Biomedical subjects

J Lammens

Publications and source records attributed to J Lammens.

At least 19 recordsLinked to original sources

PubMed2005

Prolonged clinical benefit from joint distraction in the treatment of ankle osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is a degenerative disabling joint disease affecting more than 10% of the adult population. No validated disease-modifying treatment is available. Joint distraction is a relatively new approach to the treatment of severe ankle OA. Short-term (3 years) clinical benefit has been proven, but long-term effects remain to be evaluated. METHODS: Patients with severe OA of the tibio-talar joint, who had been treated with Ilizarov joint distraction more than 7 years previously, were included. Pre-treatment data were obtained by retrospective analysis using questionnaires and patients' charts. Post-treatment assessments were undertaken using the same questionnaires and by physical examination. Three approaches were used and results were compared: the van Valburg score, the Ankle Osteoarthritis Scale (AOS), and a patient satisfaction questionnaire. Retrospectively and prospectively obtained data were available from eight patients for comparison. RESULTS: Twenty-five out of 27 patients with severe ankle OA treated with Ilizarov joint distraction could be traced. Appropriate retrospective data could not be obtained from three patients. Six out of the 22 patients (27%) were failures. In 16 patients (73%), significant improvement in all clinical parameters was observed using each of the three approaches. Good correlations were found between the results of the three methods of assessment and retrospectively obtained pre-treatment values were very similar to the prospective data. CONCLUSIONS: In 73% of the patients, significant clinical benefit from joint distraction of severe OA ankles was maintained for at least 7 years. There is, however, a need for further research to try and predict which patients will not respond to this unconventional form of major surgical intervention.

Adult↗

PubMed2003

Melorheostosis in a family with autosomal dominant osteopoikilosis: report of a third family.

We describe a three-generation family with clinical and radiological findings of osteopoikilosis in five and melorheostosis in one individual. The co-occurrence of both rare bone disorders suggests that both conditions might be related as suggested previously by Butkus et al. [1997: Am J Med Genet 72:43-46] and Nevin et al. [1999: Am J Med Genet 82:409-414]. The findings in this family strengthen the hypothesis that osteopoikilosis is an autosomal dominant condition and that an early postzygotic second hit mutation in the second allele results in melorheostosis.

Child↗

PubMed2003

Gonial angle changes after bilateral unidirectional mandibular distraction in sheep.

It was the aim of this study to investigate radiologically the distraction site in the gonial angle area after three different protocols of unidirectional mandibular distraction in sheep. Bilateral mandibular distraction was performed in nine sheep, and one other sheep served as a sham-operated control. In the nine experimental sheep, three different distraction protocols were used. In three sheep, an oblique corticotomy line was applied and the distractors were positioned perpendicular to the corticotomy line. In three other sheep, a horizontal corticotomy line was applied and the distractors were also positioned perpendicular to this corticotomy line. In the remaining three sheep, again, a horizontal corticotomy was performed, but with an angular positioning of the distractors relative to this corticotomy line. Distraction of 20 mm was performed over 20 days at a rate of 1 mm per day. After 3 weeks of retention the sheep were sacrificed, the mandibles were dissected and hemisectioned, and standardized hemimandibular contact radiographs were made of the specimens. The distracted gaps were traced from the radiograph and the gonial angle was measured. The displacements of the distracted parts were measured, the gonial angles were determined, and the values were compared with four additional control non-distracted sheep mandibles. The results show that there was a very large variability in the distracted gaps as well as in the gonial angle changes after distraction, and it was not possible to recognize any of the three different distraction protocols radiographically after distraction. Although performed under standardized conditions it is difficult to reproduce intended mandibular corticotomy lines in sheep.

Animals↗

PubMed2001

Short amputation stump lengthening with the Ilizarov method: risks versus benefits.

The authors point out the indications for lengthening of short amputation stumps. Referring to their own experience they discuss the problems and pitfalls related to this surgical procedure. Sufficient soft tissue coverage is the most important factor for a good outcome whereas limitation of adjacent joint function may have a detrimental effect on the clinical result.

Amputation Stumps↗

PubMed2000

[The treatment of congenital tibial pseudarthrosis].

Congenital tibial pseudarthrosis (CTP) remains one of the most challenging problems in paediatric orthopaedic surgery. With the abandonment of older grafting techniques in favor of vascularized fibular transplants or the Ilizarov method the final outcome has improved and made the prognosis for patients less cumbersome. Using the latter technique in 10 patients, a success rate of 90 % could be reached. Nevertheless, although solid healing occurs in most of the patients nowadays, this is often at the cost of multiple operations before a definite well united, equalized and normally aligned limb can be obtained.

Child, Preschool↗

PubMed2000

Collagen structure regulates fibril mineralization in osteogenesis as revealed by cross-link patterns in calcifying callus.

Although >80% of the mineral in mammalian bone is present in the collagen fibrils, limited information is available about factors that determine a proper deposition of mineral. This study investigates whether a specific collagen matrix is required for fibril mineralization. Calcifying callus from dog tibias was obtained at various times (3-21 weeks) after fracturing. At 3 weeks, hydroxylysine (Hyl) levels were almost twice as high as in control bone, gradually reaching normal levels at 21 weeks. The decrease in Hyl levels can only be the result of the formation of a new collagen network at the expense of the old one. The sum of the cross-links hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) in callus matched that of bone at all stages of maturation. However, the ratio HP/LP was 2.5-4.5 times higher in callus at 3-7 weeks than in normal bone and was normalized at 21 weeks. Some 40% of the collagen was nonmineralized at the early stages of healing, reaching control bone values (approximately 10%) at 21 weeks. In contrast, only a small increase in callus mineral content from 20.0 to 22.6 (% of dry tissue weight) from week 3 to 21 was seen, indicating that initially a large proportion of the mineral was deposited between, and not within, the fibrils. A strong relationship (r = 0.80) was found between the ratio HP/LP and fibril mineralization; the lower the HP/LP ratio, the more mineralized the fibrils were. Because the HP/LP ratio is believed to be the result of a specific packing of intrafibrillar collagen molecules, this study implies that mineralization of fibrils is facilitated by a specific orientation of collagen molecules in the fibrils.

Amino Acids↗

PubMed2000

Shortening of the calcaneus treated with Ilizarov's method.

The author reports the case of a sixteen year old young lady with heel shortening, due to a growth arrest of the calcaneal epiphysis, secondary to its septic involvement by a heel puncture. At the age of sixteen a lengthening according to Ilizarov's method was performed, using progressive distraction of an osteotomy of the calcaneal tuberosity. The result was satisfying with a cosmetical improvement, a painless function and a more comfortable shoe fitting.

Adolescent↗

PubMed1999

Joint distraction in treatment of osteoarthritis: a two-year follow-up of the ankle.

OBJECTIVE: Osteoarthritis (OA) is a degenerative joint disease with an incidence exceeding 10% of the adult population. In end stages, OA can result in severe restriction of activity and consequent disability. For these severe cases of OA, no effective remedy is available yet. Joint distraction is a new experimental approach in treatment of OA. Studied in retrospect it appeared that this treatment results in prolonged clinical improvement in the case of ankle OA. Presently the results of a prospective two-year follow-up are given. METHODS: Patients with severe ankle OA, who were considered for joint fusion (arthrodesis), were treated with distraction, by use of an Ilizarov external ring fixator. Distraction was carried out for 3 months during which full weight bearing (walking) was allowed. Standardized clinical examination was conducted before and at yearly intervals after treatment, including physical examination, functional ability questionnaire, pain scale, joint mobility, and radiographic evaluation. RESULTS: More than two thirds of the patients improved significantly as shown by physical examination, functional ability questionnaires and pain scale; effects were progressive in the second year of follow-up. On average, joint mobility and radiographic joint space were preserved, whilst improvement was observed in a significant number of patients. DISCUSSION: Results of the present prospective study confirm the findings of the previous retrospective study and suggest that Ilizarov joint distraction is a promising treatment for severe ankle OA, at least delaying the need for a joint fusion. Considering the high prevalence of OA and the lack of a remedy for this disorder, Ilizarov joint distraction as a treatment for OA may have great medical, social and economic impact.

Adolescent↗

PubMed1999

Molecular signaling in bone fracture healing and distraction osteogenesis.

The process of fracture healing has been described in detail in many histological studies. Recent work has focused on the mechanisms by which growth and differentiation factors regulate the fracture healing process. Rapid progress in skeletal cellular and molecular biology has led to the identification of many signaling molecules associated with the formation of skeletal tissues, including members of the transforming growth factor-beta (TGF-beta) superfamily and the insulin-like growth factor (IGF) family. Increasing evidence indicates that they are critical regulators of cellular proliferation, differentiation, extracellular matrix biosynthesis and mineralization. Limb lengthening procedure (distraction osteogenesis) is a relevant model to investigate the in vivo correlation between mechanical stimulation and biological responses as the callus is stretched by a proper rate and rhythm of mechanical strain. This model also provides additional insights into the molecular and cellular events during bone fracture repair. TGF-beta 1 was significantly increased in both the distracted callus and the fracture callus. The increased level of TGF-beta 1, together with a low concentration of calcium and an enhanced level of collagen synthesis, was maintained in the distracted callus as long as mechanical strain was applied. Less mineralization is also associated with a low level of osteocalcin production. These observations provide further insights into the molecular basis for the cellular events during distraction osteogenesis.

Animals↗

PubMed1998

Treatment of nonunion of the humerus using the Ilizarov external fixator.

Ilizarov's method of monofocal compression was used in 30 humeri with a diaphyseal pseudarthrosis. Twenty-one patients had previous surgery but had loosening of the osteosynthesis material. Nine patients initially were treated with a hanging cast, resulting in interfragmentary distraction. Fourteen nonunions were hypertrophic, and 16 were atrophic, of which six were infected. A complete circular frame was used only in the first nine patients, whereas the remaining 21 patients were treated with the modified semicircular fixator. Union was obtained in all but two patients, with an average consolidation time of 4.5 months (range, 2.5-10 months). No patient required additional bone grafting. Apart from superficial pin tract infection seen in most of the patients, three had a minor temporary sensory neurologic problem. Four patients experienced a second fracture after removal of the fixator that required a second application of an Ilizarov frame. Although similar results with regard to union are reported after plate osteosynthesis, there was no radial nerve palsy or deep infection in this series, indicating that the treatment by the Ilizarov technique is associated with less complications. The authors' findings suggest that the Ilizarov method is a reliable treatment for humeral nonunions, even after multiple previous operations or in the event of infection.

Adolescent↗

PubMed1998

Distraction bone healing versus osteotomy healing: a comparative biochemical analysis.

This study investigates the biochemical changes in a canine tibia lengthening model in comparison with a nonlengthened osteotomy model. The lengthened and the osteotomized callus and a contralateral corresponding segment were analyzed for their mineralization profile, collagen content, osteocalcin, insulin-like growth factor I (IGF-I), and transforming growth factor beta1 (TGF-beta1). Examinations of bone samples were performed using specimens excised at different time intervals (respectively at 3, 5, 7, 9, and 13 weeks postoperatively). Several serum parameters (alkaline phosphatase [ALP], osteocalcin, IGF-I, and TGF-beta1) were also measured during the experimental period. A progressive increase in mineral parameters was noticed in both the lengthened and the osteotomized areas. A higher level of hydroxyproline and TGF-beta1 was observed in the lengthened area compared with the osteotomized area. IGF-I showed a significant increase in both the lengthened and contralateral control area at the later stage of the experimental period in the lengthened group. In serum, a high level of TGF-beta1 and a progressively increasing osteocalcin concentration were observed in the lengthened dogs in comparison with the osteotomized dogs. Serum ALP was significantly increased in both models during the experimental period. Serum IGF-I was increased in the lengthened models during the distraction period and decreased in the osteotomized models at the early stage of the experimental period. These results suggest that the mechanical strain induced by the Ilizarov distraction procedure stimulates osteoblast proliferation and promotes biosynthesis of bone extracellular matrix in distracted callus. Our data furthermore show that this process is different compared with normal fracture healing.

Alkaline Phosphatase↗

PubMed1997

Biochemical and density assessment of the new bone in late remodeling after callus distraction.

Biochemical changes in a canine bone-lengthening model were characterized 5 months after surgery. The mineral content and the total amount of EDTA-extractable noncollagenous proteins, insulin-like growth factor-I, and osteocalcin were determined for the lengthened callus, and a gradient density fractionation analysis of bone powder particles was performed. The results were compared with two other areas of the lengthened tibia and one region of the contralateral tibia. The mineral and osteocalcin contents showed significant decreases, whereas the hydroxyproline concentration was significantly increased. Neither the insulin-like growth factor-I content nor the concentration of EDTA-extractable proteins was significantly different in any of the examined regions.

Animals↗

PubMed1996

The Ilizarov external fixator for treatment of deformities in Paget's disease.

Paget's disease of bone may cause progressive bowing of affected femurs and tibiae. Fractures or osteotomies in these patients technically are difficult to treat and may lead to delayed union or nonunion. The authors report their early results with the use of the Ilizarov external fixator to affix 3 corrective closing wedge osteotomies, 1 fracture, and 1 delayed union. Deformities were corrected fully during the surgery, with an option to correct remaining deformation progressively during the rest of treatment. Compression of the healing bone was applied to enhance osseous healing, when necessary. Three-dimensional control is possible, and the stability of the fixation is excellent in this structurally weak bone. Bony union was achieved without complications in all patients within 4 months.

Aged↗

PubMed1996

The Judet quadricepsplasty: a retrospective analysis of 16 cases.

Sixteen quadricepsplasties performed for severe extension contractures of the knee were reviewed. Preoperatively all cases showed a severe extension contracture with an average of 23 degrees flexion. Only two patients had more than 30 degrees flexion preoperatively. The average improvement in knee flexion at follow-up was 69 degrees with 11 (68.7%) patients achieving a final flexion of 90 degrees or more. In four cases there was a 15 degrees loss of terminal active extension. In one case a rapid recurrence of the contracture was seen during the initial postoperative weeks. One patient developed a deep infection, and another an acute compartment syndrome.

Adolescent↗

PubMed1996

Slipped capital femoral epiphysis: a long-term follow-up, with special emphasis on the capacities for remodeling.

We reviewed 59 hips in 44 children with slipped capital femoral epiphysis (SCFE), all treated by in situ pinning. The average clinical and radiographic follow-up was 11.4 years. Fifty-three hips (90%) were rated as either excellent or good. Osteonecrosis or chondrolysis developed in five patients. Postoperative remodeling was noted, not only by a process of local resorption and apposition of bone, but also by correction of the disturbed anatomic axes, in proportion to the severity of the slip, together with global thickening of the femoral neck. We believe that the good long-term results after in situ pinning are the consequence of this important remodeling process.

Adolescent↗

PubMed1995

Can Ilizarov joint distraction delay the need for an arthrodesis of the ankle? A preliminary report.

We applied joint distraction using an Ilizarov apparatus in 11 patients with post-traumatic osteoarthritis of the ankle to try to delay the need for an arthrodesis. Distraction for three months resulted in clinical improvement in pain and mobility for a mean of two years, with an increase in the joint space. We considered that these effects may be produced by the absence of mechanical stress on the cartilage combined with the intra-articular hydrostatic pressures during distraction. We measured these pressures during walking with distraction, and found levels very similar to those reported to improve osteoarthritic cartilage when applied in vitro.

Adult↗

PubMed1995

Femoral derotation for increased hip anteversion. A new surgical technique with a modified Ilizarov frame.

We describe a technique of femoral derotation osteotomy performed according to the Ilizarov principles of percutaneous corticotomy and fixation with a frame. We performed 24 femoral osteotomies in 16 patients, four with cerebral palsy and 12 with idiopathic femoral anteversion. All had rapid union and there were few complications. The advantages of the method include early ambulation, good control of rotation and axial alignment, and minimal scarring.

Adolescent↗

PubMed1994

Salmonella typhi osteomyelitis.

Salmonella infections in man can be divided in five clinical groups: enteric fever, septicaemia without localization, focal disease, gastroenteritis and the carrier state. Salmonella typhi is mostly associated with enteric fever and the carrier state. Bone infections due to S. typhi have been reported relatively seldom. They usually occur as the result of metastatic spread during septicaemia or, more rarely, after direct inoculation. Two patients with S. typhi osteomyelitis of the forearm without evidence of a primary infection or direct inoculation are presented here.

Adult↗