone formation and histologic examination. The poly(ortho ester) provoked little inflammation; it was largely absorbed by 4 weeks, and no qualitative or quantitative effect on bone formation was found. The poly(DL-lactic acid) provoked a chronic inflammation with multinuclear giant cells, macrophages with engulfed material, and proliferating fibroblasts; part of the material was still present, and the bone formation was inhibited.

European Surgical Research, 2001

Bone formation generally depends on adequate blood flow. Failure of bone grafts has been attribut... more Bone formation generally depends on adequate blood flow. Failure of bone grafts has been attributed to delayed revascularisation of the graft. We compared the relationship between revascularisation and osteogenesis, evaluated as entrapment of 141 Ce-labelled microspheres and uptake of 85 Sr, respectively, in fresh or demineralised syngeneic bone grafts 3 weeks after heterotopic implantation in rats. Whereas a moderately high linear correlation between 85 Sr and 141 Ce radioactivity was found both in the (intact) host iliac bone (r = 0.75, p = 0.0001) and implanted fresh syngeneic grafts (r = 0.50, p = 0.001), no correlation could be demonstrated in demineralised grafts (r = 0.09, p = 0.6). The results may indicate differences in the mechanisms of vascularisation and osteogenesis in the grafts used fresh or after demineralization but are, at present, difficult to fully explain.

Acta Orthopaedica, 1992

Heterotopic bone formation in the abdominal muscle of 45 male 8-week-old Wistar rats induced by i... more Heterotopic bone formation in the abdominal muscle of 45 male 8-week-old Wistar rats induced by implantation of 5, 10, or 15 mg demineralized bone (DBM) powder was evaluated at 4 weeks by 85Sr uptake of the implants and area histomorphometry of the induced bone. Two indices of 85Sr uptake were calculated: the osteogenic index [(counts/min/mg implant)/(counts/min/mg os ilium)l and an index that we have called the osteoquantum index in which the weight of the implant is disregarded [(counts/min

Journal of Biomedical Materials Research, 2000

International Journal of Sports Medicine, 1995

Z Strand and E. Solheim. Clinical Tests Versus KT-1000 Instrumented Laxity Test in Acute Anterior... more Z Strand and E. Solheim. Clinical Tests Versus KT-1000 Instrumented Laxity Test in Acute Anterior Cruciate Ligament Tears. Int.

$Research paper thumbnail of Autologous Chondrocyte Implantation Compared with Microfracture in the Knee$

Background: New methods have been used, with promising results, to treat full-thickness cartilage... more Background: New methods have been used, with promising results, to treat full-thickness cartilage defects. The ob-

Knee, 2010

We evaluated short-and medium-term results of the treatment of articular cartilage defects of the... more We evaluated short-and medium-term results of the treatment of articular cartilage defects of the knee with autogenous cylindrical osteochondral grafts (mosaicplasty) in 69 patients (median age 33 years) with symptomatic articular cartilage defects. Data of Lysholm score and visual analogue scale (VAS) of pain (0 = no pain; 100 = worst possible pain) were collected before the surgery, at 12 months postoperatively and 5 to 9 (median 7) years after the surgery. At the last follow-up the patients were also asked to state their degree of satisfaction with the outcome on a VAS (0 = not at all satisfied; 100 = completely satisfied), and to answer if they would have undergone the surgery again if necessary (yes or no). The mean Lysholm score and VAS of pain improved from 48 and 62, respectively, at the time of surgery to 81 and 24, respectively, at the 12-months follow-up (p b 0.001 for both comparisons). From 12 months postoperatively, the Lysholm score and VAS of pain deteriorated to 68 and 32, respectively at the 5-to 9-year follow-up (p b 0.001 and p = 0.018, respectively). The mean degree of satisfaction with the outcome was 70 (SD 28), and 61 patients (88%) stated that they would have undergone the surgery again. In conclusion, the mosaicplasty leads to improvement of symptoms and function at short-and medium-term follow-up. A deterioration of the results is observed from 12 months postoperatively to 5-9 years postoperatively.

Arthroscopy-the Journal of Arthroscopic and Related Surgery, 2002

Purpose: Focal chondral or osteochondral defects can be painful and disabling, have a poor capaci... more Purpose: Focal chondral or osteochondral defects can be painful and disabling, have a poor capacity for repair, and may predispose patients for osteoarthritis. New surgical procedures that aim to reestablish hyaline cartilage have been introduced and the results seem promising. The purpose of this study is to provide reliable data on chondral and osteochondral defects in patients with symptomatic knees requiring arthroscopy and to calculate the prevalence of patients who might benefit from cartilage repair surgery. Type of Study: Prospective study. Methods: One thousand consecutive knee arthroscopies were included in this study. Immediately after each arthroscopy, the surgeon completed a questionnaire providing detailed information about the findings. Chondral and osteochondral lesions were classified in accordance with the system recommended by the International Cartilage Repair Society (ICRS). Results: Chondral or osteochondral lesions (of any type) were found in 61% of the patients. Focal chondral or osteochondral defects were found in 19% of the patients. In these patients, 61% related their current knee problem to a previous trauma, and a concomitant meniscal or anterior cruciate ligament injury was found in 42% (n ϭ 81) and 26% (n ϭ 50), respectively. The mean chondral or osteochondral total defect area was 2.1 cm 2 (range, 0.5 to 12; standard deviation [SD], 1.5). The main focal chondral or osteochondral defect was found on the medial femoral condyle in 58%, patella in 11%, lateral tibia in 11%, lateral femoral condyle in 9%, trochlea in 6%, and medial tibia in 5%. It has been suggested that cartilage repair surgery may be most suitable in patients younger than 40 to 50 years old. A single, well-defined ICRS grade III or IV defect with an area of at least 1 cm 2 in a patient younger than 40, 45, or 50 years accounted for 5.3%, 6.1%, and 7.1% of all arthroscopies, respectively. Conclusions: Our study supports the contention that articular cartilage defects are common. It has the advantages of a prospective design and use of a new classification system recommended by the ICRS. This modern system focuses on objectively measurable parameters of the lesion's extent and not its surface appearance.

American Journal of Sports Medicine, 1993

approach Postoperative pain after anterior cruciate ligament reconstruction using a transligamentous

Scandinavian Journal of Medicine & Science in Sports, 2007

All cruciate ligament injuries in the three upper divisions for men and women (3392 players) in N... more All cruciate ligament injuries in the three upper divisions for men and women (3392 players) in Norwegian team handball in the 1989-90 and 1990–91 seasons were registered. A questionnaire was mailed to all injured players. Ninety-three cruciate ligament injuries were registered; 87 in the anterior cruciate ligament (ACL), and six in the posterior cruciate ligament (PCL). Among women, 1.8% were injured compared with 1.0% of the men. In the first division, the risk of being injured was considerably higher: 4.5% of the players had a cruciate ligament injury. There were 0.97 cruciate ligament injuries per 1000 playing hours in the three divisions taken together. Seventy-five per cent of the injuries occurred during games. Ninety-five per cent involved no contact between players. Activities in which the friction between shoe and floor was significant caused 55% of the injuries. Injuries caused by running into another player contributed to only 5% of the injuries. No significant differences were observed in injury incidence during matches between different types of floors (parquet, Pulastic and other synthetic sufaces).

$Research paper thumbnail of Paper #123 Autologous chondrocyte implantation versus microfracture$